Autonomic Adaption to Clinical Simulation in Psychology Students: Teaching Applications

Simulation is used to facilitate new learning in a variety of situations. One application of simulation could be to help therapists gain therapeutic skills prior to seeing clients. This particular study was interested in measuring changes in stress response by looking at subjective and objective measures of distress (as measured by SUDS, HR, and HRV) over three sessions of simulated therapy. 16 second year psychology students participated in three sessions, and had their HR and HRV measured by Polar watches. Over the three sessions, there was a decrease in perceived distress, as measured by SUDS ratings. During and between sessions, there was inconclusive change in physiological parameters.     

The detection of two antigenic groups among Renibacterium salmoninarum isolates

The analysis of the membrane proteins and their antigenic properties in a group of 14 geographically diverse strains of Renibacterium salmoninarum revealed the existence of antigenic diversity within this species. Eleven isolates, including the type strain ATCC 33209, shared a similar protein profile with a major component of 57 kDa whereas three strains showed a common pattern with a major protein of 30 kDa. The quantitative agglutination tests and Western blotting assays seem to indicate the existence of serological heterogeneity, with two distinct groups being detected.     

Polymorphisms at 13 expressed human sequences containing CAG/CTG repeats and analysis in autosomal dominant cerebellar ataxia (ADCA) patients

Genetic anticipation – increasing severity and a decrease in the age of onset with successive generations of a pedigree – is clearly present in autosomal dominant cerebellar ataxia (ADCA). Anticipation is correlated with expansion of the CAG/CTG repeat sequence to sizes above those in the normal range through the generations of a pedigree. Genetic heterogeneity has been demonstrated for ADCA, with four cloned genes (SCA1, SCA2, SCA3/MJD, and SCA6) and three mapped loci (SCA4, SCA5 and SCA7). Another related dominant ataxia, dentatorubral-pallidoluysian atrophy (DRPLA), presents anticipation with CAG/CTG repeat expansions. We had previously analysed ADCA patients who had not shown repeat expansions in cloned genes for CAG/CTG repeat expansions by the repeat expansion detection method (RED) and had detected expansions of between 48 and 88 units in 17 unrelated familial cases. We present here an analysis of 13 genes and expressed sequence tags (ESTs) containing 10 or more CAG/ CTG repeat sequences selected from public databases in the 17 unrelated ADCA patients. Of the 13 selected genes and ESTs, 9 were found to be polymorphic with heterozygosities ranging between 0.09 and 0.80 and 2 to 17 alleles. In ADCA patients none of the loci showed expansions above the normal range of the CAG/CTG repeat sequences, excluding them as the mutation causing ADCA. Received: 28 May 1997 / Accepted: 30 June 1997     

Differential interactions of the antimicrobial peptide,RQ18, with phospholipids and cholesterol modulate its selectivity for microorganism membranes

BackgroundAntimicrobial peptides (AMPs) are molecules with potential application for the treatment of microorganism infections. We, herein, describe the structure, activity, and mechanism of action of RQ18, an α-helical AMP that displays antimicrobial activity against Gram-positive and Gram-negative bacteria, and yeasts from the Candida genus.MethodsA physicochemical-guided design assisted by computer tools was used to obtain our lead peptide candidate, named RQ18. This peptide was assayed against Gram-positive and Gram-negative bacteria, yeasts, and mammalian cells to determine its selectivity index. The secondary structure and the mechanism of action of RQ18 were investigated using circular dichroism, large unilamellar vesicles, and molecular dynamic simulations.ResultsRQ18 was not cytotoxic to human lung fibroblasts, peripheral blood mononuclear cells, red blood cells, or Vero cells at MIC values, exhibiting a high selectivity index. Circular dichroism analysis and molecular dynamic simulations revealed that RQ18 presents varying structural profiles in aqueous solution, TFE/water mixtures, SDS micelles, and lipid bilayers. The peptide was virtually unable to release carboxyfluorescein from large unilamellar vesicles composed of POPC/cholesterol, model that mimics the eukaryotic membrane, indicating that vesicles' net charges and the presence of cholesterol may be related with RQ18 selectivity for bacterial and fungal cell surfaces.ConclusionsRQ18 was characterized as a membrane-active peptide with dual antibacterial and antifungal activities, without compromising mammalian cells viability, thus reinforcing its therapeutic application.General significanceThese results provide further insight into the complex process of AMPs interaction with biological membranes, in special with systems that mimic prokaryotic and eukaryotic cell surfaces.     

Actualización en el manejo de la degeneración macular asociada a la edad

Age-related macular degeneration is the leading cause of legal blindness in people over 50 in developed countries. It is a multifactorial disease resulting from the interaction of genetic and environmental factors, and the age is the only worldwide admitted risk factor. The socioeconomic impact of the disease reaches enormous proportions, if we take into account the high cost of the available antiangiogenic therapy, the strict schedule of medical visits that it requires, and the impairment that it gives rise to. The response to treatment and the visual outcomes improve with early management of the retinal lesions, thus the early diagnosis of the disease in its initial phases, based on self-control with an Amsler grid and with regular ophthalmologic assessments, is essential.     

Unusual D:B-friedobaccharane and oxygenated friedelane-type triterpenoids from Salvadorean Celastraceae species

Three new triterpenoids, including two rare D:B-friedobaccharanes (leonatriol, 1 and leonatriolone, 2) and a 2,3-seco-2,24-epoxy-3,24-olide-D:A-friedooleanane (cassinolide, 3) were isolated from the root bark of Cassine xylocarpa and Celastrus vulcanicola, collected in El Salvador. Their stereostructures were elucidated on the basis of spectroscopic analyses, mainly ¹D and ²D NMR techniques, spectrometric analyses, and comparison with data reported in the literature. The absolute configuration of 1 and 2 were determined by the application of the Riguera ester procedure and biogenetic considerations. The possible biogenetic pathway for cassinolide (3) is also discussed.     

Liver autofluorescence properties in animal model under altered nutritional conditions

Autofluorescence spectroscopy is a promising and powerful approach for an in vivo, real time characterization of liver functional properties. In this work, preliminary results on the dependence of liver autofluorescence parameters on the nutritional status are reported, with particular attention to vitamin A and lipid accumulation in liver tissue. Normally fed and 24 h starving rats were used as animal models. Histochemical and autofluorescence analysis showed that lipids and vitamin A colocalize in the liver parenchyma. Fasting condition results in a parallel increase in both lipids and vitamin A. Autofluorescence imaging and microspectrofluorometric analysis carried out on unfixed, unstained tissue sections under 366 nm excitation, evidenced differences in both spectral shape and response to continuous irradiation between liver biopsies from fed and starving rats. As to photobleaching, in particular, fitting analysis evidenced a reduction of about 85% of the signal attributable solely to vitamin A during the first 10 s of irradiation. The tissue whole emission measured in fed and starving rat livers exhibited reductions of about 35% and 52%, respectively, that are closely related to vitamin A contents. The findings open interesting perspectives for the set up of an in situ, real time diagnostic procedure for the assessment of liver lipid accumulation, exploiting the photophysical properties of vitamin A.