Japan has the longest life expectancy in the world. It was an average 85.59 years for women and 78.64 years for men and 77.2 years for women and 71.9 years for men in average health expectancy in 2004. As the diet becomes more western- ized, the number of patients with diabetic, cardiovascular, and cerebrovascular diseases due to the metabolic syndrome is increasing. In 2002, our university was selected as a COE21st century participant by the Ministry of Education, Culture, Sports, Science and Technology. Our program is entitled “Center of Excellence for Evolutionary Human Health Sciences”. The aim of this program is to obtain and provide significant information for maintaining human health through research/education on food and medicine. The combined use of specialized foods and medicines will enhance the effectiveness and decrease the adverse effects of medicines. Safety evaluation methods will be developed for the combined use, thus establishing a novel academic field for human health sciences. We call this “borderless sciences of food and medicine” (yaku-shoku dogen).
Proper combination of diet, exercise and rest is important for healthier life. Concerning diet in particular, proper balance of nutrient intake and avoidance of its excess or deficiency are essential to keep good health and thus, not to induce risks leading to lifestyle-related diseases. Even nutrients and functional ingredients in foods are chemical substances but we need to draw a line of demarcation between such substances based on long history of dietary habits and novel substances and/or xenobiotics. However, even FOSHU contains highly purified or concentrated functional ingredients present in ordinary foods and thus, it is very important to take safety issues into consideration. FOSHU is the only type of food product (not ingredients) that can carry health claims and is composed of functional ingredients that affect the structure/function (physiological functions) of the body. These food products are intended to be consumed for the maintenance/promotion of health or special health uses by people who wish to control specified health conditions, such as gastrointestinal conditions and blood pressure. Therefore, FOSHU products target healthy people and people in a preliminary stage of a disease or a borderline condition. When the products are manufactured or distributed, permission or approval from the government is required after rigorous evaluation of the safety and effectiveness of proposed specified health uses. To understand the outline overall, comprehensive knowledge on maintaining health is required, i.e., structure/function of human body, pathogenesis of diseases, role of dietary life, nutrients and their metabolism etc., as well as understanding mechanisms of the effectiveness of FOSHU, which ranges over pharmacology, medicine, and food and nutrition.
The 21st Century's Center of Excellence (COE) Program “Coastal Marine Environmental Research” in Ehime University, funded by the Ministry of Education, Culture, Sports, Science and Technology, Government of Japan, started its activities in October 2002. One of the core projects of the COE Program in Ehime University is “studies on environmental behavior of hazardous chemicals and their toxic effects on wildlife”. This core project deals with studies of the local and global distribution of environmental contaminants in aquatic ecosystems, retrospective analysis of such chemicals, their toxicokinetics in humans and wildlife, molecular mechanisms to determine species-specific reactions, and sensitivity of chemically induced effects, and with the development of methodology for risk assessment for the conservation of ecological and species diversity. This presentation describes our recent achievements of this project, including research on contamination by arsenic and organohalogen pollutants in the Mekong River basin and molecular mechanisms of morphologic deformities in dioxin-exposed red seabream (Pagrus major) embryos. We established the Environmental Specimen Bank (es-BANK) in Ehime University in 2004, archiving approximately 100000 cryogenic samples containing tissues of wildlife and humans that have been collected for the past 40 years. The CMES homepage offers details of samples through online database retrieval. The es-BANK facility was in operation by the end of 2005.
Many hazardous chemicals are absorbed into human body through respiration and have effects on human health. The 21st Century COE (center of excellence) “Environmental Monitoring and Prediction of Long- and Short-term Dynamics of Pan-Japan Sea Area—Construction of Monitoring Network and Assessment of Human Effects” (Leader: Kazuichi Hayakawa, Graduate School of Natural Science and Technology, Kanazawa University) concentrates on atmospheric pollution caused by human activities occurred in countries, Japan, China, Korea and Russia, surrounding Pan-Japan Sea as one of major projects. My talk focuses on atmospheric pollution caused by polycyclic aromatic hydrocarbon (PAH) and nitropolycyclic aromatic hydrocarbon (NPAH), which clearly exists in this area, and demonstrates the following aspects concerning this issue: 1) The 21st Century “Environmental Monitoring and Prediction of Long- and Short-term Dynamics of Pan-Japan Sea Area—Construction of Monitoring Network and Assessment of Human Effects,” 2) Importance of PAH and NPAH as hazardous pollutants emitted from combustion of fossil fuels such as coal and oil, 3) Current status of atmospheric pollution of PAH and NPAH of Pan-Japan Sea Area, focusing on coal combustion systems such as heating in China and diesel-engine automobiles in Japan, and 4) Health effects of PAH and NPAH such as lung cancer and endocrine disruption.
Advanced fate assessment and its application/implication for hazardous chemicals is discussed. The spatially resolved fate assessment of chemicals has been performed using a newly developed spatially resolved multimedia environmental fate model (G-CIEMS: Grid-Catchment Integrated Modeling System) based on the geographical information system environment. The G-CIEMS modeling system has roughly 5×5-km resolution on the entire Japanese terrestrial region, combining a gridded-air and catchment-based surface and river geographic structure. A summary of the model description is given and validation results are discussed, which showed generally acceptable agreement between measured and simulated environmental levels for several tested chemicals. By applying the results of spatially resolved environmental concentration, the geographic distribution of exposure to humans is estimated, which showed that the majority of exposure occurred in Japan's land area with higher environmental concentration at the level of 99 percentiles or higher. The impact on the geographic distribution of environmental levels on human exposure from fish is analyzed based on monitoring, modeling, and several social and fisheries statistics. The results of estimation were compared to those of total diet studies. The estimated results are in a range close to the results of the total diet survey and thus basic validation was achieved in this study. However, as the nature of samples differed, more in-depth comparison may be necessary for future study.
Trimethyltin (TMT) is a toxic organotin compound that produces injury to the central nervous systems of mammals. Recently, high-dose TMT (2.8 mg/kg) has been shown to produce neurodegeneration and subsequent neurogenesis specifically in the hippocampal dentate gyrus of mice, indicating that mice injected with TMT serve as a useful in vivo model to study neurogenesis as well as neurodegeneration in this brain region. In addition, gene-engineered mice have allowed research to focuse on the mechanisms of TMT toxicity. These studies have revealed the involvement of stannin, nuclear factor kappa B (NF-kB), presenilin-1, apolipoprotein E, and pituitary adenylyl cyclase-activating polypeptide (PACAP) in TMT toxicity and suggested the relationship between genetic mutations and neuronal susceptibility to degeneration. In this review, we briefly summarize the previous studies and discuss the current status of research on TMT.
To elucidate the mechanism of toxicity of methylmercury (MeHg), we searched for factors that determine the sensitivity of yeast cells to MeHg and found that overexpression of Cdc34 or Rad23, both proteins related to the ubiquitin-proteasome (UP) system, induces resistance to MeHg toxicity. The acquisition of resistance to MeHg in Cdc34-overexpressing yeast cells requires the ubiquitin-conjugating activity of Cdc34 and the proteolytic activity of proteasomes. Therefore, it seems likely that certain as-yet-unidentified proteins that increase MeHg toxicity might exist in cells and that the toxicity of MeHg might be reduced by the enhanced degradation of such proteins through the UP system when Cdc34 is overexpressed. Unlike Cdc34, Rad23 suppresses the degradation of ubiquitinated proteins by proteasomes. This activity of Rad23 might be involved in the acquisition of resistance to MeHg toxicity when Rad23 is overexpressed. Overexpression of Rad23 might induce resistance to MeHg by suppressing the degradation of proteins that reduce the MeHg toxicity. Moreover, when we overexpressed Cdc34 in normal and Rad23-defective yeasts, resistance to MeHg was enhanced to almost the same extent in both lines of yeast cells. Thus it is possible that the binding of Rad23 to ubiquitinated proteins might be regulated by a mechanism that involves the recognition of substrate proteins and that the functions of Rad23 might not affect the protein-degradation system in which Cdc34 is involved. Many proteins that reduce or enhance MeHg toxicity and are ubiquitinated might exist in cells. The UP system and related proteins might determine the extent of MeHg toxicity by regulating the cellular concentrations of these various proteins.
Aberrant methylation patterns of genomic DNA are well-studied epigenetic mutations in cancer. Hypermethylation of CpG islands in tumor-suppressor genes promotes oncogenesis and hypomethylation of global genomic DNA affects genomic stability. Cancer is recognized as a genetic and epigenetic disease. However, it is not clear how epigenetic regulatory factors, including histone modification enzymes, chromatin components and other factors are involved in carcinogenesis. To gain insights into the molecular mechanisms mediated by these factors at the early stage of hepatocarcinogenesis and hepatotoxicity induced by chemicals, we investigated gene expression profiles by DNA microarray and Western blot analyses. We prepared RNA and nuclear extracts from livers with hyperplastic nodules expressing Glutathione S-transferase placental form (GST-P) and compared findings with those of normal liver. GST-P is a phase II detoxification enzyme and a well-known tumor marker. We identified several epigenetic regulatory factors that showed dysregulated expression during chemically induced hepatocarcinogenesis. Here I review the characterization and functions of these factors and discuss the mechanisms of tumor marker gene expression during chemical hepatocarcinogenesis.
The potential carcinogenic hazard of chemical agents to humans is presently based primarily on the results of long-term animal bioassays. The validity of this toxicologic approach to human risk assessment depends on two fundamental assumptions. First, the results of an animal bioassay are directly applicable to humans (interspecies extrapolation). Second, the doses used in an animal bioassay are relevant for estimating risk at known or expected human exposure levels (dose extrapolation). Although progress has been made over the past four decades in understanding the mode of action of chemical carcinogens, it is increasingly important to determine mechanistically the relevance of these modes of action in humans. There is now evidence that M6P/IGF2R functions as a novel tumor-suppressor gene in a variety of human and rodent cancers. M6p/Igf2r is imprinted in rodents and expressed only from the maternal allele after embryonic implantation. In contrast, both alleles are functional in humans. This marked species difference in M6P/IGF2R imprinting has important implications for human carcinogen risk assessment since only one rather than two alleles needs to be mutated in rodents to completely inactivate the function of this tumor suppressor gene. This striking species difference in the imprint status of M6P/IGF2R clearly demonstrates that we need to understand better variations in epigenetic mechanisms of gene regulation between rodents and humans to perform accurately chemical safety assessments.
Rodent models have great utility for evaluating the potential of environmental chemicals to alter human reproductive development. However, animal studies have some problems of species differences in extrapolating to human developmental toxicity induced by xenobiotics, because the placental endocrine functions in particular vary considerably among different species. For example, estrogen biosynthesis during pregnancy in humans is much different from that in rodents. In humans, ovarian function gradually declines after fertilization, as the placenta becomes the primary site of estrogen biosynthesis during pregnancy. In contrast to the process in humans, the ovary (not the placenta) is the main source of estrogen during pregnancy in rodents, because the placenta of rodents does not express the catalytic enzymes for estrogen biosynthesis, such as aromatase. The regulation of estrogen biosynthesis in the placenta is very important for human embryos because altering placental function can cause permanent effects on embryos. It has been suggested that rodents are therefore unsuitable for evaluating the potential effects of xenobiotics on the human reproductive system and developmental toxicity induced by the alteration of placental endocrine functions. Consequently, there is an urgent need to establish effective tools to evaluate the in vivo reproductive and developmental toxicity of environmental contaminants that disrupt the placental endocrine functions, including maintenance of local estrogen concentrations in the placenta. To resolve the problems, in this review we propose using transgenic mice, in which the transgene is controlled by placental-specific promoters, and local transgene systems into the placenta using viral vectors.
Rho-kinase has been identified as one of the effectors of the small GTP-binding protein Rho. Accumulating evidence has demonstrated that the Rho/Rho-kinase pathway plays an important role in various cellular functions, not only in vascular smooth muscle cell (VSMC) contraction but also in VSMC proliferation, cell migration, and gene expression. Two isoforms of Rho-kinase encoded by two different genes have been identified: ROCK1 and ROCK2. These isoforms are ubiquitously expressed, but with preferential expression of ROCK2 in the brain and skeletal muscle. The expression of Rho-kinase itself is mediated by the protein kinase C/NF-κB pathway with an inhibitory and stimulatory modulation by estrogen and nicotine, respectively. At the cellular level, Rho-kinase mediates VSMC contraction, stimulates VSMC proliferation and migration, and enhances inflammatory cell motility. Rho-kinase also upregulates various molecules that accelerate inflammation/oxidative stress, thrombus formation, and fibrosis, while it downregulates endothelial nitric oxide synthase and inhibits insulin signaling. Rho-kinase activity regulates major morphogenetic events during embryonic development through cell migration, differentiation, and axis formation. In animal and clinical studies, Rho-kinase has been shown to be substantially involved in the pathogenesis of vasospasm, arteriosclerosis, hypertension, pulmonary hypertension, and ischemia/reperfusion injury. Fasudil, a selective Rho-kinase inhibitor developed in Japan, is effective for the treatment of a wide range of cardiovascular diseases, with reasonable safety. Thus Rho-kinase is an important therapeutic target in cardiovascular medicine. This review summarizes the recent progress in the study of Rho-kinase and addresses future perspectives of Rho-kinase inhibitors.
There are evidences describing that the prices of prescription medicines can affect users, suppliers, and, in particular, payers in the health care system. Despite the significant effects of prices, the information regarding their characteristics is scarce. The objective of this study was to examine the prices and price variations of prescription medicines in an actual setting. A cross-sectional study on the prices of prescription medicines listed in a hospital formulary was undertaken. The medicines (n=1531) listed in the formulary were recorded according to the category of the medicine (essential or non-essential medicines), manufacturer types (local or foreign), dosage forms, therapeutic classifications (classes), and prices per unit in Baht. This study used coefficients of relative variations (CRVs) to determine the extent of price variations. Results revealed that the mean prices of non-essential and foreign medicines were significantly greater than those of its counterparts by 1.7 and 21.2 times, respectively. On an average, the classes with the highest prices were blood-related, antineoplastic, and endocrinological agents, while those with the lowest prices were the psychotherapeutic, CNS, and cardiovascular agents. The majority of the medicines (37%) were in the price range of >10—100 Baht. The price variations of different classes of medicines varied from about 100% to 600%. The mean price and CRV levels (low and high) formed four groups of medicines with different risks of high prices and variations to payers. In conclusion, the prices are associated with the category and manufacturer type. The prices and their variations could be used to distinguish the classes of medicines that possess different risks of high prices and variations to payers. Identifying the classes with high prices and high variations, high prices and low variations, and low prices and high variations is necessary for careful intervention to reduce the effect of prices and their variations on payers.
Cyclooxygenase 2 (COX-2) pathway inhibitors were regarded as promising nonsteroidal antiinflammatory drugs (NSAIDs). We discovered that the COX-2 pathway in A549 cells, a human lung cancer cell line, was activated by serum-free stimulation, and a drug screening model for NSAIDs was established based on this principle with simple performance and sufficient reliability. The COX-2 pathway was activated by treating with serum-free medium for 12 h. The activated cells were incubated with NS398 (selective COX-2 inhibitor), SC560 (selective COX-1 inhibitor), acetyl salicylic acid (ASA) (nonselective COX inhibitor) at 37°C for 15 min. Then the cells were incubated with 10 μM of arachidonic acid (AA) for another 30 min prostaglandin E2 and 6-keto-prostaglandin F1α were assayed in an enzyme immunoassay (EIA). The results showed that the COX-2 pathway was dominant in A549 cells whether activated by serum-free medium or not, and the COX-1 pathway could be ignored. The model accepted the positive inhibition threshold as NS398 2 μM; if a compound (10 μM) inhibited COX-2 pathway more than NS398 (2 μM), it was regarded as a hit. The COX-2 pathway inhibition experiment showed that the Z`-factor of the screening model was 0.62, which suggests that the model is suitable for COX-2 pathway inhibitor screening.
We developed a novel transferrin modified non-viral gene delivery system, transferrin-modified procationic-liposome-protamine-DNA complexes (Tf-PLPD) and investigated its characteristics. Blank procationic liposomes were prepared using the film dispersion filter method. Protamine was used to condense plasmid DNA to form protamine-DNA complexes and the complexes were further incubated with blank procationic liposomes to form PLPD. Transferrin was adsorbed onto the surface of PLPD via an electrostatic interaction, and thus Tf-PLPD was produced. Characteristics such as stability in rat serum, morphology, average particle size, zeta potential, and transfection efficiency in HepG2 cells were further investigated. The results indicated that the procationic liposomes remained stable in rat serum for 24 h. Tf-PLPD protected plasmid DNA from enzymatic degradation even after lyophilization. The size distribution of Tf-PLPD was in the range of 240±12 nm and the zeta potential was -24.10±2.5 mV (n=3), respectively. The transfection efficiencies of Tf-PLPD were 24.26±2.6 mU β-galactosidase/mg protein. Lyophilization and the presence of serum did not affect the transfectivity of Tf-PLPD and the procationic liposomes also had low cytotoxicity to cells.
Growth in the use of generic drugs remains flat in Japan, and one of the reasons cited is information availability. We previously showed that the amount of information available on generic drugs differs greatly from one pharmaceutical industry to another, though, on average, it is inferior to that for original, brand name drugs. This report looks at information on individual generic drug products, rather than the active ingredients contained therein. In May 2004, we studied ingredients sold by at least 20 pharmaceutical industries. Here, for the same, particular ingredient, we evaluate current availability of generic-specific information (as of August 2005), as well as change over time. On the basis of ingredient, the amount of information provided for generic drugs is 31.1±17.5—57.3±11.7% that for the corresponding original drugs (Mean±S.D.), but in the company-by-company comparison, a large dispersion of 16.6±5.0—69.4±11.9% (Mean ±S.D.) is observed. In terms of information content, generic drugs provided less than 50% as much information on “drug interactions”, “clinical efficacy”, and “outline of side effects”, as that for original drugs. The difference between generic and original drugs was smaller in comparisons focusing on information specific to generics than on those including all drug information. Our study also revealed that, over time, some pharmaceutical industries have added to the amount of information provided. When information is a deciding factor, the quantity available at the current time is not the only relevant aspect; it is best to select a pharmaceutical industry that is proactive about supplementing information post-release.
Objective: To clarify the mechanism of the action of Hochu-Ekki-To (HET) on collagen-induced arthritic (CIA) mice by analyzing the CD40L-expressing cells population. Methods: CIA was induced in male DBA/1J mice by immunization with two injections of bovine type II collagen (CII). HET or water was orally administered. The subpopulations of lymphocytes obtained from lymph nodes and spleen were detected at 3 weeks after boost using flow cytometry. Results: Although the population of CD4+CD40L+ cells tended to be decreased in the HET group compared to that in control mice, there was no significant difference between the two groups. These findings were observed in lymphocytes obtained from both lymph nodes and spleen. Conclusion: HET suppresses the development of CIA. These effects may be partially induced via the decrease in the population of CD4+CD40L+ cells, but the role of this action is probably limited.