Temporal and regional changes of superoxide dismutase and glutathione peroxidase activities in rats exposed to focal cerebral ischemia

Reactive oxygen species are important cause of tissue injury during cerebral ischemia and reperfusion (I/R). Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) are intracellular enzymes responsible for endogenous antioxidant defense of tissues affected by I/R. The aim of this study was to examine temporal and regional changes of SOD and GSH-Px activities in animals exposed to transient focal cerebral ischemia. Male Wistar Hannover rats were subjected to the right middle cerebral artery occlusion for 2?h. The animals were sacrificed immediately, 0·5, 1, 2, 3, 6, 24, 48, 72 or 168?h after ischemic procedure. SOD and GSH-Px activities were determined spectrophotometrically in the hippocampus and parietal cortex, both unilaterally and contralaterally to the occlusion. Sham-operated animals were used as the control group. Our results indicated that transient focal cerebral ischemia causes significant changes in SOD activities in the hippocampus and parietal cortex such as in GSH-Px activities in the parietal cortex, unilaterally and contralaterally to the lesion in rats during different reperfusion periods. Statistically significant activation of GSH-Px was registered neither in the right nor in the left hippocampus of ischemic animals. Copyright ? 2012 John Wiley & Sons, Ltd.     

Energy exploitation in Chirocephalus croaticus (Steuer, 1899) (Crustacea: Anostraca): survival strategy in an intermittent lake

Electron transport system (ETS) activity was measured in Chirocephalus croaticus from the intermittent lake, Petelinjsko Jezero. The ETS activities were measured at 5, 10, 15, 20, and 25 °C, and were studied separately in juveniles, females and males. Juveniles had significantly higher activity than adults at a standard temperature of 20 °C. The mass-specific ETS activity decreased with increasing size of the animals; the value b was 0.787. Respiration rates (R) were determined at 20 °C and the ratio ETS/R (±standard deviation) for C. croaticus was 1.43±0.46 (n=38). ETS activity increased with temperature. Females had higher Q₁₀ than males in higher temperature range (t-test; t=2.50; d.f.=8; p<0.05). Activation energy E_a was higher for females than males (t-test; t=2.35; d.f.=8; p<0.05). Females exhibited lower ETS activity than males over the lower temperature range, but their ETS could function more efficient at higher temperature.     

Atherosclerotic lesions of supra-aortic arteries in diabetic patients

The aim of this prospective study was to determine the prevalence and localization of stenotic atherosclerotic lesions of supra-aortic arteries in diabetic patients according to age and sex. Angiograms obtained by digital subtraction angiography were analyzed in 150 diabetic patients (study group) and 150 non-diabetic patients (control group) with symptoms of cerebral ischemia. Diabetic patients were found to have a significantly higher prevalence of stenotic atherosclerotic lesions of the internal carotid artery. Lesions of the large supra-aortic arteries were significantly more common in the left than in the right side of the neck (p < 0.001), but the difference between the diabetic and the non-diabetic group did not reach statistical significance. Hemodynamic conditions were found to be more important than diabetes for the occurrence of atherosclerotic lesions in these arteries. Changes in the proximal segment of the left common carotid artery were the most common finding in diabetic patients, hence attention should be paid to this localization on control examinations.     

Water-Induced Finger Wrinkles Do Not Affect Touch Acuity or Dexterity in Handling Wet Objects

Human non-hairy (glabrous) skin of the fingers, palms and soles wrinkles after prolonged exposure to water. Wrinkling is a sympathetic nervous system-dependent process but little is known about the physiology and potential functions of water-induced skin wrinkling. Here we investigated the idea that wrinkling might improve handling of wet objects by measuring the performance of a large cohort of human subjects (n = 40) in a manual dexterity task. We also tested the idea that skin wrinkling has an impact on tactile acuity or vibrotactile sensation using two independent sensory tasks. We found that skin wrinkling did not improve dexterity in handling wet objects nor did it affect any aspect of touch sensitivity measured. Thus water-induced wrinkling appears to have no significant impact on tactile driven performance or dexterity in handling wet or dry objects.     

TGF-β1 Expression in Chromophobe Renal Cell Carcinoma and Renal Oncocytoma

Distinguishing renal oncocytoma (RO) from the eosinophilic variant of chromophobe renal cell carcinoma (ChRCC) under the light microscope is a common diagnostic problem. Our recent research has shown significant difference between the presence of tumor fibrous capsule in ChRCCs and ROs. Transforming growth factor beta 1 (TGF-β1) is a potent cytokine involved in regulating a number of cellular processes. Two main purposes of this research were to investigate whether the TGF-β1 staining could be related to the presence of tumor fibrous capsule and if it could be used in the differential diagnosis between ChRCC and RO. We investigated 34 cases: 16 ChRCCs (8 eosinophilic and 8 classic) and 18 ROs. All available slides of each tumor, routinely stained with hematoxylin and eosin (H&E) were first analyzed to note the presence of tumor fibrous capsule. One paraffin embedded tissue block matching the representative H&E slide was selected for the immunohistochemical analysis. TGF-β1 expression was analyzed semiquantitatively in the tumor tissue, the tumor fibrous capsule, if present and the peritumoral renal parenchyma. Intensity of TGF-β1 expression was weaker in ChRCCs than the one observed in ROs (P<0.05). The type of reaction in ChRCCs was predominantly membranous unlike in ROs, which exhibited a predominantly cytoplasmic reaction (P<0.05). Moreover, none of the ROs showed membranous type of reaction for TGF-β1. In the group of ChRCCs, tumors with capsule had statistically significant higher quantity of TGF-β1 expression in tumor tissue and in peritumoral renal parenchyma compared to the tumors without capsule (P<0.05). Our results showed different types of TGF-β1 expression in ChRCCs and ROs: ChRCCs had predominantly membranous type of reaction, and ROs predominantly cytoplasmic. Furthermore, ChRCCs with capsule had statistically significant higher quantity of TGF-β1 expression in tumor tissue and in peritumoral renal parenchyma compared to the tumors without capsule. Based on these findings we can speculate that it could be possible that TGF-β1 plays a role in the formation of fibrous capsule in ChRCCs.Key words: capsule, chromophobe renal cell carcinoma, renal oncocytoma, TGF-β1     

The calcium-binding C-terminal domain of Escherichia coli alpha-hemolysin is a major determinant in the surface-active properties of the protein

alpha-Hemolysin (HlyA) from Escherichia coli is a protein toxin (1024 amino acids) that targets eukaryotic cell membranes, causing loss of the permeability barrier. HlyA consists of two main regions, an N-terminal domain rich in amphipathic helices, and a C-terminal Ca(2+)-binding domain containing a Gly- and Asp-rich nonapeptide repeated in tandem 11-17 times. The latter is called the RTX domain and gives its name to the RTX protein family. It had been commonly assumed that membrane interaction occurred mainly if not exclusively through the amphipathic helix domain. However, we have cloned and expressed the C-terminal region of HlyA, containing the RTX domain plus a few stabilizing sequences, and found that it is a potent surface-active molecule. The isolated domain binds Ca(2+) with about the same affinity (apparent K(0.5) approximately 150 microM) as the parent protein HlyA, and Ca(2+) binding induces in turn a more compact folding with an increased proportion of beta-sheet structure. Both with and without Ca(2+) the C-terminal region of HlyA can interact with lipid monolayers spread at an air-water interface. However, the C-terminal domain by itself is devoid of membrane lytic properties. The present results can be interpreted in the light of our previous studies that involved in receptor binding a peptide in the C-terminal region of HlyA. We had also shown experimentally the distinction between reversible membrane adsorption and irreversible lytic insertion of the toxin. In this context, the present data allow us to propose that both major domains of HlyA are directly involved in membrane-toxin interaction, the nonapeptide repeat, calcium-binding RTX domain being responsible for the early stages of HlyA docking to the target membrane.     

Comparative research on substance abuse and self-perception among adolescents with physical handicap

The research on substance (alcohol, tobacco and drug) abuse and on self-perception was done by comparing a test group of physically disabled adolescents and a test group of non-disabled adolescents. The respondents of the experimental group were students of the only special high school for physically handicapped persons in Croatia, Zagreb. The respondents of the control group were the students of two regular high schools in the capital of Croatia. The instrument used in this research was a self-reported, anonymous questionnaire. The respondents completed the questionnaire in the classroom. The data analysis regarding alcohol abuse indicated that physically disabled adolescents drink more often and out of quite different motives than their non-disabled peers. Regarding the prevalence, frequency, quantity and motives for smoking, no statistically significant difference has been found between the tested groups. On the contrary, significant differences between handicapped and non-disabled adolescents were evident regarding drug abuse. Only one physically disabled examinee used a drug--marijuana, only a few times a year. On the other hand, almost one quarter of the non-disabled adolescents use at least one, five at the most, type of drug sometimes or often. The results on the self-perception scale show that adolescent with physical disabilities have a much more negative attitude toward themselves than non-disabled controls. Their self-esteem and self-confidence are seriously diminished. Described findings could have a mighty impact on ways of preventing substance abuse, and on ways of increasing self-esteem among disabled and non-disabled adolescents.     

A Simple and Efficient DNA Isolation Method for Salvia officinalis

We report an efficient, simple, and cost-effective protocol for the isolation of genomic DNA from an aromatic medicinal plant, common sage (Salvia officinalis L.). Our modification of the standard CTAB protocol includes two polyphenol adsorbents (PVP 10 and activated charcoal), high NaCl concentrations (4?M) for removing polysaccharides, and repeated Sevag treatment to remove proteins and other carbohydrate contaminants. The mean DNA yield obtained with our Protocol 2 was 330.6?μg DNA g^?1 of dry leaf tissue, and the absorbance ratios 260/280 and 260/230?nm averaged 1.909 and 1.894, respectively, revealing lack of contamination. PCR amplifications of one nuclear (26S rDNA) and one chloroplast (rps16-trnK) locus indicated that our DNA isolation protocol may be used in common sage and other aromatic and medicinal plants containing essential oil for molecular biologic and biotechnological studies and for population genetics, phylogeographic, and conservation surveys in which nuclear or chloroplast genomes would be studied in large numbers of individuals.     

Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation

Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell-cell and cell-matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph system from S. domuncula was used. During the formation of these three-dimensional aggregates composed of proliferating cells, the expression of Iroquois depends on ferric iron and water current. An increased expression in response to water current is paralleled with the formation of canal-like pores in the primmorphs. It is suggested that Iroquois expression is involved in the formation of the aquiferous system, the canals in sponges and the canal-like structures in primmorphs.