Background
The COVID-19 pandemic has altered organ and tissue donations as well as transplantation practices. SARS-CoV-2 serological tests could help in the selection of donors. We assessed COVID-19 ...seroprevalence in a population of tissue donors, at the onset of the outbreak in France, before systematic screening of donors for SARS-CoV-2 RNA.
Methods
235 tissue donors at the Lille Tissue Bank between November 1, 2019 and March 16, 2020 were included. Archived serum samples were tested for SARS-CoV-2 antibodies using two FDA-approved kits.
Results
Most donors were at higher risks for severe COVID-19 illness including age over 65 years (142/235) and/or presence of co-morbidities (141/235). According to the COVID-19 risk assessment of transmission, 183 out of 235 tissue donors presented with a low risk level and 52 donors with an intermediate risk level of donor derived infection. Four out of the 235 (1.7%) tested specimens were positive for anti-SARS-CoV-2 antibodies: 2 donors with anti-N protein IgG and 2 other donors with anti-S protein total Ig. None of them had both type of antibodies.
Conclusion
Regarding the seroprevalence among tissue donors, we concluded that the transmission probability to recipient via tissue products was very low at the beginning of the outbreak.
Background. Bacterial vaginosis is a risk factor for preterm birth. The various conventional methods for its diagnosis are laborious and not easily reproducible. Molecular quantification methods have ...been reported recently, but the specific risk factors they might identify remain unclear. Methods. A prospective multicenter national study included pregnant women at risk of preterm birth. A quantitative molecular tool using a specific real-time polymerase chain reaction assay and serial dilutions of a plasmid suspension quantified Atopobium vaginae, Gardneralla vaginalis, loctobacilli, Mycoplasma hominis, and the human albumin gene (for quality control). Results. In 813 pregnancies, high vaginal loads of either or both of A. vaginae and G. vaginalis were associated with preterm birth (hazard ratio HR, 3.9; 95% confidence interval {CI}, 1.1–14.1; P = .031). A high vaginal load of A. vaginae was significantly associated with shortened time to delivery and therefore pregnancy length. These times were, respectively, 152.2 and 188.2 days (HR, 5.6; 95% CI, 1.5–21.3; P< .001) before 22 weeks, 149.0 and 183.2 days (HR, 2.8; 95% CI, 1.1–8.2; P = .048) before 28 weeks, and 132.6 and 170.4 days (HR, 2.2; 95% CI, 1.1–4.6; P = .033) before 32 weeks. After multivariate analysis, A. vaginae levels ≥108 copies/mL remained significantly associated with delivery before 22 weeks of gestation (adjusted HR, 4.7; 95% CI, .2–17.6; P = .014). Conclusions. High vaginal loads of A. vaginae and G. vaginalis are associated with late miscarriage and prematurity in high-risk pregnancies. A high vaginal load of A. vaginae (DNA level ≥108 copies/mL) identifies a population at high risk of preterm birth. Further studies that both screen for and then treat A. vaginae are needed. Clinical Trials Registration. NCT00484653.
Seeping of methane-rich fluids at submarine cold seeps drives intense microbial activity and precipitation of authigenic carbonates. Some trace elements play an important role in the biogeochemical ...processes operating at cold seeps, especially as specific enzymatic co-factors related to methanogenesis and the anaerobic oxidation of methane (AOM). However, it is unclear whether microbial trace metal utilization can be traced by the geochemical composition of seep carbonates. In this study, we analyzed a series of authigenic carbonate samples recovered from various seep settings worldwide and report for the first time trace element concentrations for total lipid fractions, combined with biomarker analyses and determination of elemental abundances in associated inorganic mineral phases (carbonate phases, sulfides, organic compounds and detrital fractions). Our results indicate marked enrichments of Co, Ni, Cu, Mo and W in the archaeal and bacterial lipids associated with authigenic carbonates, which can all be ascribed to previously identified enzymatic pathways. In addition to the microbial communities involved in AOM, which most likely control specific lipid-bound enrichments of Co, Ni, Mo and W in seep carbonates, Cu was found to display higher concentrations in the lipid fractions extracted from a few authigenic carbonate samples formed closer to the sediment-water interface, hence possibly related to the presence of aerobic methane-oxidizing bacterial assemblages in the near seafloor environment. While the above mentioned trace metals are relatively enriched in all studied inorganic and organic fractions, the very low W concentrations measured in carbonate phases, combined with their pronounced enrichment in associated lipid fractions and inferred microbial requirement, suggest that tungsten depletion in pore waters could possibly act as a limiting factor on AOM at cold seeps. Finally, two other trace elements (Li and Ti) also displayed particular enrichments in studied lipid fractions, which, despite no reported evidence, could possibly indicate that they are also involved as metalloenzymes in microbial methane oxidation processes at cold seeps.
The outcome of tumors results from genetic and epigenetic modifications of the transformed cells and also from the interactions of the malignant cells with their tumor microenvironment (TME), which ...includes immune and inflammatory cells. For a given cancer type, the composition of the immunological TME is not homogeneous. Heterogeneity is found between different cancer types and also between tumors from patients with the same type of cancer. Some tumors exhibit a poor infiltration by immune cells, and others are highly infiltrated by lymphocytes. Among the latter, the architecture of the TME, with the localization of immune cells in the invasive front and the center of the tumor, the presence of tumor-adjacent organized lymphoid aggregates, and the type of inflammatory context, determines the prognostic impact of the infiltrating cells. The description and the understanding of the immune and inflammatory landscape in human tumors are of paramount importance at different levels of patient's care. It completes the mutational, transcriptional, and epigenetic patterns of the malignant cells and open paths to understand how tumor cells shape their immune microenvironment and are shaped by the immune reaction. It provides prognostic and theranostic markers, as well as novel targets for immunotherapies.
The C-type lectin dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN) mediates the innate immune recognition of microbial carbohydrates. We investigated the ...function of this molecule in the host response to pathogens in vivo, by generating mouse lines lacking the DC-SIGN homologues SIGNR1, SIGNR3, and SIGNR5. Resistance to Mycobacterium tuberculosis was impaired only in SIGNR3-deficient animals. SIGNR3 was expressed in lung phagocytes during infection, and interacted with M. tuberculosis bacilli and mycobacterial surface glycoconjugates to induce secretion of critical host defense inflammatory cytokines, including tumor necrosis factor (TNF). SIGNR3 signaling was dependent on an intracellular tyrosine-based motif and the tyrosine kinase Syk. Thus, the mouse DC-SIGN homologue SIGNR3 makes a unique contribution to protection of the host against a pulmonary bacterial pathogen.
Malignant transformation of melanocytes frequently coincides with an alteration in the expression of cell-cell adhesion molecules (cadherins) and cell-extracellular matrix proteins (integrins). How ...these two adhesion systems interplay to impact on cell invasion remains to be described in melanoma.
Cell adhesion networks were localised by immunofluorescence in human primary cutaneous melanoma, metastatic melanoma in the lymph nodes, and melanoma cell lines. The role of these cell adhesion networks was assessed both in vivo, by analysing their impact on tumour growth in mice, and in vitro, with the use of functional tests including cell aggregation and cell migration.
We found that α2β1 integrin associates with both E-cadherin and N-cadherin to form two adhesive networks, distinguishable by the interaction-or not-of α2β1 integrin with type I collagen. N-cadherin/α2β1 integrin and E-cadherin/α2β1 integrin networks differently participated towards tumour growth in mice. The N-cadherin/α2β1 integrin network showed specific involvement in melanoma cell invasion and migration towards type I collagen. On the other hand, the E-cadherin/α2β1 network regulated cell-cell adhesion.
This suggests that different signalling environments can be generated, depending on the type and/or local concentration of cadherin present in the adhesion complex, which potentially leads to differential cell responses. Further clarification of how these adhesive networks are regulated is fundamental to understanding important physiological and pathological processes such as morphogenesis, wound healing, tumour invasion and metastasis.
Cyanide is a toxic substance found in several plants roots amongst which cassava. The objectives of this study were to quantify cyanide contents in the roots of the main cassava varieties cultivated ...in Cameroon and evaluate the effect of some traditional cassava processing methods on their initial contents. Ten local and ten improved varieties of cassava samples were collected in the locality of Mbankomo, Ongot village, Centre region. These roots were processed into traditional foods: “Chips”, “Gari” and “Fufu”. The cyanide content was determined in the parenchyma, cortex, and cassava derived foods. Local varieties had cyanide contents varying from 79.34±3.58 to 181.33±0.48 ppm, while contents in improved varieties varied from 61.03±9.44 to 118.04±7.16 ppm. Cyanide content quantitative classification revealed that studied cassava varieties fell within the range “moderately” to “highly” toxic. Results showed no clear link between morphological characteristic and cyanide contents of the studied cassava varieties. Although cyanide contents were higher in the cortex varying from 117.80±11.32 to 210.07±9.15 ppm for local, and from 98.43±15.49 to 155.44±12.11 ppm for improved varieties. Processing of cassava into different traditional foods contributed to reduce cyanide content. Elimination rates were as a function of the process involved: 47%, 80% and 91%, respectively, for “Chips”, “Gari” and “Fufu”. Cassava processing reduce cyanide content, however extent of reduction varies from one product to another. Keywords: Cyanide, Cassava cultivars, Traditional processing, Detoxification
Since several years, whiteflies of the species complex of Bemisia tabaci (Gennadius) are causing several damages on vegetable crops in Côte d'Ivoire. These sap-sucking insects are the main vector of ...many viruses on tomato and several species of this complex have developed resistances against insecticides. Nevertheless, there is very little information about whitefly species on vegetable crops in Côte d'Ivoire. Here, we investigated the species diversity and their genetic diversity and structuring on samples from vegetable crops in the major tomato production areas of Côte d'Ivoire. To assess this diversity, 535 whitefly samples from different localities and plant species were collected and analysed with nuclear (microsatellite) and mitochondrial (mtCOI) markers. In each site, and ecological data were recorded, including whiteflies abundance and plant species colonised by B. tabaci. The analysis of mtCOI sequences of whiteflies indicated the presence of four cryptic species on tomato and associated crops in Côte d'Ivoire. These were MED ASL, MED Q1, SSA 1 and SSA3. The MED ASL species dominated over all samples in the different regions and plant species. One haplotype of MED ASL out of the 15 identified predominated on most plant species and most sites. These results suggested that MED ASL is probably the main phytovirus vector in the Ivorian vegetable cropping areas. In contrast, only five haplotypes of MED Q1 were identified on vegetables but in the cotton-growing areas of the country. Its low prevalence, low nuclear and mitochondrial diversity might indicate a recent invasion of this species on vegetable crops in Côte d'Ivoire. The Bayesian nuclear analysis indicated the presence of hybrid genotypes between the two main species MED ASL and MED Q1, however in low prevalence (10%). All these results highlight the need to maintain whitefly populations monitoring for a more effective management in Côte d'Ivoire.
Robot-assisted laparoscopic rectopexy for total rectal prolapse is safe and feasible. Small series proved clinical and functional short-term results comparable with conventional laparoscopy. No ...long-term results have been reported yet.
The primary objective of the study was to evaluate long-term functional and anatomic results of robot-assisted laparoscopic rectopexy. The secondary objective was to evaluate the learning curve of this procedure.
Monocentric study data, both preoperative and perioperative, were collected prospectively, and follow-up data were assessed by a telephone questionnaire.
The study was performed in an academic center by 3 different surgeons.
We evaluated all of the consecutive patients who underwent a robot-assisted laparoscopic rectopexy between June 2002 and August 2010.
Rectopexy was performed with 2 anterolateral meshes or with 1 ventral mesh, and in 9 patients a sigmoidectomy was associated with rectopexy.
The actuarial recurrence rate was evaluated using the Kaplan-Meier method.
During the study period, 77 patients underwent a robot-assisted laparoscopic rectopexy, and the mean age was 59.9 years (range, 23-90 y). Average operating time was 223 minutes (range, 100-390 min); the learning curve was completed after 18 patients were seen. Two patients died of causes unrelated to surgery at 5 and 24 months. There were 5 conversions (6%) to open procedure. Overall morbidity was low and concerned only 8 patients (10.4%). Mean follow-up time was 52.5 months (range, 12-115 mo). Recurrences have been observed in 9 patients (12.8%). Preoperatively, 24 (34%) of the patients had constipation. Postoperatively, constipation disappeared for 12 (50%) of 24 and constipation appeared for 11 (24%) of 46 patients. Fecal incontinence decreased after surgery from Wexner score 10.5 to 5.1 of 20.
There was a lack of standardization of the surgical procedure. The study was monocentric. Seven patients (9%) were lost to follow-up.
Long-term results of robot-assisted laparoscopic rectopexy are satisfying. Further studies comparing robot-assisted and conventional laparoscopy, including cost-effectiveness, are needed.
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