Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 71
Filter
1.
Arzneimittelforschung ; 62(10): 490-5, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22918856

ABSTRACT

Metronidazole is a BCS (Biopharmaceutics Classification System) class 1 drug, traditionally considered the choice drug in the infections treatment caused by protozoa and anaerobic microorganisms. This study aimed to evaluate bioequivalence between 2 different marketed 250 mg metronidazole immediate release tablets. A randomized, open-label, 2×2 crossover study was performed in healthy Brazilian volunteers under fasting conditions with a 7-day washout period. The formulations were administered as single oral dose and blood was sampled over 48 h. Metronidazole plasma concentrations were determined by a liquid chromatography mass spectrometry (LC-MS/MS) method. The plasma concentration vs. time profile was generated for each volunteer and the pharmacokinetic parameters Cmax, Tmax, AUC0-t, AUC0-∞, ke, and t1/2 were calculated using a noncompartmental model. Bioequivalence between pharmaceutical formulations was determined by calculating 90% CIs (Confidence Intervall) for the ratios of Cmax, AUC0-t, and AUC0-∞ values for test and reference using log-transformed data. 22 healthy volunteers (11 men, 11 women; mean (SD) age, 28 (6.5) years [range, 21-45 years]; mean (SD) weight, 66 (9.3) kg [range, 51-81 kg]; mean (SD) height, 169 (6.5) cm [range, 156-186 cm]) were enrolled in and completed the study. The 90% CIs for Cmax (0.92-1.06), AUC0-t (0.97-1.02), and AUC0-∞ (0.97-1.03) values for the test and reference products fitted in the interval of 0.80-1.25 proposed by most regulatory agencies, including the Brazilian agency ANVISA. No clinically significant adverse effects were reported. After pharmacokinetics analysis, it concluded that test 250 mg metronidazole formulation is bioequivalent to the reference product according to the Brazilian agency requirements.


Subject(s)
Antitrichomonal Agents/administration & dosage , Metronidazole/administration & dosage , Administration, Oral , Adolescent , Adult , Analysis of Variance , Antitrichomonal Agents/adverse effects , Antitrichomonal Agents/pharmacokinetics , Area Under Curve , Biological Availability , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Cross-Over Studies , Double-Blind Method , Drugs, Generic , Female , Humans , Male , Mass Spectrometry , Metronidazole/adverse effects , Metronidazole/pharmacokinetics , Middle Aged , Reference Standards , Therapeutic Equivalency , Young Adult
2.
FEMS Microbiol Lett ; 204(1): 105-10, 2001 Oct 16.
Article in English | MEDLINE | ID: mdl-11682187

ABSTRACT

We evaluated a biochemical assay based on the ability to metabolise beta-phenylpropionic acid (PPA) as a diagnostic aid in the identification of typical enteropathogenic Escherichia coli (EPEC) strains. A total of 1061 E. coli strains of serogroups O55, O111, and O119 were initially characterised regarding their H types (serotypes) and the presence of EPEC DNA sequences, eae, EAF, and bfpA. In case of the serogroup O111 strains, 84.6% carried the typical EPEC markers, and the great majority of those (98.1%) were PPA-positive. In contrast, only 0.9% of the serogroups O55 and O119 strains carrying the typical EPEC markers (53.6% and 75.4%, respectively) were PPA-positive. We conclude that the PPA test is a useful method to detect typical EPEC strains only among strains of the O111 serogroup.


Subject(s)
Escherichia coli Infections/diagnosis , Escherichia coli/classification , Escherichia coli/metabolism , Phenylpropionates/metabolism , Bacterial Proteins/genetics , Bacterial Typing Techniques/methods , Child , Child, Preschool , Escherichia coli/genetics , Escherichia coli/pathogenicity , Escherichia coli Infections/microbiology , Humans , Serotyping , Virulence/genetics
3.
Int J Mol Med ; 8(4): 417-22, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11562781

ABSTRACT

Both adriamycin (ADM) and hyperthermia show thermal chemo-enhancement. Tolerance induction against ADM in heated cells has been reported resulting in clinical difficulty of cancer therapy. We investigated thermo-enhancement induced with ADM (0.2 microg/ml) treatment alone or combined with ADM and 42 degrees C hyperthermia in Chinese hamster V79 cells in vitro. Intracellular accumulation of hsc70 and hsp72 proteins after hyperthermia or ADM was observed to examine the possible relationship between cell killing effect and their accumulations. Thermosensitivity of V79 cells at 42 degrees C after the simultaneous treatments with ADM showed marked thermo-enhancement within the short-term treatments for less than 1 h, while the combined treatments for longer than 1 h, the cells showed reduced thermosensitivity. Survival from the simultaneous treatments for less than 1 h was reduced markedly less than the single treatment both with ADM or 42 degrees C hyperthermia alone. Thermotolerance was markedly induced in a step-up hyperthermia (42 degrees C 2 h-44 degrees C). The combined treatments with ADM and 44 degrees C hyperthermia following the 42 degrees C preheating alone does not inhibit thermotolerance development. The combined treatments with ADM and 42 degrees C preheating showed markedly interactive cell killing, but no thermo-enhancement to the following 44 degrees C hyperthermia was shown. The leveling slope of the 44 degrees C heating period-survival curve was drawn. In the Western blot analyses, hsc70 existed constitutively in the V79 cells. Following the 42 or 44 degrees C hyperthermia alone, intracellular accumulation of hsp72 was determined. ADM treatment alone did not induce any accumulation of hsp72. In the simultaneous treatments with ADM and hyperthermia, the accumulation of hsp72 was markedly reduced. The accumulation of hsp72 after the combined treatment with ADM and hyperthermia was not observed as markedly as that after hyperthermia alone.


Subject(s)
Antineoplastic Agents/pharmacology , Doxorubicin/pharmacology , Hot Temperature , Adaptation, Physiological/drug effects , Animals , Cell Line , Cell Survival/drug effects , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/drug effects , Heat-Shock Proteins/metabolism , Time Factors
4.
Radiat Res ; 156(1): 103-9, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11418078

ABSTRACT

Ohtsubo, T., Igawa, H., Saito, T., Matsumoto, H., Park, H. J., Song, C. W., Kano, E. and Saito, H. Enhancement of Cell Killing by Induction of Apoptosis after Treatment with Mild Hyperthermia at 42 degrees C and Cisplatin. Radiat. Res. 156, 103-109 (2001). We examined the interactive effects of cisplatin (1.0 microg/ml) combined with hyperthermia on cell killing and on the induction of apoptosis in IMC-3 human maxillary carcinoma cells. The cytotoxic effects of hyperthermia on IMC-3 cells at 44 degrees C were greater than at 42 degrees C, as has been reported for many other cells. The induction of apoptosis, DNA fragmentation and poly(ADP-ribose) polymerase cleavage were greater after hyperthermia at 44 degrees C for 30 min compared with treatment at 42 degrees C for 105 min, even though both of these heat doses were isoeffective in reducing cell survival to 50%. Treatment with cisplatin at 37 degrees C for up to 120 min did not result in cytotoxicity or the induction of apoptosis. The enhancement ratio for treatment with cisplatin at 42 degrees C was greater than that at 44 degrees C. More apoptosis was induced after the treatment with cisplatin at 42 degrees C compared to treatment with cisplatin at 44 degrees C. Taking these findings together, the combination of cisplatin and hyperthermia at 42 degrees C appeared to be more effective than cisplatin with hyperthermia at 44 degrees C for the induction of apoptosis in IMC-3 cells.


Subject(s)
Apoptosis/drug effects , Apoptosis/physiology , Carcinoma, Squamous Cell/metabolism , Cisplatin/pharmacology , Hyperthermia, Induced , Maxillary Neoplasms/metabolism , Antineoplastic Agents/pharmacology , Cell Survival/drug effects , Cell Survival/physiology , DNA Fragmentation/drug effects , DNA Fragmentation/physiology , Humans , Poly(ADP-ribose) Polymerases/metabolism , Temperature , Tumor Cells, Cultured , Tumor Stem Cell Assay
5.
Int J Radiat Oncol Biol Phys ; 49(5): 1391-8, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11286847

ABSTRACT

PURPOSE: The effects of hyperthermia or irradiation on cell killing and induction of apoptosis were evaluated using human maxillary carcinoma IMC-3 cells and low pH (pH 6.8) adapted cells (IMC-3-pH). METHODS AND MATERIALS: Cellular heat-sensitivity or radiosensitivity was determined using the clonogenic assay. Apoptosis was assessed on the basis of a flow cytometric determination of the DNA content, DNA fragmentation, and poly(ADP-ribose)polymerase cleavage. RESULTS: When IMC-3 cells or IMC-3-pH cells were exposed to heat at 44 degrees C in pH 6.8 medium, an increase in thermosensitivity was observed compared with when the IMC-3 cells were exposed to heat at 44 degrees C in pH 7.4 medium. However, the selective reduction in survival was not observed after irradiation. In IMC-3 cells, apoptosis after heating at 44 degrees C for 60 min in pH 7.4 medium occurred earlier than that after 8 Gy irradiation, although both thermal and irradiated doses decreased the cell count to 10%. The degree of apoptosis after heating at pH 6.8 in IMC-3 cells or IMC-3-pH cells was greater than that at pH 7.4 in IMC-3 cells. However, the degree of apoptosis after 8 Gy irradiation at pH 6.8 in IMC-3 cells or IMC-3-pH cells was smaller than that at pH 7.4 in IMC-3 cells. CONCLUSION: Hyperthermia treatment is more effective at inducing apoptosis than radiation is in tumors that contain a population of low pH adapted cells.


Subject(s)
Apoptosis/physiology , Cell Survival/physiology , Hydrogen-Ion Concentration , Hyperthermia, Induced , Maxillary Neoplasms/physiopathology , Cell Division/physiology , Combined Modality Therapy , Culture Media/chemistry , DNA Fragmentation , Humans , Maxillary Neoplasms/metabolism , Maxillary Neoplasms/therapy , Neoplasm Proteins/metabolism , Poly(ADP-ribose) Polymerases/metabolism , Radiobiology , Time Factors , Tumor Cells, Cultured/chemistry , Tumor Cells, Cultured/radiation effects
6.
Radiat Res ; 155(3): 387-96, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11182788

ABSTRACT

To elucidate whether nitric oxide secreted from irradiated cells affects cellular radiosensitivity, we examined the accumulation of inducible nitric oxide synthase, TP53 and HSP72, the concentration of nitrite in the medium of cells after X irradiation, and cellular radiosensitivity using two human glioblastoma cell lines, A-172, which has a wild-type TP53 gene, and a transfectant of A-172 cells, A-172/mp53, bearing a mutated TP53 gene. Accumulation of inducible nitric oxide synthase was caused by X irradiation of the mutant TP53 cells but not of the wild-type TP53 cells. Accumulation of TP53 and HSP72 in the wild-type TP53 cells was observed by cocultivation with irradiated mutant TP53 cells, and the accumulation was abolished by the addition of an inhibitor for inducible nitric oxide synthase, aminoguanidine, to the medium. Likewise, accumulation of these proteins was observed in the wild-type TP53 cells after exposure to conditioned medium from irradiated mutant TP53 cells, and the accumulation was abolished by the addition of a specific nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide, to the medium. The radiosensitivity of wild-type TP53 cells was reduced when the cells were cultured in conditioned medium from irradiated mutant TP53 cells compared to conventional fresh growth medium. Collectively, these findings indicate the potential importance of an intercellular signal transduction pathway initiated by nitric oxide in the cellular response to ionizing radiation.


Subject(s)
Nitric Oxide/physiology , Penicillamine/analogs & derivatives , Radiation Tolerance/physiology , Cell Line , Coculture Techniques , Culture Media, Conditioned , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/metabolism , Humans , Nitric Oxide/biosynthesis , Nitric Oxide Donors/pharmacology , Penicillamine/pharmacology , Radiation Tolerance/genetics , Signal Transduction/physiology , Tumor Cells, Cultured , Tumor Suppressor Protein p53/metabolism , X-Rays
8.
Int J Radiat Biol ; 76(12): 1649-57, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11133047

ABSTRACT

PURPOSE: To investigate whether nitric oxide excreted from cells irradiated with accelerated carbon-ion beams modulates cellular radiosensitivity against irradiation in human glioblastoma A-172 and T98G cells. MATERIALS AND METHODS: Western-blot analysis of inducible nitric oxide synthase, hsp72 and p53, the concentration assay of nitrite in medium and cell survival assay after irradiation with accelerated carbon-ion beams were performed. RESULTS: The accumulation of inducible nitric oxide synthase was caused by accelerated carbon-ion beam irradiation of T98G cells but not of A-172 cells. The accumulation of hsp72 and p53 was observed in A-172 cells after exposure to the conditioned medium of the T98G cells irradiated with accelerated carbon-ion beams, and the accumulation was abolished by the addition of an inhibitor for inducible nitric oxide synthase to the medium. The radiosensitivity of A-172 cells was reduced in the conditioned medium of the T98G cells irradiated with accelerated carbon-ion beams compared with conventional fresh growth medium, and the reduction of radiosensitivity was abolished by the addition of an inducible nitric oxide synthase inhibitor to the conditioned medium. CONCLUSIONS: Nitric oxide excreted from the irradiated donor cells with accelerated carbon-ion beams could modulate the radiosensitivity of recipient cells. These findings indicate the importance of an intercellular signal transduction pathway initiated by nitric oxide in the cellular response to accelerated heavy ions.


Subject(s)
Carbon , Glioblastoma/radiotherapy , Ions , Nitric Oxide/metabolism , Blotting, Western , Cell Survival/drug effects , Cell Survival/radiation effects , Coculture Techniques , Culture Media, Conditioned/pharmacology , Dose-Response Relationship, Radiation , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/metabolism , Humans , Kinetics , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type II , Nitrites/metabolism , Radiotherapy, Conformal , Time Factors , Tumor Cells, Cultured , Tumor Suppressor Protein p53/metabolism , X-Rays
9.
J Exp Clin Cancer Res ; 18(2): 181-9, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10464705

ABSTRACT

Murine L cells showed markedly high lethal thermosensitivity. Survivals from fractionated heating at 44 degrees C with variety of interval time at 37 degrees C (44 degrees C for 10 min--variety of interval time at 37 degrees C-44 degrees C for 10 min) increased markedly in accordance with elongation of the internal time; i.e. survival fraction of 0.9% from 44 degrees C for 20 min alone without the interval time to those of 25% from the fractionated heating with interval time at 37 degrees C for 3-10 hrs. Incidence of apoptosis of the L cells from heating at 44 degrees C for 6.5 min (LD50) increased from 7% immediately after the heating to 30% 6-12 hrs after the post-incubation time at 37 degrees C. Accumulation of both hsp72 and p53 proteins markedly increased after a heating at 44 degrees C for 10 min alone in accordance with elongation of post-incubation time at 37 degrees C, representing a peak 6 hrs after the post incubation. Status of p53 gene in L cells were determined with Reverse Transcription-Polymerase Chain Reaction-Single Strand Conformational Polymorphism (RT-PCR-SSCP), i.e. wild type.


Subject(s)
Apoptosis , Heat-Shock Proteins/metabolism , L Cells/metabolism , Temperature , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Animals , Cells, Cultured , DNA Fragmentation , Fibroblasts , HSP72 Heat-Shock Proteins , Hot Temperature , Mice , Polymorphism, Single-Stranded Conformational , Reverse Transcriptase Polymerase Chain Reaction , Survival Rate , Time Factors , Tumor Suppressor Protein p53/analysis
10.
Cancer Res ; 59(13): 3239-44, 1999 Jul 01.
Article in English | MEDLINE | ID: mdl-10397271

ABSTRACT

Nitric oxide is known to be a multifunctional physiological substance. Recently, it was suggested that nitric oxide is involved in p53-dependent response to many kinds of stress, such as heat shock and changes in cellular metabolism. To verify this hypothesis, we examined the effect of nitric oxide produced endogenously by heat-shocked cells on nonstressed cells using a human glioblastoma cell line, A-172, and its mutant p53 (mp53) transfectant (A-172/mp53). The accumulation of inducible nitric oxide synthase was caused by heat treatment of the mtp53 cells but not of the wild-type p53 (wtp53) cells. The accumulation of heat shock protein 72 (hsp72) and p53 was observed in nontreated mtp53 cells cocultivated with heated mp53 cells, and the accumulation of these proteins was suppressed by the addition of a specific inducible nitric oxide synthase inhibitor, aminoguanidine, to the medium. Furthermore, the accumulation of these proteins was observed in the wtp53 cells after exposure to the conditioned medium by preculture of the heated mp53 cells, and the accumulation was completely blocked by the addition of a specific nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide, to the medium. In addition, the accumulation of hsp72 and p53 in the wtp53 cells was induced by the administration of an nitric oxide-generating agent, S-nitroso-N-acetylpenicillamine, to the medium. Finally, the thermosensitivity of the wtp53 cells was reduced in the conditioned medium by preculture of the heated mp53 cells as compared with conventional fresh growth medium. Our finding of the accumulation of hsp72 and p53 in nitric oxide-recipient cells cocultivated with heated nitric oxide-donor cells provides the first evidence for an intercellular signal transduction pathway via nitric oxide as intermediate without cell-to-cell interactions such as gap junctions.


Subject(s)
Genes, p53 , Nitric Oxide/physiology , Signal Transduction/physiology , Benzoates/pharmacology , Brain Neoplasms , Cell Division , Coculture Techniques , Glioblastoma , Guanidines/pharmacology , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/biosynthesis , Heat-Shock Proteins/genetics , Hot Temperature , Humans , Hyperthermia, Induced , Imidazoles/pharmacology , Kinetics , Mutagenesis , Nitric Oxide Donors/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase Type II , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , S-Nitroso-N-Acetylpenicillamine , Signal Transduction/drug effects , Tumor Cells, Cultured , Tumor Suppressor Protein p53/biosynthesis
11.
Nitric Oxide ; 3(2): 180-9, 1999.
Article in English | MEDLINE | ID: mdl-10369188

ABSTRACT

The accumulation of inducible nitric oxide synthase was caused by heat shock of human glioblastoma T98G cells but not of A-172 cells. The accumulation of hsp72 and p53 was observed in A-172 cells cocultivated with heat-shocked T98G cells, which was suppressed by the addition of aminoguanidine to the medium. The accumulation of these proteins was observed in A-172 cells after exposure to the conditioned medium of heat-shocked T98G cells, which was completely blocked by the addition of 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide to the medium. In addition, the accumulation of these proteins in A-172 cells was induced by the administration of S-nitroso-N-acetylpenicillamine to the medium. Finally, the thermosensitivity of A-172 cells was reduced in the conditioned medium of heat-shocked T98G cells compared with conventional fresh growth medium. Our findings demonstrate that the accumulation of stress-induced proteins and thermoresistance in NO recipient cells cocultivated with heat-shocked NO donor cells is induced through an intercellular signal transduction pathway initiated by NO without cell-to-cell interactions such as gap junctions.


Subject(s)
Brain Neoplasms/metabolism , Glioblastoma/metabolism , Heat-Shock Response , Nitric Oxide/physiology , Signal Transduction/physiology , Brain Neoplasms/enzymology , Brain Neoplasms/pathology , Culture Media , Glioblastoma/enzymology , Glioblastoma/pathology , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/metabolism , Humans , Nitric Oxide Donors/pharmacology , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type II , Nitrites/metabolism , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , S-Nitroso-N-Acetylpenicillamine , Tumor Cells, Cultured , Tumor Suppressor Protein p53/metabolism
12.
J Neurooncol ; 39(3): 197-203, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9821105

ABSTRACT

Hyperthermia has been introduced as a new modality of treatment for glioma. In these experiments, the cytotoxicity of hyperthermia in C6 glioma cells was enhanced by increasing the intracellular acidity with amiloride and/or 4,4'-diisothiocyanatostilbene-2,2' disulfonic acid (DIDS). Intracellular pH (pHi) is regulated mainly by Na+/H+ and HCO3-/Cl- antiports through the cell membrane, and amiloride acts on the former, DIDS on the latter to lower pHi. The cellular thermosensitivity to clinically achievable brain hyperthermia at 42 degrees C was enhanced by 0.5 mM amiloride (Na+/H+ antiport inhibitor). T0 values (T0 = the heating period required to reduce experimental survival rate by 1/e) at 42 degrees C without and with amiloride was 192 and 81 min, respectively. The addition of DIDS (HCO3-/Cl- antiport inhibitor) further enhanced. T0 value was 25 min. Fluorophotometric measurement of pHi was employed using the pH sensitive dye, bis(carboxyethyl)carboxyfluorescein, which is trapped in viable cells. The average pHi in control C6 glioma cells in pH 7.2 media was 7.21. In the untreated cells heated at 42 degrees C for 1 hour, the pHi was 7.12. The pHi of the cells heated in the presence of amiloride was decreased to 6.83. The pHi was further lowered to 6.67 by the treatment with amiloride in combination with DIDS for 2 hours. Hyperthermia with amiloride and DIDS may be a more effective treatment for malignant gliomas.


Subject(s)
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/therapeutic use , Amiloride/therapeutic use , Brain Neoplasms/therapy , Glioma/therapy , Hyperthermia, Induced/methods , Sodium-Hydrogen Exchangers/antagonists & inhibitors , Acids , Animals , Brain Neoplasms/drug therapy , Cell Survival/drug effects , Glioma/drug therapy , Hydrogen-Ion Concentration , Rats , Tumor Cells, Cultured
13.
Int J Oncol ; 13(4): 741-7, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9735404

ABSTRACT

We showed that the prominent suppressions of heat-induced accumulation and activation of p53 by CDDP or X-rays were observed in A-172 cells, but not in T98G cells. In addition, the interactive hyperthermic enhancement of CDDP or X-ray cytotoxicity was observed in A-172 cells, but not in T98G cells. Our findings indicate that suppressions of heat-induced accumulation and activation of p53 by CDDP or X-rays contribute positively to an interactive hyperthermic enhancement of CDDP- or X-ray cytotoxicity.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Glioblastoma/metabolism , Tumor Suppressor Protein p53/drug effects , Tumor Suppressor Protein p53/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Glioblastoma/pathology , Hot Temperature , Humans , Tumor Cells, Cultured/cytology , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/radiation effects , Tumor Suppressor Protein p53/metabolism , X-Rays
14.
Int J Radiat Oncol Biol Phys ; 41(4): 915-20, 1998 Jul 01.
Article in English | MEDLINE | ID: mdl-9652857

ABSTRACT

PURPOSE: The kinetics of the accumulation of inducible 72-kD heat shock protein (hsp72) and the activation of heat shock transcriptional factor (HSF) after hyperthermia and/or CDDP treatment in two human glioblastoma cell lines, A-172 having the wild-type p53 gene and T98G having the mutated p53 gene were evaluated. METHODS AND MATERIALS: Western blot analysis of hsp72, gel-mobility shift assay of HSF, cell survival, and development of thermotolerance were examined. RESULTS: The prominent suppression of heat-induced hsp72 accumulation by CDDP was seen in A-172 cells, but not in T98G cells. This was due to the p53-dependent inhibition of heat-induced HSF activation by CDDP. The interactive hyperthermic enhancement of CDDP cytotoxicity was observed in A-172 cells, but not in T98G cells. In addition, the heat-induced thermotolerance was suppressed by the presence of CDDP in the pretreatment. CONCLUSION: Suppression of heat-induced hsp72 accumulation by CDDP contributes to an interactive hyperthermic enhancement of CDDP cytotoxicity in the cells bearing the wild-type p53 gene.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Glioblastoma/metabolism , Heat-Shock Proteins/drug effects , Hyperthermia, Induced , Neoplasm Proteins/drug effects , Radiation-Sensitizing Agents/pharmacology , Transcription Factors/drug effects , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/metabolism , Humans , Neoplasm Proteins/metabolism , Transcription Factors/metabolism , Tumor Cells, Cultured/drug effects
15.
J Exp Clin Cancer Res ; 16(2): 147-52, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9261739

ABSTRACT

Modification effects of low hyperthermia (40 degrees C) on cellular chemosensitivity to bleomycin (BLM), and of BLM on thermosensitivity (40 degrees C) were investigated in cultured murine L cells with simultaneous or sequential treatments of these two agents. The heating of L cells at 40 degrees C up to 6 hours resulted in no remarkable lethal damage. Treatment with low hyperthermia followed by BLM for 4 hours showed no more than additive effect. However, a significant chemical (BLM) enhancement effect on the cellular thermosensitivity was observed by the treatment with BLM for 4 hours prior to the low hyperthermia at 40 degrees C. No appreciable thermal enhancement effect on the cellular chemosensitivity to BLM was shown by preheating at 40 degrees C for 3 hours, while post-heating at 40 degrees C showed a significant thermal enhancement effect as well as in the simultaneous treatments. The cell phase response to BLM was levelled in the clinical range of the doses. It is possible that the repair of sublethal damage (SLDR) from treatment with BLM was inhibited by 40 degrees C post-heating and this SLDR was completed at 3 hours of the interval at 37 degrees C between BLM and 40 degrees C heating.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Bleomycin/pharmacology , Hyperthermia, Induced/methods , Animals , Antibiotics, Antineoplastic/toxicity , Antineoplastic Agents/pharmacology , Bleomycin/toxicity , Cell Cycle/drug effects , Cell Survival/drug effects , Combined Modality Therapy , Drug Screening Assays, Antitumor , Hydroxyurea/pharmacology , L Cells , Mice , Time Factors
16.
Int J Hyperthermia ; 13(1): 59-67, 1997.
Article in English | MEDLINE | ID: mdl-9024927

ABSTRACT

We examined the interactive effects of hyperthermia combined with cisplatin (CDDP) (0.5 micrograms/ml) or peplomycin (PEP) (1.0 microgram/ml) on surviving fractions of human maxillary carcinoma IMC-2 cells. Either CDDP or PEP enhanced the 44 degree C thermosensitivity of thermotolerant cells after heating at 42 degrees C for 2 hours. The development of thermotolerance at 42 degrees C with either of the two drugs for 2 hours was not inhibited by CDDP, but it was partially inhibited by PEP. Moreover, for PEP throughout the entire period of 42-44 degrees C step-up heating, the 44 degree C thermosensitivity of thermotolerant cells after heating at 42 degrees C with PEP for 2 hours was enhanced similarly to that at 44 degrees C with PEP. Heating at 42 degrees C combined with either of the two drugs showed a marked interactive effect.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Hyperthermia, Induced , Maxillary Neoplasms/pathology , Peplomycin/pharmacology , Antineoplastic Agents/therapeutic use , Cell Count/drug effects , Cell Survival/drug effects , Cisplatin/therapeutic use , Combined Modality Therapy , Humans , Maxillary Neoplasms/therapy , Peplomycin/therapeutic use , Time Factors , Tumor Cells, Cultured
17.
Chemotherapy ; 43(1): 43-50, 1997.
Article in English | MEDLINE | ID: mdl-8996741

ABSTRACT

The purpose of this study was to assess the efficacy of hyperthermia (42 or 44 degrees C) as a modifier of cis-diamminedichloroplatinum (II) (CDDP) cytotoxicity and platinum incorporation in human pharyngeal carcinoma KB cells. To maximize the interactive effect, we examined the time sequence of high (above 43 degrees C) or low (below 43 degrees C) hyperthermia and CDDP. Within the dose range of CDDP studied, there was a marked synergism between the effects of heating at 44 degrees C and subsequent CDDP exposure for 5 h. Pretreatment at 44 degrees C for 30 min or at 42 degrees C for 4 h enhanced CDDP cytotoxicity more than posttreatment at 44 degrees C for 30 min or at 42 degrees C for 4 h. However, the chemoenhancement ratio of pretreatment at 44 degrees C for 30 min was higher then that of pretreatment at 42 degrees C for 4 h, although the thermal isotoxic dose decreased the cell count to 60% under both conditions. There was a significant increase in CDDP uptake after hyperthermia at 44 degrees C. These results indicate that high hyperthermia effectively enhances subsequent CDDP cytotoxicity in human pharyngeal carcinoma KB cells.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Hot Temperature , Antineoplastic Agents/metabolism , Cell Survival/drug effects , Cisplatin/metabolism , Dose-Response Relationship, Drug , Humans , KB Cells
18.
Cancer Lett ; 119(1): 47-52, 1997 Oct 28.
Article in English | MEDLINE | ID: mdl-18372521

ABSTRACT

We studied the cytotoxic and pharmacological properties of 40 degrees C hyperthermia and CDDP in CDDP-sensitive (IMC-3) and CDDP-resistant (IMC-3-DDP) human maxillary carcinoma cells. Heating at 40 degrees C alone caused almost no cell killing to IMC-3 and IMC-3-DDP cells. In both cell lines, the dose-dependent cytotoxicity of 2-h exposures to CDDP was increased at 40 degrees C in comparison to 37 degrees C. Heating at 40 degrees C also potentiated CDDP cytotoxicity in both IMC-3 and IMC-3-DDP cells with thermal chemoenhancement ratios (CER) of 1.48 and 1.94, respectively. The intracellular CDDP uptake level of IMC-3-DDP at 37 degrees C was significantly reduced compared with IMC-3 cells. At 40 degrees C, however, hyperthermia increased platinum accumulation by factors of 1.4 and 1.8 in IMC-3 and IMC-3-DDP cells, respectively. These findings indicated that CDDP sensitivity was hyperthermically chemopotentiated in CDDP-resistant variants rather than in the control clones. Thus, clinical cancer chemotherapy with CDDP may be improved by an appropriate combination with hyperthermia even at 40 degrees C.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Drug Resistance, Neoplasm/physiology , Hyperthermia, Induced , Antineoplastic Agents/metabolism , Carcinoma/pathology , Cell Line, Tumor , Cisplatin/metabolism , Humans , Maxillary Neoplasms/pathology , Platinum/metabolism
19.
Cancer Lett ; 110(1-2): 253-7, 1996 Dec 20.
Article in English | MEDLINE | ID: mdl-9018110

ABSTRACT

The accumulation of the inducible hsp72 (72-kDa heat shock protein) after hyperthermia and/or cisplatin treatment in human glioblastoma cell line (A-172) was studied by Western blot analysis. The level of hsp72 increased to eight-fold 10 h after hyperthermia alone (44 degrees C for 20 min, D50) and to three-fold 10 h after cisplatin treatment (5 microg/ml) at 37 degrees C for 15 min (D50). In contrast, when the cells were simultaneously heated with cisplatin, the accumulation of hsp72 was suppressed. The level of hsp72 increased to about six-fold and two-fold 10 h after hyperthermia (44 degrees C, 15 min) in the presence of 1 and 10 microg/ml (D50 or D10) of cisplatin, respectively. In addition, we found both the enhancement of thermosensitivity and the suppression of thermotolerance by the simultaneously combined treatment of hyperthermia and cisplatin. It has been reported that the enhancement of cisplatin cytotoxicity by hyperthermia is due to increase of both cisplatin uptake and DNA damage by hyperthermia. Our results suggest that the interactive cytotoxic enhancement by the combination of hyperthermia and cisplatin may be also due to the suppression of heat-induced hsp72 accumulation by cisplatin.


Subject(s)
Antineoplastic Agents/pharmacology , Brain Neoplasms/metabolism , Cisplatin/pharmacology , Glioblastoma/metabolism , Heat-Shock Proteins/drug effects , Hyperthermia, Induced , Neoplasm Proteins/drug effects , Blotting, Western , HSP72 Heat-Shock Proteins , Heat-Shock Proteins/metabolism , Humans , Neoplasm Proteins/metabolism , Tumor Cells, Cultured/metabolism
20.
Anticancer Res ; 16(1): 297-300, 1996.
Article in English | MEDLINE | ID: mdl-8615624

ABSTRACT

To discover the point of maximum interactive effect, we examined the time sequence of high (above (42.5 degrees C) or low (below 42.5 degrees C) -hyperthermia and cis-diammine dichloroplatinum (II) (CDDP). Simultaneous or post-hyperthermic CDDP (0.5 micrograms/ml) treatment at 43 degrees C resulted in a slight synergistic effect, with thermoenhancement ratios (TER) of 1.42 or 1.38, respectively, and there was a significant increase CDDP uptake after both combinations compared with pre-hyperthermic CDDP treatment. However, at 42 degrees C, the maximal interaction (TER = 8.57) was obtained when KB cells were simultaneously heated with CDDP, there was also a significant increase of CDDP uptake by simultaneous procedures compared with pre or post-hyperthermic CDDP treatment. These results indicate that simultaneous or post-hyperthermic CDDP treatment for high-hyperthermia and simultaneous CDDP treatment for low-hyperthermia are the most effective means of CDDP thermochemotherapy with hyperthermia.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Hyperthermia, Induced , Antineoplastic Agents/pharmacokinetics , Cell Death/drug effects , Cell Death/physiology , Cisplatin/pharmacokinetics , Combined Modality Therapy , Humans , KB Cells , Temperature
SELECTION OF CITATIONS
SEARCH DETAIL
...