Fight against cold: photosynthetic and antioxidant responses of different bell pepper cultivars (Capsicum annuum L.) to cold stress.

The special metabolites of bell pepper (Capsicum annuum L.) leaves can protect the plant under possibly damaging circumstances, such as high light, UV, unfavorable temperatures, or other environmental effects. In this study, we examined the cold stress tolerance of three different Hungarian pepper varieties (Darina, Édesalma, Rekord), focusing on the antioxidant and photosynthetic responses. The plants were developed in growth chambers under optimal temperature conditions (day/night 25 °C/20 °C) until the leaves on the fourth node became fully developed, then half of the plants received a cold treatment (day/night 15 °C/10 °C). Via a detailed pigment analysis, the PS II chlorophyll fluorescence responses, gas exchange parameters and total antioxidant capacities, leaf acclimation to low temperatures has been characterized. Our results display some of the developing physiological and antioxidant properties, which are among the main factors in monitoring the damaging effects of cold temperatures. Nevertheless, despite their differences, the tested pepper varieties did not show different cold responses.

Thromboxane A(2) contributes to the mediation of flow-induced responses of skeletal muscle venules: role of cyclooxygenases 1 and 2.

BACKGROUND: It has been shown that increases in intraluminal flow elicit dilation in venules, but the mediation of response is not yet clarified. We hypothesized that - in addition to nitric oxide (NO) and dilator prostaglandins (PGI(2)/ PGE(2)) - thromboxane A(2) (TxA(2)) contributes to the mediation of flow-induced responses of venules. METHODS AND RESULTS: Isolated rat gracilis muscle venules (259 +/- 11 microm at 10 mm Hg) dilated as a function of intraluminal flow, which was augmented in the presence of the TxA(2) receptor antagonist SQ 29,548 or the TxA(2) synthase inhibitor ozagrel. In the presence of SQ 29,548, indomethacin or Nomega-nitro-L-arginine methyl-ester decreased flow-induced dilations, whereas in their simultaneous presence dilations were abolished. The selective cyclooxygenase (COX) 1 inhibitor SC 560 reduced, whereas the selective COX-2 inhibitor NS 398 enhanced flow-induced dilations. Immunohistochemistry showed that both COX-1 and COX-2 are present in the wall of venules. CONCLUSION: In skeletal muscle venules, increases in intraluminal flow elicit production of constrictor TxA(2), in addition to the dilator NO and PGI(2)/PGE(2), with an overall effect of limited dilation. These mediators are likely to have important roles in the multiple feedback regulation of wall shear stress in venules during changes in blood flow velocity and/or viscosity.

Structural and physicochemical profiling of morphine and related compounds of therapeutic interest.

A concise account of the physicochemical properties of morphine and its derivatives of therapeutic interest is provided. Such properties include macroscopic and microscopic acid/base parameters, lipophilicity, solubility, permeability that all influence the fate of drugs in the body. The dependence of these parameters on pH is discussed and subsequent implications in drug administration and formulation are presented.

Kynurenic acid inhibits intestinal hypermotility and xanthine oxidase activity during experimental colon obstruction in dogs.

Kynurenic acid (KynA), an endogenous antagonist of N-methyl-d-aspartate (NMDA) glutamate receptors, protects the central nervous system in excitotoxic neurological diseases. We hypothesized that the inhibition of enteric glutamate receptors by KynA may influence dysmotility in the gastrointestinal tract. Group 1 of healthy dogs served as the sham-operated control, in group 2, the animals were treated with KynA, while in groups 3 and 4 mechanical colon obstruction was maintained for 7 h. Group 4 was treated with KynA at the onset of ileus. Hemodynamics and motility changes were monitored, and the activities of xanthine oxidoreductase (XOR) and myeloperoxidase (MPO) were determined from tissue samples. Colon obstruction induced a hyperdynamic circulatory reaction, significantly elevated the motility index and increased the mucosal leucocyte accumulation and the XOR activity. The KynA treatment augmented the tone of the colon, permanently decreased the motility index of the giant colonic contractions and reduced the increases in XOR and MPO activities. These effects were concomitant with the in vitro inhibition of XOR activity. In conclusion, KynA antagonizes the obstruction-induced motility responses and XOR activation in the colon. Inhibition of enteric NMDA receptors may provide an option to influence intestinal hypermotility and inflammatory changes.

Modelling methods and cross-validation variants in QSAR: a multi-level analysis$.

Prediction performance often depends on the cross- and test validation protocols applied. Several combinations of different cross-validation variants and model-building techniques were used to reveal their complexity. Two case studies (acute toxicity data) were examined, applying five-fold cross-validation (with random, contiguous and Venetian blind forms) and leave-one-out cross-validation (CV). External test sets showed the effects and differences between the validation protocols. The models were generated with multiple linear regression (MLR), principal component regression (PCR), partial least squares (PLS) regression, artificial neural networks (ANN) and support vector machines (SVM). The comparisons were made by the sum of ranking differences (SRD) and factorial analysis of variance (ANOVA). The largest bias and variance could be assigned to the MLR method and contiguous block cross-validation. SRD can provide a unique and unambiguous ranking of methods and CV variants. Venetian blind cross-validation is a promising tool. The generated models were also compared based on their basic performance parameters (r2 and Q2). MLR produced the largest gap, while PCR gave the smallest. Although PCR is the best validated and balanced technique, SVM always outperformed the other methods, when experimental values were the benchmark. Variable selection was advantageous, and the modelling had a larger influence than CV variants.

Design of Corrosion Resistive SiC Nanolayers.

Recently, we have shown that the protecting layer of nanosize can be produced by means of ion beam mixing (IBM) of a Si/C multilayer system. The corrosion resistance of the layer correlated with the SiC amount and distribution, determined by Auger electron spectroscopy depth profiling. It has also been shown that the IBM of the Si/C system can be well described by TRIDYN simulation. By combining these two findings, it is possible to design protective layers for various arrangements of layer structure and irradiation conditions. Three different multilayer structures (with individual layer thicknesses falling in the range of 10-20 nm) have been irradiated by Ar+ and Xe+ ions at room temperature in the energy and fluence ranges of 40-120 keV and 0.25 × 1016 to 6 × 1016 ion/cm2, respectively. The carbon and silicon depth distributions have been calculated by TRIDYN simulation. From these profiles applying a simple rule for compound formation, the SiC in-depth distributions were calculated. The resulting corrosion resistance has been measured by potentiodynamic corrosion test in 4 M KOH solution. Excellent correlation between these results and the in-depth distribution (calculated by TRIDYN simulation) of SiC has been found. Thus, the design of a protective SiC coatings operating in harsh environments is possible by applying fast and cheap simulation techniques.

Corrosion Resistance of Nanosized Silicon Carbide-Rich Composite Coatings Produced by Noble Gas Ion Mixing.

Ion beam mixing has been used to produce a silicon carbide (SiC)-rich nanolayer for protective coating. Different C/Si/C/Si/C/Si(substrate) multilayer structures (with individual layer thicknesses falling in the range of 10-20 nm) have been irradiated by Ar+ and Xe+ ions at room temperature in the energy and fluence ranges of 40-120 keV and 1-6 × 1016 ion/cm2, respectively. The effects of ion irradiation, including the in-depth distribution of the SiC produced, was determined by Auger electron spectroscopy depth profiling. The thickness of the SiC-rich region was only some nanometers, and it could be tailored by changing the layer structure and the ion irradiation conditions. The corrosion resistance of the layers was investigated by potentiodynamic electrochemical test in 4 M KOH solution. The measured corrosion resistance of the SiC-rich layers was orders of magnitude better than that of pure silicon, and a correlation was found between the corrosion current density and the effective areal density of the SiC.

Amplification of the genes BCHE and SLC2A2 in 40% of squamous cell carcinoma of the lung.

Gene amplification is a common genetic change in human cancer cells. Previously, we provided the first evidence for gene amplification at chromosome band 3q26 in squamous cell lung carcinoma. In this study, the following analyses were performed: (a) we evaluated biopsies and paraffin-embedded tissues of 16 additional squamous cell lung carcinomas for gene amplification using reverse chromosome painting. Of the 16 tumors, 3 tumors showed an amplification of the entire long arm of chromosome 3, and 3 tumors showed various amplifications on 3q, all of which involved chromosome band 3q26; (b) we tested eight genes encompassing region 3q25-qter in two different tumors to identify amplified genes on chromosome 3q. The genes SI, BCHE, and SLC2A2 were amplified in both tumors; and (c) we analyzed 15 additional paraffin-embedded tissues to determine the amplification frequency of these genes. Of the 15 squamous cell lung carcinomas, 6 showed amplification for at least 1 of the genes, with BCHE and SLC2A2 as the genes most frequently amplified. Together, our reverse chromosome painting data and our PCR analysis indicate gene amplification at 3q26 in 40% of all squamous cell lung carcinomas with BCHE and SLC2A2 as possible target genes of the amplification unit in squamous cell lung carcinoma.

Five novel immunogenic antigens in meningioma: cloning, expression analysis, and chromosomal mapping.

Tumorigenesis of meningioma has been associated with chromosome 22, most notably the NF2 gene, but additional genes have been implicated in meningioma development. Here, we report the identification of five novel immunogenic antigens expressed in meningioma. An expression library was generated from a meningioma that retained both copies of chromosome 22. Screening with autologous patient serum identified seven cDNA clones that were indicated by antigen-antibody complexes. The clones were sequenced, and sequence comparison revealed that the seven clones represent five different genes, providing evidence that meningiomas express a spectrum of immunoreactive antigens, which were termed meningioma expressed antigens (MGEAs). One gene was identical with the connective tissue growth factor, one gene was in part homologous to an Alzheimer disease-associated gene, and a third gene was in part identical to Homo sapiens molybdenum cofactor biosynthesis proteins A and C mRNA. One gene was partially homologous to previously reported cDNA sequences of unknown function, and the fifth gene showed no significant homologies to sequences deposited in databases. Using somatic hybrid mapping, three genes were localized on chromosome 6, and two genes were localized on chromosomes 3 and 17, respectively. To distinguish the MGEAs from the so-called natural autoantigenes, we also screened the library with 12 sera from individuals without obvious disease. The clones identified by reactivity with normal sera were completely different from the clones identified by screening the same meningioma expression library with serum from the patient bearing the tumor. These data suggest that the newly identified MGEA genes may be useful for diagnosis and possibly therapy of meningioma.

Consistency of QSAR models: Correct split of training and test sets, ranking of models and performance parameters.

Recent implementations of QSAR modelling software provide the user with numerous models and a wealth of information. In this work, we provide some guidance on how one should interpret the results of QSAR modelling, compare and assess the resulting models, and select the best and most consistent ones. Two QSAR datasets are applied as case studies for the comparison of model performance parameters and model selection methods. We demonstrate the capabilities of sum of ranking differences (SRD) in model selection and ranking, and identify the best performance indicators and models. While the exchange of the original training and (external) test sets does not affect the ranking of performance parameters, it provides improved models in certain cases (despite the lower number of molecules in the training set). Performance parameters for external validation are substantially separated from the other merits in SRD analyses, highlighting their value in data fusion.

Expression analysis of genes at 3q26-q27 involved in frequent amplification in squamous cell lung carcinoma.

Gene amplifications are known to occur frequently in lung cancer. Recently, we identified gene amplifications at 3q26 in squamous cell lung carcinoma (SCC) using reverse chromosome painting. Here, our aim was to analyse the expression of genes which map within the amplified chromosomal region. The genes which were selected for their known function and their potential involvement in tumour development included the genes for ribosomal protein L22 (RPL22), butyrylcholinesterase (BCHE), glucose transporter 2 (SLC2A2), transferrin receptor (TFRC), thrombopoietin (THPO) and the phosphatidylinositol-3 kinase catalytic alpha polypeptide (PIK3CA). While five genes were expressed in the majority of the 17 samples of SCC, the gene for the glucose transporter 2 (SLC2A2) was expressed in only three cases, excluding SLC2A2 as the target gene of the amplification unit. For a subset of tumours, we determined the amplification status of the six genes. The TFRC, PIK3CA, BCHE, THPO and SLC2A2 genes were amplified in several cases, whereas the RPL22 gene was amplified in only one case. The combined amplification and expression data of this and our previous studies indicate that the amplified region at 3q26 contains several genes that are transcribed in SCC, providing the possibility that several amplified and functionally important genes at 3q26 may be involved in the pathogenesis of SCC.

Gene amplification at chromosome 1pter-p33 including the genes PAX7 and ENO1 in squamous cell lung carcinoma.

Gene amplification is a frequent event in lung cancer, specifically in squamous cell lung carcinoma. Recently, we reported amplifications on chromosomal bands 3q26.1-q26.3 with the genes BCHE and SLC2A2 amplified in 40% of squamous cell lung carcinomas. Here, we identified an amplified domain within chromosomal bands 1pter-p33 in squamous cell lung carcinoma using reverse chromosome painting. A panel of nine genes which have previously been assigned to region 1pter-p33 was tested for amplification using comparative PCR. The ENO1 gene that encodes enolase and the PAX7 gene that encodes a transcription factor were most frequently amplified. Specifically, the gene ENO1 was amplified in six and the gene PAX7 in five out of 37 cases which included both biopsies and paraffin-embedded tissues of squamous cell lung carcinomas. In total, we identified amplifications of at least one gene at bands 1pter-p33 in 10 out of 37 tumors (27%). Together, our data indicate that a novel and frequent amplification unit is present in squamous cell lung carcinoma with the center of the amplified domain in the vicinity of the genes PAX7 and ENO1.

[Awareness of hazards to health caused by pollution of the environment]. / Svijest o ugrozenosti zdravlja djelovanjem cinilaca oneciscene okoline.

This work deals with the results of an ecological/psychological study into the development of Zagreb inhabitants awareness of the potential health risks posed by the ten most significant forms of environmental pollution and into how each examinee influences the development of ecological consciousness. This research was conducted with representative population sample of two significantly differently ecologically critical Zagreb communities: the shanty town community of Kozari Bokand the highly urbanized community of Slobostina. The survey was conducted on site using the Liekert scale in 1990. The results have shown that air and water pollution are considered potentially most dangerous, as opposed to the total lack of awareness concerning noise pollution. The factors significant in the formation of ecological awareness are: occupation and the perception of immediate danger as opposed to age, sex and personal background. However, the subject's educational level and familiarity with the relevant facts are crucial elements affecting the awakening and development of ecological consciousness.

[The use of teicoplanin for Gram-positive infections in patients with kidney transplantation]. / Teicoplanin alkalmazása vesetranszplantáltak gram-pozitív infekcióiban.

Teicoplanin was used for the treatment of multiresistant Gram-positive-Staphylococcus aureus, coagulase negative Staphylococcus and Enterococcus-infections in 15 cases of kidney transplantations. The motive of the application was the once per day dosage and the spare of the transplanted kidney. Nosocomial infections were the most common. Clinical and microbiological diagnosis was the criteria in order to begin the 5-21 days treatment. These patients which were infected with Gram positive bacteria, teicoplanin was also effective in methicillin-resistant cases. In some mixed infections, after several courses of antibiotics, teicoplanin even if combined with other antibiotics could not prevent fatal sepsis.

Genetic effects on refraction and correlation with hemodynamic variables: a twin study.

Spherical equivalent (SE) has not been linked to increased cardiovascular morbidity. Methods: 132 Hungarian twins(age 43.3±16.9 years) underwent refraction measurements (Huvitz MRK-3100 Premium AutoRefractokeratometer)and oscillometry (TensioMed Arteriograph). Results: Heritability analysis indicated major role for genetic components in the presence of right and left SE (82.7%, 95%CI, 62.9 to 93.7%, and 89.3%, 95%CI, 72.8 to 96.6%),while unshared environmental effects accounted for 17% (95%CI, 6.3% to 37%), and 11% (95%CI, 3.4% to 26.7%)of variations adjusted for age and sex. Bilateral SE showed weak age-dependent correlations with augmentation index (AIx), aortic pulse wave velocity (r ranging between 0.218 and 0.389, all p < 0.01), aortic systolic blood pressure and pulse pressure (r between 0.188 and 0.289, p < 0.05). Conclusions: These findings support heritability of spherical equivalent, which does not coexist with altered hemodynamics (e.g. accelerated arterial aging).Accordingly, SE and the investigated hemodynamic parameters seem neither phenotypically nor genetically associated.

Hydrogen peroxide via thromboxane A2 receptors mediates myogenic response of small skeletal muscle veins in rats.

UNLABELLED: We aimed to test two hypotheses: (1) isolated small veins develop substantial myogenic tone in response to elevation of intraluminal pressure, (2) H2O2 contributes to the mediation of myogenic response via activation of arachidonic acid (AA) cascade and release constrictor prostaglandins. METHODS: Small veins were isolated from gracilis muscle of male rats, then cannulated. Changes of diameter to increases in intraluminal pressure, H2O2 and arachidonic acid in the presence and absence of various inhibitors were measured by videomicroscope and microangiometer. At the end of experiments the passive diameter were obtained in Ca2+ -free PSS solution. RESULTS: Isolated rat gracilis muscle small veins developed a substantial myogenic tone in response to increases in intraluminal pressure (1-12 mmHg). Calculated maximum myogenic tone was 70 ± 5% at 10 mmHg. Presence of catalase or indomethacin or SQ 29,548 reduced significantly the pressure-induced myogenic response. Also, H2O2 (10-9-10-5 M) and arachidonic acid (10-7-10-4 M) elicited concentration dependent constrictions, which were inhibited by the presence of indomethacin or SQ 29,548. CONCLUSION: We propose that both myogenic response and pressure-induced release of H2O2 play important roles in regulating the vasomotor function of venules both in physiological and pathological conditions.