Paraquat, a common herbicide, is responsible for large numbers of deaths worldwide through both deliberate and accidental ingestion. Previous studies have eluded that the bioavailability of paraquat increases substantially with increasing dose and that these changes may in part be due to the effects that these high concentrations have on the gastrointestinal tract (GI tract). To date, the actions of acute, high concentrations (20mM for 60 min) of paraquat on the GI tract, particularly the colon which is a major site of paraquat absorption, are unknown. This study examined the effects of acute paraquat administration on colonic motility in the C57BL/6 mouse. Acute paraquat exposure decreased colonic motility and the amplitude of colonic migrating motor complexes (CMMCs), which are major motor patterns involved in faecal pellet propulsion. In isolated segments of distal colon, paraquat increased resting tension and markedly attenuated electrical field stimulation-evoked relaxations. Pharmacological dissection of paraquat's mechanism of action on both the CMMCs and field stimulated tissue using the nitric oxide synthase inhibitor NG-nitro-L-arginine and direct measurement of NO release from the myenteric plexus, demonstrated that paraquat selectively attenuates nitrergic signalling pathways. These changes did not appear to be due to alterations in colonic oxidative stress, inflammation or complex 1 activity, but were most likely caused by paraquat's ability to act as a redox couple. In summary, these data demonstrate that acute paraquat exposure attenuates colonic transit. These changes may facilitate the absorption of paraquat into the circulation and so facilitate its toxicity.

The technique offers a safe and effective method for removing lesions within the head and neck.

No abstract

Identifying non‐diabetic hyperglycaemia (NDH) and intervening to halt the progression to type 2 diabetes has become an essential component of cardiovascular and cerebrovascular risk reduction. Diabetes prevention programs have been instigated to address the increasing prevalence of NDH and type 2 diabetes by targeting lifestyle modifications. Evidence suggests that the risk of progression from NDH to type 2 diabetes declines with age, and that a diagnosis of type 2 diabetes in older adults is not associated with the same risk of adverse consequences as it is in younger age groups. The current definition of NDH is not adjusted based on a person's age. Therefore, there is debate about the emphasis that should be placed upon a diagnosis of NDH in older adults. This article will explore the evidence and current clinical practice surrounding dysglycaemia through the spectrum of different age ranges, and the potential implications this has for older adults.