Is visceral sympathoexcitation to heat stress dependent on activation of ionotropic excitatory amino acid receptors in the rostral ventrolateral medulla?

Acute heat stress activates visceral sympathetic nerve discharge (SND) in young rats, and the functional integrity of the rostral ventrolateral medulla (RVLM) is required for sustaining visceral sympathoexcitation during peak increases in internal body temperature (T(c)). However, RVLM mechanisms mediating SND activation to hyperthermia remain unknown. In the present study, we investigated the role of RVLM ionotropic excitatory amino acid receptors in mediating visceral SND activation to heat stress in anesthetized, young rats. The effects of bilateral RVLM kynurenic acid (Kyn; 2.7 and 5.4 nmol), saline, or muscimol (400-800 pmol) microinjections on renal SND and splenic SND responses to heat stress were determined at peak hyperthermia (T(c) 41.5°C), during progressive hyperthermia (T(c) 40°C), and at the initiation of heating (T(c) increased from 38 to 38.5°C). RVLM Kyn microinjections did not reduce renal and splenic SND recorded during progressive or peak hyperthermia and did not attenuate SND activation at the initiation of heating. In fact, renal and splenic SND tended to be or were significantly increased following RVLM Kyn microinjections at the initiation of heating and during hyperthermia (40 and 41.5°C). RVLM muscimol microinjections at 39, 40, and 41.5°C resulted in immediate reductions in SND. These data indicate that RVLM ionotropic glutamate receptors are required for mediating visceral sympathoexcitation to acute heating and suggest that acute heating activates an RVLM ionotropic excitatory amino acid receptor dependent inhibitory input, which reduces the level of visceral SND to heating.

Effectiveness of a publicly-funded demonstration program to promote management of dryland salinity.

Community and catchment-based approaches to salinity management continue to attract interest in Australia. In one such approach, Catchment Demonstration Initiative (CDI) projects were established by the Western Australian (WA) Government in 2000 for targeted investment in large-scale catchment-based demonstrations of integrated salinity management practices. The aim was to promote a process for technically-informed salinity management by landholders. This paper offers an evaluation of the effectiveness of one CDI project in the central wheatbelt of WA, covering issues including: its role in fostering adoption of salinity management options, the role of research and the technical requirements for design and implementation of on-ground works, the role of monitoring and evaluation, the identification and measurement of public and private benefits, comparison and identification of the place and value of plant-based and engineering-based options, reliance on social processes and impacts of constraints on capacity, management of governance and administration requirements and an appreciation of the value of group-based approaches. A number of factors may reduce the effectiveness of CDI-type approaches in facilitating landholder action to address salinity, many of these are socially-based. Such approaches can create considerable demands on landholders, can be expensive (because of the planning and accountability required) on the basis of dollars per hectare impacted, and can be difficult to garner ownership from all involved. An additional problem could be that few community groups would have the capacity to run such programs and disseminate the new knowledge so that the CDI-type projects can impact outside the focus catchment. In common with many publicly-funded approaches to salinity, we found that direct benefits on public assets are smaller than planned and that results from science-based requirements of monitoring and evaluation have long lead times, causing farmers to either wait for the information or act sooner and take risks based on initial results. We also found that often it is a clear outline of the process that is of most importance in decision making as opposed to the actual results. We identified limitations in regulatory processes and the capacity for local government to engage in the CDI. The opportunities that CDI-type approaches provide centre around the value of its group-based approach. We conclude that they can overcome knowledge constraints in managing salinity by fostering group-based learning, offer a structured process of trialling options so that the costs and benefits can be clearly and transparently quantified, and avoid the costly mistakes and "learning failures" of the past.

Can alcohol-based hand-rub solutions cause you to lose your driver's license? Comparative cutaneous absorption of various alcohols.

We assessed cutaneous ethanol (ETOH) and isopropanol (ISOP) absorption after intensive (30 times per h) use of alcohol-based hand-rub solutions by healthcare workers (HCWs). ETOH was detectable in the breath of 6/20 HCWs (0.001 to 0.0025%) at 1 to 2 min postexposure and in the serum of 2/20 HCWs at 5 to 7 min postexposure. Serum ISOP levels were unrecordable at all time points.

Midtarsal dislocations in children.

Four children with midtarsal dislocations are described. Two of the four patients had a delay in diagnosis because of associated midtarsal injuries detracting from the main pathology. The key pathology was a dislocation or subluxation of the calcaneocuboid joint. The lateral radiograph was the most consistent view in making the diagnosis.