16 research outputs found

    Mechanisms controlling anaemia in Trypanosoma congolense infected mice.

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    Trypanosoma congolense are extracellular protozoan parasites of the blood stream of artiodactyls and are one of the main constraints on cattle production in Africa. In cattle, anaemia is the key feature of disease and persists after parasitaemia has declined to low or undetectable levels, but treatment to clear the parasites usually resolves the anaemia. The progress of anaemia after Trypanosoma congolense infection was followed in three mouse strains. Anaemia developed rapidly in all three strains until the peak of the first wave of parasitaemia. This was followed by a second phase, characterized by slower progress to severe anaemia in C57BL/6, by slow recovery in surviving A/J and a rapid recovery in BALB/c. There was no association between parasitaemia and severity of anaemia. Furthermore, functional T lymphocytes are not required for the induction of anaemia, since suppression of T cell activity with Cyclosporin A had neither an effect on the course of infection nor on anaemia. Expression of genes involved in erythropoiesis and iron metabolism was followed in spleen, liver and kidney tissues in the three strains of mice using microarrays. There was no evidence for a response to erythropoietin, consistent with anaemia of chronic disease, which is erythropoietin insensitive. However, the expression of transcription factors and genes involved in erythropoiesis and haemolysis did correlate with the expression of the inflammatory cytokines Il6 and Ifng. The innate immune response appears to be the major contributor to the inflammation associated with anaemia since suppression of T cells with CsA had no observable effect. Several transcription factors regulating haematopoiesis, Tal1, Gata1, Zfpm1 and Klf1 were expressed at consistently lower levels in C57BL/6 mice suggesting that these mice have a lower haematopoietic capacity and therefore less ability to recover from haemolysis induced anaemia after infection

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Expansion of <FONT FACE=Symbol>gd</font><FONT FACE=Symbol> </font>T cells in patients infected with cutaneous leishmaniasis with and without glucantime therapy

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    The expansion of <FONT FACE=Symbol>gd </font>T cells in patients with active cutaneous leishmaniasis, with or without glucantime therapy, was investigated. Twenty patients with local cutaneous leishmaniasis including glucantime-treated (n=10) and untreated (n=10) patients were selected. The controls were healthy individuals (n=10) living in endemic areas. Whole blood was obtained and the T cell subpopulations were analyzed by flow cytometry. Significantly more <FONT FACE=Symbol>gd</FONT> CD3+ T cells were observed in untreated patients (15.9% ± 5.9), when compared with glucantime-treated patients (4.6% ± 1.4) and controls (5.3% ± 2.3). On the other hand, when the percentages of ab CD3+ T-cells were analyzed different results were obtained. A significant increase in <FONT FACE=Symbol>ab</FONT> T cells was seen in glucantime-treated patients (62.4% ± 7.6), when compared to the untreated patients (55.7% ± 5.5) and controls (55.1% ± 9.6). The percentage of total CD3+ T cells was statistically greater in both glucantime-treated (68.8% ± 7.4) and untreated patients (73.4% ± 5.9) when compared to the controls (61% ± 10.3). These results are consistent with previous results on the expansion of <FONT FACE=Symbol>gd</FONT>T cells during the course of cutaneous leishmaniasis. They also indicate that glucantime therapy can reverse the expansion of <FONT FACE=Symbol>gd</FONT>T cells and as a result increase the percentages of <FONT FACE=Symbol>ab</FONT> CD3+ T cells

    Neglected role of hookah and opium in gastric carcinogenesis:A cohort study on risk factors and attributable fractions

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    A recent study showed an association between hookah/opium use and gastric cancer but no study has investigated the relationship with gastric precancerous lesions. We examined the association between hookah/opium and gastric precancerous lesions and subsequent gastric cancer. In a population-based cohort study, 928 randomly selected, healthy, Helicobacter pylori-infected subjects in Ardabil Province, Iran, were followed for 10 years. The association between baseline precancerous lesions and lifestyle risk factors (including hookah/opium) was analyzed using logistic regression and presented as odds ratios (ORs) and 95% confidence intervals (CIs). We also calculated hazard ratios (HRs) and 95% CIs for the associations of lifestyle risk factors and endoscopic and histological parameters with incident gastric cancers using Cox regression models. Additionally, the proportion of cancers attributable to modifiable risk factors was calculated. During 9,096 person-years of follow-up, 36 new cases of gastric cancer were observed (incidence rate: 3.96/1,000 persons-years). Opium consumption was strongly associated with baseline antral (OR: 3.2; 95% CI: 1.2-9.1) and body intestinal metaplasia (OR: 7.3; 95% CI: 2.5-21.5). Opium (HR: 3.2; 95% CI: 1.4-7.7), hookah (HR: 3.4; 95% CI: 1.7-7.1) and cigarette use (HR: 3.2; 95% CI: 1.4-7.5), as well as high salt intake, family history of gastric cancer, gastric ulcer and histological atrophic gastritis and intestinal metaplasia of body were associated with higher risk of gastric cancer. The fraction of cancers attributable jointly to high salt, low fruit intake, smoking (including hookah) and opium was 93% (95% CI: 83-98). Hookah and opium use are risk factors for gastric cancer as well as for precancerous lesions. Hookah, opium, cigarette and high salt intake are important modifiable risk factors in this high-incidence gastric cancer area. What's new? Gastric cancer strikes Iranian men more often than any other cancer, and previous studies report a connection between gastric cancer and hookah, a traditional smoking device in the region. This study probed the factors associated with precancerous lesions and gastric cancer, including hookah and opium use. They found that both hookah and opium use increased the likelihood of developing cancer, as did high salt intake and cigarette smoking

    Transcription factors regulating erythropoiesis.

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    <p><i>Tal1</i>, <i>Gata1</i>, <i>Lmo2</i>, <i>Ldb1</i>, <i>TcfE2a</i> and <i>Zfpm1</i> (<i>Fog1</i>) form a multimeric DNA binding complex, which regulates primitive haematopoiesis. All six genes were highly expressed and had similar patterns of expression consistent with co-ordinate regulation. <i>Klf1</i> is involved in erythroid cell proliferation and had similar levels and patterns of expression suggesting that it may be regulated by the same mechanisms. In all cases C57BL/6 mice tended to have the lowest levels of expression after day 3.</p

    EPO responsive genes.

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    <p><i>Kif3a</i> and <i>Eif1a</i> are EPO responsive genes but respond to inflammatory signals as well. Consequently their positive response to infection may not be related to induction of erythropoiesis.</p
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