2,122 research outputs found
Activation of human meningeal cells is modulated by lipopolysaccharide (LPS) and non-LPS components of Toll-like receptor (TLR)4 and TLR2 signalling
No full textThe interactions of Neisseria meningitidis with cells of the meninges are critical to progression of the acute, compartmentalized intracranial inflammatory response that is characteristic of meningococcal meningitis. An important virulence mechanism of the bacteria is the ability to shed outer membrane (OM) blebs containing lipopolysaccharide (LPS), which has been assumed to be the major pro-inflammatory molecule produced during meningitis. Comparison of cytokine induction by human meningeal cells following infection with wild-type meningococci, LPS-deficient meningococci or after treatment with OM isolated from both organisms, demonstrated the involvement of non-LPS bacterial components in cell activation. Significantly, recognition of LPS-replete OM did not depend on host cell expression of Toll-like receptor (TLR)4, the accessory protein MD-2 or CD14, or the recruitment of LPS-accessory surface proteins heat shock protein (HSP)70, HSP90?, chemokine receptor CXCR4 and growth differentiation factor (GDF)5. In addition, recognition of LPS-deficient OM was not associated with the expression of TLR2 or any of these other molecules. These data suggest that during meningococcal meningitis innate recognition of both LPS and non-LPS modulins is dependent on the expression of as yet uncharacterized pattern recognition receptors on cells of the meninges. Moreover, the biological consequences of cellular activation by non-LPS modulins suggest that clinical intervention strategies based solely on abrogating the effects of LPS are likely to be only partially effective
Cinq années de voyage en Orient 1846-1851 par Israel-Joseph Benjamin II, voyageur et auteur, demeurant à Faltischan (Moldavie). Paris en vente chez Michel Levy Frères, rue Vivienne, 2 bis 1856 L' auteur se réserve le droit de traduction et de reproduction
No full textPreface: by Benjamin, J.Dedication: by the author to M.J. Altaras aîné de Marseille et M. Albert Cohn.Content description: Detailed contentsPagination: PP28+240PVolumes: 1Text Genre:Pros
Microtrombicula felis
No full textMicrotrombicula felis (Vercammen-Grandjean, 1965) (Fig. 9A, B) Eltonella (Eltonella) ugandae felis Vercammen-Grandjean, 1965a: 70 ; Kolebinova & Vercammen-Grandjean 1980: 69. Microtrombicula felis: Stekolnikov 2018: 151.Published as part of AlghamdiK, Samia Q., AlkathiryK, Hadil A., Stekolnikov K, Alexandr A., AlagailiK, Abdulaziz N. & Makepeace K, Benjamin L., 2023, Additions to the chigger mite fauna (Acariformes: Trombiculidae) of Saudi Arabia, with the description of a new species, pp. 3-23 in Acarologia 63 (1) on page 18, DOI: 10.24349/dsrx-oryy, http://zenodo.org/record/794589
Schoengastiella hypoderma Vercammen-Grandjean 1956
No full textSchoengastiella hypoderma Vercammen-Grandjean, 1956 (Fig. 1C, D) Schoengastiella (Jadiniella) hypoderma Vercammen-Grandjean, 1956: 354. Gahrliepia (Jadiniella) hypoderma: Zumpt 1961: 173. Schoengastiella hypoderma: Stekolnikov 2018: 30.Published as part of AlghamdiK, Samia Q., AlkathiryK, Hadil A., Stekolnikov K, Alexandr A., AlagailiK, Abdulaziz N. & Makepeace K, Benjamin L., 2023, Additions to the chigger mite fauna (Acariformes: Trombiculidae) of Saudi Arabia, with the description of a new species, pp. 3-23 in Acarologia 63 (1) on page 9, DOI: 10.24349/dsrx-oryy, http://zenodo.org/record/794589
Microtrombicula abyssinica
No full textMicrotrombicula abyssinica (Radford, 1947) (Figs 4A, B, 5, 6) Trombicula abyssinica Radford, 1947: 590 ; Audy & Vercammen-Grandjean 1961: 131 ; Zumpt 1961: 137. Trombicula (Trombicula) abyssinica: Wharton & Fuller 1952: 61. Eltonella (Eltonella) abyssinica: Vercammen-Grandjean 1965a: 66 ; 1965b: 41. Microtrombicula abyssinica: Stekolnikov 2018: 145.Published as part of AlghamdiK, Samia Q., AlkathiryK, Hadil A., Stekolnikov K, Alexandr A., AlagailiK, Abdulaziz N. & Makepeace K, Benjamin L., 2023, Additions to the chigger mite fauna (Acariformes: Trombiculidae) of Saudi Arabia, with the description of a new species, pp. 3-23 in Acarologia 63 (1) on page 10, DOI: 10.24349/dsrx-oryy, http://zenodo.org/record/794589
Mining nematode protein secretomes to explain lifestyle and host specificity
No full textParasitic nematodes are highly successful pathogens, inflicting disease on humans, animals and plants. Despite great differences in their life cycles, host preference and transmission modes, these parasites share a common capacity to manipulate their host’s immune system. This is at least partly achieved through the release of excretory/secretory proteins, the most well-characterized component of nematode secretomes, that are comprised of functionally diverse molecules. In this work, we analyzed published protein secretomes of parasitic nematodes to identify common patterns as well as species-specific traits. The 20 selected organisms span 4 nematode clades, including plant pathogens, animal parasites, and the free-living species Caenorhabditis elegans. Transthyretin-like proteins were the only component common to all adult secretomes; many other protein classes overlapped across multiple datasets. The glycolytic enzymes aldolase and enolase were present in all parasitic species, but missing from C. elegans. Secretomes from larval stages showed less overlap between species. Although comparison of secretome composition across species and life-cycle stages is challenged by the use of different methods and depths of sequencing among studies, our workflow enabled the identification of conserved protein families and pinpointed elements that may have evolved as to enable parasitism. This strategy, extended to more secretomes, may be exploited to prioritize therapeutic targets in the future
Interactions of Neisseria gonorrhoeae with mature human macrophage opacity proteins influence production of proinflammatory cytokines
No full textThe pathological features of ascending gonococcal infection suggest that proinflammatory mediators secreted by tissue-resident macrophages are important components of the host response. Challenge of fully differentiated, mature macrophages with variants of Neisseria gonorrhoeae strain P9 or purified bacterial surface components (pili, lipooligosaccharide, and outer membrane vesicles) induced the secretion of interleukin 6 (IL-6), tumor necrosis factor alpha, growth-related protein alpha, macrophage inflammatory protein 1alpha (MIP-1alpha), and RANTES cytokines but had no effect on IL-8 production. No secretion of IL-1beta, epithelial-derived neutrophil attractant 78, granulocyte-macrophage colony-stimulating factor, IL-10, or IL-12 cytokines was observed. Notably, the P9-Opa(b) protein, in comparison to P9-Opa(a), increased the association of gonococci with macrophages and elevated the secretion of cytokines. Thus, variation in Opa protein expression by the gonococcus may be a determining factor in the severity of pelvic inflammatory disease
Interaction of Neisseria meningitidis with human meningeal cells induces the secretion of a distinct group of chemotactic, proinflammatory, and growth-factor cytokines
No full textThe interactions of Neisseria meningitidis with cells of the leptomeninges are pivotal events in the progression of bacterial leptomeningitis. An in vitro model based on the culture of human meningioma cells was used to investigate the role of the leptomeninges in the inflammatory response. Following challenge with meningococci, meningioma cells secreted specifically the proinflammatory cytokine interleukin-6 (IL-6), the CXC chemokine IL-8, the CC chemokines monocyte chemoattractant protein 1 (MCP-1) and regulated-upon-activation, normal-T-cell expressed and secreted protein (RANTES), and the cytokine growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). A temporal pattern of cytokine production was observed, with early secretion of IL-6, IL-8, and MCP-1 followed by later increases in RANTES and GM-CSF levels. IL-6 was induced equally by the interactions of piliated and nonpiliated meningococci, whereas lipopolysaccharide (LPS) had a minimal effect, suggesting that other, possibly secreted, bacterial components were responsible. Induction of IL-8 and MCP-1 also did not require adherence of bacteria to meningeal cells, but LPS was implicated. In contrast, efficient stimulation of RANTES by intact meningococci required pilus-mediated adherence, which served to deliver increased local concentrations of LPS onto the surface of meningeal cells. Secretion of GM-CSF was induced by pilus-mediated interactions but did not involve LPS. In addition, capsule expression had a specific inhibitory effect on GM-CSF secretion, which was not observed with IL-6, IL-8, MCP-1, or RANTES. Thus, the data demonstrate that cells of the leptomeninges are not inert but are active participants in the innate host response during leptomeningitis and that there is a complex relationship between expression of meningococcal components and cytokine induction
Figure 5 in Additions to the chigger mite fauna (Acariformes: Trombiculidae) of Saudi Arabia, with the description of a new species
No full textFigure 5 Microtrombicula abyssinica(Radford, 1947), additional specimen: A – dorsal aspect of idiosoma; B – ventral idiosomal setae; C – scutum (only one broken sensillum present); D – anterior sternal seta; E – posterior sternal seta; F – coxal seta I; G – coxal seta II; H – coxal seta III; I – preanal idiosomal seta; J – humeral seta; K – dorsal idiosomal seta ofst1posthumeral row. Abbreviations: AL – anterolateral scutal seta; AM – anteromedian scutal seta; H – humeral seta; PL – posterolateral scutal seta; S – sensillum; u – uropore (anus); V – ventral idiosomal setae. Scale bars: A, B – 100 µm; C – 50 µm; D – K – 20 µm.Published as part of AlghamdiK, Samia Q., AlkathiryK, Hadil A., Stekolnikov K, Alexandr A., AlagailiK, Abdulaziz N. & Makepeace K, Benjamin L., 2023, Additions to the chigger mite fauna (Acariformes: Trombiculidae) of Saudi Arabia, with the description of a new species, pp. 3-23 in Acarologia 63 (1) on page 12, DOI: 10.24349/dsrx-oryy, http://zenodo.org/record/794589
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Hyperendemic <i>Chlamydia trachomatis</i> sexually transmitted infections among females represent a high burden of asymptomatic disease and health disparity among Pacific Islanders in Fiji
No full textBackgroundChlamydia trachomatis is the most common bacterial sexually transmitted infection worldwide with some of the highest prevalence rates among Pacific Island Countries where syndromic management is practiced. However, little is known about the true prevalence and risk indicators for infection among neglected populations in these countries that suffer from health disparities.Methodology/Principal findingsConsecutive sampling was used to enroll sexually active females, aged 18–40 years, attending 12 Fijian Ministry of Health and Medical Services Health Centers and outreach locations from February to December, 2018. A Behavioral Surveillance Survey was administered to assess risk indicators for infection. Signs and symptoms were recorded, and vaginal swabs were tested for C. trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Candida and bacterial vaginosis. Bivariate and multivariate logistic regression analyses were performed using R-Studio. Of 577 participants, 103 (17.85%) were infected with C. trachomatis of whom 80% were asymptomatic and only 11 met criteria for syndromic management; 38.8% of infected women were 18–24 years old with a prevalence of 30.5%. 91.7% of participants intermittently or did not use condoms. C. trachomatis infection was associated with iTaukei ethnicity (OR 21.41 [95% CI: 6.38–133.53]); two lifetime partners (OR 2.12 [95% CI: 1.08–4.18]); and N. gonorrhoeae co-infection (OR 9.56 [95% CI: 3.67–28.15]) in multivariate analyses.ConclusionsA disproportionately high burden of C. trachomatis is present among young asymptomatic women in Fiji of iTaukei ethnicity despite the low number of lifetime partners. Syndromic management and lack of barrier contraceptives contribute to hyperendemic levels. Strategic STI education and screening of at-risk adolescents, young women, and their partner(s) with appropriate treatment are urgently needed to control the epidemic.</div
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