Radon in air and water

Radon is a natural radioactive gas that you cannot see, smell, or taste and that can only be detected with special equipment. It is produced by the radioactive decay of radium, which in turn is derived from the radioactive decay of uranium. Uranium is found in small quantities in all soils and rocks, although the amount varies from place to place. Radon decays to form radioactive particles that can enter the body by inhalation. Inhalation of the short-lived decay products of radon has been linked to an increase in the risk of developing cancers of the respiratory tract, especially of the lungs. Breathing radon in the indoor air of homes contributes to about 15,000 lung cancer deaths each year in the United States and 1,100 in the UK (HPA 2009). Only smoking causes more lung cancer deaths

Assortative mating in the online market for sperm donation

Previous studies on assortative mating have struggled to isolate preferences from actual constraints faced throughout the matching process, including the geographic and social propinquity that limit the availability of possible mates. Because such passive factors restrict the possibility set of potential partners, they may either restrict the chance of fulfilling mating preferences or lead to a high level of positive assortative mating. The possibility set may be further reduced by competition in the mating market. It is also unclear from couple’s data how much assortative mating is driven by partner selection to reduce anticipated child rearing problem and how much by a desire for parental assistance and altruistic preferences for offspring. Adopting the online market for sperm donation as the research setting reduces such problems: the more controlled setting ensures isolation of a male’s genetic impact on his offspring from other factors. By identifying the factors that influence the symmetry of characteristics between recipients and partners and recipients and donors chosen, we provide empirical evidence that even with limited constraints on available choice, women still exhibit homogamous donor preferences. Likewise, by exploring how potential donors’ characteristics match partner characteristics, we offer insights into what drives recipients’ desires to find donors who surpass both their own and their partners’ characteristics

The Pharmacology of Voltage-Gated Sodium Channels in Sensory Neurones

Voltage-gated sodium channels (VGSCs) are vital for the normal functioning of most excitable cells. At least nine distinct functional subtypes of VGSC are recognized corresponding to nine genes for their pore-forming -subunits. These have different developmental expression patterns, different tissue distributions in the adult and are differentially regulated at the cellular level by receptor-coupled cell signalling systems. Unsurprisingly, VGSC blockers are found to be useful as drugs in diverse clinical applications where excessive excitability of tissue leads to pathological dysfunction e.g. epilepsy or cardiac tachyarrhythmias. Most clinically useful VGSC blockers have a complex pharmacology in that their effects are use-dependent i.e. their efficacy depends on channel activity. In addition, many natural toxins have been discovered that interact with VGSCs in complex ways and they have been used as experimental probes to study the structure and function of the channels and to better understand how drugs interact with the channels. Here we have attempted to summarize the properties of VGSCs in sensory neurones, discussed how they are regulated by cell signalling systems and we have considered briefly current concepts of their physiological function. We discuss in detail how drugs and toxins interact with archetypal VGSCs and where possible consider how they act on VGSCs in peripheral sensory neurones. Increasingly, drugs that block VGSCs are being used as systemic analgesic agents in chronic pain syndromes but the full potential for VGSC blockers in this indication is yet to be realized and other applications in sensory dysfunction are also possible. Drugs targeting VGSC subtypes in sensory neurones are likely to provide novel systemic analgesics that are tissue specific and perhaps even pathology specific, providing much-needed novel therapeutic approaches for the relief of chronic pain

Schwann cell interactions with axons and microvessels in diabetic neuropathy

The prevalence of diabetes worldwide is at pandemic levels, with the number of patients increasing by 5% annually. The most common complication of diabetes is peripheral neuropathy, which has a prevalence as high as 50% and is characterized by damage to neurons, Schwann cells and blood vessels within the nerve. The pathogenic mechanisms of diabetic neuropathy remain poorly understood, impeding the development of targeted therapies to treat nerve degeneration and its most disruptive consequences of sensory loss and neuropathic pain. Involvement of Schwann cells has long been proposed, and new research techniques are beginning to unravel a complex interplay between these cells, axons and microvessels that is compromised during the development of diabetic neuropathy. In this Review, we discuss the evolving concept of Schwannopathy as an integral factor in the pathogenesis of diabetic neuropathy, and how disruption of the interactions between Schwann cells, axons and microvessels contribute to the disease