Phytochemical Analysis and Total Antioxidant Capacity of Rhizome,Above‐Ground Vegetative Parts and Flower of Three Iris Species

This study was aimed at investigating the phytochemical composition and antioxidant capacity of rhizomes, above‐ground vegetative parts and flowers of three Iris species: Iris humilis Georgi , Iris pumila L. and Iris variegata L. UHPLC‐Orbitrap MS analysis was used for determination of phytochemical profile. Total pigments, phenolics, flavonoids, soluble sugars and starch content as well as ABTS antioxidant capacity were also determined. In total, 52 phenolics compounds were identified with 9 compounds (derivatives of iriflophenone, apigenin C‐glycosides, luteolin O‐glycoside, isoflavones derivatives of iristectorigenin, dichotomitin, nigracin and irilone) never reported before in Iris spp. Differences in phenolic composition profile, pigments, soluble sugar, starch, total phenolics and flavonoids content and total antioxidant capacity were found among Iris species and different part of plants. Significant correlation between total phenolic content and antioxidant capacity was determined. The obtained results are comparable with those obtained for medical plants. These findings could be useful for fingerprinting characterization of Iris species and estimation of possible use in pharmaceutical industries.     

Smoking habits, signs of chronic diseases and survival in inland and coastal regions of Croatia: a follow-up study

Aim of the study was to estimate, the relationship between survival, smoking habits, and the results of medical examinations in inland and coastal regions of Croatia. Age and sex stratified sample of general population (1,571 men and 1,793 women, 37-56 years old in 1972; followed in 1982: N = 1,090 men; 1,325 women and/or 1972-1999 controlling vital status). Relative risks and 95% confidence limits were estimated using Cox regression in the model with time dependent covariates, separately by sex. In all regions, the proportion of male smokers decreased between 1972 and 1982. The proportion of female smokers increased, differently in urban and rural regions. During the follow-up between 1972 and 1999, 568 deaths were recorded among men and 382 among women. In men, in addition to age, significant hazards of death were the number of smoked cigarettes per day, body mass index, sedative intake, vital lung capacity (FVC), 100FEV1/VC, systolic blood pressure, electrocardiogram, history of heart attack, and region. In women, in addition to age, significant predictors were the number of smoked cigarettes per day, systolic blood pressure, electrocardiogram, history of heart disease (excluding coronary diseases), and region. Survival relative risk increased with each additional smoked pack of cigarettes by 2.4% in women and 1.3% in men. Regional differences vs. smoking habit were observed. These data emphasize the need for prevention of smoking.     

Renal vascular resistance in glomerular diseases--correlation of resistance index with biopsy findings

Duplex Doppler sonography has been recognized as a noninvasive method to evaluate hemodynamic features of renal blood in renal and intrarenal arteries in patients with various renal diseases. The significance of duplex Doppler sonography in the evaluation of renal vascular resistance in glomerular diseases has not yet been clearly determined. The aim of the present study was to evaluate renal vascular resistance in patients with glomerular diseases by measuring intrarenal arterial resistance (RI) and to correlate RI with renal functional tests and other clinical and laboratory data. The Doppler parameters were also correlated with histopathological findings in the kidney which underwent the percutaneous biopsy. Duplex Doppler sonography was used to measure RIs in intrarenal arteries in 50 patients with glomerular diseases and 60 age-matched control subjects. The renal vascular resistance index (RI) was determined by the use of Doppler sonography. The mean RI in 50 patients with glomerular diseases was 0.68 +/- 0.09, which was statistically significantly higher than in 60 control subjects (the mean RI was 0.596 +/- 0.035). In a group of patients with membranoproliferative glomerulonephritis the mean RI was 0.817 +/- 0.624 which was statistically significantly higher than in other groups of glomerulonephritis. The renal vascular (resistance) RI significantly correlated with serum creatinine, creatinine clearance and beta2 microglobulin. Qualitative duplex sonography measure of renal arterial resistance-resistive index does not appear to be reliable in distinguishing different types of glomerulonephritis.     

The influence of detergent, the active component of detergent and sodiumtripolyphosphate on the biochemical process of some fungi.

Detergent "Merix" (Merima-Krusevac) and its components, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol in defined concentrations have influence on the enzymatic activity, bioproduction of amino acids and proteins and total biomass of species Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum). Detergent in concentration of 1% vol., in some cases, significantly stimulated production of the majority of amino acids. Detergent and its components (ethoxyled oleyl-cetyl alcohol and sodiumtripolyphosphate) in concentration of 1% vol. showed different influences on the production of proteins by the species of fungi A. niger and F. oxysporum. The enzymatic activity of fungi A. niger and F. oxysporum changed from total inhibition up to partial or total stimulation under influence of investigated pollutants. Detergent, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol, all in concentration of 1% vol. have reduced the production of the biomass of fungi A. niger and F. oxysporum. Investigated fungi have shown different response to the used pollutants.     

Association of β<Subscript>2</Subscript>-microglobulin with the α<Subscript>3</Subscript> domain of H-2D<Superscript>b</Superscript> heavy chain

MHC class I molecules are heterotrimeric complexes composed of heavy chain, ₂-microglobulin (₂m) and short peptide. This trimeric complex is generated in the endoplasmic reticulum (ER), where a peptide loading complex (PLC) facilitates transport from the cytosol and binding of the peptide to the preassembled ER resident heavy chain/₂m dimers. Association of mouse MHC class I heavy chain with ₂m is characterized by allelic differences in the number and/or positions of amino acid interactions. It is unclear, however, whether all alleles follow common binding patterns with minimal contributions by allele-specific contacts, or whether essential contacts with ₂m are different for each allele. While searching for the PLC binding site in the ₃ domain of the mouse MHC class I molecule H-2D^b, we unexpectedly discovered a site critical for binding mouse, but not human, ₂m. Interestingly, amino acids in the corresponding region of another MHC class I heavy chain allele do not make contacts with the mouse ₂m. Thus, there are allelic differences in the modes of binding of ₂m to the heavy chain of MHC class I.     

Mismatch repair in the antimutator Escherichia coli mud

Antimutators are genetic mutants that produce mutations at reduced rates compared to the wild type strain. They are interesting because they may provide insights into the mechanisms by which spontaneous mutations occur. We have investigated a reported antimutator strain of Escherichia coli termed mud for its possible mechanism. The mud strain exhibits a decrease in both spontaneous mutagenesis and mutability with alkylated agents and base analogs. These types of DNA lesions are known to be the substrates for the E. coli methyl-directed mismatch repair encoded by the mutHLSU system. We investigated whether the putative antimutator effect results from the increased expression or activity of the mutHLSU system. To directly measure the mismatch repair capacity of mud cells, we have transfected them with phage lambda heteroduplexes and scored the fraction of mixed (unrepaired) infective centers. This transfection system has been used routinely to assay mismatch repair capacity in E. coli and other organisms. No difference between mud and wild type cells is observed. From the results of the experiments we conclude that the reported antimutator effect of mud does not result from enhanced mismatch repair capacity. This conclusion is consistent with recently published evidence that the mud effect does not represent a real antimutator effect, but is an artifact due to impaired growth of mud cells under certain selective conditions.     

The RuvABC resolvase is indispensable for recombinational repair in sbcB15 mutants of Escherichia coli

The RuvABC proteins of Escherichia coli play an important role in the processing of Holliday junctions during homologous recombination and recombinational repair. Mutations in the ruv genes have a moderate effect on recombination and repair in wild-type strains but confer pronounced recombination deficiency and extreme sensitivity to DNA-damaging agents in a recBC sbcBC background. Genetic analysis presented in this work revealed that the (Delta)ruvABC mutation causes an identical DNA repair defect in UV-irradiated recBC sbcBC, sbcBC, and sbcB strains, indicating that the sbcB mutation alone is responsible for the extreme UV sensitivity of recBC sbcBC ruv derivatives. In experiments with gamma irradiation and in conjugational crosses, however, sbcBC (Delta)ruvABC and sbcB (Delta)ruvABC mutants displayed higher recombination proficiency than the recBC sbcBC (Delta)ruvABC strain. The frequency of conjugational recombination observed with the sbcB (Delta)ruvABC strain was quite similar to that of the (Delta)ruvABC single mutant, indicating that the sbcB mutation does not increase the requirement for RuvABC in a recombinational process starting from preexisting DNA ends. The differences between the results obtained in three experimental systems used suggest that in UV-irradiated cells, the RuvABC complex might act in an early stage of recombinational repair. The results of this work are discussed in the context of recent recombination models which propose the participation of RuvABC proteins in the processing of Holliday junctions made from stalled replication forks. We suggest that the mutant SbcB protein stabilizes these junctions and makes their processing highly dependent on RuvABC resolvase.     

Editing autoreactive TCR enables efficient positive selection

Allelic exclusion is inefficient at the TCRalpha locus, allowing a sizeable portion of T cells to carry two functional TCRs. The potential danger of dual TCR expression is a rescue of autoreactive TCRs during selection in the thymus and subsequent development of autoimmunity. In this study, we examine the reason(s) for replacing an autoreactive TCR and for allowing the survival of cells carrying two TCRs. We compared development of TCR transgenic CD4(+)CD8(-) thymocytes in the presence or absence of MHC class II autoantigen that does not induce deletion of thymocytes. Contrary to the expected negative effect of the presence of autoantigen, approximately 100% more CD4(+)CD8(-) thymocytes were found in the presence of MHC class II autoantigen than in the neutral background. A further increase in the strength of autoantigenic signal via expression of a human CD4 transgene led to an additional increase in the numbers of CD4(+)CD8(-) thymocytes. Thus, editing autoreactive TCR results in more efficient positive selection, and this may be both a reason and a reward for risking autoimmunity.