The systemic toxicity of cyclic peptides produced by cyanobacteria (CCPs) is not yet completely understood. Apart from the most known damages to the liver and kidneys, symptoms of their neurotoxicity have also been reported. Hepatotoxic CCPs, like microcystins, as well as non-hepatotoxic anabaenopeptins and planktopeptins, all exhibit cytotoxic and cytostatic effects on mammalian cells.
View Article and Find Full Text PDFLeishmania mexicana infection causes localized skin lesions that can lead to tissue damage and permanent disfigurement if not resolved. Currently, recommended treatments include intravenous administration of Amphotericin B, which is undesirable due to the associated cost and patient burden related to receiving regular injections. In this study, we evaluated the effect of topical treatment with a nanoliposomal formulation of Amphotericin B that is penetrable to the skin (SinaAmphoLeish 0.
View Article and Find Full Text PDFCyanobacterial blooms are global phenomena that can occur in calm and nutrient-rich (eutrophic) fresh and marine waters. Human exposure to cyanobacteria and their biologically active products is possible during water sports and various water activities, or by ingestion of contaminated water. Although the vast majority of harmful cyanobacterial products are confined to the interior of the cells, these are eventually released into the surrounding water following natural or artificially induced cell death.
View Article and Find Full Text PDFDue to the stratospheric ozone depletion, several organisms will become exposed to increased biologically active UVB (280-320 nm) radiation, not only at polar but also at temperate and tropical latitudes. Bloom forming cyanobacteria are exposed to UVB radiation on a mass scale, particularly during the surface bloom and scum formation that can persist for long periods of time. All buoyant species of cyanobacteria are at least periodically exposed to higher irradiation during their vertical migration to the surface that usually occurs several times a day.
View Article and Find Full Text PDFEnviron Microbiol Rep
June 2012
The reasons for the apparent dominance of the toxic cyanobacterium Microcystis sp., reflected by its massive blooms in many fresh water bodies, are poorly understood. We show that in addition to a large array of secondary metabolites, some of which are toxic to eukaryotes, Microcystis sp.
View Article and Find Full Text PDFBackground: Cystoscopy with urinary cytology is the gold standard for the diagnosis and follow-up of patients with tumors of the urinary bladder. The aim of the study was to evaluate the performance of the nuclear matrix protein 22 (NMP22) tumor marker test, BladderChek® point-of-care test and voided urinary cytology for the detection and follow-up of bladder tumors.
Methods: NMP22 was measured using an ELISA assay in stabilized voided urine and using the BladderChek® test.
The involvement of the CYP11A1 gene in the synthesis of androgens makes it a compelling candidate for various hormone-dependent diseases, including prostate cancer. A microsatellite polymorphism (TTTTA)n in the promoter region of the CYP11A1 gene has been reported to be associated with an increased risk of metastatic and high-grade prostate cancer. In the present study of 110 prostate cancer patients and 96 population controls, we examined the association between the CYP11A1 (TTTTA)n polymorphism and prostate cancer risk, aggressiveness, and incidence of biochemical relapse after prostatectomy.
View Article and Find Full Text PDFToxic cyanobacterial blooms are a rich source of metabolites having a variety of biological activities. Two main groups of cyclic peptides, depsipeptides and ureido linkage-containing peptides, reportedly inhibit serine peptidases. We characterised their inhibitory properties against selected peptidases and investigated their influence on cell viability.
View Article and Find Full Text PDFAppl Immunohistochem Mol Morphol
May 2008
In urothelium, nitric oxide (NO) produced by NO synthase (NOS) plays various roles during disease processes. Because diseases influence the expression of uroplakins, the main urothelial differentiation-related proteins, we compared their expression and localization with that of inducible NOS (iNOS) in bladder outlet obstruction caused by benign prostatic hyperplasia and in noninvasive urothelial neoplasms (papilloma, low-grade, and high-grade papillary carcinoma). In all cases, we found areas with terminal and areas with partial cell differentiation.
View Article and Find Full Text PDFThe presence of planktopeptin BL1125, anabaenopeptin B and anabaenopeptin F, two types of "non-toxic" cyclic peptide produced in bloom forming cyanobacteria, can provoke lysis of different non-axenic Microcystis aeruginosa cell lines via the induction of virus-like particles. The resulting particles are also able to infect the axenic M. aeruginosa cell line without lytic effects.
View Article and Find Full Text PDFDissolved microcystins (MCs) are regularly present in water dominated by microcystin-producing, bloom-forming cyanobacteria. In vitro experiments with environmentally feasible concentrations (5 x 10(-7) M) of the three most common microcystins, MC-LR, MC-RR, and MC-YR, revealed that they influence the metabolism of different representative phytoplanktons. At light intensities that are close to the cyanobacterial bloom environment (50 micromol m(-2) s(-1)), they produce morphological and physiological changes in both microcystin-producing and -nonproducing Microcystis aeruginosa strains and also have similar effects on the green alga Scenedesmus quadricauda that is frequently present in cyanobacterial blooms.
View Article and Find Full Text PDFDissolved microcystins (MC) are regularly present in water dominated by microcystin-producing, bloom-forming cyanobacteria. In vitro experiments with environmentally feasible concentrations (5 x 10(-7) M) of the three most common microcystins, MC-LR, -RR, and -YR, revealed that they influence the metabolism of different representative phytoplanktons. At light intensities close to the cyanobacterial bloom environment (50 mumol m(-2) s(-1)), they produce morphological and physiological changes in both microcystin-producing and nonproducing Microcystis aeruginosa strains, and also have similar effects on the green alga Scenedesmus quadricauda that is frequently present in cyanobacterial blooms.
View Article and Find Full Text PDFConcurrent vinablastine-based radiochemotherapy was evaluated in 84 bladder-cancer patients. It was effective in more than half: tumour-specific survival (51% 9-year), local control rate (55% 9-year). The drawback was the impaired function of the bladder (9-year prevalence SOMA G3-4 symptoms: 66%), indicating the need for treatment aimed at reducing chronic morbidity.
View Article and Find Full Text PDFTwo novel microcystins, seco[d-Asp(3)]microcystin-RR (1) and [d-Asp(3),d-Glu(OMe)(6)]-microcystin-RR (2), along with the known [d-Asp(3)]microcystin-RR (3), were isolated from a Planktothrix rubescens toxic bloom collected in Lake Bled, Slovenia. The structures were deduced using one- and two-dimensional NMR techniques, ESIMS/CID/MS analysis, and Marfey's method for determining the amino acids' absolute stereochemistry. Compounds 1 and 3 exhibit weak PP1 inhibitory activity.
View Article and Find Full Text PDFAcute intoxication with MC-LR induces cytoskeletal alterations, apoptosis and necrosis of hepatocytes resulting in intrahepatic hemorrhage. Preliminary results have shown that chronic treatment of rats with intraperitoneal injections of sublethal doses of microcystins MC-LR and MC-YR could induce not only liver, but also kidney injuries. We aimed to investigate whether the induction of the cytoskeletal changes, apoptosis and necrosis could be the mechanisms involved in the injury of kidney cells in the chronic model of microcystin intoxication.
View Article and Find Full Text PDFMicrocystin-LR is the most frequently studied cyclic heptapeptide produced by different genera of cyanobacteria and is hepatotoxic to livestock and human populations. The adverse effects of microcystin-LR on morphology and cytoskeletal elements in different stages of early embryonal development have been studied in vitro. Embryos and whole embryo cultures have been exposed to microcystin-LR (10-100 microM).
View Article and Find Full Text PDFObjective: To assess the expression and distribution of uroplakins, protein subunits of the asymmetric unit membrane (AUM), and inducible nitric-oxide synthase (iNOS) in the urinary bladder urothelium of patients with bladder outlet obstruction (BOO) caused by benign prostatic hyperplasia (BPH).
Patients And Methods: Urinary bladder urothelium samples from 15 men (mean age 69 years) with BOO secondary to BPH were processed for light and electron immunocytochemistry. Uroplakins and iNOS were detected, and areas of apical surface covered with AUM were compared with those of iNOS-positive urothelial cells.
Microcystins are naturally occurring hepatotoxins produced by strains of Microcystis aeruginosa. They are involved in promoting primary liver tumours and a previous study showed that they might also be tumour initiators. In this study we demonstrate that microcystin-LR (MCLR) at doses that were not cytotoxic (0.
View Article and Find Full Text PDFThe microcystins (MCs) LR and YR are hepatotoxins produced by some species of freshwater cyanobacteria. Only a few reports on the acute nephrotoxicity of MCs have been published to date. Here we investigate the effects on rat kidneys of chronic administration of relatively low doses of MC LR and MC YR.
View Article and Find Full Text PDFCan J Clin Pharmacol
December 2001
Objective: To determine the relationships between age, prevalence of major depression and antidepressant treatment in Canadian populations by using data from three health surveys.
Background: Major depression is an important disorder, and there is a concern that treatment for it may be underutilized. Age may have an impact on treatment use.
Recently, short-form versions of structured psychiatric diagnostic interviews have been developed for epidemiologic and survey research. These short forms can reduce research costs in large-scale studies; however, their accuracy is likely to be less than that of a full diagnostic interview. We evaluated the positive and negative predictive values of a short-form interview derived from the Composite International Diagnostic Interview (CIDI).
View Article and Find Full Text PDFThe subchronic effects of cyanobacterial lyophilizate (CL) containing microcystins on liver were investigated in female New Zealand rabbits. Sterilised CL containing microcystins was injected i.p.
View Article and Find Full Text PDFThe subchronic effects of cyanobacterial lyophilizate (CL) containing microcystins on liver were investigated in female New Zealand rabbits. Sterilised CL containing microcystins was injected i.p.
View Article and Find Full Text PDFCyanobacterial blooms are frequent in the North-Eastern region of Slovenia, where the agricultural activities are intensive, resulting in higher water eutrophication. In a two year monitoring program we identified eighteen blooms of cyanobacteria, fifteen being hepatotoxic by intraperitoneal mouse bioassay. The approximate LD100 varied from 50-1000 mg/kg (dry cell weight/animal weight) and gross pathological signs were characteristic of cyanobacterial hepatotoxins.
View Article and Find Full Text PDF