Animals ; Carcinogenicity Tests ; Cytotoxicity Tests, Immunologic ; Humans ; Mutagenicity Tests ; Soot ; toxicity

With the increased use of cell therapy in the veterinary sector, there is a growing demand for the development of cell-based medicinal products and the determination of their safety. Currently, the Korean Animal and Plant Quarantine Agency has established a guideline for evaluating the safety of cell-based medicinal products for animal use. The guideline includes items related to definition, classification, management, manufacturing procedure and quality control (standard and test method), stability testing, toxicity testing, pharmacological testing, and performance of clinical trials. In addition, testing protocols related to safety assessment of animal cell-based products such as chromosome karyotyping, tumorigenicity testing, confirmatory testing of biodistribution and kinetics, and target animal safety testing are described in detail. Moreover, because cell-based medicinal products are novel therapies, deviations from traditional designs may be justified in order to obtain relevant safety information on the treatment. Additionally, this guideline can be amended on the basis of new scientific findings.
Animals ; Carcinogenicity Tests ; Cell- and Tissue-Based Therapy ; Classification ; Karyotyping ; Kinetics ; Plants ; Quality Control ; Quarantine ; Toxicity Tests

Preclinical evaluation of medical devices (prototype products) offers the opportunity to investigate and study the intended use of device materials. Preclinical evaluation programs are designed to determine the efficacy, safety, and biocompatibility of biomaterials, prostheses, and medical devices. The purpose of safety testing is to determine if a material presents potential harm to the human; it evaluates the interaction of the material with the in vivo environment and determines the effect of the host on the implant. Preclinical evaluation is the determination of the ability of the prototype product to perform with appropriate host response in a specific application, considered from the perspective of human clinical use. Therefore, preclinical data should include materials science and engineering, biology, biochemistry, medicine, host reactions and their evaluation, the testing of biomaterials, and the degradation of materials in a biological environment.
Animal ; Carcinogenicity Tests ; Equipment and Supplies*/adverse effects ; Hemolysis ; Human ; Pyrogens/toxicity ; Sterilization

OBJECTIVETo study the acute toxicity of C25P polypeptide, a CCR5 antagonist, in mice and its carcinogenic effect in vitro.

METHODSThe acute toxicity of C25P polypeptide in mice was assessed by determining the maximum tolerated dose (MTD). The mice were given C25P at the dose of 3.64 g/kg by tail vein injection, and the control mice received saline (40 ml/kg) injection. The mice were continuously observed for 14 days after the administration and sacrificed on day 14 for routine blood test, examination of the blood biochemistry and pathological examination. The carcinogenicity of C25P polypeptide in vitro was evaluated in cultured cell lines by chromosome aberration test, cell transformation test and non-anchorage dependent growth test.

RESULTSNo mice died following administration of the drug, but 3 mice showed mild adverse reactions. The rats in both groups showed an increase in the body weight at a comparable rate. GPT increased and ALP decreased significantly in C25P polypeptide group (P<0.05). Most of the organs of the rats treated with in C25P polypeptide remained normal, but 3 mice showed pathologies in the lung, spleen and liver. Chromosome aberration test, cell transformation test and non-anchorage-dependent growth test all yielded negative results for C25P polypeptide.

CONCLUSIONC25P polypeptide is a low-toxicity drug that produces no apparent acute toxicity in mice or obvious carcinogenicity in vitro.

Animals ; CCR5 Receptor Antagonists ; Carcinogenicity Tests ; Chemokines ; toxicity ; Female ; Male ; Mice ; Mice, Inbred Strains ; Mutagenicity Tests ; Peptides ; toxicity ; Toxicity Tests, Acute

Human fibroblasts were developed for cellular therapy with the aim of correcting of depressed scars, but the safety of that in vivo is unclear. In this study, we assessed the safety of human fibroblasts by investigating the tumorigenicity, 13-week toxicity and through distribution studies. In the tumorigenicity test, nude mice were divided into three dosage level treatment groups with a negative/positive control group. At 6 months after intradermal transplantation, all of the treatment groups showed no development of a nodule on the injection sites and organs. Toxicity studies were performed using ICR and BALB/c mice for 13 weeks. The mice were divided into three dosage level treatment groups with a control and a syngeneic group. There was no treatment-related effect on clinical signs, mortality, body weight, food/water consumption, hematology, serum biochemistry, urine, necropsy findings and histopathological findings in any groups. These results suggest that the no-observed-effect level (NOEL) of the human fibroblasts was greater than 7.5x10(7) cells/kg for mice. In the distribution study, groups were treated with fibroblasts labeled with a fluorescent dye (CM-DiI) at low and high doses with a control and a syngeneic group. At 24 hours, a large percentage of the labeled fibroblasts were observed at the dermal layer. At 3 months, fluorescence of the labeled fibroblasts continued to be observed. Other tissues were not detected the fluorescence at any time. These studies demonstrate that the safety of human fibroblasts is reasonable with no toxic effect, no tumorigenicity and retention in the dermis. Our studies define preclinical safety testing standards relevant to the development of cellular therapeutics.
Animals ; Biochemistry ; Body Weight ; Carcinogenicity Tests ; Cicatrix ; Dermis ; Fibroblasts ; Fluorescence ; Hematology ; Humans ; Mice ; Mice, Nude ; No-Observed-Adverse-Effect Level ; Retention (Psychology) ; Tissue Therapy ; Transplants

OBJECTIVETo discuss the tumorigenicity of immortalized endothelial cells differentiated from embryonic stem cells.

METHODSThe embryoid bodies (EB) formed in vitro from embryonic stem cells, were induced to differentiate into many "round cells" (the precursor of endothelial cells). These "round cells" later formed the vascular tube-like structures. To immortalize these cells, human telomerase reverse transcriptase (hTERT) cDNA was transfected into "round cells" by lipofectin, RT-PCR and immunocytochemistry were used to evaluate the immortalized cells. And the tumorigenicity of these cells were evaluated by being injected into nude mice subcutaneously.

RESULTS95% of these transfected cells expressed Flk-1, CD34 and vWF, and could proliferate in large quantity in vitro (cell number was doubled in 2 days, and increased 12 times in 3 days), and were able to form tubular structures.

CONCLUSIONSThese results suggest that hTERT cDNA transfection can immortalize induced endothelial cells and tumorigenicity is found after immortalized cells are injected into nude mice subcutaneously.

Animals ; Carcinogenicity Tests ; Cell Differentiation ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; Endothelial Cells ; cytology ; Endothelium, Vascular ; cytology ; Mice ; Mice, Inbred Strains ; Mice, Nude ; Telomerase ; genetics ; Transfection

OBJECTIVETo detect the response of lymphocytes to radiation in untreated breast cancer patients with three different genetic assays.

METHODSBlood samples were collected from 25 untreated patients and 25 controls. Each blood sample was divided into two parts: one was irradiated by 3-Gy X-ray (irradiated sample), the other was not irradiated (non-irradiated sample). The radiosensitivity of lymphocytes was assessed by comet assay, cytokinesis-block micronucleus (CBMN) assay and 6-TG-resistant cells scored (TG) assay.

RESULTSThe baseline values of micronucleated cell frequency (MCF) and micronucleus frequency (MNF) in the patients were significantly higher than those in the controls (P < 0.01), and 3-Gy X-ray induced genetic damage to lymphocytes in the patients increased significantly as compared with that in the controls as detected with the three genetic assays (P < 0.01). The proportion of radiosensitive cases in the patient group was 48% for the mean tail length (MTL), 40% for the mean tail moment (MTM), 40% for MCF, 44% for MNF, and 48% for mutation frequencies of the hprt gene (Mfs-hprt), respectively, whereas the proportion of radiosensitive cases in the control group was only 8% for all the parameters.

CONCLUSIONThe difference in the lymphocyte radiosensitivity between the breast cancer patients and the controls is significant. Moreover, there are wide individual variations in lymphocyte radiosensitivity of patients with breast cancer. In some cases, the radiosensitivity of the same patient may be different as detected with the different assays. It is suggested that multiple assays should be used to assess the radiosensitivity of patients with breast cancer before therapy.

Breast Neoplasms ; blood ; genetics ; Carcinogenicity Tests ; Case-Control Studies ; Comet Assay ; Cytokinesis ; radiation effects ; Drug Resistance ; Female ; Humans ; Lymphocytes ; metabolism ; pathology ; radiation effects ; Micronucleus Tests ; Middle Aged ; Radiation Tolerance ; radiation effects ; Thioguanine ; X-Rays

OBJECTIVES: A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. METHODS: Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor (“Survey on the work environment”) and by the Ministry of Environment (“Survey on the circulation amount of chemicals”). Risk was determined according to exposure in workplaces and chemical hazard. RESULTS: In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be 0.990 mg/m³, as compared to the threshold exposure level of 5 mg/m³. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. CONCLUSIONS: DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below 5 mg/m³ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.
Carcinogenicity Tests ; Chemical Safety ; Clergy ; Dataset ; Diethylhexyl Phthalate ; Employment ; Humans ; Ink ; Insecticides ; International Agencies ; Liver ; Liver Neoplasms ; Lung ; Mass Screening ; No-Observed-Adverse-Effect Level ; Occupational Exposure ; Occupational Health ; Plasticizers ; Plastics ; Risk Assessment* ; Rodentia ; Testis ; Toxicity Tests, Acute ; Ventilation

Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and 3.7+/-0.6 to 1.4+/-0.3, respectively. The occurrence of histidine revertant by 20 micromole DMBA was inhibited 25.6 to 81.7% by 1 to 5 microM CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.
9,10-Dimethyl-1,2-benzanthracene ; Animals ; Carcinogenesis ; Carcinogenicity Tests ; Cheek* ; Chemoprevention ; Chlorophyll ; Codon ; Copper ; Cricetinae* ; Drug Therapy ; Genes, ras ; Histidine ; Mutagenicity Tests ; Mutation Rate ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sodium

BACKGROUND/AIMS: It is essential to develop an in vitro culture model of primary hepatocytes for the study of hepatocellular function and the pathogenesis of hepatitis C virus (HCV) infection. In this study, we have established the immortalized primary human hepatocyte (IPHH) and performed in vitro culture of HCV derived from human patient. METHODS: Primary human hepatocytes were isolated from surgically resected liver tissue and then were immortalized by transfection with the SV40 large T antigen. The characterization of the IPHH during culture was analyzed by immunocytochemistry, RT-PCR, Western blot, ELISA, and soft agar assay. Next, sera and/or liver tissue homogenates from surgically resected liver tissues of patients with HCV infection were inoculated for the culture of HCV in IPHH. After HCV RNA extraction from IPHH and culture media, positive or negative stranded HCV RNA was examined by specific nest RT-PCR. RESULTS: IPHH expressed liver-associated proteins but did not express alpha-fetoprotein. Also IPHH showed ammonia removal activity. With regard to its malignant potential, colony formation in soft agar assay was not observed. Next, positive and negative stranded HCV RNAs in IPHH infected with patient's sera plus liver tissue homogenates were clearly detected whereas those in IPHH infected with only patient's sera were not detected. CONCLUSIONS: These results demonstrated the phenotypic characteristics of IPHH and the feasibility in vitro culture system of HCV infected human samples. This system might be useful for study of pathogenesis of HCV infection or hepatocyte-based applications.
Antigens, Viral, Tumor/genetics ; Base Sequence ; Carcinogenicity Tests ; Cell Culture Techniques ; Cells, Cultured ; Cells, Immobilized ; Hepacivirus/isolation & purification/*physiology ; Hepatocytes/metabolism/physiology/*virology ; Humans ; Liver Function Tests ; Models, Biological ; RNA Probes ; RNA, Viral/analysis ; Reverse Transcriptase Polymerase Chain Reaction