Search results for "toxicity"
showing 10 items of 2261 documents
Tellurite-dependent blackening of bacteria emerges from the dark ages
2019
Environmental contextAlthough tellurium is a relatively rare element in the earth’s crust, its concentration in some niches can be naturally high owing to unique geology. Tellurium, as the oxyanion, is toxic to prokaryotes, and although prokaryotes have evolved resistance to tellurium, no universal mechanism exists. We review the interaction of tellurite with prokaryotes with a focus on those unique strains that thrive in environments naturally rich in tellurium. AbstractThe timeline of tellurite prokaryotic biology and biochemistry is now over 50 years long. Its start was in the clinical microbiology arena up to the 1970s. The 1980s saw the cloning of tellurite resistance determinants whil…
Impact of antigen presentation on TCR modulation and cytokine release: implications for detection and sorting of antigen-specific CD8+ T cells using …
2002
Abstract Soluble MHC class I molecules loaded with antigenic peptides are available either to detect and to enumerate or, alternatively, to sort and expand MHC class I-restricted and peptide-reactive T cells. A defined number of MHC class I/peptide complexes can now be implemented to measure T cell responses induced upon Ag-specific stimulation, including CD3/CD8/ζ-chain down-regulation, pattern, and quantity of cytokine secretion. As a paradigm, we analyzed the reactivity of a Melan-A/MART-1-specific and HLA-A2-restricted CD8+ T cell clone to either soluble or solid-phase presented peptides, including the naturally processed and presented Melan-A/MART-1 peptide AAGIGILTV or the peptide ana…
Synthesis and Pharmacological Activities of Novel 3-(Isoxazol-3-yl)-quinazolin-4(3H)-one Derivatives
1999
Several new 3-(isoxazol-3-yl)-quinazolin-4(3H)-one derivatives were synthesized and tested for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effect. A few compounds were as active as phenylbutazone in the writhing and acetic acid peritonitis tests. They had a very low ulcerogenic effect.
Differential toxicity of simazine and diuron to Torilis arvensis and Lolium rigidum
1990
Summary: In a soil application, Torilis arvensis was nearly as susceptible as Lolium rigidum to simazine but was 18-fold more tolerant to diuron. Treat ment with diuron inhibited photosynthesis in L. rigidum but had only a limited effect in T. arvensis although chloroplasts isolated from both species displayed similar susceptibility. 14C-diuron degradation in plants was limited, with the formation of conjugates of mono-methyl-diuron in T. arvensis and N-dealkylated derivatives of diuron in L. rigidum. 14C-diuron entered the roots and was translocated throughout the leaves of L. rigidum but was restricted to stems, leaf petioles and leaf veins of T. arvensis. This difference in transport pat…
Effects of lindane on fish carbohydrate metabolism.
1991
Exposure of the European eel (Anguilla anguilla) to a high sublethal concentration of 0.335 ppm (0.50 of the 96-hr LC50) of lindane for 6, 12, 24, 48, 72, and 96 hr affected carbohydrate metabolism. Muscle glycogen levels decreased significantly (P less than 0.05) at 6, 12, 24, 48, 72, and 96 hr; liver glycogen content did not decline at any time. Muscle glucose levels in fish were elevated at 6, 12, 24, 48, 72, and 96 hr but in liver, the levels increased only at 96 hr. Mean values of muscle and liver pyruvate were elevated significantly (P less than 0.05) at 6, 12, 24, 48, and 72 hr. Muscle lactate levels increased at 6, 12, 24, and 48 hr in pesticide-treated fish. Liver lactate levels we…
New methods of delivery of amphotericin B.
1993
Fungal infections continue to be a major problem in the management of immunocompromised patients. Despite its formidable toxicity and treatment failures, amphotericin B is still the drug of choice for most of these infections. One strategy for reducing the toxicity of amphotericin B and thus permitting administration of higher doses is that of using less toxic formulations. Entrapping amphotericin B into liposomes or binding it to other substances reduces its toxicity to host cells, whereas the selective binding of amphotericin B to ergosterol preserves its toxicity to fungal cells. Adding fungus-specific antibodies to such liposomes may further increase the efficiency of drug targeting. Th…
Cáncer en los primeros 18 meses de vida
2020
Resumen: Introducción: La enfermedad oncohematológica continúa siendo la primera causa de mortalidad no traumática en la infancia y una importante causa de morbilidad. El paciente menor de 18 meses presenta particularidades clínicas, diagnósticas y terapéuticas que es interesante conocer por todo pediatra, con el fin de lograr una mayor supervivencia y una menor comorbilidad a lo largo de su vida. Material y métodos: Estudio descriptivo retrospectivo de variables clínicas, diagnósticas y terapéuticas en pacientes menores de 18 meses diagnosticados de enfermedad oncohematológica que reciben quimioterapia en una unidad de oncología pediátrica entre enero 2007 y agosto 2019. Resultados: Setent…
Cytoprotective effect of resveratrol diastereomers in CHO-K1 cells exposed to beauvericin
2015
Beauvericin (BEA) causes cytotoxicity, lipid peroxidation and reactive oxygen species in CHO-K1 cells. Resveratrol (RSV) is a polyphenol with multiple biological properties, including antioxidant effects. RSV has two forms: trans and cis. The aims of this study were to determine the cytoprotective effect of trans-RSV and diastereomers mixtures (50:50 trans/cis-RSV and 70:30 trans/cis-RSV) incubated alone and in combination with BEA in ovarian (CHO-K1) cells. The results demonstrated that cell viability increases (from 9% to 77%) when they were exposed to low concentration of RSV. Moreover, when the cells were pre-treated with RSV and then exposed to BEA, a cytoprotective effect (from 25% to…
Acute cardio-respiratory effects in rats of PS4α, an antineoplastic peptidoglycan from Mycobacterium vaccae
2001
Abstract PS4α is a high molecular weight peptidoglycan extracted from Mycobacterium vaccae, which has demonstrated considerable antineoplastic activity in-vivo without apparent toxicity. Available for testing in only small quantities, a sensitive in-vivo method for measuring pulse and breathing rates in cannulated rats was applied to this compound at doses of 5, 50 and 500 μg kg−1. Various parameters (mean arterial pressure, maximum transpulmonary pressure, compliance, heart rate, minute volume, respiratory rate and tidal volume) were followed for up to 1 h and demonstrated no significant deviation in the baseline values obtained before injection. This compound at doses up to 500 μg kg−1 ha…
Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.
2005
During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a …