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Silver nanoparticle (Ag NP)/chitosan (Ch) composites with antiviral activity against H1N1 influenza A virus were prepared. The Ag NP/Ch composites were obtained as yellow or brown floc-like powders following reaction at room temperature in aqueous medium. Ag NPs (3.5, 6.5, and 12.9 nm average diameters) were embedded into the chitosan matrix without aggregation or size alternation. The antiviral activity of the Ag NP/Ch composites was evaluated by comparing the TCID50 ratio of viral suspensions treated with the composites to untreated suspensions. For all sizes of Ag NPs tested, antiviral activity against H1N1 influenza A virus increased as the concentration of Ag NPs increased; chitosan alone exhibited no antiviral activity. Size dependence of the Ag NPs on antiviral activity was also observed: antiviral activity was generally stronger with smaller Ag NPs in the composites. These results indicate that Ag NP/Ch composites interacting with viruses exhibit antiviral activity.

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Selective activation of the peripheral cannabinoid receptor 1 (CB 1 R) has been shown to suppress neuropathic pain symptoms in rodents. However, relatively little is known about changes in CB 1 R and its endogenous ligands during development or maintenance of neuropathic pain. Using immunohistochemistry, Western blot, real-time reverse transcription polymerase chain reaction, as well as liquid chromatography/mass spectrometry, we studied the changes in CB 1 Rs and endocannabinoids N-arachidonoylethanolamine/anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in rat lumbar (L4 and L5) dorsal root ganglia (DRG) after neuropathic pain induction (L5 spinal nerve ligation: SNL). Immunohistochemistry revealed that in control rats, CB 1 R is expressed in the majority (76-83%) of nociceptive neurons as indicated by co-labeling with isolectin B4 (IB4) or antibodies recognizing transient receptor potential vanilloid (TRPV1), calcitonin gene related peptide (CGRP), and the NR2C/2D subunits of the N-methyl-D-aspartate receptor. After L5 SNL, CB 1 R mRNA and protein increases in the ipsilateral uninjured L4 DRG whereas the percentages of CB 1 R immunoreactive (CB 1 R-ir) neurons remain unchanged in L4 and L5 DRG. However, for these CB 1 R-ir neurons, we observe significant increases in percentage of TRPV1-ir cells in ipsilateral L4 DRG, and decreases in percentage of IB4-and CGRP-co-labeled cells in ipsilateral L5 DRG. Levels of both AEA and 2-AG increase significantly only in the ipsilateral L5 DRG. These results are consistent with the preserved analgesic effects of cannabinoids in neuropathic pain and provide a rational framework for the development of peripherally acting endocannabinoid-based therapeutic interventions for neuropathic pain.

Malaria starts with the infection of the liver of the host by Plasmodium sporozoites, the parasite form transmitted by infected mosquitoes. Sporozoites migrate through several hepatocytes by breaching their plasma membranes before finally infecting one with the formation of an internalization vacuole. Migration through host cells induces apical regulated exocytosis in sporozoites. Here we show that apical regulated exocytosis is induced by increases in cAMP in sporozoites of rodent (P. yoelii and P. berghei) and human (P. falciparum) Plasmodium species. We have generated P. berghei parasites deficient in adenylyl cyclase α (ACα), a gene containing regions with high homology to adenylyl cyclases. PbACα-deficient sporozoites do not exocytose in response to migration through host cells and present more than 50% impaired hepatocyte infectivity in vivo. These effects are specific to ACα, as re-introduction of ACα in deficient parasites resulted in complete recovery of exocytosis and infection. Our findings indicate that ACα and increases in cAMP levels are required for sporozoite apical regulated exocytosis, which is involved in sporozoite infection of hepatocytes.

The papillomavirus E2 gene product plays a pivotal role in viral replication. E2 has multiple functions, including (i) transcriptional activation and repression of viral promoters and (ii) the enhancement of viral DNA replication. It was previously reported that E2 suppressed the growth of papillomavirus-positive cervical carcinoma cell lines. In the present study, we investigated the mechanisms of E2 growth inhibition. We found that the transcriptional activation function of E2 is required for inhibition of the growth of HeLa cells as well as for transcriptional repression of the viral E6/E7 promoter. It had been previously postulated that transcriptional repression of the E6/E7 promoter results from E2 binding its cognate sites proximal to the E6/E7 promoter and displacing other cellular transcriptional factors. In this study, we report a requirement for the transcription activation function for the binding of E2 to transcriptionally active templates.The papillomavirus replication cycle is regulated by the viral E2 protein, a sequence-specific DNA binding protein (1,35,53). Depending on the promoter context, E2 can act either as a transcriptional activator or as a repressor of viral gene expression. The promoters for E6/E7 gene expression of human papillomavirus type 16 (HPV16) and HPV18 are negatively regulated by E2. This repression is thought to be mediated by the binding of E2 to its recognition sites within the promoter and the displacement of cellular transcriptional factors from the promoter (3,12,14,15,20,23,28,41,42,54,55,58,59,61,62). E2 is also involved in the regulation of viral DNA replication through its association with E1, the viral replication factor (36,50,63,65,66,67,68). The conserved N-terminal domain of E2 is required for transactivation (TA), E1 binding, and DNA replication functions. The conserved C-terminal domain forms a dimer and functions as a DNA binding domain. Both conserved domains are linked by a hinged region (reviewed in reference 24).The loss of E2 expression has been also implicated in the development of HPV-induced carcinoma. Most human cervical carcinoma cells contain integrated HPV DNA and actively express E6/E7 genes (2, 52, 69). The E2 gene is frequently disrupted as a consequence of the integration of the viral genome, and it has been postulated that the loss of E2 somehow contributes to carcinogenic progression (9,40,47,64). E6/E7 genes are invariably expressed in HPV-positive cancers and are considered to be involved in the development of HPVassociated cancers. E6 targets the ubiquitination and proteolysis of p53 through its association with the ubiquitin protein ligase, E6AP (25,45,46). E7 binds pRB and inactivates its tumor suppressor function (17,38). Although E6 and E7 may have additional functions and cellular targets, it is believed that their inactivation of these important tumor suppressor proteins is critical for HPV-associated carcinogenesis. As mentioned above, E2 has the ability to suppress E6/E7 expression; thus, disruption of the E2 gene results in the...

To determine the daily energy requirements of professional soccer players during a competitive season, we measured total energy expenditure in seven players (age 22.1+/-1.9 years, height 1.75+/-0.05 m, mass 69.8+/-4.7 kg; mean +/- s) using the doubly labelled water method. Energy intake was simultaneously estimated from 7 day self-report dietary records. Mean total energy expenditure and energy intake were 14.8+/-1.7 MJ x day(-1) (3532+/-408 kcal x day(-1)) and 13.0+/-2.4 MJ x day(-1) (3113+/-581 kcal x day(-1)), respectively. Although there was a significant difference between total energy expenditure and energy intake (P < 0.01), there was a strong relationship between the two (r= 0.893, P< 0.01). Basal metabolic rate and recommended energy allowance calculated from the Recommended Dietary Allowances for the Japanese were 7.0+/-0.3 MJ x day(-1) (1683+/-81 kcal x day(-1)) and 15.6+/-0.8 MJ x day(-1) (3739+/-180 kcal x day(-1)), respectively. A physical activity level (total energy expenditure/ basal metabolic rate) of 2.11+/-0.30 indicated that, during the competitive season, professional soccer players undertake much routine physical activity, similar to that of competitive athletes during moderate training. Energy intake estimated using dietary records was under-reported, suggesting that its calculation from these data does not predict energy expenditure in soccer players.