Silver/silver chloride nanoparticles inhibit the proliferation of human glioblastoma cells

Glioblastomas (GBM) are aggressive brain tumors with very poor prognosis. While silver nanoparticles represent a potential new strategy for anticancer therapy, the silver/silver chloride nanoparticles (Ag/AgCl-NPs) have microbicidal activity, but had not been tested against tumor cells. Here, we analyzed the effect of biogenically produced Ag/AgCl-NPs (from yeast cultures) on the proliferation of GBM02 glioblastoma cells (and of human astrocytes) by automated, image-based high-content analysis (HCA). We compared the effect of 0.1–5.0 µg mL^?1 Ag/AgCl-NPs with that of 9.7–48.5 µg mL^?1 temozolomide (TMZ, chemotherapy drug currently used to treat glioblastomas), alone or in combination. At higher concentrations, Ag/AgCl-NPs inhibited GBM02 proliferation more effectively than TMZ (up to 82 and 62% inhibition, respectively), while the opposite occurred at lower concentrations (up to 23 and 53% inhibition, for Ag/AgCl-NPs and TMZ, respectively). The combined treatment (Ag/AgCl-NPs?+?TMZ) inhibited GBM02 proliferation by 54–83%. Ag/AgCl-NPs had a reduced effect on astrocyte proliferation compared with TMZ, and Ag/AgCl-NPs?+?TMZ inhibited astrocyte proliferation by 5–42%. The growth rate and population doubling time analyses confirmed that treatment with Ag/AgCl-NPs was more effective against GBM02 cells than TMZ (~?67-fold), and less aggressive to astrocytes, while Ag/AgCl-NP?+?TMZ treatment was no more effective against GBM02 cells than Ag/AgCl-NPs monotherapy. Taken together, our data indicate that 2.5 µg mL^?1 Ag/AgCl-NPs represents the safest dose tested here, which affects GBM02 proliferation, with limited effect on astrocytes. Our findings show that HCA is a useful approach to evaluate the antiproliferative effect of nanoparticles against tumor cells.     

Oral Activated Charcoal Prevents Experimental Cerebral Malaria in Mice and in a Randomized Controlled Clinical Trial in Man Did Not Interfere with the Pharmacokinetics of Parenteral Artesunate

Background

Safe, cheap and effective adjunct therapies preventing the development of, or reducing the mortality from, severe malaria could have considerable and rapid public health impact. Oral activated charcoal (oAC) is a safe and well tolerated treatment for acute poisoning, more recently shown to have significant immunomodulatory effects in man. In preparation for possible efficacy trials in human malaria, we sought to determine whether oAC would i) reduce mortality due to experimental cerebral malaria (ECM) in mice, ii) modulate immune and inflammatory responses associated with ECM, and iii) affect the pharmacokinetics of parenteral artesunate in human volunteers.

Methods/Principal Findings

We found that oAC provided significant protection against P. berghei ANKA-induced ECM, increasing overall survival time compared to untreated mice (p<0.0001; hazard ratio 16.4; 95% CI 6.73 to 40.1). Protection from ECM by oAC was associated with reduced numbers of splenic TNF⁺ CD4⁺ T cells and multifunctional IFNγ⁺TNF⁺ CD4⁺ and CD8⁺ T cells. Furthermore, we identified a whole blood gene expression signature (68 genes) associated with protection from ECM. To evaluate whether oAC might affect current best available anti-malarial treatment, we conducted a randomized controlled open label trial in 52 human volunteers (ISRCTN NR. 64793756), administering artesunate (AS) in the presence or absence of oAC. We demonstrated that co-administration of oAC was safe and well-tolerated. In the 26 subjects further analyzed, we found no interference with the pharmacokinetics of parenteral AS or its pharmacologically active metabolite dihydroartemisinin.

Conclusions/Significance

oAC protects against ECM in mice, and does not interfere with the pharmacokinetics of parenteral artesunate. If future studies succeed in establishing the efficacy of oAC in human malaria, then the characteristics of being inexpensive, well-tolerated at high doses and requiring no sophisticated storage would make oAC a relevant candidate for adjunct therapy to reduce mortality from severe malaria, or for immediate treatment of suspected severe malaria in a rural setting.

Trial Registration

Controlled-Trials.com ISRCTN64793756     

First record of Lagocephalus laevigatus (Tetraodontiformes, Tetraodontidae) from Galician waters (north-west Spain), a northernmost occurrence in the north-east Atlantic Ocean

The first record of the smooth puffer Lagocephalus laevigatus from Galician waters (north-west Spain) is reported. Three possible mechanisms of introduction of the specimen are considered: natural displacement, the aquarist trade and transport in ballast water.     

Cryptosporidium pig genotype II diagnosed in pigs from the state of Rio De Janeiro, Brazil

Pigs may represent a source of Cryptosporidium sp. infection to humans. The objective of this study was to identify the Cryptosporidium species present in pigs from the State of Rio de Janeiro, Brazil, and verify what risks pigs represent in the transmission of human cryptosporidiosis, because there is no such information to date in Brazil. Ninety-one samples of pig feces were collected from 10 piggeries in 2 municipalities located in the north and northwest regions of the State of Rio de Janeiro, Brazil. A nested polymerase chain reaction (PCR) protocol to amplify an 830-bp fragment of the small subunit rDNA (SSU rRNA) gene was followed by sequencing of all positive PCR samples. Two samples (2.2%) were Cryptosporidium sp. positive and were identified as pig genotype type II (PGII). This genotype has been observed in an immunocompetent person, in cattle without pigs nearby, and from a potential human source. Its potential for zoonotic transmission is little known and should be rigorously studied.     

Occurrence of Cryptosporidium andersoni in Brazilian cattle

Feces were collected from 68 dairy cattle, 1 to 12 mo of age, on 12 farms in the municipality of Campos dos Goytacazes, Rio de Janeiro, Brazil, and examined for the presence of Cryptosporidium sp. All samples were subjected to molecular analysis by polymerase chain reaction (nested PCR) of the 18S rRNA. Four positive samples (4.54%) were sequenced and identified as Cryptosporidium andersoni. This species represents a risk for Brazilian cattle because infection can affect cattle productivity. Moreover, C. andersoni is considered a zoonotic species.     

Effect of phytohormones and tungsten on light-induced and nitrate-induced nitrate reductase activity of mustard cotyledons

Mustard (Brassica juncea Coss cv. T-59 ‘Varuna’) seedlings pretreated with gibberellic acid (GA) and kinetin (KiN) were grown in light. In vivo nitrate reductase (NR) activity was estimated and effect of tungsten on light-induced and NO ₃ ^su− -induced NR activity was investigated. Different concentrations of GA did not show any effect on induction of light-induced NR; addition of nitrate promoted in vivo NR activity but no concentration effect of GA was evident. Light-induced NR was promoted by KiN and like in GA treatment, addition of nitrate increased NR activity. Addition of Na-tungstate inhibited NO ₃ ⁻ induced NR while light-induced NR was not much affected in both GA and KiN treated seedlings. The two forms of NRs were further characterized by studying the decay kinetics using Na-tungstate. In light-induced NR, tungstate did not affect NR activity up to 11 h, while at later periods, a slight decay was observed. On the other hand, NO ₃ ⁻ -induced NR activity increased up to 4 h and subsequently a rapid fall was observed. It was therefore apparent that light-induced NR had a very low turnover rate as compared to NO ₃ ⁻ -induced NR. These results further support the earlier conclusion that in mustard seedlings two distinct types of NR enzyme exist and that nitrate requirement for NR induction is not absolute.     

Fungal cell membrane—promising drug target for antifungal therapy

Increase in invasive fungal infections over the past few years especially in immunocompromised patients prompted the search for new antifungal agents with improved efficacy. Current antifungal armoury includes very few effective drugs like Amphotericin B; new generation azoles, including voriconazole and posaconazole; echinocandins like caspofungin and micafungin to name a few. Azole class of antifungals which target the fungal cell membrane are the first choice of treatment for many years because of their effectiveness. As the fungal cell membrane is predominantly made up of sterols, glycerophospholipids and sphingolipids, the role of lipids in pathogenesis and target identification for improved therapeutics were largely pursued by researchers during the last few years. Present review focuses on cell membrane as an antifungal target with emphasis on membrane biogenesis, structure and function of cell membrane, cell membrane inhibitors, screening assays, recent advances and future prospects.