Fluctuations of Serum Neuron Specific Enolase and Protein S-100B Concentrations in Relation to the Use of Shunt during Carotid Endarterectomy

Objective

To evaluate the changes in serum neuron specific enolase and protein S-100B, after carotid endarterectomy performed using the conventional technique with routine shunting and patch closure, or eversion technique without the use of shunt.

Materials and Methods

Prospective non-randomized study included 43 patients with severe (>80%) carotid stenosis undergoing carotid endarterectomy in regional anesthesia. Patients were divided into two groups: conventional endarterectomy with routine use of shunt and Dacron patch (csCEA group) and eversion endarterectomy without the use of shunt (eCEA group). Protein S-100B and NSE concentrations were measured from peripheral blood before carotid clamping, after declamping and 24 hours after surgery.

Results

Neurologic examination and brain CT findings on the first postoperative day did not differ from preoperative controls in any patients. In csCEA group, NSE concentrations decreased after declamping (P<0.01), and 24 hours after surgery (P<0.01), while in the eCEA group NSE values slightly increased (P=ns), accounting for a significant difference between groups on the first postoperative day (P=0.006). In both groups S-100B concentrations significantly increased after declamping (P<0.05), returning to near pre-clamp values 24 hours after surgery (P=ns). Sub-group analysis revealed significant decline of serum NSE concentrations in asymptomatic patients shunted during surgery after declamping (P<0.05) and 24 hours after surgery (P<0.01), while no significant changes were noted in non-shunted patients (P=ns). Decrease of NSE serum levels was also found in symptomatic patients operated with the use of shunt on the first postoperative day (P<0.05). Significant increase in NSE serum levels was recorded in non-shunted symptomatic patients 24 hours after surgery (P<0.05).

Conclusion

Variations of NSE concentrations seemed to be influenced by cerebral perfusion alterations, while protein S-100B values were unaffected by shunting strategy. Routine shunting during surgery for symptomatic carotid stenosis may have the potential to prevent postoperative increase of serum NSE levels, a potential marker of brain injury.     

Effect of Blood Vessel Segmentation on the Outcome of Electroporation-Based Treatments of Liver Tumors

Electroporation-based treatments rely on increasing the permeability of the cell membrane by high voltage electric pulses applied to tissue via electrodes. To ensure that the whole tumor is covered with sufficiently high electric field, accurate numerical models are built based on individual patient anatomy. Extraction of patient''s anatomy through segmentation of medical images inevitably produces some errors. In order to ensure the robustness of treatment planning, it is necessary to evaluate the potential effect of such errors on the electric field distribution. In this work we focus on determining the effect of errors in automatic segmentation of hepatic vessels on the electric field distribution in electroporation-based treatments in the liver. First, a numerical analysis was performed on a simple ''sphere and cylinder'' model for tumors and vessels of different sizes and relative positions. Second, an analysis of two models extracted from medical images of real patients in which we introduced variations of an error of the automatic vessel segmentation method was performed. The results obtained from a simple model indicate that ignoring the vessels when calculating the electric field distribution can cause insufficient coverage of the tumor with electric fields. Results of this study indicate that this effect happens for small (10 mm) and medium-sized (30 mm) tumors, especially in the absence of a central electrode inserted in the tumor. The results obtained from the real-case models also show higher negative impact of automatic vessel segmentation errors on the electric field distribution when the central electrode is absent. However, the average error of the automatic vessel segmentation did not have an impact on the electric field distribution if the central electrode was present. This suggests the algorithm is robust enough to be used in creating a model for treatment parameter optimization, but with a central electrode.     

Chronic Social Isolation Compromises the Activity of Both Glutathione Peroxidase and Catalase in Hippocampus of Male Wistar Rats

Chronic neuroendocrine stress usually leads to the elevation of the stress hormones and increased metabolic rate, which is frequently accompanied by oxidative damage to the CNS. In the present study we hypothesized that chronic psychosocial isolation (CPSI) of male Wistar rats, characterized by decreased serum corticosterone (CORT), unaltered catecholamines (CTs), and low blood glucose (GLU), may also promote oxidative imbalance in the CNS, by targeting antioxidant defense system. To test it, we have examined the relation between these input signals and protein expression/activity of antioxidant enzymes (AOEs): superoxide dismutases (SODs), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GLR) in the hippocampus (HIPPO) of CPSI animals. We found that CPSI did not affect SODs or CAT, but decreased activity of GPx and compromised GLR, an enzyme highly dependent on blood GLU for its substrate precursor. Further, we have tested whether the CPSI experience altered AOEs response to a novelty stress, and found that it attenuated peroxide-metabolizing enzymes, CAT and GPx, and decreased GLR activity, even though blood GLU was restored. The altered ratios of hippocampal AOEs in CPSI animals, which were worsened under the combined stress conditions, may lead to the accumulation of peroxide products and oxidative imbalance. The mechanism by which CPSI generate oxidative imbalance in the HIPPO is most likely based on poor systemic energy conditions set by this stress. Such conditions may cause functional decline of CNS structures, such as HIPPO, and are likely to promote state linked to onset of many mood disorders.     

Identification of the reactive cysteine residues in yeast dipeptidyl peptidase III

Dipeptidyl peptidases III (DPPs III) form a distinct metallopeptidase family characterized by the unique HEXXGH motif. High susceptibility to inactivation by organomercurials suggests the presence of a reactive cysteine residue(s) in, or close to, their active site. Yeast DPP III contains five Cys, none of which is absolutely conserved within the family. In order to identify reactive residue(s), site-directed mutagenesis on yeast His₆-tagged DPP III was employed to substitute specifically all five cysteine residues to serine. The variant enzymes thus obtained were enzymatically active and showed an overall structure not greatly affected by the mutations as judged by circular dichroism. Analysis by native and SDS-PAGE under non-reducing conditions revealed the existence of a monomeric and dimeric form in all DPP III proteins except in the C130S, implying that dimerization of yeast DPP III is mediated by the surface-exposed cysteine 130.     

RFLP analysis of cpDNA in the genus <Emphasis Type="Italic">Hypericum</Emphasis>

The chloroplast DNA of 43 species including 16 sections from the genus Hypericum was studied by PCR-RFLP analysis. The PCR-amplified products of four cpDNA regions, trnC-trnD, psbC-trnS, trnL-trnF and rbcL were digested with four restriction endonucleases. A high level of interspecific variation was detected while intraspecific diversity was not observed. The resulting parsimony analysis indicated the monophyletic assemblage of the sections Androsaemum, Olympia, Drosocarpium and Trigynobrathys. Monophyly of Hypericum is weakly supported, but close relationships of H. perforatum and H. maculatum are indicated. The members of Ascyreia are weakly resolved, but clustering of H. kouytchense and H. oblongifolium is well supported, however, H. reptans is nested with Olympia. CpDNA profiles and the positions on the parsimony tree indicate that the chloroplast donor among the putative parents of the hybrid species H. ×inodorum is H. androsaemum.     

Human Y‐chromosome short tandem repeats: A tale of acculturation and migrations as mechanisms for the diffusion of agriculture in the Balkan Peninsula

Southeastern Europe and, particularly, the Balkan Peninsula are especially useful when studying the mechanisms responsible for generating the current distribution of Paleolithic and Neolithic genetic signals observed throughout Europe. In this study, 404 individuals from Montenegro and 179 individuals from Serbia were typed for 17 Y‐STR loci and compared across 9 Y‐STR loci to geographically targeted previously published collections to ascertain the phylogenetic relationships of populations within the Balkan Peninsula and beyond. We aim to provide information on whether groups in the region represent an amalgamation of Paleolithic and Neolithic genetic substrata, or whether acculturation has played a critical role in the spread of agriculture. We have found genetic markers of Middle Eastern, south Asian and European descent in the area, however, admixture analyses indicate that over 80% of the Balkan gene pool is of European descent. Altogether, our data support the view that the diffusion of agriculture into the Balkan region was mostly a cultural phenomenon although some genetic infiltration from Africa, the Levant, the Caucasus, and the Near East has occurred. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Arbuscular mycorrhizal symbiosis can counterbalance the negative influence of the exotic tree species Eucalyptus camaldulensis on the structure and functioning of soil microbial communities in a sahelian soil

The hypothesis of the present study was that bacterial communities would differentiate under Eucalyptus camaldulensis and that an enhancement of arbuscular mycorrhizal (AM) density would minimize this exotic plant species effect. Treatments consisted of control plants, preplanting fertilizer application and AM inoculation. After 4 months of culture in autoclaved soil, E. camaldulensis seedlings were either harvested for growth measurement or transferred into containers filled with the same soil but not sterilized. Other containers were kept without E. camaldulensis seedlings. After 12 months, effects of fertilizer amendment and AM inoculation were measured on the growth of Eucalyptus seedlings and on soil microbial communities. The results clearly show that this plant species significantly modified the soil bacterial community. Both community structure (assessed by denaturing gradient gel electrophoresis profiles) and function (assessed by substrate-induced respiration responses including soil catabolic evenness) were significantly affected. Such changes in the bacterial structure and function were accompanied by disturbances in the composition of the herbaceous plant species layer. These results highlight the role of AM symbiosis in the processes involved in soil bio-functioning and plant coexistence and in afforestation programmes with exotic tree species that target preservation of native plant diversity.