Galanin-receptor ligand M40 peptide distinguishes between putative galanin-receptor subtypes

The galanin-receptor ligand M40 [galanin-(1-12)-Pro3-(Ala-Leu)2-Ala amide] binds with high affinity to [mono[125I]iodo-Tyr26]galanin-binding sites in hippocampal, hypothalamic, and spinal cord membranes and in membranes from Rin m5F rat insulinoma cells (IC50 = 3-15 nM). Receptor autoradiographic studies show that M40 (1 microM) displaces [mono[125I]iodo-Tyr26]galanin from binding sites in the hippocampus, hypothalamus, and spinal cord. In the brain, M40 acts as a potent galanin-receptor antagonist: M40, in doses comparable to that of galanin, antagonizes the stimulatory effects of galanin on feeding, and it blocks the galaninergic inhibition of the scopolamine-induced acetylcholine release in the ventral hippocampus in vivo. In contrast, M40 completely fails to antagonize both the galanin-mediated inhibition of the glucose-induced insulin release in isolated mouse pancreatic islets and the inhibitory effects of galanin on the forskolin-stimulated accumulation of 3',5'-cAMP in Rin m5F cells; instead M40 is a weak agonist at the galanin receptors in these two systems. M40 acts as a weak antagonist of galanin in the spinal flexor reflex model. These results suggest that at least two subtypes of the galanin receptor may exist. Hypothalamic and hippocampal galanin receptors represent a putative central galanin-receptor subtype (GL-1-receptor) that is blocked by M40. The pancreatic galanin receptor may represent another subtype (GL-2-receptor) that recognizes M40, but as a weak agonist. The galanin receptors in the spinal cord occupy an intermediate position between these two putative subtypes.     

Acute porphyria and multiple organ failure during treatment with lamotrigine

A 38-year-old female suffered from an acute porphyric attack, multi-organ failure and disseminated intravascular coagulation (DIC) within two weeks of starting lamotrigine, a new antiepileptic drug. The porphyric attack was characterized by excess urinary excretion of aminolevulinic acid (ALA), porphobilinogen (PBG) and coproporphyrin III, a pattern similar to that seen in hereditary coproporphyria, however the diagnostic criteria for this specific porphyria were not fulfilled. We suggest that the observed clinical picture represents a rare adverse reaction to lamotrigine.     

Practicing in relation to the outcome of the driving test

In Sweden, a written and a driving test must be passed for licensure, and these two examinations are the only means of verifying that learner drivers have acquired the competencies stipulated in the national curriculum. The present study investigated 18-24-year olds regarding the effects of personal background and mode of driver education instruction on the outcome of the driving test. This was done by analysing the following for individual subjects: data on practicing obtained using a questionnaire, and test results of license tests. The results suggest that among the candidates under study, there are equal opportunities in the context of obtaining a driver's license independent of a person's background. The rate of passing was higher for those who started behind-the-wheel training at 16 and applied to take the driving test via a driving school, than for those who started the training at an older age and applied to take the test in person. It was also found that the probability of passing the test was greater if there is successful cooperation between learner and driving school instructor, and if a large proportion of the training been devoted to the task speed adaptation.     

Topography characterization of a deep grating using near-field imaging

Using near-field optical microscopy at the wavelength of 633 nm, we image light intensity distributions at several distances above an approximately 2-microm-deep and a 1-microm-period glass grating illuminated from below under the condition of total internal reflection. The intensity distributions are numerically modeled, and an inversion procedure based on a least-squares-fit optimization is employed to extract the grating geometry from the optical images.     

Young drivers--reduced crash risk with passengers in the vehicle

Studies have shown that the effect of passengers on accident propensity among young drivers is ambiguous--in some cases positive and some negative. In Sweden, various kinds of information are compiled in registers, including a national accident database and exposure data collected in a national investigation of the driving habits of license holders. Access to such data offers a good opportunity to study crash risks related to driving with and without passengers. This was done for drivers in three different age groups (18-24, 25-64 and >65 years) accompanied by one, two or three or more passengers. Differences in crash risk were estimated using incidence density ratios (IDRs) and 95% confidence intervals. The results show that passengers had an overall protective effect, that is, the crash risk was higher for those who drove alone, regardless of their age or gender. This protective effect increased with every extra passenger (up to eight), indicating that the more passengers in the vehicle, the safer the driving. The influence of passengers was weakest (albeit still positive) among the youngest drivers (ages 18-24 years), especially the males in that group. The protective impact showed the same pattern on all days of the week, but was most marked from Friday to Sunday for most of the drivers, regardless of age.     

Characterizing biological tissue using scanning laser acousticmicroscopy

The scanning laser acoustic microscopy (SLAM) technique offers high resolution for determining the properties of individual layers. To introduce the SLAM technique as a method for measuring the speed of sound in tubular layered organs, and possibly distinguish between the layers by this measure, the authors chose the guinea-pig urethra, due to its relatively simple layered structure. To obtain more data of the acoustic properties of tissue, the attenuation coefficient was determined for the wall in toto