Estimation of biological variance in coherent Raman microscopy data of two cell lines using chemometrics.

Broadband Coherent Anti-Stokes Raman Scattering (BCARS) is a valuable spectroscopic imaging tool for visualizing cellular structures and lipid distributions in biomedical applications. However, the inevitable biological changes in the samples (cells/tissues/lipids) introduce spectral variations in BCARS data and make analysis challenging. In this work, we conducted a systematic study to estimate the biological variance in BCARS data of two commonly used cell lines (HEK293 and HepG2) in biomedical research. The BCARS data were acquired from two different experimental setups (Leibniz Institute of Photonics Technology (IPHT) in Jena and Politecnico di Milano (POLIMI) in Milano) to evaluate the reproducibility of results. Also, spontaneous Raman data were independently acquired at POLIMI to validate those results. First, Kramers-Kronig (KK) algorithm was utilized to retrieve Raman-like signals from the BCARS data, and a pre-processing pipeline was subsequently used to standardize the data. Principal component analysis - Linear discriminant analysis (PCA-LDA) was performed using two cross-validation (CV) methods: batch-out CV and 10-fold CV. Additionally, the analysis was repeated, considering different spectral regions of the data as input to the PCA-LDA. Finally, the classification accuracies of the two BCARS datasets were compared with the results of spontaneous Raman data. The results demonstrated that the CH band region (2770-3070 cm-1) and spectral data in the 1500-1800 cm-1 region have significantly contributed to the classification. A maximum of 100% balanced accuracies were obtained for the 10-fold CV for both BCARS setups. However, in the case of batch-out CV, it is 92.4% for the IPHT dataset and 98.8% for the POLIMI dataset. This study offers a comprehensive overview for estimating biological variance in biomedical applications. The insights gained from this analysis hold promise for improving the reliability of BCARS measurements in biomedical applications, paving the way for more accurate and meaningful spectroscopic analyses in the study of biological systems.

GH136-encoding gene (perB) is involved in gut colonization and persistence by Bifidobacterium bifidum PRL2010.

Bifidobacteria are commensal microorganisms that typically inhabit the mammalian gut, including that of humans. As they may be vertically transmitted, they commonly colonize the human intestine from the very first day following birth and may persist until adulthood and old age, although generally at a reduced relative abundance and prevalence compared to infancy. The ability of bifidobacteria to persist in the human intestinal environment has been attributed to genes involved in adhesion to epithelial cells and the encoding of complex carbohydrate-degrading enzymes. Recently, a putative mucin-degrading glycosyl hydrolase belonging to the GH136 family and encoded by the perB gene has been implicated in gut persistence of certain bifidobacterial strains. In the current study, to better characterize the function of this gene, a comparative genomic analysis was performed, revealing the presence of perB homologues in just eight bifidobacterial species known to colonize the human gut, including Bifidobacterium bifidum and Bifidobacterium longum subsp. longum strains, or in non-human primates. Mucin-mediated growth and adhesion to human intestinal cells, in addition to a rodent model colonization assay, were performed using B. bifidum PRL2010 as a perB prototype and its isogenic perB-insertion mutant. These results demonstrate that perB inactivation reduces the ability of B. bifidum PRL2010 to grow on and adhere to mucin, as well as to persist in the rodent gut niche. These results corroborate the notion that the perB gene is one of the genetic determinants involved in the persistence of B. bifidum PRL2010 in the human gut.

Interaction Between Diet and Microbiota in the Pathophysiology of Alzheimer's Disease: Focus on Polyphenols and Dietary Fibers.

Animal studies increasingly indicate that the gut microbiota composition and function can be involved in the pathophysiology and progression of Alzheimer's disease (AD) at multiple levels. However, few studies have investigated this putative gut-brain axis in human beings, and none of them considered diet as a determinant of intestinal microbiota composition. Epidemiological studies highlight that a high intake of fruit and vegetables, such as that typical of the Mediterranean diet, can modulate AD progression. Thus, nutritional interventions are being increasingly studied as a possible non-pharmacological strategy to slow down the progression of AD. In particular, polyphenols and fibers represent the nutritional compounds with the higher potential of counterbalancing the pathophysiological mechanisms of dementia due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. These actions are mediated by the gut microbiota, that can transform polyphenols and fibers into biologically active compounds including, among others, phenyl-γ-valerolactones, urolithins, butyrate, and other short-chain fatty acids. In this review, the complex mechanisms linking nutrition, gut microbiota composition, and pathophysiology of cognitive decline in AD are discussed, with a particular focus on the role of polyphenols and fibers. The gaps between pre-clinical and clinical studies are particularly emphasized, as well as the urgent need for studies comprehensively evaluating the link between nutrition, microbiome, and clinical aspects of AD.

Gastric microbiota composition in patients with corpus atrophic gastritis.

BACKGROUND: In corpus atrophic gastritis (CAG), hypochlorhydria makes plausible the overgrowth of intragastric bacteria, whose role in gastric carcinogenesis is under debate. AIMS: To characterize the antrum/corpus composition of the gastric bacterial microbiota in CAG patients compared to controls without CAG. METHODS: A cross-sectional monocentric study on consecutive patients with known histological diagnosis of CAG undergoing gastroscopy for gastric cancer surveillance and patients without CAG undergoing gastroscopy for dyspepsia or anemia (108 biopsies from 55 patients, median age 61.5). Genomic DNA from one antral and one corpus biopsy from each case (n = 23) and control (n = 32) was extracted. Gastric microbiota was assessed by sequencing hypervariable regions of the 16SrRNA gene. RESULTS: Bacterial abundance and diversity were significantly lower in CAG cases than in controls (p < 0.001). Firmicutes were more frequent in cases, Bacteroidetes and Fusobacteria in controls (p < 0.0001). Streptococcaceae were more abundant in cases (p < 0.0001), Prevotellaceae in controls (p < 0.0001). The genus Streptococcus was positively correlated with severe OLGA/OLGIM stages linked to a higher risk of gastric cancer. CONCLUSION: Gastric bacterial microbiota in CAG showed a reduced abundance and complexity but was characterized by higher colonization of Firmicutes, in particular Streptococcus, increased in subjects with severe atrophy/metaplasia stages at higher risk of gastric cancer.

Impact of Extreme Obesity and Diet-Induced Weight Loss on the Fecal Metabolome and Gut Microbiota.

SCOPE: A limited number of human studies have characterized fecal microbiota and metabolome in extreme obesity and after diet-induced weight loss. METHODS AND RESULTS: Fecal samples from normal-weight and extremely obese adults and from obese participants before and after moderate diet-induced weight loss are evaluated for their interaction with the intestinal adenocarcinoma cell line HT29 using an impedance-based in vitro model, which reveals variations in the interaction between the gut microbiota and host linked to obesity status. Microbiota composition, short chain fatty acids, and other intestinal metabolites are further analyzed to assess the interplay among diet, gut microbiota, and host in extreme obesity. Microbiota profiles are distinct between normal-weight and obese participants and are accompanied by fecal signatures in the metabolism of biliary compounds and catecholamines. Moderate diet-induced weight loss promotes shifts in the gut microbiota, and the primary fecal metabolomics features are associated with diet and the gut-liver and gut-brain axes. CONCLUSIONS: Analyses of the fecal microbiota and metabolome enable assessment of the impact of diet on gut microbiota composition and activity, supporting the potential use of certain fecal metabolites or members of the gut microbiota as biomarkers for the efficacy of weight loss in extreme obesity.

Assessing the Genomic Variability of Gardnerella vaginalis through Comparative Genomic Analyses: Evolutionary and Ecological Implications.

Gardnerella vaginalis is described as a common anaerobic vaginal bacterium whose presence may correlate with vaginal dysbiotic conditions. In the current study, we performed phylogenomic analyses of 72 G. vaginalis genome sequences, revealing noteworthy genome differences underlying a polyphyletic organization of this taxon. Particularly, the genomic survey revealed that this species may actually include nine distinct genotypes (GGtype1 to GGtype9). Furthermore, the observed link between sialidase and phylogenomic grouping provided clues of a connection between virulence potential and the evolutionary history of this microbial taxon. Specifically, based on the outcomes of these in silico analyses, GGtype3, GGtype7, GGtype8, and GGtype9 appear to have virulence potential since they exhibited the sialidase gene in their genomes. Notably, the analysis of 34 publicly available vaginal metagenomic samples allowed us to trace the distribution of the nine G. vaginalis genotypes identified in this study among the human population, highlighting how differences in genetic makeup could be related to specific ecological properties. Furthermore, comparative genomic analyses provided details about the G. vaginalis pan- and core genome contents, including putative genetic elements involved in the adaptation to the ecological niche as well as many putative virulence factors. Among these putative virulence factors, particularly noteworthy genes identified were the gene encoding cholesterol-dependent cytolysin (CDC) toxin vaginolysin and genes related to microbial biofilm formation, iron uptake, adhesion to the vaginal epithelium, as well as macrolide antibiotic resistance.IMPORTANCE The identification of nine different genotypes among members of G. vaginalis allowed us to distinguish an uneven distribution of virulence-associated genetic traits within this taxon and thus suggest the potential occurrence of putative pathogen and commensal G. vaginalis strains. These findings, coupled with metagenomics microbial profiling of human vaginal microbiota, permitted us to get insights into the distribution of the genotypes among the human population, highlighting the presence of different structural communities in terms of G. vaginalis genotypes.

Microbiota and Cancer: The Emerging Beneficial Role of Bifidobacteria in Cancer Immunotherapy.

Many intestinal bacteria are believed to be involved in various inflammatory and immune processes that influence tumor etiology because of their metabolic properties and their ability to alter the microbiota homeostasis. Although many functions of the microbiota are still unclear, there is compelling experimental evidence showing that the intestinal microbiota is able to modulate carcinogenesis and the response to anticancer therapies, both in the intestinal tract and other body sites. Among the wide variety of gut-colonizing microorganisms, various species belonging to the Bifidobacterium genus are believed to elicit beneficial effects on human physiology and on the host-immune system. Recent findings, based on preclinical mouse models and on human clinical trials, have demonstrated the impact of gut commensals including bifidobacteria on the efficacy of tumor-targeting immunotherapy. Although the underlying molecular mechanisms remain obscure, bifidobacteria and other microorganisms have become a promising aid to immunotherapeutic procedures that are currently applied to treat cancer. The present review focuses on strategies to recruit the microbiome in order to enhance anticancer responses and develop therapies aimed at fighting the onset and progression of malignancies.

A systematic review of contralateral carotid stenosis progression after carotid endarterectomy.

OBJECTIVE: Progression of contralateral carotid artery stenosis after carotid endarterectomy (CEA) has been described by several authors. The aim of this study is to determine such disease progression and its related transient ischemic attacks (TIAs) or strokes by reviewing the existing literature. METHODS: We performed a systematic literature review to select randomized controlled trials and observational studies reporting outcomes of patients treated by CEA and with concomitant contralateral carotid stenosis, regardless its degree of stenosis. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO registration number: CRD42019127595). The primary study end point was the progression of contralateral carotid artery stenosis after CEA, and the secondary end point was incidence of TIAs and strokes owing to contralateral carotid stenosis. RESULTS: Seventeen studies were retrieved, reporting data on a total of 7679 patients who had undergone CEA, in particular they were one post hoc analysis of a randomized controlled trial, nine prospective, and seven retrospective observational studies. Among these patients, follow-up information on the contralateral carotid artery was available for 5454 cases. Disease progression was observed in 18% of patients: single class progression from mild (<50%) and from moderate (50%-70%) stenosis was observed in 15% and 23% of cases, respectively. We found 105 TIAs (4%) and 88 strokes (3%) among 2781 patients with stenosis progression, based on result from 11 studies. CONCLUSIONS: We found a progression of contralateral carotid stenosis in a significant number of patients treated with CEA and with baseline carotid stenosis. This systematic literature review suggests that patients with moderate contralateral carotid stenosis demonstrate more rapid progression to significant or symptomatic stenosis than patients with mild contralateral stenosis.

Untangling Species-Level Composition of Complex Bacterial Communities through a Novel Metagenomic Approach.

16S small-subunit (SSU) rRNA gene-based bacterial profiling is the gold standard for cost-effective taxonomic reconstruction of complex bacterial populations down to the genus level. However, it has been proven ineffective in clinical and research settings requiring higher taxonomic resolution. We therefore developed a bacterial profiling method based on the internal transcribed spacer (ITS) region employing optimized primers and a comprehensive ITS database for accurate cataloguing of bacterial communities at (sub)species resolution. Performance of the microbial ITS profiling pipeline was tested through analysis of host-associated, food, and environmental matrices, while its efficacy in clinical settings was assessed through analysis of mucosal biopsy specimens of colorectal cancer, leading to the identification of putative novel biomarkers. The data collected indicate that the proposed pipeline represents a major step forward in cost-effective identification and screening of microbial biomarkers at (sub)species level, with relevant impact in research, industrial, and clinical settings.IMPORTANCE We developed a novel method for accurate cataloguing of bacterial communities at (sub)species level involving amplification of the internal transcribed spacer (ITS) region through optimized primers, followed by next-generation sequencing and taxonomic classification of amplicons by means of a comprehensive database of bacterial ITS sequences. Host-associated, food, and environmental matrices were employed to test the performance of the microbial ITS profiling pipeline. Moreover, mucosal biopsy samples from colorectal cancer patients were analyzed to demonstrate the scientific relevance of this profiling approach in a clinical setting through identification of putative novel biomarkers. The results indicate that the ITS-based profiling pipeline proposed here represents a key metagenomic tool with major relevance for research, industrial, and clinical settings.

Multimodal Neurophysiological Monitoring Reduces Shunt Incidence during Carotid Endarterectomy.

BACKGROUND: The use of shunt during carotid surgery is controversial. Different experiences are found in literature with transcranial Doppler (TCD), electroencephalogram (EEG), stump pressure (SP), and somatosensorial evoked potentials (SSEP). METHODS: We realized a retrospective analysis of patients treated with carotid endarterectomy in our unit in the last 2 years. We use several cerebral monitoring: until 2017 we preferred SP + TCD, and, if not available, EEG. Since 2017 we introduced EEG with SSEP, always in association with SP. We analyzed those 2 groups of patients: before and after introduction of EEG with SSEP. RESULTS: From January 2016 to December 2018 we performed 156 carotid revascularizations. In the first group of 93 patients treated under combined SP + TCD (or EEG), we observed 1 stroke (1.1%) and 2 transient ischemic attacks (TIAs) (2.1%); we selectively used a shunt in 21 cases (22.5%). In the second group, 63 patients had an SP + EEG with SSEP monitoring; we observed 1 stroke (1.5%) and 2 TIAs (3.1%), a shunt was necessary in 12 cases (12.9%). CONCLUSIONS: In our experience, EEG with SSEP represents an effective parameter to indicate shunt positioning, as we were able to reduce its use, with the same incidence of stroke and TIA.

The human gallbladder microbiome is related to the physiological state and the biliary metabolic profile.

BACKGROUND: The microbial populations of the human intestinal tract and their relationship to specific diseases have been extensively studied during the last decade. However, the characterization of the human bile microbiota as a whole has been hampered by difficulties in accessing biological samples and the lack of adequate methodologies to assess molecular studies. Although a few reports have described the biliary microbiota in some hepatobiliary diseases, the bile microbiota of healthy individuals has not been described. With this in mind, the goal of the present study was to generate fundamental knowledge on the composition and activity of the human bile microbiota, as well as establishing its potential relationship with human bile-related disorders. RESULTS: Human bile samples from the gallbladder of individuals from a control group, without any record of hepatobiliary disorder, were obtained from liver donors during liver transplantation surgery. A bile DNA extraction method was optimized together with a quantitative PCR (qPCR) assay for determining the bacterial load. This allows the selection of samples to perform functional metagenomic analysis. Bile samples from the gallbladder of individuals suffering from lithiasis were collected during gallbladder resection and the microbial profiles assessed, using a 16S rRNA gene-based sequencing analysis, and compared with those of the control group. Additionally, the metabolic profile of the samples was analyzed by nuclear magnetic resonance (NMR). We detected, for the first time, bacterial communities in gallbladder samples of individuals without any hepatobiliary pathology. In the biliary microecosystem, the main bacterial phyla were represented by Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. Significant differences in the relative abundance of different taxa of both groups were found. Sequences belonging to the family Propionibacteriaceae were more abundant in bile samples from control subjects; meanwhile, in patients with cholelithiasis members of the families Bacteroidaceae, Prevotellaceae, Porphyromonadaceae, and Veillonellaceae were more frequently detected. Furthermore, the metabolomics analysis showed that the two study groups have different metabolic profiles. CONCLUSIONS: Our results indicate that the gallbladder of human individuals, without diagnosed hepatobiliary pathology, harbors a microbial ecosystem that is described for the first time in this study. Its bacterial representatives and metabolites are different from those detected in people suffering from cholelithiasis. In this regard, since liver donors have been subjected to the specific conditions of the hospital's intensive care unit, including an antibiotic treatment, we must be cautious in stating that their bile samples contain a physiologically normal biliary microbiome. In any case, our results open up new possibilities to discover bacterial functions in a microbial ecosystem that has not previously been explored.

Exploring the effects of COLOSTRONONI on the mammalian gut microbiota composition.

COLOSTRONONI is a dietary supplement consisting of bovine colostrum and Morinda citrifolia fruit (Noni). In this study, we tested the capability of COLOSTRONONI to influence gut microbiota composition using an in vivo evaluation in rats. Furthermore, we analyzed the effect of COLOSTRONONI on the systemic inflammatory responses as well as on the gut permeability of the animals. Altogether, our analyses supported the concept of COLOSTRONONI as a natural food supplement that doesn't affect (neither negatively nor positively) gut microbiota homeostasis in healthy conditions. Moreover, COLOSTRONONI highlighted a lower effect in the expression of genes coding for IL-10, Il-12 and TNF-α response allowing us to hypothesize an immunomodulatory activity of this dietary supplement.

Influence of earthquakes on the occurrence of aortic aneurysm ruptures.

BACKGROUND: Catastrophic events have been correlated to increased incidence of cardio-vascular events, but no correlation between RAA and seismic activities have ever been investigated. METHODS: Hospital admissions related to RAA between January 2014 and December 2016 were retrospectively assessed in nine vascular centers of central Italy and correlated with date-matched seismic events. Correlation between RAA presentation and seismic event was first evaluated by Linear Regression analysis. Incidence of RAA events, mortality rate, and type of intervention were analyzed during seismic days (SD) and compared to outcomes during non-seismic days (nSD). RESULTS: A total of 376 patients were admitted with a diagnosis of RAA, and a total of 783 seismic events were reviewed. Twenty patients died before intervention (untreated). Open surgery was performed in 72.8%, endovascular treatment in 27.2%. General mortality at 30 days was 26.6% (30.5% for open surgery; 21.6% for endovascular treatment; P=0.24). Linear regression analysis between RAA and seismic periods revealed a significant correlation (slope=0.11±0.04, equation: y = 0.1143 x + 3.034, P=0.02). Incidence of RAA was 0.34 event per day during the entire period, 0.32 during nSD and 0.44 during SD (P=0.006). During seismic days, patients with RAA were older (80.5 years during SD vs. 77 years during nSD, P=0.12), were in poorer general condition at admission and remained untreated more frequently (8% SD vs. 4.7% nSD, P=0.3), and had a higher mortality rate at 30 days (46.2% SD vs. 27.2% nSD, P=0.012). CONCLUSIONS: During seismic days, the incidence of RAA is higher in comparison to non-seismic days. Patients with rupture during seismic days have a higher risk of death.

Endovenous Laser Ablation with 1,470-nm Diode with Tumescence Anesthesia and Saphenofemoral Ligation: Propensity Score Match Comparison.

BACKGROUND: The aim of this study is to compare 2 groups of patients treated for great saphenous vein (GSV) reflux with open surgical saphenofemoral ligation (SFL) and endovenous laser ablation (EVLA). METHODS: Consecutive patients with primary unilateral GSV reflux undergoing EVLA treatment since 2014 were enrolled, and another series of patients treated with SFL was considered. The patients were stratified according to treatment and the results were compared using the propensity score (1:1). The covariables were age, gender, body mass index, CEAP (Clinical class, Etiology, Anatomy and Pathophysiology) staging, and GSV and saphenofemoral junction diameters. Primary outcomes were GSV occlusion or recurrent groin varicose veins at 1 year after treatment. Secondary outcomes included vein thrombosis, hyperpigmentation, paresthesia, postoperative pain, analgesic requirement, and ecchymosis assessed at discharge and CEAP stage and quality of life (QoL) assessment 1 month after surgery. RESULTS: A total of 123 patients were included in the study: 59 were treated with EVLA and 64 with SFL. At 12 months, we observed 10 recurrent groin varicose veins after SFL (15.6%) and 6 GSV recanalization after EVLA (10.2%, P = 0.369). Extra-saphenous recurrent varicose veins were observed in 36 patients (29.3%): 20 in the open group (31.2%) and 16 in EVLA group (27.1%, P = 0.615). After matching procedure 74 patients were analyzed (37 patients by group), logistic regression model showed that the risk of outcome was not associated with the surgical treatment (odds ratio 1.76, 95% confidence interval 0.52-6.01). CONCLUSIONS: Both techniques to treat saphenous impairment have demonstrated to be safe, with good results in terms of efficacy and symptomatic improvement at follow-up. EVLA with 1,470 nm seems to have lower rates of recurrence and good perceived QoL. Tumescent anesthesia is a good option with good results and may be extended to open surgical ligation.

Inflammation and myointimal hyperplasia. Correlation with hemodynamic forces.

OBJECTIVES: The aim of our study was to correlate flow dynamics and the release of inflammatory cytokines Interleukin 1, 2, 6, TNF (Tumour Necrosis Factor) alfa, both in vitro and in vivo. MATERIALS AND METHODS: Endothelial cells were exposed to laminar flow (6dyne/cm2) in an in vitro circulatory system and the release of Interleukin 1, 2, 6 and TNF alfa was quantified by ELISA. Interleukin 1, 2, 6 and TNF alfa release was also assessed in vein grafts implanted in the arterial circulation of Lewis rats. Arterial vein grafts were explanted at different time intervals from 3days to 12weeks after surgery. Vein grafts implanted in the arterial circulation for 4weeks, were re implanted in the venous circulation of syngenic Lewis rats, and the release of Interleukin 1, 2, 6 and TNF alfa, was assessed in an organ culture. Six vein grafts (4 occluded, 2 patent) implanted in humans as femorodistal bypass were examined for the presence of myointimal hyperplasia and perigraft inflammatory cells. RESULTS: In vitro, endothelial cells exposed to laminar flow released an increased amount of Interleukin 1, 2, 6 and TNF alfa in comparison to endothelial cells not exposed to flow. In experimental vein grafts implanted in the arterial circulation there was an increased release of inflammatory cytokines associated to inflammatory changes in the adventitia. Once the vein grafts were re implanted in the venous circulation, the release of these cytokines diminished, while the inflammatory changes in the adventitia regressed. CONCLUSIONS: Increased shear stress induces release of cytokines and inflammatory changes in the adventitia. These inflammatory changes can contribute to plaque progression and to un stable plaque. These findings support the use of anti-inflammatory therapy in patients prone to develop atherosclerosis and in those who had arterial reconstructive surgery.

Mucosal microbiota of intestinal polyps reveals putative biomarkers of colorectal cancer.

The human intestine retains a complex microbial ecosystem, which performs crucial functions that impact on host health. Several studies have indicated that intestinal dysbiosis may impact on the establishment of life-threatening intestinal diseases such as colorectal cancer. An adenomatous polyp is the result of abnormal tissue growth, which is benign but is considered to be associated with a high risk of developing colorectal cancer, based on its grade of dysplasia. Development of diagnostic tools that are based on surveying the gut microbiota and are aimed at early detection of colorectal cancer represent highly desirable target. For this purpose, we performed a pilot study in which we applied a metataxonomic analysis based on 16S rRNA gene sequencing approach to unveil the composition of microbial communities of intestinal polyps. Moreover, we performed a meta-analysis involving the reconstructed microbiota composition of adenomatous polyps and publicly available metagenomics datasets of colorectal cancer. These analyses allowed the identification of microbial taxa such as Faecalibacterium, Bacteroides and Romboutsia, which appear to be depleted in cancerogenic mucosa as well as in adenomatous polyps, thus representing novel microbial biomarkers associated with early tumor formation. Furthermore, an absolute quantification of Fusubacterium nucleatum in polyps further compounded the important role of this microorganism as a valuable putative microbial biomarker for early diagnosis of colorectal cancer.

Fecal microbiota profile in a group of myasthenia gravis patients.

The intestinal microbiota plays a key role in the maintenance of human health. Alterations in this microbiota have been described in several autoimmune diseases, including nervous system diseases. Nevertheless, the information regarding neuromuscular conditions is still limited. In this study, we aimed at characterizing the intestinal microbiota composition in myasthenia gravis patients (MG). To this end fecal samples were taken from ten patients, with antibodies against the acetylcholine receptor, and ten age and sex matched controls from the same population (Asturias region, Spain). Fecal samples were submitted to microbiota analyses by 16S rRNA gene profiling, bifidobacterial ITS-region profiling and qPCR. The fecal levels of short chain fatty acids were determined by gas chromatography. MG patients were found to harbor lower relative proportions of Verrucomicrobiaceae and Bifidobacteriaceae, among others, and increased of the phylum Bacteroidetes and the family Desulfovibrionaceae. The increase of these latter microbial groups was also confirmed at quantitative level by qPCR. In contrast, no statistically significant differences were found between MG patients and the control group in the bifidobacterial population at the species level or in short chain fatty acids profiles. Our data indicates an altered fecal microbiota pattern in MG patients and point out at specific microbiota targets for intervention in this population.

Characterization and induction of prophages in human gut-associated Bifidobacterium hosts.

In the current report, we describe the identification of three genetically distinct groups of prophages integrated into three different chromosomal sites of human gut-associated Bifidobacterium breve and Bifidobacterium longum strains. These bifidobacterial prophages are distantly related to temperate actinobacteriophages of several hosts. Some prophages, integrated within the dnaJ2 gene, are competent for induction, excision, replication, assembly and lysis, suggesting that they are fully functional and can generate infectious particles, even though permissive hosts have not yet been identified. Interestingly, several of these phages harbor a putative phase variation shufflon (the Rin system) that generates variation of the tail-associated receptor binding protein (RBP). Unlike the analogous coliphage-associated shufflon Min, or simpler Cin and Gin inversion systems, Rin is predicted to use a tyrosine recombinase to promote inversion, the first reported phage-encoded tyrosine-family DNA invertase. The identification of bifidobacterial prophages with RBP diversification systems that are competent for assembly and lysis, yet fail to propagate lytically under laboratory conditions, suggests dynamic evolution of bifidobacteria and their phages in the human gut.

The Debatable Choice of Iliac Inflow Source for Redo Femoropopliteal and Infrapopliteal Bypass.

BACKGROUND: Redo area region operation is associated with a significant morbidity such as neurovascular injury, infection, and lymphorrhea. The traditional management of occluded femoropopliteal grafts often includes redissection of a scarred groin to obtain adequate inflow via the common femoral artery. These procedures are more technically demanding and require more expertise and judgment than the primary operation. We describe a case of using the ipsilateral iliac branch prosthesis of aortobifemoral bypass as inflow for iliac-peroneal bypass, avoiding the previous groin incisions, to minimize the local complications related to a redo groin dissection and to decrease the operative time required to obtain an adequate inflow source. CASE REPORT: An 86-year-old man was referred to our hospital with severe pain in the right lower extremity one day before the present admission. He underwent aortobifemoral bypass for Leriché syndrome, in our department, 10 years before the present admission. Eight and 9 years later, a femoral popliteal suprageniculate bypass and jump to deep femoral artery bypass (when femoropopliteal bypass was occluded) were performed with 6-mm polytetrafluoroethylene grafts, both in some other institution. The patient's right foot was colder than the left, and he had some difficulty with movement. Absence of signal Doppler continous wave at right tibial vessels was recorded (category IIA of Rutherford classification for acute limb ischemia). Computed tomography (CT) confirmed the following duplex ultrasound (US) findings: occlusion of the femoral graft and popliteal artery below the knee and preocclusive stenosis of deep femoral artery with patency of aortobifemoral bypass and peroneal artery. Taking into consideration the multiple groin scars and the occlusion of superficial femoral and popliteal arteries and preocclusive lesion of deep femoral artery, we decided to perform a sequential composite and extra anatomical bypass from the right iliac prosthesis to the peroneal artery, with graft tunnellization through the lateral groin subfascial layer. The proximal component of the graft was made with a 6-mm Dacron prosthesis routed through a suprasartorial tunnel from iliac prosthesis to the proximal great saphenous vein. Proximal anastomosis was performed in a conventional side-to-end fashion. A tunnel was created between the abdominal flank incision and the median prosthesis-vein anastomosis of the bypass under inguinal ligament laterally with respect to femoral vessels, in lateral to median route, avoiding groin scars. The vein segment was orientated in a nonreversed format, with a LeMaitre Valvulotome to secure antegrade flow. The intermediate anastomosis was performed in an end-to-end way, whereas the distal anastomosis was carried out between the vein and peroneal artery in a conventional end-to-side fashion. Immediate intraoperative and postoperative assessments of graft patency were carried out with angiography and hand-held Doppler examination, respectively. Duplex US scan was used for graft surveillance at regular intervals up to 12 months after surgery. The patient recovered at 12 months postoperatively, and the CT imaging demonstrated the good patency of the entire graft. CONCLUSION: We believe that the external iliac artery (or prosthesis such as in our case) inflow should be considered selectively rather than preferentially, mostly in the subset of patients selected for reoperative distal bypass.