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OBJECTIVE: Insecticide-impregnated bednets and curtains have been shown by many studies to be effective against malaria. However, because of possible interactions with immunity development, treated bednets may cause no effect at all or even an increase in malaria morbidity and mortality in areas of high transmission. To clarify this issue, we did a randomized controlled trial to assess the long-term effects of bednet protection during early infancy. METHODS: A total of 3387 neonates from 41 villages in rural Burkina Faso were individually randomized to receive either bednet protection from birth (group A) or from age 6 months (group B). Primary outcomes were all-cause mortality in all study children and incidence of falciparum malaria in a representative subsample of the study population. FINDINGS: After a mean follow-up of 27 months, there were 129 deaths in group A and 128 deaths in group B rate ratio (RR) 1.0 (95% confidence interval (CI): 0.78-1.27)). Falciparum malaria incidence was lower in group A than in group B, during early (0-5 months) and late infancy (6-12 months) (RR 3.1, 95% CI: 2.0-4.9; RR 1.3, 95% CI: 1.1-1.6) and rates of moderate to severe anaemia were significantly lower during late infancy (11.5% vs 23.3%, P = 0.008), but there were no differences between groups in these parameters in children older than 12 months. CONCLUSION: The findings from this study provide additional evidence for the efficacy of insecticide-treated nets in young children living in areas of intense malaria transmission.

Abstract Background Insecticide-treated bed nets (ITNs) are known to be highly effective in reducing malaria morbidity and mortality. The effectiveness of ITNs is largely influenced by behavioural factors and not much is known regarding such factors under programme conditions. Methods This descriptive study was nested into a large ITN effectiveness study in rural Burkina Faso. During two cross-sectional surveys in the dry and rainy season of 2003, random samples of young children from nine representative villages (n = 180 per survey) were investigated for compliance with ITN protection and related behaviour. Data were collected through direct observations and through interviews with mothers. Results ITNs were perceived as very important for protection against mosquitoes and malaria particularly during the rainy season, but there were problems with their use during the dry season. Young children usually slept with their mother under the ITN and self-reported compliance was 66% and 98% during dry and rainy season, respectively (confirmed by direct observation in 34% and 79%, respectively). Important reasons for low compliance during the dry season were high temperatures inside houses and problems related to changing sleeping places during the night. Conclusion Under programme conditions, compliance with ITN protection in young children is sufficient during the rainy season, but is rather low during the hot and dry season. Greater emphasis needs to be placed on information/education efforts to make people aware of the fact that the risk of contracting malaria may persist throughout the year.

Effective in vivo delivery of small interfering (siRNA) has been a major obstacle in the development of RNA interference therapeutics. One of the first attempts to overcome this obstacle utilized intravenous injection of cholesterol-conjugated siRNA (chol-siRNA). Although studies in mice revealed target gene knockdown in the liver, delivery was relatively inefficient, requiring 3 daily injections of 50 mg/kg of chol-siRNA to obtain measurable reduction in gene expression. Here we present a new delivery approach that increases the efficacy of the chol-siRNA over 500-fold and allows over 90% reduction in target gene expression in mice and, for the first time, high levels of gene knockdown in non-human primates. This improved efficacy is achieved by the co-injection of a hepatocyte-targeted and reversibly masked endosomolytic polymer. We show that knockdown is absolutely dependent on the presence of hepatocyte-targeting ligand on the polymer, the cognate hepatocyte receptor, and the cholesterol moiety of the siRNA. Importantly, we provide evidence that this increase in efficacy is not dependent on interactions between the chol-siRNA with the polymer prior to injection or in the bloodstream. The simplicity of the formulation and efficacy of this mode of siRNA delivery should prove beneficial in the use of siRNA as a therapeutic.

Tumor protein D52 is expressed at high levels in exocrine cells containing large secretory granules where it regulates Ca(2+)-dependent protein secretion; however, D52 expression is also highly induced in multiple cancers. The present study investigated a role for the Ca(2+)-dependent phosphorylation of D52 at the single major phospho-acceptor site serine 136 on cell division. Ectopic expression of wild type D52 (D52wt) and the phosphomutants serine 136/alanine (S136A) or serine 136/glutamate (S136/E) resulted in significant multinucleation of cells. D52wt and S136/E each resulted in a greater than 2-fold increase in multinucleated cells compared to plasmid-transfected controls whereas the S136/A phospho-null mutant caused a 9-fold increase in multinucleation at 48h post-transfection. Electron microscopy revealed D52 expression induced a marked accumulation of vesicles along the mid-line between nuclei where the final stages of cell abscission normally occurs. Supporting this, D52wt strongly colocalized on vesicular structures containing the endosomal regulatory protein vesicle associated membrane protein 8 (VAMP 8) and this colocalization significantly increased with elevations in cellular Ca(2+). As VAMP 8 is known to be necessary for the endo-membrane fusion reactions that mediate the final stages of cytokinesis, these data indicate that D52 expression and phosphorylation at serine 136 play an important role in supporting the Ca(2+)-dependent membrane trafficking events necessary for cytokinesis in rapidly proliferating cancer cells., (Copyright © 2010 Elsevier Inc. All rights reserved.)

SK&F 107647, a previously described synthetic immunomodulatory peptide, indirectly stimulates bone marrow progenitor cells and phagocytic cells, and enhances host defense effector mechanisms in bacterial and fungal infection models in vivo. In vitro, SK&F 107647 induces the production of a soluble mediator that augments colony forming cell (CFU-GM) formation in the presence of CSFs. In this paper we purified and sequenced the stromal cell-derived hematopoietic synergistic factors (HSF) secreted from both murine and human cell lines stimulated with SK&F 107647. Murine HSF is an N-terminal 4-aa truncated form of the CXC chemokine, KC, while human HSF was identified as an N-terminal 4-aa truncated form of the CXC chemokine, GRO beta. In comparison to their full-length forms, truncated KC and truncated GRO beta were 10 million times more potent as synergistic growth stimulants for CFU-GM. Enhanced potency of these novel truncated chemokines relative to their full-length forms was also demonstrated in respiratory burst assays, CD11b Ag expression, and intracellular killing of the opportunistic pathogen, Candida albicans. Administration of truncated KC significantly enhanced survival of mice lethally infected with C. albicans. The results reported herein delineate the biological mechanism of action of SK&F 107647, which functions via the induction of unique specific truncated forms of the chemokines KC and GRO beta. To our knowledge, this represents the first example where any form of KC or GRO beta were purified from marrow stromal cells. Additionally, this is the first demonstration of in vivo efficacy of a CXC chemokine in an animal infectious fungal disease model.

SK&F 107647, a novel synthetic low-molecular-weight peptide, has demonstrated potent antiinfective activities in murine models of fungal and viral infection. To determine if the hematoregulatory activities of SK&F 107647 could offer protection over conventional antibiotic therapy or as a single agent in animal models of bacterial sepsis, rats were implanted intraperitoneally with a live bacteria-containing fibrin-thrombin clot. Rats pretreated subcutaneously or orally with SK&F 107647 and then infected with either a gram-negative (Escherichia coli) or a gram-positive (Staphylococcus aureus) bacteria-containing clot demonstrated significantly improved survival over control formulation-treated animals. Treated animals showed increased effector cell activation, measured by CD11b expression on neutrophils and monocytes, and up to 1000-fold reduction in the number of E. coli recovered from blood. Thus, the hematoregulatory activities of SK&F 107647 can increase natural host resistance to infections caused by both gram-negative and gram-positive bacteria.

SK&F 107647, a novel synthetic dimeric pentapeptide, has been shown to be a potent hematoregulatory agent. The potential for the hematoregulatory factors elicited by SK&F 107647 to confer protection in experimental models of systemic Candida albicans infection was evaluated in immunosuppressed and immunocompetent mice. Prophylactic treatment with recombinant human interleukin-1 (rhIL-1), recombinant human granulocyte colony stimulating factor (rhG-CSF), or the hematoregulatory peptide SK&F 107647 significantly increased survival times in gamma irradiated immunosuppressed as well as non-irradiated immunocompetent mice challenged with a lethal dose of C. albicans. Protection was also observed in athymic nu/nu "nude" mice. Additionally, significant increases in survival in non-irradiated immunocompetent mice dosed by oral gavage were observed. These results indicate that SK&F 107647 can significantly enhance natural host resistance to experimental C. albicans infections both in immunosuppressed and immunocompetent mice.

A series of side chain modified analogues of cholesterol and lanosterol (1-10) have been synthesized and evaluated as inhibitors of the Candida albicans delta 24-sterol methyltransferase. Two sterol substrate analogues 1 and 2 which contained a 24-thia substituent were relatively modest inhibitors of the enzyme (Ki = 1.5-72 microM). Compounds which mimic the carbocation intermediates proposed for the methyltransferase reaction, including sulfonium salts 4-6, amidines 7 and 8, and imidazoles 9 and 10 were substantially more potent inhibitors (Ki = 5-500 nM). All of the sterol analogues examined displayed less than 10-fold selectivity for inhibition of the methyltransferase versus the rat liver delta 24-sterol reductase. The sterol analogues were tested for in vitro antifungal activity against C. albicans, Candida tropicalis, and Torulopsis glabrata. The minimum inhibitory concentrations versus C. albicans correlated well with the Ki values for methyltransferase inhibition, and the potency of several compounds approached that of amphotericin B, although only modest fungicidal activity was observed.

A nonautopsy, retrospective analysis of severe motor-vehicle accident trauma can provide valuable information in regard to volume of trauma and quality of care. In a 6-county region surrounding a large metropolitan area trauma care, as reviewed by this method, had deficiencies at all levels of delivery. Patients were taken to the nearest hospital. Hospitals then had not been classified or designated according to capability. Twenty-five per cent of the fatalities and 16% of all outcomes were considered inappropriate for the severity of injury incurred. A regional trauma system with categorization and designation of hospitals providing trauma care would have eliminated or improved these deficiencies, resulting in improved outcomes for a significant percentage of these patients.

Polymorphonuclear neutrophils (PMNs) possess phagocytic and fungicidal activity against Coccidioides immitis that declines during maturation from arthroconidia to round cells, is lost throughout spherule maturation, and returns when endospores are released from ruptured spherules. Studies of PMN chemiluminescence, iodination, and degranulation give similar results. Phagocytosis of forms other than spherules is strain dependent and enhanced by immune serum. The absence of adequate PMN-spherule interaction may be attributed to the production of an extracellular fibrillar matrix, glycoprotein in composition, that restricts intimate PMN-spherule contact. When the spherule ruptures, PMNs enter to phagocytose endospores that are themselves invested by a matrix derived from the inner spherule wall. The immunochemical relationship between the outer matrix and the inner matrix remains to be discovered. Nevertheless, presence of the outer matrix may help to explain the long-standing histopathologic observation that PMNs fail to attack spherules until they release their endospores.

Athymic nude (nu/nu) mice are uniformly more susceptible than euthymic nu/+ mice to lethal infection with intranasally inoculated Blastomyces dermatitidis, whether infection is initiated by yeasts or conidia. Conidial infection requires a high inoculum size; the disease produced is prolonged and disseminated. Yeasts are infective at a low inoculum size and produce a rapidly fatal pneumonia. Thymus transplantation is more protective for conidia-infected than yeast-infected nude mice, presumably because the disease course is long enough for an effect to become demonstrable. Yeast inocula multiply more rapidly in the lungs than do conidial inocula. This may relate to the greater susceptibility of conidia to heterophils evoked in the airways, and the fact that yeasts derived from conidial inocula must survive in the face of an established inflammatory reaction. When yeasts and conidia are inoculated simultaneously, the disease produced is less severe than when yeasts are inoculated alone, presumably because of a more intense and diffuse inflammatory response engendered by the conidia. Suppression of conidia-derived yeast replication is demonstrable for at least 1 wk in nu/nu mice and for 2 to 3 wk in nu/+ mice. The latter delay appears attributable to the intact immune system in nu/+ mice, and the probability that cellular immunity limits the subsequent replication of yeasts. Eventually, the immune response fails to control yeast replication, and the mice succumb. These studies provide further insights into the role of the thymus in host defense against B. dermatitidis and the basis for the differential pace of infection when mice are infected with yeasts or conidia.

The lesions of blastomycosis are characterized by both suppuration and granuloma formation, but the relative roles of human neutrophils, monocytes, and macrophages against Blastomyces dermatitidis are poorly defined. Our studies reveal that B. dermatitidis yeasts are generally too large to be ingested by polymorphonuclear neutrophils (PMNs), and are killed predominantly by external PMN attachment and degranulation, whereas conidia are first ingested, then killed. PMN function is maximal in the presence of serum, divalent cations, and complement, and killing is more efficient for conidia (approximately 50%) than for yeasts (approximately 20%). PMNs that have degranulated, but remain attached to yeasts, block access by contiguous PMNs. When degranulated PMNs are removed, allowing access by fresh PMNs, there is a further increment in yeast killing. Both conidia and yeasts are killed by predominantly oxidative PMN mechanisms, with conidia being greater activators of the respiratory burst, and proportionately more influenced by oxidative inhibitors. Peripheral blood monocytes can kill conidia (approximately 35%), but are feebly active against yeasts (approximately 5%). Monocyte-derived macrophages kill approximately 90% of conidia and 40% of yeasts. The dramatic susceptibility of conidia, the infective particles of B. dermatitidis, to nonspecific phagocytic host defenses may help to explain the relative rarity of blastomycosis as a clinical problem. The presence of PMNs in lesions of blastomycosis may indicate an active, although limited, role of these cells in host defense against B. dermatitidis yeasts.