Physicians must cast off grief over change if they're to move forward,anthropologist advises

It''s time for physicians to stop grieving over the massive changes occurring in health care and instead create a new vision that will lead them forward into the future, a cultural anthropologist told the CMA''s 8th annual Leadership Conference in March. About 175 physicians attended the 2-day conference on regaining the perspective on values in times of change.     

Characterization of Spontaneous,Transient Adenosine Release in the Caudate-Putamen and Prefrontal Cortex

Adenosine is a neuroprotective agent that inhibits neuronal activity and modulates neurotransmission. Previous research has shown adenosine gradually accumulates during pathologies such as stroke and regulates neurotransmission on the minute-to-hour time scale. Our lab developed a method using carbon-fiber microelectrodes to directly measure adenosine changes on a sub-second time scale with fast-scan cyclic voltammetry (FSCV). Recently, adenosine release lasting a couple of seconds has been found in murine spinal cord slices. In this study, we characterized spontaneous, transient adenosine release in vivo, in the caudate-putamen and prefrontal cortex of anesthetized rats. The average concentration of adenosine release was 0.17±0.01 µM in the caudate and 0.19±0.01 µM in the prefrontal cortex, although the range was large, from 0.04 to 3.2 µM. The average duration of spontaneous adenosine release was 2.9±0.1 seconds and 2.8±0.1 seconds in the caudate and prefrontal cortex, respectively. The concentration and number of transients detected do not change over a four hour period, suggesting spontaneous events are not caused by electrode implantation. The frequency of adenosine transients was higher in the prefrontal cortex than the caudate-putamen and was modulated by A₁ receptors. The A₁ antagonist DPCPX (8-cyclopentyl-1,3-dipropylxanthine, 6 mg/kg i.p.) increased the frequency of spontaneous adenosine release, while the A₁ agonist CPA (N⁶-cyclopentyladenosine, 1 mg/kg i.p.) decreased the frequency. These findings are a paradigm shift for understanding the time course of adenosine signaling, demonstrating that there is a rapid mode of adenosine signaling that could cause transient, local neuromodulation.     

The increasing desiccation sensitivity of recalcitrant Avicennia marina seeds with storage time

To test the hypothesis that desiccation sensitivity increases with storage time, recalcitrant seeds of Avicennia marina (Forssk.) Vierh. were dehydrated by soaking in polyethylene glycol solutions after inreasing periods of storage. Germination characteristics and the ultrastructure of root primorida were assessed before and after dehydration. Short-term storage enhanced the apparent rate of germination, consistent with the hypothesis that these seeds commence germination in storage. Root primordia of stored seeds initially showed enhanced subcellular activity, including cell division and vacuolation. Increased storage time resulted in the onset and progression of deleterious changes.
Newly shed seeds and seeds stored up to the stage of cell division were comparatively resistant to desiccation. As storage time increased, subsequent dehydration caused increasing subcellular damange and consequent reduction in the rates of germination relative to non-dehydrated controls. Ultrastructural results suggest that after the initiation of cell division of seeds in storage, there is a requirement for additional water for the germination process to continue. A model for the behaviour of recalcitrant seeds is proposed.     

LY226936 Administered Orally and Centrally to Obese Zucker Rats Suppresses Food Intake and Body Weight Gain

LY226936, methylcarbamothoic acid-S-(4,5-dihydro-2-thiazolyl) ester, is a new compound that, when administered to obese Zucker rats, caused reduced food intake. LY226936 reduced the food consumption after a single oral dose of 50 and 100 mg/kg. On chronic oral administration to meal-fed obese (5 to 35 mg/kg. once daily) and to fed obese and lean (15 mg/kg. twice daily) Zucker rats, LY226936 reduced food intake and body weight gain for periods ranging from 40 to 48 days. The effect on both parameters was statistically significant. There is no evidence in our studies that tolerance to the actions of LY226936 developed. LY226936 decreased the consumption of both high carbohydrate and high fat diets. Food consumption of meal-fed obese Zucker rats was reduced significantly each time a single dose of 10 ugm LY226936 per rat was infused intracerebroventricularly. None of the receptors studied (mu and kappa opioid, CCK, serotonin, neuropeptide Y, galinin, N-methyl-D-aspartic acid) appeared to bind LY226936 and therefore, appear not to be involved in the depression of food intake by the obese Zucker rat.     

Spatially explicit decision support for selecting translocation areas for Mojave desert tortoises

Spatially explicit decision support systems are assuming an increasing role in natural resource and conservation management. In order for these systems to be successful, however, they must address real-world management problems with input from both the scientific and management communities. The National Training Center at Fort Irwin, California, has expanded its training area, encroaching U.S. Fish and Wildlife Service critical habitat set aside for the Mojave desert tortoise (Gopherus agassizii), a federally threatened species. Of all the mitigation measures proposed to offset expansion, the most challenging to implement was the selection of areas most feasible for tortoise translocation. We developed an objective, open, scientifically defensible spatially explicit decision support system to evaluate translocation potential within the Western Mojave Recovery Unit for tortoise populations under imminent threat from military expansion. Using up to a total of 10 biological, anthropogenic, and/or logistical criteria, seven alternative translocation scenarios were developed. The final translocation model was a consensus model between the seven scenarios. Within the final model, six potential translocation areas were identified.