39 research outputs found

    Successful Small Intestine Colonization of Adult Mice by Vibrio cholerae Requires Ketamine Anesthesia and Accessory Toxins

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    Vibrio cholerae colonizes the small intestine of adult C57BL/6 mice. In this study, the physical and genetic parameters that facilitate this colonization were investigated. Successful colonization was found to depend upon anesthesia with ketamine-xylazine and neutralization of stomach acid with sodium bicarbonate, but not streptomycin treatment. A variety of common mouse strains were colonized by O1, O139, and non-O1/non-O139 strains. All combinations of mutants in the genes for hemolysin, the multifunctional, autoprocessing RTX toxin (MARTX), and hemagglutinin/protease were assessed, and it was found that hemolysin and MARTX are each sufficient for colonization after a low dose infection. Overall, this study suggests that, after intragastric inoculation, V. cholerae encounters barriers to infection including an acidic environment and an immediate immune response that is circumvented by sodium bicarbonate and the anti-inflammatory effects of ketamine-xylazine. After initial adherence in the small intestine, the bacteria are subjected to additional clearance mechanisms that are evaded by the independent toxic action of hemolysin or MARTX. Once colonization is established, it is suggested that, in humans, these now persisting bacteria initiate synthesis of the major virulence factors to cause cholera disease. This adult mouse model of intestinal V. cholerae infection, now well-characterized and fully optimized, should serve as a valuable tool for studies of pathogenesis and testing vaccine efficacy

    Constitutive Type VI Secretion System Expression Gives Vibrio cholerae Intra- and Interspecific Competitive Advantages

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    The type VI secretion system (T6SS) mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae – the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria) and a eukaryote (the social amoeba Dictyostelium discoideum). Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.Canadian Institutes of Health Research (Operating Grant MOP-84473)Alberta Heritage Foundation for Medical Research (Alberta Innovates-Health Solutions, Endowment Fund)National Institutes of Health (U.S.) (grant MD001091-01)National Institutes of Health (U.S.) (grant GM068855-02)Olegario V. Rana FellowshipAlberta Heritage Foundation for Medical Research (Alberta Innovates-Health Solutions Graduate Studentships

    Oncoplastic breast reconstruction after IORT

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    Prospective randomized clinical trials have shown that breast-conserving surgery followed by radiotherapy gives equivalent survival rates compared with mastectomy. The indications for breast-conserving therapy in breast cancer are expanding. The integration of oncoplastic surgery techniques with breast-conserving segmentectomy is a new approach that allows more extensive resections and results in more cosmetic favourable outcomes. During the last years we have defined five reconstruction principles in oncoplastic breast-conserving surgery. With these five principles we were able to perform more than 95% of all immediate reconstructions of partial mastectomy defects during breast-conserving surgery, resulting in optimized local and aesthetic outcomes. The oncoplastic reconstruction principles of partial mastectomy defects during breast-conserving surgery are as follows: glandular rotation, dermoglandular rotation, tumoradapted reduction mammoplasty, thoracoepigastric flap, Latissimus dorsi flap. Usually the whole breast is percutaneously irradiated after breast-conserving surgery. Depending on different risk factors, a local boost dose is applied to the tumor bed, which leads to a further reduction of local recurrences. Recently, the concept of intraoperative radiotherapy (IORT) as boost during breast-conserving surgery has been introduced internationally. From a surgical point of view intraoperative boost radiotherapy with a mobile device generating low-energy X-rays (Intrabeam (R)) can be combined with all oncoplastic principles for reconstructing partial mastectomy defects. The advantage of an oncoplastic reconstruction after breast-onserving surgery and IORT boost irradiation should be recommended to improve local outcome, to avoid seroma formation and to improve the cosmetic outcome after treatment

    Emergency department use during pregnancy: a prospective observational study in a single center institution

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    Gynecologists working in emergency department services in hospitals lately have the impression that the number of pregnant women who present themselves because of anxiety or uncertainty is increasing. Hence, the aim of this study was to assess reasons of pregnant women for presenting themselves to an emergency department. Of special interest was how far a diagnosis could be confirmed for the symptoms pregnant women complained about. This is a prospective questionnaire-based study conducted between April 2015 and April 2016 in the Department of Gynecology and Obstetrics of the University Hospital of Cologne. The questionnaire was placed in the waiting area of the emergency department service for pregnant women. Pregnant patients were included with a gestational age of above 20 weeks of gestation. 331 patients were enrolled in this study. The most frequent reason for emergency department use was pain in 28.3% and cervical insufficiency in 19.7% of all cases. 45.6% (n = 151) of the patients had a recommendation of an outpatient practice for presentation to emergency department service. 36.3% (n = 120) of all patients were admitted to hospital for further treatment, 58.6% (n = 194) could be released from hospital. 3.3% (n = 11) of all patients rejected recommended further treatment in hospital. A trend was demonstrated concerning former abortion and hospital admission (p = 0.062). The high amount of patients making nonurgent use of emergency department services indicates potential uncertainty in interpretation of symptoms. Patients with former abortion history were admitted more often to hospital, and therefore need special attention during pregnancy

    Staging for Breast Cancer: A Nationwide Survey about Adherence to Guidelines in German Breast Centers

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    Introduction: The risk for metastasis at primary diagnosis of breast cancer is about 4%. The German guidelines give clear indications on when, who, and how to stage breast cancer patients. Ideally, this should be done via computerized axial tomography (CAT) scan of the thorax and abdomen and an additional bone scan. But daily practice shows that the way health-care providers handle staging recommendations can vary. To objectify adherence to guidelines we started a nation-wide survey. Methods: Between July and September 2020, we sent out a survey via email to all certified and noncertified breast centers and in addition to all Departments of Obstetrics and Gynecology in Germany. We asked for timing of staging, conditions that cause staging, and the applied method. In case we did not get any reply, we sent out a reminder. Results: A total of 220 certified breast centers, 28 noncertified breast centers, and 48 Departments of Obstetrics and Gynecology who care for breast cancer patients took part in our survey. A general pretherapeutic staging was performed in 16.4%, 39.3%, and 66.7% of all institutions and a general postoperative staging was performed in 4.1%, 0%, and 6.3% of each institutional type, respectively. In terms of the applied method, 75% of all certified breast centers used a CAT scan and bone scan, while 23.3% primarily used chest X-ray, ultrasound of the abdomen (27.7%), or MRI. As a potential reason for using X-ray and ultrasound, the presence of a low-risk breast cancer was mentioned. Summary: Although certified breast centers show the highest adherence to current guidelines, some still perform a general staging or do not use the recommended staging method. The low probability of primary metastatic breast cancer and the use of a reasonable exposure to radiation warrant a critical discussion

    Factors Predictive of Sentinel Lymph Node Involvement in Primary Breast Cancer

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    Background/Aim: Sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) for axillary staging in patients with early-stage breast cancer. The need for therapeutic ALND is the subject of ongoing debate especially after the publication of the ACOSOG Z0011 trial. In a retrospective trial with univariate and multivariate analyses, factors predictive of sentinel lymph node involvement should be analyzed in order to define tumor characteristics of breast cancer patients, where SLNB should not be spared to receive important indicators for adjuvant treatment decisions (e.g. thoracic wall irradiation after mastectomy with or without reconstruction). Patients and Methods: Between 2006 and 2010, 1,360 patients with primary breast cancer underwent SLNB withlwithout ALND with evaluation of tumor localization, multicentricity and multifocality, histological subtype, tumor size, grading, lymphovascular invasion (LVI), and estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 status. These characteristics were retrospectively analyzed in univariate and multivariate logistic regression models to define significant predictive factors for sentinel lymph node involvement. The multivariate analysis demonstrated that tumor size and LVI (p<0.001) were independent predictive factors for metastatic sentinel lymph node involvement in patients with early-stage breast cancer. Conclusion: Because of the increased risk for metastatic involvement of axillary sentinel nodes in cases with larger breast cancer or diagnosis of LVI, patients with these breast cancer characteristics should not be spared from SLNB in a clinically node-negative situation in order to avoid falsenegative results with a high potential for wrong indication of primary breast reconstruction or wrong non-indication of necessary post-mastectomy radiation therapy. The prognostic impact of avoidance of axillary staging with SLNB is analyzed in the ongoing prospective INSEMA trial

    GDM Alters Expression of Placental Estrogen Receptor α in a Cell Type and Gender-Specific Manner

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    Objective: The nuclear receptor estrogen receptor α (ERα) is one of the key players in energy balance, insulin resistance, and trophoblast differentiation. We tested the hypothesis that gestational diabetes mellitus (GDM) alters expression of placental ERα in a cell type-specific manner and that this regulation may involve epigenetic changes. Study Design: Expression of ERα was analyzed by immunohistochemistry using the semiquantitative immunoreactive score in 80 placentas (40 GDM/40 controls). Quantitative real-time polymerase chain reaction (PCR) measured ERα messenger RNA (mRNA) in decidual tissue. Methylation-specific PCR was performed to analyze cytosine-phosphatidyl-guanine-island methylation of the ERα promoter. Results: Expression of ERα protein is upregulated (P = .011) in GDM in extravillous trophoblasts but not in syncytiotrophoblast. Gestational diabetes mellitus downregulated ERα in decidual vessels only in pregnancies with male but not female fetuses. Furthermore, mRNA of the ERα encoding gene estrogen receptor gene 1 (ESR1) was increased (+1.77 fold) in GDM decidua when compared to controls (P = .024). In parallel, the promoter of ESR1 was methylated only in decidua of healthy control individuals but not in GDM. Conclusion: Gestational diabetes mellitus affects expression of placental ERα in a cell type-dependent way, on epigenetic level. These data link GDM with epigenetic deregulations of ERα expression and open new insights into the intrauterine programming hypothesis of GDM

    Predictors of sentinel lymph node metastases in breast cancer-radioactivity and Ki-67

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    Objectives: Since the introduction of the sentinel node technique for breast cancer in the 1990s patient's morbidity was reduced. Tracer uptake is known to be dependent from lymph node integrity and activity of macrophages. The aim of this study was to assess whether radioactivity of the tracer can predict sentinel lymph node metastases. Furthermore, a potential association with Ki-67 index was examined. Non-invasive prediction of lymph node metastases could lead to a further decrease of morbidity. Methods: We retrospectively analyzed patients with primary breast cancer who underwent surgery at the Department of Obstetrics and Gynecology in the University Hospital of Cologne between 2012 and 2013. Injection of radioactive tracer was done a day before surgery in the department of Nuclear Medicine. Clinical data and radioactivity of the sentinel node measured the day before and intraoperatively were abstracted from patient's files. Results: Of 246 patients, 64 patients had at least one, five patients had two and one patient had three positive sentinel lymph nodes. Occurrence of sentinel lymph node metastases was not associated with preoperative tracer activity (p = 0,319), intraoperative tracer activity of first sentinel node (p = 0,086) or with loss of tracer activity until operation (p = 0,909). There was no correlation between preoperative Ki-67 index and occurrence of lymph node metastases (p = 0,403). Conclusion: In our cohort, there was no correlation between radioactivity and sentinel node metastases. Tracer uptake might not only be influenced by lymph node metastases and does not predict metastatic lymph node involvement. (C) 2016 Elsevier Ltd. All rights reserved
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