649 research outputs found

    Luminescent bacterial sensor for cadmium and lead

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    A sensor plasmid was constructed by inserting the regulation unit from the cadA determinant of plasmid pI258 to control the expression of firefly luciferase. The resulting sensor plasmid pTOO24 is capable of replicating in Gram-positive and Gram-negative bacteria. The expression of the reporter gene as a function of added extracellular heavy metals was studied in Staphylococcus aureus strain RN4220 and Bacillus subtilis strain BR151. Strain RN4220(pTOO24) mainly responded to cadmium, lead and antimony, the lowest detectable concentrations being 10 nM, 33 nM and 1 nM respectively. Strain BR151(pTOO24) responded to cadmium, antimony, zinc and tin at concentrations starting from 3.3 nM, 33 nM, 1 mu M and 100 mu M, respectively. The luminescence ratios between induced and uninduced cells, the induction coefficients, of strains RN4220(pTOO24) and BR151(pTOO24) were 23-50 and about 5, respectively. These results were obtained with only 2-3 h incubation times. Freeze-drying of the sensor strains had only moderate effects on the performance with respect to sensitivity or induction coefficients. (C) 1998 Elsevier Science S.A. All rights reserved

    Recombinant luminescent bacteria for measuring bioavailable arsenite and antimonite

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    Luminescent bacterial strains for the measurement of bioavailable arsenite and antimony were constructed, The expression of firefly luciferase was controlled by the regulatory unit of the ars operon of Staphylococcus aureus plasmid pI258 in recombinant plasmid pT0021, with S. aureus RN4220, Bacillus subtilis BR151, and Escherichia coli MC1061 as host strains, Strain RN4220(pT0021) was found to be the most sensitive for metal detection responding to arsenite, antimonite, and cadmium, the lowest detectable concentrations being 100, 33, and 330 nhl, respectively, Strains BR151(pT0021) and MC1061(pT0021) responded to arsenite, arsenate, antimonite, and cadmium, the lowest detectable concentrations being 3.3 and 330 mu M and 330 and 330 nM with BR151(pT0021), respectively, and 3.3, 33, 3.3, and 33 CIM with MC1061(pT0021), respectively, In the absence of the mentioned ions, the expression of luciferase was repressed and only a small amount of background light was emitted, Other ions did not notably interfere with the measurement in any of the strains tested, Freeze-drying of the cells did not decrease the sensitivity of the detection of arsenite; however, the induction coefficients were somewhat lower

    Long-term changes in the incidence of childhood epilepsy. A population study from Finland

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    BackgroundThe incidence of childhood epilepsy has changed during the past decades, but it is unclear whether it increased or decreased.MethodsChanges in drug-treated childhood epilepsy between 1968 and 2012 were evaluated using the Finnish nationwide register of all children, aged ≤ 15 years, on antiepileptic drugs (AEDs) prescribed for the treatment of epilepsy. The first registered entitlement to full-refundable AEDs was used as a proxy for newly diagnosed epilepsy. Incidence densities were calculated as ratios of annual new cases per 100,000 person-years in each calendar year during 1968 to 2012.ResultsThe annual incidence density of newly treated childhood epilepsy increased from 35 in the 1960s to 87 per 100,000 person-years in the 1990s and decreased thereafter to 61 per 100,000 person-years. Since 1996, the incidence density decreased 1–2% per year in children aged ConclusionThe incidence of drug-treated childhood epilepsy from the late 1960s to the early 1990s distinctly increased. The reasons for the increase are not fully understood but may include increasing ascertainment through improved diagnosis and a wider acceptance of AED treatment. Since the 1990s, a slight decline can be seen, probably reflecting the recent improvement in child health and safety.</p

    Length of sickness absence and sustained return-to-work in mental disorders and musculoskeletal diseases: a cohort study of public sector employees

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    OBJECTIVES: The aim of this study was to investigate the association between the length of sickness absence and sustained return to work (SRTW) and the predictors of SRTW in depression, anxiety disorders, intervertebral disc disorders, and back pain in a population-based cohort of employees in the Finnish public sector. METHODS: We linked data from employers' registers and four national population registers. Cox proportional hazards regression analysis with a cluster option was applied. SRTW was defined as the end of the sickness benefit period not followed by a recurrent sickness benefit period in 30 days. RESULTS: For depression, the median time to SRTW was 46 and 38 days among men and women, respectively. For anxiety disorders, the figures were 24 and 22 days, for intervertebral disc disorders, 42 and 41 days, and, for back pain, 21 and 22 days among men and women respectively. Higher age and the persistence of the health problem predicted longer time to SRTW throughout the diagnostic categories. Comorbid conditions predicted longer time to SRTW in depression and back pain among women. CONCLUSIONS: This large cohort study adds scientific evidence on the length of sickness absence and SRTW in four important diagnostic categories among public sector employees in Finland. Further research taking into account, eg, features of the work environment is suggested. Recommendations on the length of sickness absence at this point should be based on expert opinion and supplemented with research findings

    Antibody responses to nasopharyngeal carriage of Streptococcus pneumoniae in adults: A longitudinal household study

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    Background. Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques.Methods. We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members 118 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples.Results. Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .0006). There was a small (similar to 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA.Conclusions. Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage

    Supporting Craft Sense in Early Education

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    The research task was to describe and construct theoretical background for Craft Sense in early education. Craft Sense represents a learner&rsquo;s skill for obtaining Sloyd (Craft, Design &amp; Technology) related knowledge, skills and understanding. The development of Craft Sense is based on producing artefacts and evaluating the production process. In this research, the concept of Craft Sense is based on the integration of Sloyd and meta-cognitive regulation of learning activities. Based on theoretical information, an empirical research question was formulated: &ldquo;What kind of Craft Sense do children have in early education Sloyd?&rdquo; The method of study was assessing picture supported learning on a Sloyd course for young children. The data was analyzed by qualitative content analysis and Child Behaviour Rating Scale (CBRS). Findings indicate that the development of children&rsquo;s Craft Sense can be supported with pictures. Furthermore, the CBRS can be used to evaluate and understand children&rsquo;s Craft Sense. Keywords: Craft Sense, Sloyd, Sloyd Education, Meta-cognition </div

    Temporal reprogramming of calcium signalling via crosstalk of gonadotrophin receptors that associate as functionally asymmetric heteromers.

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    Signal crosstalk between distinct G protein-coupled receptors (GPCRs) is one mechanism that underlies pleiotropic signalling. Such crosstalk is also pertinent for GPCRs activated by gonadotrophic hormones; follicle-stimulating hormone (FSH) and luteinising hormone (LH), with specific relevance to female reproduction. Here, we demonstrate that gonadotrophin receptor crosstalk alters LH-induced Gαq/11-calcium profiles. LH-induced calcium signals in both heterologous and primary human granulosa cells were prolonged by FSHR coexpression via influx of extracellular calcium in a receptor specific manner. LHR/FSHR crosstalk involves Gαq/11 activation as a Gαq/11 inhibitor abolished calcium responses. Interestingly, the enhanced LH-mediated calcium signalling induced by FSHR co-expression was dependent on intracellular calcium store release and involved Gβγ. Biophysical analysis of receptor and Gαq interactions indicated that ligand-dependent association between LHR and Gαq was rearranged in the presence of FSHR, enabling FSHR to closely associate with Gαq following LHR activation. This suggests that crosstalk may occur via close associations as heteromers. Super-resolution imaging revealed that LHR and FSHR formed constitutive heteromers at the plasma membrane. Intriguingly, the ratio of LHR:FSHR in heterotetramers was specifically altered following LH treatment. We propose that functionally significant FSHR/LHR crosstalk reprograms LH-mediated calcium signalling at the interface of receptor-G protein via formation of asymmetric complexes

    Rab8, a small GTPase involved in vesicular traffic between the TGN and the basolateral plasma membrane

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    Small GTP-binding proteins of the rab family have been implicated as regulators of membrane traffic along the biosynthetic and endocytic pathways in eukaryotic cells. We have investigated the localization and function of rab8, closely related to the yeast YPT1/SEC4 gene products. Confocal immunofluorescence microscopy and immunoelectron microscopy on filter-grown MDCK cells demonstrated that, rab8 was localized to the Golgi region, vesicular structures, and to the basolateral plasma membrane. Two-dimensional gel electrophoresis showed that rab8p was highly enriched in immuno-isolated basolateral vesicles carrying vesicular stomatitis virus-glycoprotein (VSV-G) but was absent from vesicles transporting the hemagglutinin protein (HA) of influenza virus to the apical cell surface

    VIP21, a 21-kD membrane protein is an integral component of trans-Golgi-network-derived transport vesicles

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    In simple epithelial cells, apical and basolateral proteins are sorted into separate vesicular carriers before delivery to the appropriate plasma membrane domains. To dissect the putative sorting machinery, we have solubilized Golgi-derived transport vesicles with the detergent CHAPS and shown that an apical marker, influenza haemagglutinin (HA), formed a large complex together with several integral membrane proteins. Remarkably, a similar set of CHAPS-insoluble proteins was found after solubilization of a total cellular membrane fraction. This allowed the cloning of a cDNA encoding one protein of this complex, VIP21 (Vesicular Integral-membrane Protein of 21 kD). The transiently expressed protein appeared on the Golgi-apparatus, the plasma membrane and vesicular structures. We propose that VIP21 is a component of the molecular machinery of vesicular transport

    The Resistome of Farmed Fish Feces Contributes to the Enrichment of Antibiotic Resistance Genes in Sediments below Baltic Sea Fish Farms

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    Our previous studies showed that particular antibiotic resistance genes (ARGs) were enriched locally in sediments below fish farms in the Northern Baltic Sea, Finland, even when the selection pressure from antibiotics was negligible. We assumed that a constant influx of farmed fish feces could be the plausible source of the ARGs enriched in the farm sediments. In the present study, we analyzed the composition of the antibiotic resistome from the intestinal contents of 20 fish from the Baltic Sea farms. We used a high-throughput method, WaferGen qPCR array with 364 primer sets to detect and quantify ARGs, mobile genetic elements (MGE), and the 16S rRNA gene. Despite a considerably wide selection of qPCR primer sets, only 28 genes were detected in the intestinal contents. The detected genes were ARGs encoding resistance to sulfonamide (sul1), trimethoprim (dfrA1), tetracycline [tet(32), tetM, tetO, tetW], aminoglycoside (aadA1, aadA2), chloramphenicol (catA1), and efflux-pumps resistance genes (emrB, matA, mefA, msrA). The detected genes also included class 1 integron-associated genes (intI1, qacE?1) and transposases (tnpA). Importantly, most of the detected genes were the same genes enriched in the farm sediments. This preliminary study suggests that feces from farmed fish contribute to the ARG enrichment in farm sediments despite the lack of contemporaneous antibiotic treatments at the farms. We observed that the intestinal contents of individual farmed fish had their own resistome compositions. Our result also showed that the total relative abundances of transposases and tet genes were significantly correlated (p = 0.001, R-2 = 0.71). In addition, we analyzed the mucosal skin and gill filament resistomes of the farmed fish but only one multidrug-efflux resistance gene (emrB) was detected. To our knowledge, this is the first study reporting the resistome of farmed fish using a culture-independent method. Determining the possible sources of ARGs, especially mobilized ARGs, is essential for controlling the occurrence and spread of ARGs at fish farming facilities and for lowering the risk of ARG spread from the farms to surrounding environments.Peer reviewe
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