The Fur regulon in anaerobically grown Salmonella enterica sv. Typhimurium: identification of new Fur targets

<p>Abstract</p> <p>Background</p> <p>The Ferric uptake regulator (Fur) is a transcriptional regulator that controls iron homeostasis in bacteria. Although the regulatory role of Fur in <it>Escherichia coli </it>is well characterized, most of the studies were conducted under routine culture conditions, i.e., in ambient oxygen concentration. To reveal potentially novel aspects of the Fur regulon in <it>Salmonella enterica </it>serovar Typhimurium under oxygen conditions similar to that encountered in the host, we compared the transcriptional profiles of the virulent wild-type strain (ATCC 14028s) and its isogenic Δ<it>fur </it>strain under anaerobic conditions.</p> <p>Results</p> <p>Microarray analysis of anaerobically grown Δ<it>fur S</it>. Typhimurium identified 298 differentially expressed genes. Expression of several genes controlled by Fnr and NsrR appeared to be also dependent on Fur. Furthermore, Fur was required for the activity of the cytoplasmic superoxide disumutases (MnSOD and FeSOD). The regulation of FeSOD gene, <it>sodB</it>, occurred via small RNAs (i.e., the <it>ryhB </it>homologs, <it>rfrA </it>and <it>rfrB</it>) with the aid of the RNA chaperone Hfq. The transcription of <it>sodA </it>was increased in Δ<it>fur; </it>however, the enzyme was inactive due to the incorporation of iron instead of manganese in SodA. Additionally, in Δ<it>fur</it>, the expression of the gene coding for the ferritin-like protein (<it>ftnB</it>) was down-regulated, while the transcription of the gene coding for the nitric oxide (NO^·) detoxifying flavohemoglobin (<it>hmpA</it>) was up-regulated. The promoters of <it>ftnB </it>and <it>hmpA </it>do not contain recognized Fur binding motifs, which indicated their probable indirect regulation by Fur. However, Fur activation of <it>ftnB </it>was independent of Fnr. In addition, the expression of the gene coding for the histone-like protein, H-NS (<it>hns</it>) was increased in Δ<it>fur</it>. This may explain the observed down-regulation of the <it>tdc </it>operon, responsible for the anaerobic degradation of threonine, and <it>ftnB </it>in Δ<it>fur</it>.</p> <p>Conclusions</p> <p>This study determined that Fur is a positive factor in <it>ftnB </it>regulation, while serving to repress the expression of <it>hmpA</it>. Furthermore, Fur is required for the proper expression and activation of the antioxidant enzymes, FeSOD and MnSOD. Finally, this work identified twenty-six new targets of Fur regulation, and demonstrates that H-NS repressed genes are down-regulated in Δ<it>fur</it>.</p

Advanced wet-dry cooling tower concept

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering.The purpose of this years' work has been to test and analyze the new dry cooling tower surface previously developed. The model heat transfer test apparatus built last year has been instrumented for temperature, humidity and flow measurement and performance has been measured under a variety of operating conditions. Tower Tests showed approximately 40-50% of the total energy transfer as taking place due to evaporation. This can be compared to approximately 80 to 85% for a conventional wet cooling tower. Comparison of the model tower test results with those of a computer simulation has demonstrated the validity of that simulation and its use as a design tool. Computer predictions have been made for a full-size tower system operating at several locations. Experience with this counterflow model tower has suggested that several design problems may be avoided by blowing the cooling air horizontally through the packing section. This crossflow concept was built from the previous counterflow apparatus and included the design and fabrication of new packing plates. Instrumentation and testing of the counterflow model produced data with an average experimental error of 10%. These results were compared to the predictions of a computer model written for the crossflow configuration. In 14 test runs the predicted total heat transfer differed from the measured total heat transfer by no more than 8% with most runs coming well within 5%. With the computer analogy's validity established, it may now be used to help predict the performance of fullscale wet-dry towers

Outplayed: Regaining Strategic Initiative in the Gray Zone, A Report Sponsored by the Army Capabilities Integration Center in Coordination with Joint Staff J-39/Strategic Multi-Layer Assessment Branch

U.S. competitors pursuing meaningful revision or rejection of the current U.S.-led status quo are employing a host of hybrid methods to advance and secure interests contrary to those of the United States. These challengers employ unique combinations of influence, intimidation, coercion, and aggression to incrementally crowd out effective resistance, establish local or regional advantage, and manipulate risk perceptions in their favor. So far, the United States has not come up with a coherent countervailing approach. It is in this “gray zone”—the awkward and uncomfortable space between traditional conceptions of war and peace—where the United States and its defense enterprise face systemic challenges to U.S. position and authority. Gray zone competition and conflict present fundamental challenges to U.S. and partner security and, consequently, should be important pacers for U.S. defense strategy.https://press.armywarcollege.edu/monographs/1924/thumbnail.jp

Membranous nephropathy and lupus-like syndrome after hematopoietic cell transplantation: a case report

<p>Abstract</p> <p>Introduction</p> <p>The kidney is increasingly recognised as a target organ of chronic graft-versus-host disease after hematopoietic cell transplantation in the context of the development of the nephrotic syndrome. Chronic graft-versus-host disease is associated with autoimmune phenomena similar, but not identical, to those observed in various rheumatologic disorders, implicating autoimmunity as an important component of the disease.</p> <p>Case presentation</p> <p>We report the case of a 57-year-old Caucasian man who developed the nephrotic syndrome due to membranous nephropathy in association with recurrent chronic graft-versus-host disease, along with a lupus-like syndrome manifested with pancytopenia, hair loss, positive anti-DNA antibodies and sub-epithelial and mesangial immune deposits. To the best of our knowledge, this is the first case reported in the literature. The nephrotic syndrome subsided soon after he was treated with a short course of cyclosporin with steroids. Unfortunately he died seven months later due to a relapse of leukemia.</p> <p>Conclusions</p> <p>Our case report confirms the notion that chronic graft-versus-host disease is characterized by the appearance of autoimmune phenomena similar, but not identical, to those seen in autoimmune diseases. The decision for more immunosuppression has to be weighed against the need for preservation of the graft versus leukemia phenomenon.</p

Clinical array-based karyotyping of breast cancer with equivocal HER2 status resolves gene copy number and reveals chromosome 17 complexity

<p>Abstract</p> <p>Background</p> <p><it>HER2 </it>gene copy status, and concomitant administration of trastuzumab (Herceptin), remains one of the best examples of targeted cancer therapy based on understanding the genomic etiology of disease. However, newly diagnosed breast cancer cases with equivocal HER2 results present a challenge for the oncologist who must make treatment decisions despite the patient's unresolved HER2 status. In some cases both immunohistochemistry (IHC) and fluorescence <it>in situ </it>hybridization (FISH) are reported as equivocal, whereas in other cases IHC results and FISH are discordant for positive versus negative results. The recent validation of array-based, molecular karyotyping for clinical oncology testing provides an alternative method for determination of HER2 gene copy number status in cases remaining unresolved by traditional methods.</p> <p>Methods</p> <p>In the current study, DNA extracted from 20 formalin fixed paraffin embedded (FFPE) tissue samples from newly diagnosed cases of invasive ductal carcinoma referred to our laboratory with unresolved HER2 status, were analyzed using a clinically validated genomic array containing 127 probes covering the HER2 amplicon, the pericentromeric regions, and both chromosome 17 arms.</p> <p>Results</p> <p>Array-based comparative genomic hybridization (array CGH) analysis of chromosome 17 resolved HER2 gene status in [20/20] (100%) of cases and revealed additional chromosome 17 copy number changes in [18/20] (90%) of cases. Array CGH analysis also revealed two false positives and one false negative by FISH due to "ratio skewing" caused by chromosomal gains and losses in the centromeric region. All cases with complex rearrangements of chromosome 17 showed genome-wide chromosomal instability.</p> <p>Conclusions</p> <p>These results illustrate the analytical power of array-based genomic analysis as a clinical laboratory technique for resolution of HER2 status in breast cancer cases with equivocal results. The frequency of complex chromosome 17 abnormalities in these cases suggests that the two probe FISH interphase analysis is inadequate and results interpreted using the HER2/CEP17 ratio should be reported "with caution" when the presence of centromeric amplification or monosomy is suspected by FISH signal gains or losses. The presence of these pericentromeric copy number changes may result in artificial skewing of the HER2/CEP17 ratio towards false negative or false positive results in breast cancer with chromosome 17 complexity. Full genomic analysis should be considered in all cases with complex chromosome 17 aneusomy as these cases are likely to have genome-wide instability, amplifications, and a poor prognosis.</p

LgG4 immunostaining and its implications in orbital inflammatory disease

OBJECTIVE: IgG4-related disease is an emerging clinical entity which frequently involves tissue within the orbit. In order to appreciate the implications of IgG4 immunostaining, we analyzed gene expression and the prevalence of IgG4- immunostaining among subjects with orbital inflammatory diseases. METHODS: We organized an international consortium to collect orbital biopsies from 108 subjects including 22 with no known orbital disease, 42 with nonspecific orbital inflammatory disease (NSOI), 26 with thyroid eye disease (TED), 12 with sarcoidosis, and 6 with granulomatosis with polyangiitis (GPA). Lacrimal gland and orbital adipose tissue biopsies were immunostained for IgG4 or IgG secreting plasma cells. RNA transcripts were quantified by Affymetrix arrays. RESULTS: None of the healthy controls or subjects with TED had substantial IgG4 staining. Among the 63 others, the prevalence of significant IgG4-immunostaining ranged from 11 to 39% depending on the definition for significant. IgG4 staining was detectable in the majority of tissues from subjects with GPA and less commonly in tissue from subjects with sarcoidosis or NSOI. The detection of IgG4+ cells correlated with inflammation in the lacrimal gland based on histology. IgG4 staining tissue expressed an increase in transcripts associated with inflammation, especially B cell-related genes. Functional annotation analysis confirmed this. CONCLUSION: IgG4+ plasma cells are common in orbital tissue from patients with sarcoidosis, GPA, or NSOI. Even using the low threshold of 10 IgG4+ cells/high powered field, IgG4 staining correlates with increased inflammation in the lacrimal gland based on histology and gene expression.Amanda J. Wong .. Dinesh Selva ... et al