Comparative Analysis of the Morphology,Ultrastructure, and Glycosylation Pattern of the Jejunum and Ileum of the Wild Rodent Lagostomus maximus

Morphological and histochemical analyses were performed to characterize the histology, ultrastructure, and glycosylation pattern of the jejunum and ileum of the wild rodent Lagostomus maximus. Enterocytes, goblet cells, Paneth cells, and enteroendocrine cells were identified in both intestinal epithelia. Two morphological types of enterocytes were identified only in the ileum based on their cytoplasm electron density. Although the histological and ultrastructural examination showed that the epithelia of both anatomical regions were morphologically similar, a certain specialization in their secretory products was evident. The glycosylation pattern of the jejunum and ileum was characterized in situ by histochemical and lectin histochemical methods. Histochemical results revealed the presence of carboxylated and sulfated gycoconjugates in both regions, although sulfomucins were clearly prevalent in the ileum. Sialic acid was highly O‐acetylated and particularly abundant in the jejunum. The KOH/PA*/Bh/PAS technique evidenced a more intense histochemical reaction in the jejunal than in the ileum goblet cells, demonstrating a reduction of neutral mucin secretion in the distal small intestine. Further specific differences were revealed by lectin histochemistry. These data evidenced that the nature of mucus varies at different anatomical regions, probably adapted to physiological requirements. Anat Rec, 299:630–642, 2016. © 2016 Wiley Periodicals, Inc.     

Similarity and Divergence among Adherent-Invasive Escherichia coli and Extraintestinal Pathogenic E. coli Strains

Adherent-invasive Escherichia coli (AIEC) pathovar strains, which are associated with Crohn''s disease, share many genetic and phenotypic features with extraintestinal pathogenic E. coli (ExPEC) strains, but little is known about the level of genetic similarity between the two pathovars. We aimed to determine the frequency of strains with the “AIEC phenotype” among a collection of ExPEC strains and to further search for a common phylogenetic origin for the intestinal and extraintestinal AIEC strains. The adhesion, invasion, and intramacrophage replication capabilities (AIEC phenotype) of 63 ExPEC strains were determined. Correlations between virulence genotype and AIEC phenotype and between intestinal/extraintestinal origin, serotype, and phylogroup were evaluated for the 63 ExPEC and 23 intestinal AIEC strains. Phylogenetic relationships between extraintestinal and intestinal AIEC strains were determined using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis. Only four (6.35%) ExPEC strains, belonging to the O6:H1, O83:H1, and O25:H4 serotypes, were classified as having an AIEC phenotype. These strains were found to be genetically related to some intestinal AIEC strains of the same serotypes as revealed by MLST. No particular virulence gene sets correlated with the intestinal/extraintestinal origin of the strains or with the AIEC phenotype, whereas the gene sets did correlate with the serogroup. We identified two intestinal AIEC strains and one extraintestinal AIEC strain belonging to the O25:H4 serotype that also belonged to the emerging and virulent clonal group ST131. In conclusion, the ExPEC and AIEC pathovars share similar virulence gene sets, and certain strains are phylogenetically related. However, the majority of ExPEC strains did not behave like AIEC strains, thus confirming that the AIEC pathovar possesses virulence-specific features that, to date, are detectable only phenotypically.Members of the Enterobacteriaceae family, especially Escherichia coli, have been repeatedly suggested to play a role in the origin and/or perpetuation of Crohn''s disease (CD). In part, this suggestion was based on the higher abundance of this bacterium in CD patients than in control subjects (4, 10, 20, 23, 28, 29, 32, 41, 48, 51). Although considerable effort has been devoted to the search for intestinal pathogenic E. coli strains associated with CD, to date none of the six previously described pathovars (27) has been implicated in this condition. Darfeuille-Michaud et al. (18) observed that E. coli strains with adhesion and invasion properties colonized the ileal mucosae of CD patients more frequently than those of control subjects. Darfeuille-Michaud et al. further characterized these strains and proposed a new potential E. coli pathovar associated with CD, which was designated adherent-invasive E. coli (AIEC) (10). The implication of AIEC in CD is becoming increasingly relevant because several independent studies from different countries have reported a higher prevalence of invasive E. coli in CD patients (4, 17, 33, 34, 47).The main characteristics of AIEC are (i) the ability to adhere to and invade intestinal epithelial cells, (ii) the ability to survive and replicate expansively within macrophages without triggering host cell death and inducing the release of tumor necrosis factor alpha (21), and (iii) the lack of known invasive determinants (17). Recently, Glasser and Darfeuille-Michaud (22) proposed a model explaining the mechanism of pathogenesis for AIEC strains. The AIEC strains isolated to date are clonally diverse and belong to distinct serotypes. Moreover, despite the fact that they fall primarily into the B2 phylogroup, AIEC strains belonging to the A, B1, and D phylogroups have also been isolated (4, 33-35, 47). Although no specific virulence factors have been described for this pathovar, AIEC strains carry many virulence-associated genes characteristic of extraintestinal pathogenic E. coli (ExPEC) strains, which suggests that the AIEC pathovar could be closely related to the ExPEC pathovar (4, 17, 34).The aim of this work was to determine the frequency of strains with the “AIEC phenotype” among E. coli strains that cause extraintestinal infections, including uropathogenic E. coli (UPEC), septicemic E. coli, and neonatal meningitis E. coli strains. To achieve this objective, we determined the ability of a collection of ExPEC strains to adhere to and invade intestinal epithelial cells, as well as their capacity to survive and replicate within macrophages. In parallel, we compared the distributions of virulence-associated genes among ExPEC and AIEC strains. Furthermore, we searched for a common phylogenetic origin of the ExPEC strains that had an AIEC phenotype (referred to in this study as extraintestinal AIEC) and a collection of AIEC strains isolated mainly from the intestinal mucosae of CD patients (intestinal AIEC).     

Neutralization of alpha,gamma, and D614G SARS-CoV-2 variants by CoronaVac vaccine-induced antibodies

Vaccination generates a neutralizing immune response against SARS-CoV-2. The genomic surveillance is showing the emergence of variants with mutations in spike, the main target of neutralizing antibodies. To understand the impact of these variants, we report the neutralization potency against alpha, gamma, and D614G SARS-CoV-2 variants in 44 individuals that received two doses of CoronaVac vaccine, an inactivated SARS-CoV-2 vaccine. Plasma samples collected at 60 days after the second dose of CoronaVac were analyzed by the reduction of cytopathic effect in Vero E6 cells with the three infectious variants of SARS-CoV-2. Plasma showed lower neutralization with alpha (geometric mean titer [GMT] = 18.5) and gamma (GMT = 10.0) variants than with D614G (GMT = 75.1) variant. Efficient neutralization against the alpha and gamma variants was not detected in 31.8% and 59.1% of plasma, respectively. These findings suggest the alpha and gamma variants could escape from neutralization by antibodies elicited by vaccination. Robust genomic and biological surveillance of viral variants could help to develop effective strategies for the control of SARS-CoV-2.     

Telomerase activity in well-differentiated papillary thyroid carcinoma corrrelates with advanced clinical stage of the disease

Clinical relevance and stage correlation of telomerase activity in well-differentiated papillary thyroid carcinoma (WD PTC) has not been well determined, as its reported activity could be due to the analysis of tumors with lymphocytic infiltrates or aggressive variants of papillary carcinomas. We conducted a prospective study of telomerase activity in WD PTC without inflammatory infiltrates and correlated it with clinical stage. Fifty WD PTCs were analyzed for telomerase activity by PCR-based TRAP (telomeric repeat amplification protocol) assay. Results were correlated with stage and other clinicopathologic variables. Twenty-one (42%) WD PTCs demonstrated telomerase activity. The enzyme was detected more frequently in stage III/IVa WD PTCs (p=0.02) and in tumors with extra thyroidal extension (p=0.04). The risk of presenting advanced disease (stage III/IVa) and extrathyridal growth was significantly increased in telomerase-positive tumors (p=0.01; odds ratio [OR] 4.4 [95%Cl 1.3–14.7]) and (p=0.04; OR 3.6 [95%Cl 1.1–11.7]), respectively. Also, a correlation was found between telomerase activity and age. There was no correlation of telomerase activity with gender, histologic variant, tumor size, or cervical lymph node metastasis. Telomerase activity was observed in 42% of WD PTC and was detected more frequently in AJCC TNM stage III/IVa cases. This finding suggests that telomerase deregulation could be involved in tumor progression.     

Social anxiety and autism spectrum traits among adult FMR1 premutation carriers

Behavioral symptoms and traits have been proposed as early markers in neurodegenerative diseases. The aim of this study was to evaluate social anxiety and autism in FMR1 premutation carriers using the Social Phobia Inventory (SPIN) and the Autism‐Spectrum Quotient (AQ) questionnaires. Fifty‐nine premutation carriers were compared with 50 controls. The SPIN test showed statistically significant differences between female but not male carriers. The AQ questionnaire found statistically significant differences between premutation carriers and controls in the total AQ as well as in the social skills and attention switching subdomains. A gender effect was only observed for the social skills subdomain. Spearman's correlation analysis revealed a moderately positive correlation with the total AQ scores as well as the social skills and communication subdomains. Our results show that fragile X‐associated tremor/ataxia syndrome (FXTAS) patients have higher AQ scores. Moreover, this is the first study to find statistically significant differences between FXTAS and no‐FXTAS premutation carriers in the communication and the imagination subdomains, suggesting that FXTAS patients present a broader autistic phenotype than premutation carriers without FXTAS. Based on our results, a wide range of behavioral/psychiatric traits should be included within the broader phenotypic presentation of individuals with the FMR1 premutation.     

Detection of pap, sfa and afa adhesin-encoding operons in uropathogenic Escherichia coli strains: Relationship with expression of adhesins and production of toxins

A total of 243 Escherichia coli strains isolated from patients with urinary tract infections (UTI) were investigated for the presence of pap, sfa and afa adhesinencoding operons by using the polymerase chain reaction. It was found that 54%, 53% and 2% of the strains exhibited the pap, sfa and afa genotypes, respectively. Pap⁺ and/or sfa⁺ strains were more frequent in cases of acute pyelonephritis (94%) than in cases of cystitis (67%) (P < 0.001) and asymptomatic bacteriuria (57%) (P < 0.001). The pap and/or sfa operons were found in 90% of strains expressing mannose-resistant haemagglutination (MRHA) versus 37% of MRHA-negative strains (P < 0.001). The presence of pap and sfa operons was especially significant in strains belonging to MRHA types III (100%) (without P adhesins) and IVa (97%) (expressing the specific Gal-Gal binding typical of P adhesins). Both pap and sfa operons were closely associated with toxigenic E. coli producing a-haemolysin (Hly⁺) and/or the cytotoxic necrotizing factor type 1. There was an apparent correlation between the pap and sfa operons and the O serogroups of the strains. Thus, 93% of strains belonging to O1, O2, O4, O6, O7, O14, O15, O18, O22, O75 and O83 possessed pap and/or sfa operons, versus only 32% of strains belonging to other serogroups (P < 0.001). The results obtained in this study confirm the usefulness of our MRHA typing system for presumptive identification of pathogenic E. coli exhibiting different virulence factors. Thus, 85% of strains that possessed both pap and sfa adhesinencoding operons showed MRHA types III or IVa previously associated with virulence of E. coli strains that cause UTI and bacteraemia.La PCR a permis de détecter les opérons pap, sfa et afa chez 243 souches de Escherichia coli isolées d'infections de l'arbre urinaire. On observe que respectivement 54, 53 et 2% des souches sont du génotype pap, sfa et afa. Les souches pap⁺ et/ou sfa⁺ sont plus fréquentes dans les pyelonephritis aiguës (94%) que dans les cystites (67%) (P < 0,001) et dans les bactériuries asymptomatiques (57%) (P < 0,001). Les opérons pap et/ou sfa sont décelés chez 90% des souches MRHA⁺ (hémagglutination mannoserésistante) et 37% des souches MRHA⁻ (P < 0,001). La présence des opérons pap et sfa est spécialement significative chez les souches appartenant au type III de MRHA (100%) sans adhésines P, et au type IVa (97 %) exprimant la liaison Gai-Gal typique des adhésines P. Les opérons pap et sfa sont tous deux étroitement associés aux souches toxigéniques produisant l'α-hémolysine (Hly⁺) et le facteur cytotoxique nécrotique de type 1. Une corrélation apparaît entre les opérons pap et sfa et le sérogroupe: 93 % des souches appartenant aux groupes O1, O2, O4, O6, O7, O14, O15, O18, O22, O75 et O83 possèdent ces opérons, et seulement 37 % des souches appartenant à d'autres sérogroupes (P < 0,001) les possèdent. Ces résultats confirment l'utilité de notre typage MRHA pour l'identification (présomptive) des souches pathogènes de E. coli porteuses de divers facteurs de virulence. Ainsi, 85 % des souches possédant à la fois les opérons pap et sfa codant les adhésines sont du type III ou IVa (de MRHA) en relation avec la virulence des souches responsables d'infections urinaires et de bactériémies.     

Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells

Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime na?ve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis.     

Accumulation of toxic metals (Pb and Cd) in the sea urchin Diadema aff. antillarum Philippi, 1845, in an oceanic island (Tenerife,Canary Islands)

This document shows the results obtained from a study on the concentration of toxic heavy metals in the internal tissue and exoskeleton of sea urchins, collected from their natural habitat. The levels of lead and cadmium were measured by Graphite Furnace Atomic Absorption Spectrometry. The mean concentrations of lead and cadmium in the internal tissue were 304.04 and 260.54 μg/kg respectively, whereas in the shell they were 185.02 and 142.48 μg/kg. We also performed a statistical analysis of the differences in the distribution of metals between their exoskeleton and their internal content, a correlation study of the metal content in internal tissue and shell and sampling areas, and a correlation study between the metal content and sample size. Since the sea urchin Diadema antillarum presents a wide range of variation in metal content, this study suggests that this species is an excellent bioindicator of heavy metal contamination. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.     

Effects of velocity loss during resistance training on athletic performance,strength gains and muscle adaptations

We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional adaptations. Twenty‐two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8‐week velocity‐based RT program using the squat exercise while monitoring repetition velocity. Pre‐ and post‐training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross‐sectional area (CSA) and fiber type analyses, one‐repetition maximum strength and full load‐velocity squat profile, countermovement jump (CMJ), and 20‐m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.     

Quantitation and characterization of a species-specific and embryo stage-dependent 55-kilodalton phosphoprotein also present in cells transformed by simian virus 40.

A 55-kilodalton (kDal) protein was detected recently in primary cultures of day 12 mouse embryos by immunoprecipitation with serum from simian virus 40 (SV40) tumor-bearing hamsters (T serum), Preliminary evidence suggested that this protein was similar to a cellular 55-kDal protein induced after SV40 transformation of mouse cells. We now show that specific approximately 55-kDal [35S]methionine-labeled proteins precipitate from primary cultures of midgestation mouse, rat, and hamster embryos on addition of T serum or monoclonal antiserum prepared against the SV40-induced mouse 55-kDal proteins. The two-dimensional maps of the [35S]methionine-labeled tryptic peptides of the mouse, hamster, and rat embryo proteins are similar to the maps of the corresponding proteins from SV40-transformed cells. Primary cells from midgestation mouse, hamster, or rat embryos contain one-third to one-half as much 55-kDal protein as a SV40-transformed mouse fibroblast cell and nearly the same amount as F9 mouse embryonal carcinoma cells. The amount of 55-kDal protein is greatly reduced on replating the mouse, rat, or hamster embryo primary cells. The amount of this protein in mouse embryos is dependent on the stage of the embryo. The embryo proteins are phosphoproteins.