Applied environmental metrology for studying health-pollution interactions

Nuclear and isotopic techniques are valuable tools in assessing the levels of environmental pollution by toxic elements and for studying how these contaminants affect human health. More than 90 counterparts from 55 countries around the world have participated in projects on these topics, supported by the International Atomic Energy Agency (IAEA), during last ten years. With the support of the IAEA, for example, an appropriate metrology for compositional characterization of size fractionated airborne particulate matter was developed, verified and implemented in more than 40 countries. This paper reviews the development and application of environmental metrology tools involving nuclear analytical and isotopic techniques, as seen from the particular perspective of IAEA programmes.     

Electrochemical sensing of trypanosome- and flavivirus-related neglected tropical diseases

Virus infections and parasitic diseases that are often found in tropical countries represent a large burden on societies in those regions but are unfortunately rarely studied by electrochemistry. These neglected tropical diseases (NTDs) are a concerning issue, especially in developing nations because a challenged healthcare system often negatively affects the economy. Besides the exploration of new treatment strategies, the development of early diagnostic methods is crucial to attenuate negative impacts related to NTDs. This review highlights the most recent developments of electrochemical biosensing efforts for five NTDs, Chagas disease, leishmaniasis, sleeping sickness, dengue fever and Zika virus infection, which affect a number of Latin American, African, and Asian countries. Special focus is placed on the design and fabrication of genosensors and immunosensors, designed as innovative and promising diagnostic tools with the potential of being integrated into portable systems to advance the development of point-of-care devices.     

Up-to-date status of food irradiation

The last decade has witnessed significant advancement of the acceptance of food irradiation processing. At present 37 countries have approved one or more food items for human consumption and 25 countries have commercialized this process. More developing countries are showing keen interest to introduce irradiation processing in order to reduce post-harvest food losses, to increase export potentials and to ensure safety of food to their people. Although progress towards acceptance of food irradiation by the industry is slow, actual market trials have shown that once consumers have understood this technology, they are willing to buy irradiated foods.This paper deals with the latest developments in the field of food irradiation with particular reference to legislation, consumer acceptance, commercialization and potential application in developing countries. This paper also deals with the role played by the International Organizations, aimed at facilitating the acceptance of food irradiation.     

Prodrugs for the treatment of neglected diseases

Recently, World Health Organization (WHO) and Medicins San Frontieres (MSF) proposed a classification of diseases as global, neglected and extremely neglected. Global diseases, such as cancer, cardiovascular and mental (CNS) diseases represent the targets of the majority of the R&D efforts of pharmaceutical companies. Neglected diseases affect millions of people in the world yet existing drug therapy is limited and often inappropriate. Furthermore, extremely neglected diseases affect people living under miserable conditions who barely have access to the bare necessities for survival. Most of these diseases are excluded from the goals of the R&D programs in the pharmaceutical industry and therefore fall outside the pharmaceutical market. About 14 million people,mainly in developing countries, die each year from infectious diseases. From 1975 to 1999,1393 new drugs were approved yet only 1% were for the treatment of neglected diseases[3]. These numbers have not changed until now, so in those countries there is an urgent need for the design and synthesis of new drugs and in this area the prodrug approach is a very interesting field. It provides, among other effects, activity improvements and toxicity decreases for current and new drugs, improving market availability. It is worth noting that it is essential in drug design to save time and money, and prodrug approaches can be considered of high interest in this respect. The present review covers 20 years of research on the design of prodrugs for the treatment of neglected and extremely neglected diseases such as Chagas' disease (American trypanosomiasis), sleeping sickness (African trypanosomiasis), malaria, sickle cell disease, tuberculosis, leishmaniasis and schistosomiasis.     

A novel colorimetric PCR-based biosensor for detection and quantification of hepatitis B virus

Hepatitis B virus (HBV) can cause viral infection that attacks the liver and it is a major global health problem that put people at a high risk of death from cirrhosis of the liver and liver cancer. HBV has infected one third of the worldwide population, and 350 million people suffer from chronic HBV infection. For these reasons, development of an accurate, sensitive and expedient detection method for diagnosing, monitoring and assessing therapeutic response of HBV is very necessary and urgent for public health and disease control. Here we report a new strategy for detection of viral load quantitation of HBV based on colorimetric polymerase chain reaction (PCR) with DNAzyme-containing probe. The special DNAzyme adopting a G-quadruplex structure exhibited peroxidase-like activity in the presence of hemin to report colorimetric signal. This method has shown a broad range of linearity and high sensitivity. This study builds important foundation to achieve the specific and accurate detection level of HBV DNA with a low-cost and effective method in helping diagnosing, preventing and protecting human health form HBV generally all over the world and especially in developing countries.     

Chemical safety in a vulnerable world

The title of this article is the motto of the fourth meeting of the Intergovernmental Forum on Chemical Safety (Forum IV), which is to be held in Bangkok in November 2003. The IFCS has been in existence for 10 years. During this period politicians, scientists, and the general public have become increasingly aware of the risks associated with chemicals. International conventions providing for prohibitions and restrictions of dangerous chemicals, and for better control of trade have been set up. These conventions will soon be binding under international law. In developing countries many people who handle or use hazardous chemicals are illiterate or poorly educated; they may not fully understand what they are handling. The industrialized countries therefore have a special duty to incorporate chemical safety in development cooperation measures. Through their presence at this year's forum, prominent chemists such as Carl Djerassi will seek to underline the fact that a long term preventive approach to healthcare and the environment is only possible through international cooperation. This overview describes current developments in the field of chemical safety policy and presents a selection of the legislation currently in force for chemicals in the European Union. It also provides an insight into the interwoven structure of international cooperation that takes place at both the political and the technical level.     

Schistosomiasis Chemotherapy

After malaria, schistosomiasis (or bilharzia) is the second most prevalent disease in Africa, and is occurring in over 70 countries in tropical and subtropical regions. It is estimated that 600 million people are at risk of infection, 200 million people are infected, and at least 200 000 deaths per year are associated with the disease. All schistosome species are transmitted through contact with fresh water that is infested with free‐swimming forms of the parasite, which is known as cercariae and produced by snails. When located in the blood vessels of the host, larval and adult schistosomes digest red cells to acquire amino acids for growth and development. Vaccine candidates have been unsuccessful up to now. Against such devastating parasitic disease, the antischistosomal arsenal is currently limited to a single drug, praziquantel, which has been used for more than 35 years. Because the question of the reduction of the activity of praziquantel was raised recently, it is thus urgent to create new and safe antischistosomal drugs that should be combined with praziquantel to develop efficient bitherapies.     

Progress in hydrogels for sensing applications: a review

There are several developments taking place in the field of sensors driven by the world today requirements. One of the most important novelties of the last two decades in the field is represented by the hydrogel-based sensors which constitute a wide family of innovative smart sensing devices relevant for many different applications. Hydrogels in fact are hydrophilic, biocompatible and highly water swellable polymer networks able to convert chemical energy into mechanical energy, with the great peculiarity to be able to respond to external stimuli. These characteristics have ensured them considerable recognition as valuable tool for smart sensing and diagnostics. The aim of this review is to focus on the advances obtained in the field in the last ten years.     

New antimalarial drugs

Approximately 40% of the world population live in areas with the risk of malaria. Each year, 300-500 million people suffer from acute malaria, and 0.5-2.5 million die from the disease. Although malaria has been widely eradicated in many parts of the world, the global number of cases continues to rise. The most important reason for this alarming situation is the rapid spread of malaria parasites that are resistant to antimalarial drugs, especially chloroquine, which is by far the most frequently used. The development of new antimalarial drugs has been neglected since the 1970s owing to the end colonialism, changes in the areas of military engagement, and the restricted market potential. Only in recent years, in part supported by public funding programs, has interest in the development of antimalarial drugs been renewed. New data available from the recently sequenced genome of the malaria parasite Plasmodium falciparum and the application of methods of modern drug design promise to bring significant development in the fight against this disease.     

Active colloids: Progress and challenges towards realising autonomous applications

Active colloids are small scale materials capable of producing enhanced motion within fluid environments. The field of active colloids has grown rapidly over the last ten years and is approaching maturity where viable applications are within reach. In this review, recent advances are surveyed with a strong emphasis on developments that can enable autonomous applications, where colloids execute useful tasks without external interventions. These applications are likely to prove transformative as the resulting technologies will be significantly less complex than current methods. A survey of the requirements to achieve autonomous applications is provided, considering guidance, solution compatibilities, manufacture and function; with reference to recent developments in these capacities. Following on from this, progress towards applications in environmental remediation, lab-on-a-chip microfluidics and in vivo drug delivery is highlighted.     

Chemistry on the world-wide-web: a ten year experiment

The server logs for access to the Cambridge Chemistry webserver show how use of the server has increased over the last ten years, with access doubling every year and a half. This growth has started to slow, and extrapolation of the data suggests that the current rate of access is close to a plateau of ten million downloads a year. The transition for chemists from no internet access to saturation coverage, therefore, appears almost complete.     

UV doses worldwide

UV radiation affects human health. Human exposure to UV radiation causes a few beneficial health effects like vitamin D3 formation but it causes many detrimental health effects: sunburn, ocular damage, photoaging, immune suppression, DNA damage and skin cancer. In countries with fair-skinned populations, skin cancer is the most diagnosed of all cancers. In the United States in 2002, there were over one million new skin cancer cases. That means one out of every 285 people got skin cancer. Skin cancer of fair-skinned individuals is increasing at an alarming rate (4-6% per year) around the world and has now reached so-called "pandemic" proportions. Thus, it is important to know what UV doses people around the world get throughout their lives. This review covers how the outdoor UV doses are weighted for different biological effects, the most commonly used measuring devices for terrestrial and personal UV doses, the natural and other effects on terrestrial and personal UV doses, the time people spend outside, their ambient exposures and the terrestrial and personal UV doses of adult outdoor and indoor workers as well as children and adolescents around the world. Overall, outdoor-working adults get about 10%, while indoor-working adults and children get about 3% (2-4%) of the total available annual UV (on a horizontal plane). People's UV doses increase with increasing altitude and decreasing latitude; most indoor-working adult Europeans get 10,000-20,000 J/m2 per year, Americans get 20,000-30,000 J/m2 per year and Australians are estimated to get 20,000-50,000 J/m2 per year (excluding vacation, which can increase the dose by 30% or more).     

Nanomaterials as Pseudocatalysts in the Construction of Electrochemical Nonenzymatic Sensors for Healthcare: A Review

Enzymes, primarily different types of oxidases and most commonly peroxidase, are often used in the construction of biosensors. Enzymatic biosensors, due to their small size, easy to handle construction, accuracy and specificity, are powerful healthcare tools commonly used for the diagnosis of diseases for more than 20 years. Unfortunately, the loss of enzymatic activity during the immobilization of enzymes into biosensors has been a recent major problem. Hence, nonenzymatic electrochemical sensors based on organic and inorganic nanostructures have gained great attention in the last few years. In this short review, different types of nanostructures and nanocomposites and their practical applications in the construction of nonenzymatic electrochemical sensors in healthcare and diagnosis are described and summarized.     

Activity of trioxaquine PA1259 in mice infected by Schistosoma mansoni

Schistosomiasis is a chronic life-threatening parasitic disease concerning more than 200 million people in the World. Little attention has been paid to schistosomiasis over the last 30 years, and praziquantel is the only drug in use to control this disease. In the absence of a vaccine, there is a real need for new drugs in order both to improve the efficacy of the treatment and to delay the development of praziquantel resistant schistosomes. The present note reports the significant reduction of the worm burden after oral administration of trioxaquine PA1259 to mice infected by Schistosoma mansoni.     

NMR-based methods and strategies for drug discovery

Nuclear Magnetic Resonance (NMR) spectroscopy has long been a favourite tool of chemists interested in host-guest systems because it permits access to a wealth of information about the molecular recognition reaction. NMR has evolved dramatically in the last 15 years and, in parallel with the development of NMR methods for the determination of protein structure, a variety of tools aimed at detecting protein ligand interactions have been proposed and are being now used both in industrial and academic laboratories as valuable tools for structure-based drug discovery. Very recent developments have considerably increased the fraction of therapeutic targets that can be tackled by NMR and significantly reduced the amount of sample required for analysis; in this tutorial review we outline the essential NMR-based techniques and describe some examples of their implementation as part of drug discovery programmes.     

Electrochemical approaches for the detection of amyloid-β, tau,and α-synuclein

According to the World Health Organization, there are 47 million people worldwide who are afflicted with dementia today, and this is expected to rise to 132 million by 2050. Therefore, it is pertinent to develop efficient analytical methods such as electrochemical biosensors to study these disorders and diagnose them early. This review highlights some of the recent key developments in the use of electrochemical biosensors to study the biomarkers related to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Especially, we focus on the applications of electrochemistry to analyze amyloid-β and tau related to Alzheimer's disease and α-synuclein related to Parkinson's disease.     

Food irradiation—past, present and future

A review is presented of historical developments, the present situation, and expected future developments in the field of food irradiation. Acceptance of the process in different parts of the world is not uniform. In the USA and in some other countries where health authorities actively encourage the use of this technology, commercial application has greatly advanced in recent years. In contrast, progress in the European Union is still slow.