Immunologic effects of interleukin 2 in primary immunodeficiency diseases

Five children with primary deficiencies of T cell function were studied to assess the effects of highly purified exogenous Interleukin 2 (IL 2) on their in vitro T cell responses. The lymphocytes from one child with Nezelof's T cell deficiency demonstrated absence of endogenous IL 2 production and improved proliferative responses to mitogen or alloantigen in the presence of exogenous IL 2. Moreover, during in vitro mixed lymphocyte culture in the presence of exogenous IL 2, his lymphocytes were able to develop into cytotoxic effector cells. A second child with Nezelof's syndrome demonstrated a different type of defect. The lymphocytes from this child had less impairment of endogenous IL 2 production. Although IL 2 increased the proliferation of his cells in response to PHA, similar augmentation was not seen after stimulation with OKT3 or alloantigen. In cell-mediated cytotoxicity assays, after mixed lymphocyte culture, natural killer-like activity was strongly boosted in the cultures that contained IL 2, but T cell-mediated cytotoxicity was not. The lymphocytes from three patients with severe combined immunodeficiency did not show improved proliferative responses in the presence of IL 2. Thus, only one of the five patients demonstrated the combination of defective endogenous IL 2 production, but preservation of the ability to respond appropriately to exogenous IL 2. This child may therefore have suffered from a T cell defect pathophysiologically similar to that seen in nude or aged mice.     

Distribution,causal agents,and infection dynamic of emerging ink disease of sweet chestnut in Southern Switzerland

Emerging diseases caused by both native and exotic pathogens represent a main threat to forest ecosystems worldwide. The two invasive soilborne pathogens Phytophthora cinnamomi and Phytophthora × cambivora are the causal agents of ink disease, which has been threatening Castanea sativa in Europe for several centuries and seems to be re-emerging in recent years. Here, we investigated the distribution, causal agents, and infection dynamics of ink disease in southern Switzerland. A total of 25 outbreaks were identified, 19 with only P. cinnamomi, 5 with only P. × cambivora, and 1 with both species. Dendrochronological analyses showed that the disease emerged in the last 20–30 years. Infected trees either died rapidly within 5–15 years post-infection or showed a prolonged state of general decline until death. Based on a generalized linear model, the local risk of occurrence of ink disease was increased by an S-SE aspect of the chestnut stand, the presence of a pure chestnut stand, management activities, the proximity of roads and buildings, and increasing annual mean temperature and precipitation. The genetic structure of the local P. cinnamomi population suggests independent introductions and local spread of the pathogen.     

The Interplay Between NSAIDs and Candida albicans on the Gastrointestinal Tract of Guinea Pigs

Recent studies suggest that Candida albicans colonization is associated with several gastrointestinal inflammatory disorders and is also responsible for the delay in ulcer healing. No data are reported about the effects of C. albicans on the nonsteroidal anti-inflammatory drugs (NSAIDs)-induced necroinflammatory lesions. On the other hand, beneficial effects of NSAIDs regarding the colonization potential with C. albicans have been reported. Our aim was to investigate whether the association between NSAIDs and C. albicans could potentially induce necroinflammatory lesions in the guinea pigs gastric and enteral mucosa. Three interventional groups of 11 guinea pigs each were investigated after 5 days of receiving indomethacin, C. albicans or the association of both. C. albicans and necroinflammatory lesions were graded based on histological examinations. Statistical analysis used Mann–Whitney nonparametric test. NSAIDs did not significantly decrease C. albicans colonization grades on gastrointestinal mucosa. Administration of indomethacin subsequent to C. albicans determined significantly more severe necroinflammatory lesions compared to group that only received C. albicans. The association of NSAIDs and C. albicans did not cause significantly more severe degenerative or inflammatory lesions compared to the administration of only NSAIDs in this experimental model. Associations between NSAIDs and C. albicans caused significantly more severe necroinflammatory injuries than the lesions produced by C. albicans, without enhancing the mucosal injury or inflammation caused by NSAIDs.     

Nonsteroidal compounds designed to mimic potent steroid sulfatase inhibitors

Chemical synthesis and enzyme inhibition results are reported for a series of nonsteroidal sulfatase inhibitors, 1-(p-sulfamoyloxyphenyl)-5-(p-t-butylbenzyl)-5-alkanols and the lower active phenolic analogues. These compounds conserve some structural elements from the previously reported potent steroidal inhibitor 3-O-sulfamate-17alpha-(p-t-butylbenzyl)-17beta-hydroxy-estra-1,3,5(10)-triene, while the C18-methyl group and the hydrocarbon backbone represented by the steroid rings B, C, and D were replaced with a free conformational chain. Using estrone sulfate (100 microM) as substrate and homogenate of transfected HEK-293 cells as source of steroid sulfatase activity, the IC(50) values of the best inhibitors, the undecanol derivatives, were 0.4+/-0.1 and >300 nM, respectively, in the sulfamate and phenolic series. Although these sulfamoylated nonsteroidal inhibitors appear a bit less active than their steroidal analogues, they are however more potent than known inhibitors estrone-3-O-sulfamate and p-(O-sulfamoyl)-N-tetradecanoyl tyramine. The optimal side-chain length for the inhibition of steroid sulfatase activity was found to be six carbons, which corresponds to the number of carbons that mimic the B, C and D steroid rings, between C6 and C17. Furthermore, compounds with only the t-butylbenzyl group or the alkyl chain of six carbons are less potent inhibitors compared to the one that include both of these hydrophobic substituents. Such results suggest that compound from this later category better mimic the steroidal inhibitor.     

3Beta-sulfamate derivatives of C19 and C21 steroids bearing a t-butylbenzyl or a benzyl group: synthesis and evaluation as non-estrogenic and non-androgenic steroid sulfatase inhibitors

A series of C19 and C21 steroids bearing one or two inhibiting groups (3beta-sulfamate and 17alpha- or 20(S)-t-butylbenzyl or benzyl) were synthesized and tested for inhibition of steroid sulfatase activity. When only a sulfamate group was added to dehydroepiandrosterone, androst-5-ene-3beta,17beta-diol, pregnenolone and 20-hydroxy-pregnenolone, no significant inhibition of steroid sulfatase occurred at concentrations of 0.3 and 3 microM. With only a t-butylbenzyl or a benzyl group, a stronger steroid sulfatase inhibition was obtained in the androst-5-ene than in the pregn-5-ene series. Comparative results from the screening tests and the IC50 values have shown that the effect of a sulfamate moiety as a second inhibiting group can be combined to the t-butylbenzyl or benzyl effect in the C19 and C21 steroid series. The 3beta-sulfamoyloxy-17alpha-t-butylbenzyl-5-androsten-17beta-ol (10) was thus found to be the most active compound with IC50 values of 46 +/- 8 and 14 +/- 1 nM, respectively for the transformations of E1S to E1 and DHEAS to DHEA. The IC50 values of compound 10 are similar to that of 17alpha-t-butylbenzyl-estradiol, which was previously reported by our group as a good steroid sulfatase reversible inhibitor, but remains higher than that of the potent inactivators estrone-3-O-sulfamate (EMATE) and 17alpha-t-butylbenzyl-EMATE. However, contrary to these two latter inhibitors, compound 10 did not induce any proliferative effect on estrogen-sensitive ZR-75-1 cells nor on androgen-sensitive Shionogi cells at concentrations tested, suggesting that this steroid sulfatase inhibitor is non estrogenic and non androgenic.     

Bioactive poly(ethylene terephthalate) fibers and fabrics: grafting, chemical characterization, and biological assessment

The grafting of poly(sodium styrene sulfonate) (pNaSS) onto ozone-treated poly(ethylene terephthalate) (PET) fabric surfaces was characterized by X-ray photoelectron spectroscopy and toluidine blue colorimetry. Significant amounts of pNaSS were grafted over the range of experimental conditions examined in this study (30-120 min of ozonation, reaction at 65 or 70 degrees C, and reaction times up to 240 min). Within these ranges the amount of grafted pNaSS increased with both ozonation time and reaction temperature. The amount of grafted pNaSS increased over the first 60 min of reaction, then remained relatively constant from 60 to 240 min. For the biological experiments pNaSS-grafted samples were prepared with 30 min of ozonation and 60 min of reaction at a grafting temperature of 70 degrees C. The ozonation time was limited to 30 min to minimize any possible degradation of the PET fabrics by the ozonation treatment. The pNaSS-grafted PET surface adsorbed a factor of 4 more compared to the nongrafted surfaces. The strength of fibroblast adhesion was an order of magnitude higher on pNaSS-grafted PET fabrics compared to that on nongrafted PET fabrics. This difference in the cell attachment was correlated to the cell spreading, which was better and more homogeneous on the grafted fibers compared to the nongrafted fibers. Fibroblasts adhered more strongly on surfaces precoated with normal human plasma compared to surfaces precoated with 10% fetal calf serum in Dulbecco's modified Eagle's medium.     

The yeast APC/C subunit Mnd2 prevents premature sister chromatid separation triggered by the meiosis-specific APC/C-Ama1

Cohesion established between sister chromatids during pre-meiotic DNA replication mediates two rounds of chromosome segregation. The first division is preceded by an extended prophase wherein homologous chromosomes undergo recombination. The persistence of cohesion during prophase is essential for recombination and both meiotic divisions. Here we show that Mnd2, a subunit of the anaphase-promoting complex (APC/C) from budding yeast, is essential to prevent premature destruction of cohesion in meiosis. During S- and prophase, Mnd2 prevents activation of the APC/C by a meiosis-specific activator called Ama1. In cells lacking Mnd2 the APC/C-Ama1 enzyme triggers degradation of Pds1, which causes premature sister chromatid separation due to unrestrained separase activity. In vitro, Mnd2 inhibits ubiquitination of Pds1 by APC/C-Ama1 but not by other APC/C holo-enzymes. We conclude that chromosome segregation in meiosis depends on the selective inhibition of a meiosis-specific form of the APC/C.     

The use of nuclear DNA molecular markers for studying speciation and systematics as exemplified by the “Lacerta agilis complex” (Sauria: Lacertidae)

Four types of nuclear DNA markers identified by the taxonprint, RAPD, and IMP (Inter-MIR-PCR) methods, and the nucleotide sequences of satellite DNA monomers have been used to analyze the molecular genetic similarity between some populations, subspecies, and species of lizards combined into the group Lacerta s. str., as well as representatives of some other genera. The notions on the systematics and phylogeny of this group based on morphological and zoogeographic criteria have been compared to the conclusions based on molecular genetic data. The genus and species subdivisions of populations based on nuclear molecular markers and morphological characters generally agree with each other, the degree of genetic differences being correlated with the taxonomy suggested by zoomorphologists. The degree of differences between the subspecies of one of the species studied, Lacerta agilis, varies depending on the molecular markers used: according to the results of RAPD analysis, all subspecies substantially differ from one another, the variation within populations being small; with respect to other markers, the differences are smaller and not equivalent. The existence of the so-called eastern and western clades of this species earlier assumed by other researchers on the basis of mtDNA and morphological data has been confirmed. There are no distinct gradations exceeding individual variation in 14 populations of L. agilis exigua (the eastern clade) with respect to IMP markers, although these populations inhabit a vast area from the Ural Mountains to the Kabardino-Balkar Republic (the Caucasus). These data suggest that the subspecies has been rapidly spreading northwards since the Pleistocene glaciation (about 15,000 years ago).