Sabella spallanzanii mucus contain a galactose-binding lectin able to agglutinate bacteria. Purification and characterization

Lectins are present in almost all living organisms and are involved in several biological processes, including immune responses. In the present study, a calcium dependent galactose-binding lectin exhibiting an apparent MW of 43 kDa has been characterized and purified from the mucus of the polychaete Sabella spallanzanii by using both affinity chromatography and high-pressure liquid chromatographic methods. Its agglutinating activity towards rabbit erythrocytes was significantly modified by the addition of calcium or EDTA. The activity was optimal at temperature values comprised between 4 and 18 \ub0C, maintain a 50% of activity between 20 and 37 \ub0C, was significant deleted after exposure at 50 \ub0C, and was depleted at 90 \ub0C. The S. spallanzanii Galactose-Binding Lectin (SsGBL) was able to agglutinate bacteria and to preferentially recognize Gram-negative bacteria. The strongest agglutinating activity was observed towards Vibrio alginolyticus and Escherichia coli, by contrast mucus agglutinated in a lesser extent both Aeromonas hydrophyla and the Gram-positive Micrococcus lysodeikticus thus suggesting its involvement in host pathogen interactions

A serum fucose-binding lectin (D1FBL) from adult Didentrarchus labrax is expressed in larva and juvenile tissue and contained in eggs

The purification, cloning, sequencing, molecular properties and expression of a fucose-binding lectin from the serum of Dicentrarchus labrax (DlFBL) have been previously reported. We now describe the distribution and expression of DlFBL during fish ontogeny. Immunohistochemistry and in situ hybridization assays were carried out at various developmental stages (from 10 days posthatching larvae to juveniles). Another fucose-binding lectin, similar to DlFBL in biochemical, immunochemical and agglutinating properties, was extracted and purified from eggs and appeared to be localized in the embryo yolk sack residual. DlFBL was found in columnar and goblet cells of the intestinal epithelium of larvae (from 20 days post-hatching) and juveniles and in parenchymal tissue of juveniles. DlFBL mRNA and protein were detected in the intestinal epithelium and in hepatocytes. An amplification product from degenerate primers indicates that lectin isotypes with DlFBL epitopes are expressed in eggs and embryos. Whether the lectin fraction isolated from eggs and embryos includes DlFBL of maternal origin remains unclear

Whole genome profiling of spontaneous and chemically induced mutations in Toxoplasma gondii

BACKGROUND: Next generation sequencing is helping to overcome limitations in organisms less accessible to classical or reverse genetic methods by facilitating whole genome mutational analysis studies. One traditionally intractable group, the Apicomplexa, contains several important pathogenic protozoan parasites, including the Plasmodium species that cause malaria. Here we apply whole genome analysis methods to the relatively accessible model apicomplexan, Toxoplasma gondii, to optimize forward genetic methods for chemical mutagenesis using N-ethyl-N-nitrosourea (ENU) and ethylmethane sulfonate (EMS) at varying dosages. RESULTS: By comparing three different lab-strains we show that spontaneously generated mutations reflect genome composition, without nucleotide bias. However, the single nucleotide variations (SNVs) are not distributed randomly over the genome; most of these mutations reside either in non-coding sequence or are silent with respect to protein coding. This is in contrast to the random genomic distribution of mutations induced by chemical mutagenesis. Additionally, we report a genome wide transition vs transversion ratio (ti/tv) of 0.91 for spontaneous mutations in Toxoplasma, with a slightly higher rate of 1.20 and 1.06 for variants induced by ENU and EMS respectively. We also show that in the Toxoplasma system, surprisingly, both ENU and EMS have a proclivity for inducing mutations at A/T base pairs (78.6% and 69.6%, respectively). CONCLUSIONS: The number of SNVs between related laboratory strains is relatively low and managed by purifying selection away from changes to amino acid sequence. From an experimental mutagenesis point of view, both ENU (24.7%) and EMS (29.1%) are more likely to generate variation within exons than would naturally accumulate over time in culture (19.1%), demonstrating the utility of these approaches for yielding proportionally greater changes to the amino acid sequence. These results will not only direct the methods of future chemical mutagenesis in Toxoplasma, but also aid in designing forward genetic approaches in less accessible pathogenic protozoa as well. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-354) contains supplementary material, which is available to authorized users

Haemolytic activity and characterization of nematocyst venom from Pelagia noctiluca (Cnidaria: Scyphozoa)

We investigated the haemolytic capacity of the crude venom extracted from isolated nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa), and evidenced the proteic fractions responsible for this activity. The nematocyst venom was used at various concentrations to evaluate the haemolytic activity and the lysosomal membrane stability of red blood cells of two teleostean species treated with the extract. The nematocyst extract was assayed against erythrocytes of the two teleostean species living in different environments, Carassius auratus as a common freshwater species, and Liza aurata as a representative of seawater species. Experiments on the haemolytic activity of P. noctiluca in the presence of lipid components of erythrocyte membranes showed that sphyngomyelin strongly inhibited this activity. The crude venom was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE and high performance liquid chromatography (HPLC) to detect the proteic composition, and it was found that the active haemolytic components of this venom are distributed in at least four protein fractions. The results of our experiments indicated that Pelagia noctiluca venom induces haemolysis and lysosomal membrane destabilisation in both species and that Carassius auratus was more susceptible to jellyfish venom than was Liza aurata. No significant differences in glutathione (GSH) levels were observed between control and treatments; consequently the toxins do not cause the oxidative stress but likely recognize specific targets (i.e. sphyngomyelin) in the plasmatic membrane of red blood cells

Hydrocephalus and diffuse choroid plexus hyperplasia in primary ciliary dyskinesia-related MCIDAS mutation

OBJECTIVE: To report a neuroradiologic phenotype associated with reduced generation of multiple motile cilia (RGMC) and mutations in the multicilin gene. We hypothesize that the observed phenotype may reflect the emerging role that ependymal cilia play in regulating CSF production. METHOD: Clinical and radiologic records were retrospectively reviewed for 7 consecutive patients diagnosed by the Leicester UK national primary ciliary dyskinesia (PCD) diagnostic laboratory. RESULTS: On MRI scanning, all patients demonstrated hydrocephalus, choroid plexus hyperplasia (CPH), and arachnoid cysts. No patient had any sign of neurologic deficit. All patients had significant lung disease. CONCLUSIONS: We conclude that there is a high incidence of hydrocephalus, arachnoid cysts, and CPH in MCIDAS-associated RGMC. In all cases, the observed hydrocephalus seems arrested in childhood without progression or adverse neurologic sequelae. Our new observation of CPH, which is associated with CSF overproduction, is the first macroscopic evidence that ependymal cilia may be involved in the regulation of CSF production and flow. We suggest that brain imaging should be performed in all cases of RGMC and that a diagnosis of PCD or RGMC be strongly considered in patients with unexplained hydrocephalus and a lifelong “wet”-sounding cough

New specific skeletal muscle mass index cut-offs for the assessment of sarcopenia in patients with severe obesity

Introduction Bioelectrical impedance analysis (BIA) is the most used tool in clinical practice to evaluate body composition in patients with obesity. The skeletal muscle index (SMI) defined by BIA has been proposed for the identification of sarcopenia, but there are currently no univocal cutoffs for this condition. In this study, we aimed: 1) to determine the prevalence of sarcopenia in patients with severe obesity using the current cutoffs of SMI; 2) to define new specific cutoffs; 3) to validate the new cutoffs; and 4) to re-determine the prevalence of sarcopenia.Methods A total of 300 patients, 74% women and 26% men (mean age = 42.6 +/-; 9 years), with morbid obesity (mean BMI = 46.7 +/-; 6.5 kg/m2) followed by the Unit of Endocrinology from January 2014 to December 2020 were retrospectively evaluated. SMI was calculated as the skeletal muscle mass normalized for squared height through the BIA equation by Janssen et al.Results The prevalence of sarcopenic obesity calculated using the cutoff points reported by De Rosa et al. (7.3 kg/h2 for women and 9.5 kg/h2 for men) was 2.3%. The prevalence of sarcopenia was calculated using the new cutoffs: with the cutoff obtained from the standard deviation method (8.2 kg/h2 for women and 10.2 kg/h2 for men), a prevalence of 14.7% was observed, whereas the prevalence reached 47.6% when using the cutoff calculated through the K-means unsupervised cluster (9.2 kg/h2 for women and 11.3 kg/h2 for men). The new cutoffs were validated with a second sample consisting of 300 patients with morbid obesity (BMI = 44.9 +/-; 6.7 kg/m2): the rate of sarcopenic patients was still higher than that observed in the training cohort (56%). After the matching procedure (by BMI and age), the rates of sarcopenic patients were similar in both groups (50.2% in the validation group and 53% in the training group, p = 0.6).Conclusion The new cutoffs calculated with cluster analysis could better identify sarcopenia in morbidly obese patients. However, further studies are needed to validate these cutoffs in different patient cohorts

Multidisciplinary Approach to the Diagnosis and In-Hospital Management of COVID-19 Infection: A Narrative Review

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or COVID-19 disease) was declared a pandemic on 11th March 2020 by the World Health Organization. This unprecedented circumstance has challenged hospitals’ response capacity, requiring significant structural and organizational changes to cope with the surge in healthcare demand and to minimize in-hospital risk of transmission. As our knowledge advances, we now understand that COVID-19 is a multi-systemic disease rather than a mere respiratory tract infection, therefore requiring holistic care and expertise from various medical specialties. In fact, the clinical spectrum of presentation ranges from respiratory complaints to gastrointestinal, cardiac or neurological symptoms. In addition, COVID-19 pandemic has created a global burden of mental illness that affects the general population as well as healthcare practitioners. The aim of this manuscript is to provide a comprehensive and multidisciplinary insight into the complexity of this disease, reviewing current scientific evidence on COVID-19 management and treatment across several medical specialties involved in the in-hospital care of these patients

Hydrocephalus and diffuse choroid plexus hyperplasia in primary ciliary dyskinesia-related MCIDAS mutation

Objective: To report a neuroradiologic phenotype associated with reduced generation of multiple motile cilia (RGMC) and mutations in the multicilin gene. We hypothesize that the observed phenotype may reflect the emerging role that ependymal cilia play in regulating CSF production. Method: Clinical and radiologic records were retrospectively reviewed for 7 consecutive patients diagnosed by the Leicester UK national primary ciliary dyskinesia (PCD) diagnostic laboratory. Results: On MRI scanning, all patients demonstrated hydrocephalus, choroid plexus hyperplasia (CPH), and arachnoid cysts. No patient had any sign of neurologic deficit. All patients had significant lung disease. Conclusions: We conclude that there is a high incidence of hydrocephalus, arachnoid cysts, and CPH in MCIDAS-associated RGMC. In all cases, the observed hydrocephalus seems arrested in childhood without progression or adverse neurologic sequelae. Our new observation of CPH, which is associated with CSF overproduction, is the first macroscopic evidence that ependymal cilia may be involved in the regulation of CSF production and flow. We suggest that brain imaging should be performed in all cases of RGMC and that a diagnosis of PCD or RGMC be strongly considered in patients with unexplained hydrocephalus and a lifelong “wet”-sounding cough

Numerical model for granular compaction under vertical tapping

A simple numerical model is used to simulate the effect of vertical taps on a packing of monodisperse hard spheres. Our results are in agreement with an experimantal work done in Chicago and with other previous models, especially concerning the dynamics of the compaction, the influence of the excitation strength on the compaction efficiency, and some ageing effects. The principal asset of the model is that it allows a local analysis of the packings. Vertical and transverse density profiles are used as well as size and volume distributions of the pores. An interesting result concerns the appearance of a vertical gradient in the density profiles during compaction. Furthermore, the volume distribution of the pores suggests that the smallest pores, ranging in size between a tetrahedral and an octahedral site, are not strongly affected by the tapping process, in contrast to the largest pores which are more sensitive to the compaction of the packing.Comment: 8 pages, 15 figures (eps), to be published in Phys. Rev. E. Some corrections have been made, especially in paragraph IV