The emergence of drug-resistant bacteria is a growing concern for global public health. One possible strategy to deal with the problem of resistant bacteria is to understand the dynamics of adaptive evolution under antibiotics and then develop methods to suppress such adaptive evolution. For this purpose, we performed experimental evolution of Escherichia coli under various antibiotics and obtained resistant strains. The phenotypic changes in these resistant strains were quantified by transcriptome analysis, and the genomic changes were analyzed using next-generation sequencers. The results demonstrated that the resistance could be quantitatively predicted by changes in the expression of a small number of genes. Several candidate mutations contributing to the resistance were identified, while phenotype-genotype mapping was suggested to be complex and included various mutations that caused similar phenotypic changes. We also found that combinatorial use of appropriate pairs of antibiotics can suppress the emergence of resistant strains. In the presentation, I discussed how the integration of multi-omics data in experimentally obtained resistant strains enables us to develop methods to suppress the adaptive evolution of antibiotic resistance.
Multidrug efflux pumps are important in the multidrug resistance of Gram-negative pathogens. However, despite efforts to develop efflux inhibitors, clinically useful inhibitors are not available at present. ABI-PP (a pryridopyrimidine derivative) is a MexB-specific inhibitor that does not inhibit MexY; MexB and MexY are principal pumps in Pseudomonas aeruginosa. We previously found that drugs were exported through tandem proximal and distal multisite drug-binding pockets. Here we describe the first inhibitor-bound structures of pumps. ABI-PP binds tightly to a narrow pit located in the distal pocket and sterically hinders the functional rotation. Phenylalanine is located at the edge of this pit in MexB and contributes to the tight binding of the inhibitor molecule. On the other hand, the voluminous side chain of tryptophan located at the corresponding position in MexY prevents inhibitor binding. For the development of universal inhibitors of MexB and MexY, it is important to avoid the steric hindrance of tryptophan in MexY. Now we are developing clinically useful inhibitors on the basis of the structural information obtained. Started from the ABI-PP structure, we designed many compounds that can bind to the inhibitor-binding pits of MexB and MexY. Some of designed compounds were actually synthesized and their inhibitory activity determined. Finally, we obtained some lead compounds that showed complete prevention of the growth of strains expressing MexB and MexY with low concentrations of antibiotics.
Drug-resistant bacteria including methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa, and vancomycin-resistant enterococci (VRE) have been spreading; however, the development of new antibacterial drugs has not progressed accordingly. Novel antibacterial drugs or their candidate seeds need to be developed for effective antibiotic therapy. Under these conditions, the search for novel compounds and novel targets is important. In Okayama University, as a part of the Drug Discovery for Intractable Infectious Diseases project, we are proceeding with the development of antibacterial drugs for the treatment of drug-resistant bacterial infections. We found that riccardin C (a natural product of liverwort) and 6,6′-dihydroxythiobinupharidine (from the crude drug Senkotsu) exhibited strong antibacterial activities, particularly against Gram-positive bacteria. We showed that riccardin C induced cell membrane leakage and that 6,6′-dihydroxythiobinupharidine inhibited DNA topoisomerase IV. Moreover, 6,6′-dihydroxythiobinupharidine exerted synergistic effects with already known anti-MRSA drugs as well as with vancomycin for VRE.
In this symposium, we reported the identification and mechanistic analysis of a novel antibiotic named lysocin E. Lysocin E was identified by screening for therapeutic effectiveness in a silkworm Staphylococcus aureus infection model. The advantages of the silkworm infection model for screening and purification of antibiotics from the culture supernatant of soil bacteria are: 1) low cost; 2) no ethical issues; 3) convenient for evaluation of the therapeutic effectiveness of antibiotics; and 4) pharmacokinetics similar to those of mammals. Lysocin E has remarkable features compared with known antibiotics such as a novel mechanism of action and target. Here, we summarize our reports presented in this symposium.
The WHO and International Pharmaceutical Federation (FIP) introduced the concept of the “seven-star pharmacist” in which a pharmacist is described as a caregiver, communicator, decision-maker, teacher, lifelong learner, leader and manager. In six-year pharmaceutical education programs, which have been provided in schools of pharmacy since 2006, 5th year students participate in on-site practice experiences in hospitals and community pharmacies. Thus, Japanese pharmacists also began to have a role in pharmaceutical education as teachers in clinical settings. Not only pharmacists in clinical settings, but also faculty members of pharmacy schools, had not previously been familiar with evidence-based education, and therefore they often teach in the way they were taught. Since research on teaching and learning has not been well developed in Japanese pharmaceutical education, both the model core curriculum for six-year programs and the subject benchmark statement for four-year programs are based on insufficient scientific evidence. We should promote the scholarship of teaching and learning, which promotes teaching as a scholarly endeavor and a worthy subject for research. In this review, I will summarize the needs and expectations for the establishment of pedagogy in pharmaceutical education.
In 2006, a model core curriculum in pharmaceutical studies was developed prior to the outset of the 6-year pharmacy degree. In the 10 years that followed, medical care and life science technology has progressed, pharmaceutical laws have been revised, and the responsibilities of pharmacists have increased. In response to such social changes and needs, the Model Core Curriculum for Pharmacy Education was revised in December 2013. In order to play an active role as a pharmacist in any medical workplace, it is important for pharmacy students to develop their communication skills and attitudes in order to foster the trust of their patients and other medical professionals. In the new Model Core Curriculum, education in the humanities is clearly described as a foundation to pharmaceutical education, which pertains to the clinical role of a pharmacist; hence, each pharmacy school has outlined strategies for students to learn bioethics and medical ethics, and to develop communication skills. Today, although the importance of humanities education is rapidly increasing, it is difficult to immediately evaluate the outcome of learning humanities subjects and communication. Such an evaluation requires a longer-term perspective. This paper describes the status and problems of humanities education as a component of pharmacy education, and considers future directions of research in humanities education with respect to pharmacy education.
Basic research in pharmaceutical sciences has a long and successful history. Researchers in this field have long given prime importance to the knowledge they have gained through their pharmaceutical education. The transition of pharmacy education to a 6-year course term has not only extended its duration but also placed more emphasis on practical clinical education. The School Education Act (in article 87, second paragraph) determines that “the term of the course, whose main purpose is to cultivate practical ability in clinical pharmacy, shall be six years” (excerpt). The 6-year pharmacy education is an exception to the general 4-year university term determined by the School Education Act. Therefore, the purpose of the 6-year course in pharmacy is clearly proscribed. This is true of the basic course in pharmaceutical education as well; hence, the basic course must be oriented toward developing “practical ability in clinical” education, too. The 6-year pharmacy course, starting from practice (Do), has evolved with the development of a syllabus that includes a model core curriculum (Plan). Furthermore, improvement in the course can be seen by the promoted development of faculty (Act). Now, evidence-based education research will be introduced (Check). This is how the Plan-Do-Check-Act cycle in pharmaceutical education is expected to work. Currently, pedagogy research in pharmacy education has just begun, so it is difficult to evaluate at this time whether basic pharmaceutical education does in fact contribute to enhancing the “practical clinical ability” component of pharmaceutical education.
We have experienced a series of big revolutions in medical education in Japan. In undergraduate courses, common guidelines had been established for medical education (the model core-curriculum of medical education). Then, from 2005, a standard achievement testing system [objective structured clinical examination (OSCE) and computer based testing (CBT)] was begun, and clinical clerkships were accordingly promoted. In post-graduate courses, a new clinical resident training system was initiated in 2004, and there are currently approximately 40000 clinical instructors nationwide. Accreditation of Japanese medical schools based on global standards for quality improvement has just begun. Almost the same process has taken effect in the field of pharmaceutical education (PE), such as the preparation of guidelines for PE and clinical training, a shift to a six-year course, and the establishment of an accreditation organization. The educational guidelines were revised in 2013 to provide better clinical training. Both of these educational revolutions aim at providing the proper education to train healthcare professionals committed to practicing “patient-centered medicine” and to becoming lifelong learners. To educate such professionals naturally includes improving their communicative competency, and cultivating their professionalism along with their acquisition of scientific and medical knowledge, based on both quantitative and qualitative study. The Society for Medical Education has begun a new “Medical education specialist (MES) training system” responding to the need of MES in every medical school and training hospital. A new PE specialist educational system can be expected soon, as well.
Regulatory science is growing increasingly important, and the Health and Medical Strategy of the Japanese government reflects this. How regulatory science is covered in pharmaceutical education is an urgent issue. Education on regulatory science is also part of the modified version of the model core curriculum in the six-year pharmaceutical course that was introduced from 2015. The Regulatory Science Task Force of the Pharmaceutical Society of Japan, in response to a commission of the Ministry of Education, Culture, Sports, Science and Technology, conducted a study on the development of teaching material and educational methods for regulatory science, held a symposium with the participation of pharmaceutical educators in February 2015, and proposed draft teaching material based on the discussions during the symposium. The draft consists of two parts. Part one consists of a general statement on the purpose and definition of regulatory science and explanations of regulatory science with examples in various fields. Part two proposes case methods for participatory education. As the draft was developed in a limited time by a limited number of people, some issues remain to be resolved, such as few pharmacist-related examples for explanation and scenarios for case methods are included. Experts from various fields will make proposals for improving the teaching material, and educators will report on the status of regulatory science education. These issues will then be discussed with the audience. The organizers hope that the symposium will provide an opportunity to deepen our understanding of regulatory science and enhance education in it.
The practice of regulatory science (RS) for drug development is described. In the course material for education in pharmaceutical sciences drafted by the RS Division of the Pharmaceutical Society of Japan, RS for pharmaceuticals is defined as the science of predicting, assessing, and judging the quality, efficacy, and safety of pharmaceutical products throughout their lifespan. RS is also described as an integrated science based on basic and applied biomedical sciences, including analytical chemistry, biochemistry, pharmacology, toxicology, genetics, biostatistics, epidemiology, and clinical trial methodology, and social sciences such as decision science, risk assessment, and communication science. The involvement of RS in drug development generally starts after the optimization of lead compounds. RS plays important roles governing pharmaceuticals during their entire life cycle management phase as well as the drug development phase.
Prototypes of medical devices are made in accordance with the needs of clinical practice, and for systems required during the initial process of medical device development for new surgical practices. Verification of whether these prototypes produce the intended performance specifications is conducted using basic tests such as mechanical and animal tests. The prototypes are then improved and modified until satisfactory results are obtained. After a prototype passes through a clinical trial process similar to that for new drugs, application for approval is made. In the approval application process, medical devices are divided into new, improved, and generic types. Reviewers judge the validity of intended use, indications, operation procedures, and precautions, and in addition evaluate the balance between risk and benefit in terms of efficacy and safety. Other characteristics of medical devices are the need for the user to attain proficiency in usage techniques to ensure efficacy and safety, and the existence of a variety of medical devices for which assessment strategies differ, including differences in impact on the body in cases in which a physical burden to the body or failure of a medical device develops. Regulatory science of medical devices involves prediction, judgment, and evaluation of efficacy, safety, and quality, from which data result which can become indices in the development stages from design to application for approval. A reduction in the number of animals used for testing, improvement in efficiency, reduction of the necessity for clinical trials, etc. are expected through rational setting of evaluation items.
Review, safety, and relief services of the Pharmaceuticals and Medical Devices Agency are primarily focused on scientifically evaluating pharmaceuticals, medical devices, and cellular and tissue-based products referring to their quality, efficacy, and safety, which requires a variety of scientific knowledge and methods. Pharmaceutical regulation should be established based on the most advanced scientific expertise at all times. In order to evaluate products that use cutting-edge technology such as induced pluripotent stem cells and information and communication technology adequately, since fiscal year 2012 the Science Committee has been established as a platform to exchange opinions among members from top-ranking domestic and international academia and to enhance personnel exchanges through the Initiative to Facilitate Development of Innovative Drugs. In addition, the Regulatory Science Center will be established in 2018 to increase the integrity of our services for product reviews and safety measures. In particular, requiring electronic data submissions for clinical trial applications followed by an advanced approach to analysis should not only enhance the quality of reviews of individual products but should also support the development of pharmaceuticals and medical devices by providing pharmaceutical affairs consultations on research and development strategies with various guidelines based on new insights resulting from product-bridging data analysis. Moreover, a database including electronic health records with comprehensive medical information collected mainly from 10 cooperating medical institutions will be developed with the aim of developing safety measures in a more timely manner using methods of pharmacoepidemiological analysis.
For providing appropriate pharmacotherapy, “Doing the right things, and doing things right” are necessary. Additionally, vigilance is required for the appropriate use of pharmaceuticals. Evidence-based medicine has been a common approach to healthcare, and many guidelines have been published. In addition, risk management plans (RMPs) are developed upon the approval of new drugs. Therefore an environment to provide the best healthcare based on scientific evidence has been developed. When putting RMPs into practice, it is necessary to understand and utilize regulatory science (RS). If pharmaceuticals are not used, no adverse drug reactions will occur; at the same time, diseases will not be cured or symptoms controlled. We should exploit RS to use drugs appropriately. RS is not meant to limit the use of drugs in pharmacotherapy but to indicate the rules for their appropriate use. Pharmacists should ensure that patients receive maximum benefit from prescribed drugs in every case and should determine the best ways to minimize risk.
In the field of pharmaceutical sciences, the subject of regulatory science (RS) includes pharmaceuticals, food, and living environments. For pharmaceuticals, considering the balance between efficacy and safety is a point required for public acceptance, and in that balance, more importance is given to efficacy in curing disease. For food, however, safety is the most important consideration for public acceptance because food should be essentially free of risk. To ensure food safety, first, any hazard that is an agent in food or condition of food with the potential to cause adverse health effects should be identified and characterized. Then the risk that it will affect public health is scientifically analyzed. This process is called risk assessment. Second, risk management should be conducted to reduce a risk that has the potential to affect public health found in a risk assessment. Furthermore, risk communication, which is the interactive exchange of information and opinions concerning risk and risk management among risk assessors, risk managers, consumers, and other interested parties, should be conducted. Food safety is ensured based on risk analysis consisting of the three components of risk assessment, risk management, and risk communication. RS in the field of food safety supports risk analysis, such as scientific research and development of test methods to evaluate food quality, efficacy, and safety. RS is also applied in the field of living environments because the safety of environmental chemical substances is ensured based on risk analysis, similar to that conducted for food.
I introduce the current pharmaceutical education system in Japan, focusing on regulatory science. University schools or faculties of pharmaceutical science in Japan offer two courses: a six-year course for pharmacists and a four-year course for scientists and technicians. Students in the six-year pharmaceutical course receive training in hospitals and pharmacies during their fifth year, and those in the four-year life science course start research activities during their third year. The current model core curriculum for pharmaceutical education requires them to “explain the necessity and significance of regulatory science” as a specific behavior object. This means that pharmacists should understand the significance of “regulatory science”, which will lead to the proper use of pharmaceuticals in clinical practice. Most regulatory science laboratories are in the university schools or faculties of pharmaceutical sciences; however, there are too few to conduct regulatory science education. There are many problems in regulatory science education, and I hope that those problems will be resolved not only by university-based regulatory science researchers but also by those from the pharmaceutical industry and regulatory authorities.
In the beginning of the 1970s, only two chemical substances, acetylcholine and γ-aminobutyric acid (GABA), had been definitely established as neurotransmitters. Under such circumstances, I started my scientific career in Professor Masanori Otsuka's lab searching for the transmitter of primary sensory neurons. Until 1976, lines of evidence had accumulated indicating that the undecapeptide substance P could be released as a transmitter from primary afferent fibers into spinal synapses, although the substance P-mediated synaptic response had yet to be identified. Peripheral synapses could serve as a good model and thus, it was demonstrated in the prevertebral sympathetic ganglia by1985 that substance P released from axon collaterals of primary sensory neurons acts as the transmitter mediating non-cholinergic slow excitatory postsynaptic potential (EPSP). At that time, we also found that autonomic synapses were useful to uncover the transmitter role of the opioid peptide enkephalins, whose functions had been unknown since their discovery in 1975. Accordingly, enkephalins were found to serve a transmitter role in mediating presynaptic inhibition of cholinergic fast and non-cholinergic slow transmission in the prevertebral sympathetic ganglia. In 1990s, we attempted to devise a combined technique of brain slices and patch-clamp recordings. We applied it to study the regulatory mechanisms that operate around cerebellar GABAergic inhibitory synapses, because most of the studies then had centered on excitatory synapses and because inhibitory synapses are crucially involved in brain functions and disorders. Consequently, we discovered novel forms of heterosynaptic interactions, dual actions of a single transmitter, and receptor crosstalk, the details of which are described in this review.
Mohs paste is an external preparation containing zinc hydrochloride and zinc oxide starch as the main ingredient, and it is used for the palliative treatment of patients with surgically untreatable malignant tumors. However, it has problems, such as changes in hardness and viscoelasticity with time and liquefaction by exudate. To overcome these problems, we modified the formulation of Mohs paste by excluding starch, which is the cause of physical changes, and investigated the base. In the modified Mohs paste using the macrogol ointment for the base, no marked change with time was noted in the hardness, malleability, or elongation property, and the water-absorbing properties were equivalent to those of Mohs paste immediately after preparation. The hardness did not decrease even after absorbing water. The drug release rate increased 1.5 times with the modified Mohs paste. Based on these findings, the risk of liquefaction-associated damage of the surrounding skin decreased on using the modified Mohs paste, and preparing in advance became possible. These results suggest that the modified Mohs paste using the macrogol ointment for the base exhibits an equivalent effect for control of exudate and a high effect for tissue fixation.
We sought to clarify the relationship between the physicochemical properties of each medical supply and serious adverse drug reactions listed in the package inserts, by reviewing new information. We investigated 1) 1078 medicines currently available on the domestic Japanese market by using physicochemical data, such as cLogD, molecular weight (MW), and pKa and 2) the serious adverse drug reactions stated in the package inserts and the presence or absence of serious renal and liver disorders, as well as mental, extrapyramidal, and skin disorders. The renal disorders data showed: cLogD<0, adjusted odds ratio (aOR)=2.00; MW values ≥500, aOR=2.28; and pKa<7.4, aOR=1.95-2.06. The liver disorders data showed: pKa<8.4, aOR=1.83-1.95, and MW values ≥300, aOR=1.47-1.87. The mental disorders data showed: cLogD≥0, aOR=2.12, and MW values<400, aOR=2.46-2.85. The extrapyramidal disorders data showed: pKa≥6.4, aOR=4.50-11.32; cLogD≥0, aOR=4.71; and MW values<500, aOR=7.95-15.08. The skin disorders data showed: cLogD<0, aOR=1.46; MW values ≥500, aOR=1.69; and pKa<6.4, aOR=1.65 or<7.4-8.4, aOR=1.59. This information will be useful for investigating the relationships between new drugs entering the market and their potential future adverse drug reactions, and for establishing both precautionary and medical observational standards.