Iron Status Predicts Treatment Failure and Mortality in Tuberculosis Patients: A Prospective Cohort Study from Dar es Salaam, Tanzania

Experimental data suggest a role for iron in the course of tuberculosis (TB) infection, but there is limited evidence on the potential effects of iron deficiency or iron overload on the progression of TB disease in humans. The aim of the present analysis was to examine the association of iron status with the risk of TB progression and death.\ud We analyzed plasma samples and data collected as part a randomized micronutrient supplementation trial (not including iron) among HIV-infected and HIV-uninfected TB patients in Dar es Salaam, Tanzania. We prospectively related baseline plasma ferritin concentrations from 705 subjects (362 HIV-infected and 343 HIV-uninfected) to the risk of treatment failure at one month after initiation, TB recurrence and death using binomial and Cox regression analyses. Overall, low (plasma ferritin<30 µg/L) and high (plasma ferritin>150 µg/L for women and>200 µg/L for men) iron status were seen in 9% and 48% of patients, respectively. Compared with normal levels, low plasma ferritin predicted an independent increased risk of treatment failure overall (adjusted RR = 1.95, 95% CI: 1.07 to 3.52) and of TB recurrence among HIV-infected patients (adjusted RR = 4.21, 95% CI: 1.22 to 14.55). High plasma ferritin, independent of C-reactive protein concentrations, was associated with an increased risk of overall mortality (adjusted RR = 3.02, 95% CI: 1.95 to 4.67). Both iron deficiency and overload exist in TB patients and may contribute to disease progression and poor clinical outcomes. Strategies to maintain normal iron status in TB patients could be helpful to reduce TB morbidity and mortality

Lysophosphatidic Acid Acyltransferase β (LPAATβ) Promotes the Tumor Growth of Human Osteosarcoma

Osteosarcoma is the most common primary malignancy of bone with poorly characterized molecular pathways important in its pathogenesis. Increasing evidence indicates that elevated lipid biosynthesis is a characteristic feature of cancer. We sought to investigate the role of lysophosphatidic acid acyltransferase β (LPAATβ, aka, AGPAT2) in regulating the proliferation and growth of human osteosarcoma cells. LPAATβ can generate phosphatidic acid, which plays a key role in lipid biosynthesis as well as in cell proliferation and survival. Although elevated expression of LPAATβ has been reported in several types of human tumors, the role of LPAATβ in osteosarcoma progression has yet to be elucidated.Endogenous expression of LPAATβ in osteosarcoma cell lines is analyzed by using semi-quantitative PCR and immunohistochemical staining. Adenovirus-mediated overexpression of LPAATβ and silencing LPAATβ expression is employed to determine the effect of LPAATβ on osteosarcoma cell proliferation and migration in vitro and osteosarcoma tumor growth in vivo. We have found that expression of LPAATβ is readily detected in 8 of the 10 analyzed human osteosarcoma lines. Exogenous expression of LPAATβ promotes osteosarcoma cell proliferation and migration, while silencing LPAATβ expression inhibits these cellular characteristics. We further demonstrate that exogenous expression of LPAATβ effectively promotes tumor growth, while knockdown of LPAATβ expression inhibits tumor growth in an orthotopic xenograft model of human osteosarcoma.Our results strongly suggest that LPAATβ expression may be associated with the aggressive phenotypes of human osteosarcoma and that LPAATβ may play an important role in regulating osteosarcoma cell proliferation and tumor growth. Thus, targeting LPAATβ may be exploited as a novel therapeutic strategy for the clinical management of osteosarcoma. This is especially attractive given the availability of selective pharmacological inhibitors

Photochemically-induced ligand exchange reactions of ethoxy-oxo-molybdenum(V) tetraphenylporphyrin in chlorinated solvents

Photochemically-induced ligand exchange reactions of ethoxy-oxo-molybdenum (V) 5,10,15,20-tetraphenylporphyrin, Mo(V)O(TPP)-OEt, under irradiation at the Soret band region, were investigated. The reactions were performed in chlorinated solvents and followed with ultraviolet-visible spectroscopy, whereas the products were analyzed with FTIR spectroscopy, ESR spectroscopy and gas chromatography. The chloro-oxo(TPP)Mo(V) complex was obtained as the final product, where the chlorine came from the solvent. Nevertheless, these reactions were not photocatalytic, due to the photochemical inertness of the formed chloro-oxo complex, and an excess of ethanol could not initiate a new photocatalytic cycle unless water was added as well, resulting in the formation of the correspondign oxo-Mo(IV) complex. The studied photoassisted reactions of oxoMo(V) porphyrins appear attractive for possible applications in the detection of chlorinated pollutants in sensing devices, but also for the dechlorination of pollutants upon suitable optimization of processing conditions

Nano-scale spatial control over surface morphology of biocompatible fluoropolymers at 157 nm

Journal URL: http://www.sciencedirect.com/science/journal/0928493

The role of metal/metal oxide/organic anode interfaces in efficiency and stability of bulk heterojunction organic photodetectors

We demonstrate a transition metal oxide based hole extraction layer approach to improve the efficiency, dark current and time stability of organic photodetectors (OPDs). A significant increase in device efficiency and over two orders of magnitude lower dark current at a bias voltage of -0.5 V were obtained in OPDs based on the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) bulk heterojunctions (BHJ). This was achieved by introducing an under-stoichiometric tungsten oxide layer, after optimizing its thickness to 10 nm, at the anode/organic layer interface instead of the commonly used poly(styrenesulfonate)-doped poly(ethylenedioxythiophene) (PEDOT:PSS). The increased efficiency and lower dark current were attributed to the formation of a favorable interfacial dipole and the reduction in the device series resistance, when PEDOT:PSS was replaced by these metal oxide layers.</p

Molecular junctions made of tungsten-polyoxometalate self-assembled monolayers: Towards polyoxometalate-based molecular electronics devices

In this work, the electrical conduction of planar Au junctions electrically bridged by a polyoxometalate-based self-assembled monolayer, aimed to be used in hybrid silicon/molecular memory devices, is discussed. Tunnelling assisted by the presence of polyoxometalate anions is recognised as the main conduction mechanism for these devices. Fluctuations and hysteresis that are profoundly observed in the current-voltage characteristics for the smallest junctions suggest that the anions number is the more crucial factor in the devices behaviour. Quantitative analysis of the obtained characteristics based on Simmons's model reveals an increase in the tunnelling barrier height as the electrode distance increases from 20 to 200 nm. (C) 2011 Elsevier B.V. All rights reserved