Search

Bacterial urinary tract infections (UTI) are frequently found in the outpatient as well as in the nosocomial setting. The bacterial UTI can be stratified into uncomplicated and complicated UTI. Antibiotic resistance is continuously increasing in uncomplicated as well as complicated UTI. In uncomplicated UTI efforts are made to use antibiotic substances exclusively for this indication. In complicated UTI as broad spectrum antibiotics are increasingly used, the higher the antimicrobial resistance rates are reported. There are two predominant aims in the antimicrobial treatment of both uncomplicated and complicated UTI: 1.) rapid and effective response to therapy, prevention of complications and prevention of recurrence in the individual patient treated, and 2.) prevention of emergence of resistance to anti-infective agents in the microbial environment. The use of antibiotics has to keep up with the continuous change in antimicrobial resistance and the tailored needs in the individual patient. Antibiotic substances therefore need to become evaluated for each indication and continuously followed for clinical usage. The knowledge of structure-activity relationships of antimicrobial substances and bacterial resistance mechanisms to antibiotics help to use antibiotics better in daily routine and design new derivatives and substances. The aim of this review is to describe the chemistry and structure-activity relationships of current antibiotics and promising substances in development for the treatment of UTI.

Growth factors and cytokines control and coordinate a broad spectrum of fundamental cellular functions, and are evolutionarily conserved both in vertebrates and invertebrates. In this review, we focus our attention on the functional phylogenetic aspects of growth factors/cytokines like the Transforming Growth Factor- (TGF-), the Connective Tissue Growth Factor (CTGF), and the Vascular Endothelial Growth Factor (VEGF). We will also delve into the activites of two chemokine families, interleukin (IL)-8 (or CXCL8) and CC chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2). These molecules have been selected for their involvement in immune responses and wound healing processes, where they mediate and finely regulate various regeneration processes like angiogenesis or fibroplasia, not only in vertebrates, but also in invertebrates.

A number of in vitro studies have implicated protein kinase C(PKC) and PKC in the regulation of the immune system. In recent years, this has been convincingly demonstrated in mice deficient for PKC and PKC. The reported phenotypes for these transgenic mice indicate that PKC suppresses immunoresponsiveness and inhibits the proliferation of B-lymphocytes, while PKC is required for macrophages to mount an effective immune response to bacterial pathogens. In either case, these isoenzymes appear to cooperate in fine-tuning certain immunoreactions by either suppressing (PKC) or stimulating (PKC) the transcription of various cytokines. This review will compare and contrast the structures of these two nPKC isoenzymes and their respective roles in the modulation of cytokine production and various other cellular processes, such as growth, differentiation, apoptosis, and tumor suppression.

The angiogenic process in vertebrates and hirudineans has been compared. The leech Hirudo medicinalis, subjected to an angiogenic stimulus (surgical explant or cytokine treatment) responds, as a vertebrate, with the formation of an extensive network of new vessels accompanied by the production of circulating cells. The reviewed data confirm the surprising similarity between hirudinean and vertebrate processes in wound healing, and suggest that basic common events such as antigenic expressions of endothelial and hemopoietic cells, cytokine secretion and regulation as well as extracellular matrix interactions, are conserved and extended across diverse species, tissues and developmental phases.

An increasing body of evidence indicates that in the leech Hirudo medicinalisthe angiogenic process is finely regulated and coordinated by the botryoidal tissue. In this paper we provide evidence on the involvement of botryoidal tissue cells in angiogenesis induced in H. medicinalisby a variety of stimuli including surgical wounds or the administration of modulators of neovascularization. Interestingly, we show that either human activators of vascular cell growth, or anti-angiogenic peptides like angiostatin and endostatin, or the drug mitomycin, can induce a prompt biological response in H. medicinalis. We show as well that angiogenesis in this invertebrate shares a surprising degree of similarity with neovascularization in vertebrates, both at the biochemical and cellular levels, because it involves similar growth factors/growth factor receptors, and relies on analogous cell–cell or cell–matrix interactions. For these reasons we suggest that H. medicinaliscan be used as a reproducible model for testing activators or inhibitors of angiogenesis, and for investigating the biochemical, ultrastructural and cellular processes involved in new vessel formation.

A new method for the direct ESR detection of free radicals in rat myocardial tissue is described. Isolated rat atria are continuously monitored for heart rate and contractile force; at the end of the experimental period the beating organs are inserted into quartz ESR tubes and immediately frozen in liquid nitrogen. Spectra obtained from these preparations show the presence of very weak radical signals. When ESR spectra are recorded on samples obtained from pools of rat atria pulverized under liquid nitrogen, the radical lines are markedly stronger than those observed for intact organs: contaminating metals are also frequently detected. These findings indicate that crushing or grinding procedures carried out under liquid nitrogen produce artifactual ESR active species. The new method described in the present paper does not involve mechanical interventions and therefore should yield reliable artifact-free results.

Breast cancer patients are characterised by an enhanced chromosomal radiosensitivity pointing to a defect in the repair of DNA double strand breaks (dsb). In mammalian cells, radiation induced dsb are mainly repaired by the non homologous end-joining (NHEJ) repair pathway, a pathway in which the Ku70/Ku80 heterodimer plays a key role as it binds to the broken DNA ends. In this study we wanted to investigate the radiosensitizing effect of Ku70/80 knockdown, by lentivirus-mediated RNAinterference, in a spontaneous immortalised human mammary epithelial cell line (MCF10A). Several endpoints for measuring radiosensitivity were taken into acount: micronucleus formation (chromosomal radiosensitivity), cell survival, apoptosis and senescence. For all endpoints, MCF10A cells were infected with lentiviral vectors for RNAi of Ku70 (pLVTHM/shKu70/GFP). Western blot analysis showed that the Ku70 lentiviral vector was effective in silencing the expression of both Ku70 and Ku80. When a satisfactory knockdown was obtained (70-90% vs. mock-infected (pLVTHM/GFP) cells), the cells were used to perform radiation experiments. For the in vitro MN assay, cells were irradiated with doses of 2 and 4 Gy 60Co gamma-rays. A significantly higher radiation-induced MN yield was obtained in the Ku70/80 knock down cell line compared to the mock-infected cell line, pointing to an increased chromosomal radiosensitivity. This increased chromosomal radiosensitivity demonstrates that the repair genes, Ku70 and Ku80, are involved in the repair of DNA double strand breaks, which are the main DNA lesions resulting in chromosomal aberrations such as micronuclei. Besides chromosomal radiosensitivity we also investigated radiosensitivity at the cellular level by cell survival experiments. Cells were irradiated with doses ranging between 0 and 8 Gy and cultured for 5 days before being analysed. The results of the cell survival assay show that Ku70/80 knockdown cells have a lower survival yield after irradiation compared to mock-infected cells, pointing to an enhanced cellular radiosensitivity. Analysis of the cell death pattern showed that MCF10 cells (Ku70/80 knockdown and mock-infected) do not undergo apoptosis but go into cellular senescence. In conclusion, we can state that knockdown of Ku70 and Ku80 by RNAi of Ku70 resulted in an increased chromosomal and cellular radiosensitivity in an immortalised MCF10 human mammary cell line after irradiation with low LET 60Co gamma-rays. These results may further support the role of DNA dsb repair genes in breast cancer.

Enhanced chromosomal radiosensitivity (CR) has been observed in a significant number of breast cancer patients. Since ionising radiation induces double-strand breaks (DSB), polymorphisms in DSB repair genes could be involved in genetic predisposition to breast cancer. A family history of breast cancer is a well known risk factor for the disease. Other risk factors are also associated with breast cancer, such as early age of first menarche, nulliparity or late first childbirth, and late menopause. The principle culprit common for these risk factors is said to be the prolonged exposure to elevated levels of estrogens. As non homologous end-joining (NHEJ) is the major DSB repair pathway in mammalian cells, we investigated the association of 5 SNPs in 3 different NHEJ genes with breast cancer in a population-based case-control setting. The total patient population was composed of a selected group of patients with a family history of the disease and an unselected group. CR was previously studied in both patient groups. SNP analysis showed that the c.2099-2408G>A SNP (Ku80) has a significant odds ratio (OR) of 2.81 (95% confidence interval (CI): 1.30-6.05) for the heterozygous (He) and homozygous variant (HV) genotypes in the group of familial patients. The He+HV genotypes of the c.2099-2408G>A SNP (Ku80) also showed high and significant ORs in the group of radiosensitive, familial breast cancer patients (OR=4.62 ,95%CI: 1.28-16.74). For the c.-1310 C>G SNP (Ku70) a significant OR of 1.85 (95%CI: 1.01-3.41) was found for the He genotype in the unselected patient group. For the radiosensitive, unselected patients, increased, but non-significant ORs were observed. The c.-1310 C>G SNP (Ku70) SNP exhibits significant results in the unselected patient group only, indicating an influence of other, environmental factors besides genetic factors. As breast epithelium is exposed to endogenous oxidative stress through increased estrogen exposure, the possible effect of hormone exposure was examined in an enlarged, unselected patient population (OR enlarged population =1.68, 95%CI:1.09-2.60). The ORs of the c.-1310 C>G SNP (Ku70) SNP for patients with a longer estrogen exposure were high and significant (early menarche: OR=1.85, 95%CI:1.20-2.92; late menopause: OR=1.94, 95%CI:1.08-3.51) while the ORs for patients with a short hormone exposure were lower and non-significant. These results provide preliminary evidence that the variant allele of c.-1310C>G (Ku70) and c.2099-2408G>A (Ku80) are risk alleles for breast cancer as well as CR. Furthermore, the association of c.-1310C>G (Ku70) with breast cancer risk was stronger in women with a long estrogen exposure.