Keisuke Suzuki

Bio: Keisuke Suzuki is an academic researcher from Railway Technical Research Institute. The author has contributed to research in topics: Sleep disorder & REM sleep behavior disorder. The author has an hindex of 21, co-authored 43 publications receiving 1962 citations. Previous affiliations of Keisuke Suzuki include Imperial College London & Dokkyo Medical University.

The role of gut hormones and the hypothalamus in appetite regulation

Abstract: The World Health Organisation has estimated that by 2015 approximately 2.3 billion adults will be overweight and more than 700 million obese. Obesity is associated with an increased risk of diabetes, cardiovascular events, stroke and cancer. The hypothalamus is a crucial region for integrating signals from central and peripheral pathways and plays a major role in appetite regulation. In addition, there are reciprocal connections with the brainstem and higher cortical centres. In the arcuate nucleus of the hypothalamus, there are two major neuronal populations which stimulate or inhibit food intake and influence energy homeostasis. Within the brainstem, the dorsal vagal complex plays a role in the interpretation and relaying of peripheral signals. Gut hormones act peripherally to modulate digestion and absorption of nutrients. However, they also act as neurotransmitters within the central nervous system to control food intake. Peptide YY, pancreatic polypeptide, glucagon-like peptide-1 and oxyntomodulin suppress appetite, whilst ghrelin increases appetite through afferent vagal fibres to the caudal brainstem or directly to the hypothalamus. A better understanding of the role of these gut hormones may offer the opportunity to develop successful treatments for obesity. Here we review the current understanding of the role of gut hormones and the hypothalamus on food intake and body weight control.

Impending epidemic: future projection of heart failure in Japan to the year 2055.

Abstract: Background The future burden of heart failure in Japan was projected to 2055 in order to prospectively estimate of the number of these patients. Methods and results The statistics are based on prevalence data of left ventricular dysfunction (LVD) in Sado City using the Sado Heart Failure Study (2003) and population estimates from the Japanese National Institute of Population and Social Security Research Report (2006). The number of Japanese outpatients with LVD was 979,000 in 2005, and is predicted to increase gradually as the population ages, reaching 1.3 million by 2030. Conclusion LVD is expected to precipitate a future epidemic of heart failure in Japan.

Reduced cardiac 123I-MIBG scintigraphy in idiopathic REM sleep behavior disorder

Abstract: Idiopathic REM sleep behavior disorder (RBD) may represent prodromal synucleinopathies. We report markedly reduced cardiac 123 I-metaiodobenzylguanidine uptake, consistent with the loss of sympathetic terminals, in idiopathic RBD. We also demonstrate that this reduction is of the same magnitude as that found in patients with Parkinson disease. The results are consistent with the hypothesis that idiopathic RBD in older patients is a forme fruste of Lewy body disease.

Obesity and appetite control.

Abstract: Obesity is one of the major challenges to human health worldwide; however, there are currently no effective pharmacological interventions for obesity. Recent studies have improved our understanding of energy homeostasis by identifying sophisticated neurohumoral networks which convey signals between the brain and gut in order to control food intake. The hypothalamus is a key region which possesses reciprocal connections between the higher cortical centres such as reward-related limbic pathways, and the brainstem. Furthermore, the hypothalamus integrates a number of peripheral signals which modulate food intake and energy expenditure. Gut hormones, such as peptide YY, pancreatic polypeptide, glucagon-like peptide-1, oxyntomodulin, and ghrelin, are modulated by acute food ingestion. In contrast, adiposity signals such as leptin and insulin are implicated in both short- and long-term energy homeostasis. In this paper, we focus on the role of gut hormones and their related neuronal networks (the gut-brain axis) in appetite control, and their potentials as novel therapies for obesity.

BRIEF COMMUNICATION ARISING: Gut hormone PYY3-36 physiologically inhibits food intake

Abstract: Food intake is regulated by the hypothalamus, including the melanocortin and neuropeptide Y (NPY) systems in the arcuate nucleus. The NPY Y2 receptor (Y2R), a putative inhibitory presynaptic receptor, is highly expressed on NPY neurons in the arcuate nucleus, which is accessible to peripheral hormones. Peptide YY3-36 (PYY3-36), a Y2R agonist, is released from the gastrointestinal tract postprandially in proportion to the calorie content of a meal. Here we show that peripheral injection of PYY3-36 in rats inhibits food intake and reduces weight gain. PYY3-36 also inhibits food intake in mice but not in Y2r-null mice, which suggests that the anorectic effect requires the Y2R. Peripheral administration of PYY3-36 increases c-Fos immunoreactivity in the arcuate nucleus and decreases hypothalamic Npy messenger RNA. Intra-arcuate injection of PYY3-36 inhibits food intake. PYY3-36 also inhibits electrical activity of NPY nerve terminals, thus activating adjacent pro-opiomelanocortin (POMC) neurons. In humans, infusion of normal postprandial concentrations of PYY3-36 significantly decreases appetite and reduces food intake by 33% over 24 h. Thus, postprandial elevation of PYY3-36 may act through the arcuate nucleus Y2R to inhibit feeding in a gut–hypothalamic pathway.

Global Public Health Burden of Heart Failure.

Abstract: Heart failure (HF) is a global pandemic affecting at least 26 million people worldwide and is increasing in prevalence. HF health expenditures are considerable and will increase dramatically with an ageing population. Despite the significant advances in therapies and prevention, mortality and morbidity are still high and quality of life poor. The prevalence, incidence, mortality and morbidity rates reported show geographic variations, depending on the different aetiologies and clinical characteristics observed among patients with HF. In this review we focus on the global epidemiology of HF, providing data about prevalence, incidence, mortality and morbidity worldwide.

C-F bond activation in organic synthesis.

Abstract: Fluorine has received great attention in all fields of science. “Small atom with a big ego” was the title of the Symposium at the ACS meeting in San Francisco in 2000, where a number of the current scientific and industrial aspects of fluorine chemistry made possible by the small size and high electronegativity of the atom were discussed. This small atom has provided mankind with significant benefits in special products such as poly(tetrafluroethylene) (PTFE), freon, fluoro-liquid crystals, optical fiber, pharmaceutical and agrochemical compounds, and so on, all of which have their own unique properties that are otherwise difficult to obtain.1 For instance, at present, up to 30% of agrochemicals and 10% of pharmaceuticals currently used contain fluorine atoms. Therefore, organic fluorine compounds have received a great deal of interest and attention from the scientists involved in diverse fields of science and technology. Now, not only C-F bond formation but also selective C-F bond activation have become current subjects of active investigation from the viewpoint of effective synthesis of fluoroorganic compounds. The former is highlighted by designing a sophisticated fluorinating reagent for regioand stereocontrolled fluorination and developing versatile multifunctional and easily prepared building blocks. C-F bond formation has been treated extensively in several reviews2 and books.3 The latter is a subject that has been less explored but would be promising for selective defluorination of aliphatic fluorides, cross-coupling with aryl fluorides, and * To whom correspondence should be addressed. Phone: 81-78-803-5799. Fax: 81-78-803-5799. E-mail: amii@kobe-u.ac.jp and uneyamak@cc.okayamau.ac.jp. † Kobe University. ‡ Okayama University. Chem. Rev. 2009, 109, 2119–2183 2119

Heart failure: preventing disease and death worldwide.

Abstract: Heart failure is a life-threatening disease and addressing it should be considered a global health priority. At present, approximately 26 million people worldwide are living with heart failure. The outlook for such patients is poor, with survival rates worse than those for bowel, breast or prostate cancer. Furthermore, heart failure places great stresses on patients, caregivers and healthcare systems. Demands on healthcare services, in particular, are predicted to increase dramatically over the next decade as patient numbers rise owing to ageing populations, detrimental lifestyle changes and improved survival of those who go on to develop heart failure as the final stage of another disease. It is time to ease the strain on healthcare systems through clear policy initiatives that prioritize heart failure prevention and champion equity of care for all. Despite the burdens that heart failure imposes on society, awareness of the disease is poor. As a result, many premature deaths occur. This is in spite of the fact that most types of heart failure are preventable and that a healthy lifestyle can reduce risk. Even after heart failure has developed, premature deaths could be prevented if people were taught to recognize the symptoms and seek immediate medical attention. Public awareness campaigns focusing on these messages have great potential to improve outcomes for patients with heart failure and ultimately to save lives. Compliance with clinical practice guidelines is also associated with improved outcomes for patients with heart failure. However, in many countries, there is considerable variation in how closely physicians follow guideline recommendations. To promote equity of care, improvements should be encouraged through the use of hospital performance measures and incentives appropriate to the locality. To this end, policies should promote the research required to establish an evidence base for performance measures that reflect improved outcomes for patients. Continuing research is essential if we are to address unmet needs in caring for patients with heart failure. New therapies are required for patients with types of heart failure for which current treatments relieve symptoms but do not address the disease. More affordable therapies are desperately needed in the economically developing world. International collaborative research focusing on the causes and treatment of heart failure worldwide has the potential to benefit tens of millions of people. Change at the policy level has the power to drive improvements in prevention and care that will save lives. It is time to make a difference across the globe by confronting the problem of heart failure. A call to action: policy recommendations We urge policymakers at local, national and international levels to collaborate and act on the following recommendations. Promote heart failure prevention Support the development and implementation of public awareness programmes about heart failure. These should define heart failure in simple and accessible language, explain how to recognize the symptoms and emphasize that most types of heart failure are preventable. Highlight the need for healthcare professionals across all clinical disciplines to identify patients with illnesses that increase the risk of heart failure and to prescribe preventive medications. Prioritize the elimination of infectious diseases in parts of the world where they still cause heart failure. Improve heart failure awareness amongst healthcare professionals Encourage the development and use of heart failure education programmes for all appropriate healthcare professionals. These should aim to improve the prevention, diagnosis, treatment and long-term management of heart failure and raise awareness of clinical practice guidelines. Ensure equity of care for all patients with heart failure Provide a healthcare system that delivers timely access to diagnostic services and treatment of heart failure, as well as a seamless transition to long-term management. Ensure that the best available and most appropriate care is consistently provided to all patients with heart failure through efficient use of resources. Support and empower patients and their caregivers Provide resources for the education and practical support of patients with heart failure and their families or other caregivers, empowering them to engage proactively in long-term care. Promote heart failure research Fund and encourage international collaborative research to improve understanding of the patterns, causes and effects of modern day heart failure and how the disease can be prevented across the globe. Fund and encourage research into new and more affordable therapies and medical devices for all types of heart failure. Fund and encourage research into evidence-based healthcare performance measures that reflect improved clinical outcomes for patients with heart failure.