Characterization of a Truncated Metabotropic Glutamate Receptor in a Primitive Metazoan, the Parasitic Flatworm Schistosoma mansoni

A novel glutamate-binding protein was identified in Schistosoma mansoni. The protein (SmGBP) is related to metabotropic glutamate receptors from other species and has a predicted glutamate binding site located within a Venus Flytrap module but it lacks the heptahelical transmembrane segment that normally characterizes these receptors. The SmGBP cDNA was cloned, verified by 5′ and 3′ Rapid Amplification of cDNA Ends (RACE) and shown to be polyadenylated at the 3′end, suggesting the transcript is full-length. The cloned cDNA was subsequently expressed in bacteria and shown to encode a functional glutamate-binding protein. Other studies, using a specific peptide antibody, determined that SmGBP exists in two forms, a monomer of the expected size and a stable but non-covalent dimer. The monomer and dimer are both present in the membrane fraction of S. mansoni and are resistant to extraction with high-salt, alkaline pH and urea, suggesting SmGBP is either an integral membrane protein or a peripheral protein that is tightly associated with the membrane. Surface biotinylation experiments combined with western blot analyses and confocal immunolocalization revealed that SmGBP localized to the surface membranes of adult male schistosomes, especially the dorsal tubercles. In contrast, we detected little or no expression of SmGBP either in the females or larval stages. A comparative quantitative PCR analysis confirmed that the level of SmGBP expression is several-fold higher in male worms than cercariae, and it is barely detectable in adult females. Together, the results identify SmGBP as a new type of schistosome glutamate receptor that is both gender- and stage-specific. The high-level expression of this protein in the male tubercles suggests a possible role in host-parasite interaction

Leishmania species and clinical characteristics of Pacific and Amazon cutaneous leishmaniasis in Ecuador and determinants of health-seeking delay: a cross-sectional study

Ecuador; Leishmaniasis; PhylogenyEquador; Leishmaniosi; FilogèniaEcuador; Leishmaniosis; FilogeniaBackground Cutaneous Leishmaniasis (CL) affects up to 5.000 people in Ecuador each year. L. guyanensis and L. braziliensis are the most common of the eight CL-causing Leishmania species. Earlier CL research concentrated on the easily accessible Pacific region. This study aims to describe the Leishmania species in Pacific and Amazon ecoregions, to analyze regional differences in CL patient clinical presentation, and to identify determinants of health-seeking delay. Methods All cases in this cross-sectional study were diagnosed using smear slide microscopy, PCR, or both. Cytochrome B gene sequencing was used to identify the causative Leishmania species in qPCR-positive samples. Results This study included 245 patients, with 154 (63%) infected in the Pacific region and 91 (37%) infected in the Amazon. Causative Leishmania species were identified in 135 patients (73% of qPCR positives). L. guyanensis was identified in 76% (102/135) of the samples and L. braziliensis in 19% (26/135). The Pacific region had a low prevalence of 6% (5/89) of L. braziliensis. For the first time, we report L. guyanensis from the central Amazon, L. braziliensis from the northern Pacific, and L. lainsoni from both the central Amazon and northern Pacific. Amazon cases had a longer median health-seeking delay in months (2.0, IQR 3.0) than Pacific cases (1.0, IQR 1.5). Prolonged health-seeking delay was associated with older age, Amerindian ethnicity, infection at lower altitudes, non-ulcerative lesions, and lesions on the lower limbs. Conclusions In the Pacific region, health-seeking delay is relatively short and L. braziliensis prevalence remains low. Limited access to health care and stigma might explain the prolonged health-seeking delay in the Amazon. We recommend larger studies on the distribution of Leishmania species in Amazon CL cases and additional regional research into diagnostic test accuracy. Furthermore, the determinants of health-seeking delay in Ecuador should be investigated further.Foundation Latin Link Nederland provided funding for the current study

Does social support at home moderate the association between social support at work and work functioning among cancer patients?

PURPOSE: The aims of this study were to examine (1) the longitudinal associations of supervisor and colleague social support with work functioning in cancer patients who have returned to work and (2) the moderating role of social support at home.METHODS: Data from the longitudinal Work Life after Cancer study were used (n = 384). Work functioning (low versus moderate to high work functioning) was measured with the validated Work Role Functioning Questionnaire 2.0. Social support at work was measured from both supervisor and colleagues with the Copenhagen Psychosocial Questionnaire. Social support at home was measured with the Social Support List-Discrepancies. Logistic generalized estimating equations were used to analyse associations between supervisor and colleague social support and work functioning, and to examine the possible moderating effect of social support at home.RESULTS: More supervisor (OR: 1.21; 95% CI: 1.10, 1.32) and colleague (1.13; 1.03, 1.24) social support were significantly associated with moderate to high work functioning. The association between colleague social support and work functioning was attenuated for those who did not experience enough social support at home but remained almost significant for supervisor social support (1.17; 1.00, 1.37).CONCLUSIONS: Supervisor social support is associated with better work functioning regardless of social support at home, while colleague social support is only associated with better work functioning when cancer patients experience enough social support at home.IMPLICATIONS FOR CANCER SURVIVORS: Occupational physicians may play a key role in creating awareness that social support at work and at home are beneficial for cancer patients' work functioning.</p

A Fresh Insight into Transmission of Schistosomiasis: A Misleading Tale of Biomphalaria in Lake Victoria

Lake Victoria is a known hot-spot for Schistosoma mansoni, which utilises freshwater snails of the genus Biomphalaria as intermediate hosts. Different species of Biomphalaria are associated with varying parasite compatibility, affecting local transmission. It is thought that two species, B. choanomphala and B. sudanica, inhabit Lake Victoria; despite their biomedical importance, the taxonomy of these species has not been thoroughly examined. This study combined analysis of morphological and molecular variables; the results demonstrated that molecular groupings were not consistent with morphological divisions. Habitat significantly predicted morphotype, suggesting that the different Lake Victorian forms of Biomphalaria are ecophentoypes of one species. The nomenclature should be revised accordingly; the names B. choanomphala choanomphala and B. c. sudanica are proposed. From a public health perspective, these findings can be utilised by policy-makers for better understanding of exposure risk, resulting in more effective and efficient control initiatives

Laboratory evaluation on the sensitivity and specificity of a novel and rapid detection method for malaria diagnosis based on magneto-optical technology (MOT)

<p>Abstract</p> <p>Background</p> <p>This study describes the laboratory evaluation of a novel diagnostic platform for malaria. The Magneto Optical Test (MOT) is based on the bio-physical detection of haemozoin in clinical samples. Having an assay time of around one minute, it offers the potential of high throughput screening.</p> <p>Methods</p> <p>Blood samples of confirmed malaria patients from different regions of Africa, patients with other diseases and healthy non-endemic controls were used in the present study. The samples were analysed with two reference tests, i.e. an histidine rich protein-2 based rapid diagnostic test (RDT) and a conventional Pan-<it>Plasmodium </it>PCR, and the MOT as index test. Data were entered in 2 × 2 tables and analysed for sensitivity and specificity. The agreement between microscopy, RDT and PCR and the MOT assay was determined by calculating Kappa values with a 95% confidence interval.</p> <p>Results</p> <p>The observed sensitivity/specificity of the MOT test in comparison with clinical description, RDT or PCR ranged from 77.2 - 78.8% (sensitivity) and from 72.5 - 74.6% (specificity). In general, the agreement between MOT and the other assays is around 0.5 indicating a moderate agreement between the reference and the index test. However, when RDT and PCR are compared to each other, an almost perfect agreement can be observed (k = 0.97) with a sensitivity and specificity of >95%.</p> <p>Conclusions</p> <p>Although MOT sensitivity and specificity are currently not yet at a competing level compared to other diagnostic test, such as PCR and RDTs, it has a potential to rapidly screen patients for malaria in endemic as well as non-endemic countries.</p