304 research outputs found
Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh
Fostering local community tolerance for endangered carnivores, such as tigers (Panthera tigris), is a core component of many conservation strategies. Identification of antecedents of tolerance will facilitate the development of effective tolerance-building conservation action and secure local community support for, and involvement in, conservation initiatives. We use a stated preference approach for measuring tolerance, based on the ‘Wildlife Stakeholder Acceptance Capacity’ concept, to explore villagers’ tolerance levels for tigers in the Bangladesh Sundarbans, an area where, at the time of the research, human-tiger conflict was severe. We apply structural equation modeling to test an a priori defined theoretical model of tolerance and identify the experiential and psychological basis of tolerance in this community. Our results indicate that beliefs about tigers and about the perceived current tiger population trend are predictors of tolerance for tigers. Positive beliefs about tigers and a belief that the tiger population is not currently increasing are both associated with greater stated tolerance for the species. Contrary to commonly-held notions, negative experiences with tigers do not directly affect tolerance levels; instead, their effect is mediated by villagers’ beliefs about tigers and risk perceptions concerning human-tiger conflict incidents. These findings highlight a need to explore and understand the socio-psychological factors that encourage tolerance towards endangered species. Our research also demonstrates the applicability of this approach to tolerance research to a wide range of socio-economic and cultural contexts and reveals its capacity to enhance carnivore conservation efforts worldwide
Antiplaque Effect of Essential Oils and 0.2% Chlorhexidine on an In Situ Model of Oral Biofilm Growth: A Randomised Clinical Trial
This work was supported by project PI11/
01383 from Carlos III Institute of Health (General
Division of Evaluation and Research Promotion,
Madrid, Spain), which is integrated in National Plan of
Research, Development and Innovation (PN I+D+I
2008-2011). This project was cofinanced by
European Regional Development Fund (ERDF 2007-
2013
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
Characteristic Metabolism of Free Amino Acids in Cetacean Plasma: Cluster Analysis and Comparison with Mice
From an evolutionary perspective, the ancestors of cetaceans first lived in terrestrial environments prior to adapting to aquatic environments. Whereas anatomical and morphological adaptations to aquatic environments have been well studied, few studies have focused on physiological changes. We focused on plasma amino acid concentrations (aminograms) since they show distinct patterns under various physiological conditions. Plasma and urine aminograms were obtained from bottlenose dolphins, pacific white-sided dolphins, Risso's dolphins, false-killer whales and C57BL/6J and ICR mice. Hierarchical cluster analyses were employed to uncover a multitude of amino acid relationships among different species, which can help us understand the complex interrelations comprising metabolic adaptations. The cetacean aminograms formed a cluster that was markedly distinguishable from the mouse cluster, indicating that cetaceans and terrestrial mammals have quite different metabolic machinery for amino acids. Levels of carnosine and 3-methylhistidine, both of which are antioxidants, were substantially higher in cetaceans. Urea was markedly elevated in cetaceans, whereas the level of urea cycle-related amino acids was lower. Because diving mammals must cope with high rates of reactive oxygen species generation due to alterations in apnea/reoxygenation and ischemia-reperfusion processes, high concentrations of antioxidative amino acids are advantageous. Moreover, shifting the set point of urea cycle may be an adaption used for body water conservation in the hyperosmotic sea water environment, because urea functions as a major blood osmolyte. Furthermore, since dolphins are kept in many aquariums for observation, the evaluation of these aminograms may provide useful diagnostic indices for the assessment of cetacean health in artificial environments in the future
Dental caries in Uruguayan adults and elders: findings from the first Uruguayan National Oral Health Survey
This study aimed to assess dental caries status and associated factors in Uruguayan adults and elders using data from the first Uruguayan National Oral Health Survey. Data were representative of the country as a whole. Socio-demographic information was collected with a closed questionnaire. Dental caries was assessed by clinical examination using the DMFT index. The final sample consisted of 769 participants. Mean DMFT was 15.20 and 24.12 for the 35-44 and 65-74-year age groups, respectively. Mean number of decayed teeth was 1.70 in adults and 0.66 in elders. Multivariate analyses showed higher prevalence of dental caries associated with age 65-74 years, low socioeconomic status, use of public dental services, presence of gingivitis; for decayed teeth, age 35-44 years, low socioeconomic status, use of public dental services, infrequent tooth brushing, need for oral health care, and presence of root caries showed higher severity. Uruguayan adults and elders from disadvantaged backgrounds concentrated a heavier burden of dental caries
The surfactant protein C mutation A116D alters cellular processing, stress tolerance, surfactant lipid composition, and immune cell activation
<p>Abstract</p> <p>Background</p> <p>Surfactant protein C (SP-C) is important for the function of pulmonary surfactant. Heterozygous mutations in <it>SFTPC</it>, the gene encoding SP-C, cause sporadic and familial interstitial lung disease (ILD) in children and adults. Mutations mapping to the BRICHOS domain located within the SP-C proprotein result in perinuclear aggregation of the proprotein. In this study, we investigated the effects of the mutation A116D in the BRICHOS domain of SP-C on cellular homeostasis. We also evaluated the ability of drugs currently used in ILD therapy to counteract these effects.</p> <p>Methods</p> <p>SP-C<sup>A116D </sup>was expressed in MLE-12 alveolar epithelial cells. We assessed in vitro the consequences for cellular homeostasis, immune response and effects of azathioprine, hydroxychloroquine, methylprednisolone and cyclophosphamide.</p> <p>Results</p> <p>Stable expression of SP-C<sup>A116D </sup>in MLE-12 alveolar epithelial cells resulted in increased intracellular accumulation of proSP-C processing intermediates. SP-C<sup>A116D </sup>expression further led to reduced cell viability and increased levels of the chaperones Hsp90, Hsp70, calreticulin and calnexin. Lipid analysis revealed decreased intracellular levels of phosphatidylcholine (PC) and increased lyso-PC levels. Treatment with methylprednisolone or hydroxychloroquine partially restored these lipid alterations. Furthermore, SP-C<sup>A116D </sup>cells secreted soluble factors into the medium that modulated surface expression of CCR2 or CXCR1 receptors on CD4<sup>+ </sup>lymphocytes and neutrophils, suggesting a direct paracrine effect of SP-C<sup>A116D </sup>on neighboring cells in the alveolar space.</p> <p>Conclusions</p> <p>We show that the A116D mutation leads to impaired processing of proSP-C in alveolar epithelial cells, alters cell viability and lipid composition, and also activates cells of the immune system. In addition, we show that some of the effects of the mutation on cellular homeostasis can be antagonized by application of pharmaceuticals commonly applied in ILD therapy. Our findings shed new light on the pathomechanisms underlying SP-C deficiency associated ILD and provide insight into the mechanisms by which drugs currently used in ILD therapy act.</p
Remodeling of extracellular matrix by normal and tumor-associated fibroblasts promotes cervical cancer progression
Background:
Comparison of tissue microarray results of 29 cervical cancer and 27 normal cervix tissue samples
using immunohistochemistry revealed considerable reorganization of the fibrillar stroma of these tumors.
Preliminary densitometry analysis of laminin-1,
α
-smooth muscle actin (SMA) and fibronectin immunostaining
demonstrated 3.8-fold upregulation of laminin-1 and 5.2-fold increase of SMA in the interstitial stroma, indicating
that these proteins and the activated fibroblasts play important role in the pathogenesis of cervical cancer. In the
present work we investigated the role of normal and tumor-associated fibroblasts.
Methods:
In vitro
models were used to throw light on the multifactorial process of tumor-stroma interaction, by
means of studying the cooperation between tumor cells and fibroblasts. Fibroblasts from normal cervix and cervical
cancers were grown either separately or in co-culture with CSCC7 cervical cancer cell line. Changes manifest in
secreted glycoproteins, integrins and matrix metallo-proteases (MMPs) were explored.
Results:
While normal fibroblasts produced components of interstitial matrix and TGF-
β
1 that promoted cell
proliferation, cancer-associated fibroblasts (CAFs) synthesized ample amounts of laminin-1. The following results
support the significance of laminin-1 in the invasion of CSCC7 cells: 1.) Tumor-associated fibroblasts produced more
laminin-1 and less components of fibrillar ECM than normal cells; 2.) The production of laminin chains was further
increased when CSCC7 cells were grown in co-culture with fibroblasts; 3.) CSCC7 cells were capable of increasing
their laminin production; 4.) Tumor cells predominantly expressed integrin
α
6
β
4 laminin receptors and migrated
towards laminin. The integrin profile of both normal and tumor-associated fibroblasts was similar, expressing receptors
for fibronectin, vitronectin and osteopontin. MMP-7 secreted by CSCC7 cells was upregulated by the presence of
normal fibroblasts, whereas MMP-2 produced mainly by fibroblasts was activated in the presence of CSCC7 cells.
Conclusions:
Our results indicate that in addition to degradation of the basement membrane, invasion of cervical
cancer is accomplished by the remodeling of the interstitial stroma, which process includes decrease and partial replacement of fibronectin and collagens by a laminin-rich matrix
Promotion of protocell self-assembly from mixed amphiphiles at the origin of life
Vesicles formed from single-chain amphiphiles (SCAs) such as fatty acids probably played an important role in the origin of life. A major criticism of the hypothesis that life arose in an early ocean hydrothermal environment is that hot temperatures, large pH gradients, high salinity and abundant divalent cations should preclude vesicle formation. However, these arguments are based on model vesicles using 1–3 SCAs, even though Fischer–Tropsch-type synthesis under hydrothermal conditions produces a wide array of fatty acids and 1-alkanols, including abundant C10–C15 compounds. Here, we show that mixtures of these C10–C15 SCAs form vesicles in aqueous solutions between pH ~6.5 and >12 at modern seawater concentrations of NaCl, Mg2+ and Ca2+. Adding C10 isoprenoids improves vesicle stability even further. Vesicles form most readily at temperatures of ~70 °C and require salinity and strongly alkaline conditions to self-assemble. Thus, alkaline hydrothermal conditions not only permit protocell formation at the origin of life but actively favour it
Docosahexaenoic Acid Inhibits UVB-Induced Activation of NF-κB and Expression of COX-2 and NOX-4 in HR-1 Hairless Mouse Skin by Blocking MSK1 Signaling
Exposure to ultraviolet-B (UVB) radiation induces inflammation and photocarcinogenesis in mammalian skin. Docosahexaenoic acid (DHA), a representative ω-3 polyunsaturated fatty acid, has been reported to possess anti-inflammatory and chemopreventive properties. In the present study, we investigated the molecular mechanisms underlying the inhibitory effects of DHA on UVB-induced inflammation in mouse skin. Our study revealed that topical application of DHA prior to UVB irradiation attenuated the expression of cyclooxygenase-2 (COX-2) and NAD(P)H:oxidase-4 (NOX-4) in hairless mouse skin. DHA pretreatment also attenuated UVB-induced DNA binding of nuclear factor-kappaB (NF-κB) through the inhibition of phosphorylation of IκB kinase-α/β, phosphorylation and degradation of IκBα and nuclear translocation of p50 and p65. In addition, UVB-induced phosphorylation of p65 at the serine 276 residue was significantly inhibited by topical application of DHA. Irradiation with UVB induced phosphorylation of mitogen and stress-activated kinase-1 (MSK1), extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase, and all these events were attenuated by pretreatment with DHA. Blocking ERK and p38 MAP kinase signaling by U0126 and SB203580, respectively, diminished MSK1 phosphorylation in UVB-irradiated mouse skin. Pretreatment with H-89, a pharmacological inhibitor of MSK1, abrogated UVB-induced activation of NF-κB and the expression of COX-2 and NOX-4 in mouse skin. In conclusion, topically applied DHA inhibits the UVB-induced activation of NF-κB and the expression of COX-2 and NOX-4 by blocking the phosphorylation of MSK1, a kinase downstream of ERK and p38 MAP kinase, in hairless mouse skin
Targeting Toll-like receptor 7/8 enhances uptake of apoptotic leukemic cells by monocyte-derived dendritic cells but interferes with subsequent cytokine-induced maturation
Therapeutic vaccination with dendritic cells (DC) is an emerging investigational therapy for eradication of minimal residual disease in acute myeloid leukemia. Various strategies are being explored in manufacturing DC vaccines ex vivo, e.g., monocyte-derived DC (MoDC) loaded with leukemia-associated antigens (LAA). However, the optimal source of LAA and the choice of DC-activating stimuli are still not well defined. Here, loading with leukemic cell preparations (harboring both unknown and known LAA) was explored in combination with a DC maturation-inducing cytokine cocktail (CC; IL-1β, IL-6, TNF-α, and PGE2) and Toll-like receptor ligands (TLR-L) to optimize uptake. Since heat shock induced apoptotic blasts were more efficiently taken up than lysates, we focused on uptake of apoptotic leukemic cells. Uptake of apoptotic blast was further enhanced by the TLR7/8-L R848 (20–30%); in contrast, CC-induced maturation inhibited uptake. CC, and to a lesser extent R848, enhanced the ability of MoDC to migrate and stimulate T cells. Furthermore, class II-associated invariant chain peptide expression was down-modulated after R848- or CC-induced maturation, indicating enhanced processing and presentation of antigenic peptides. To improve both uptake and maturation, leukemic cells and MoDC were co-incubated with R848 for 24 h followed by addition of CC. However, this approach interfered with CC-mediated MoDC maturation as indicated by diminished migratory and T cell stimulatory capacity, and the absence of IL-12 production. Taken together, our data demonstrate that even though R848 improved uptake of apoptotic leukemic cells, the sequential use of R848 and CC is counter-indicated due to its adverse effects on MoDC maturation
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