89 research outputs found

    Mycobacterium tuberculosis Rv3586 (DacA) Is a Diadenylate Cyclase That Converts ATP or ADP into c-di-AMP

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    Cyclic diguanosine monophosphate (c-di-GMP) and cyclic diadenosine monophosphate (c-di-AMP) are recently identified signaling molecules. c-di-GMP has been shown to play important roles in bacterial pathogenesis, whereas information about c-di-AMP remains very limited. Mycobacterium tuberculosis Rv3586 (DacA), which is an ortholog of Bacillus subtilis DisA, is a putative diadenylate cyclase. In this study, we determined the enzymatic activity of DacA in vitro using high-performance liquid chromatography (HPLC), mass spectrometry (MS) and thin layer chromatography (TLC). Our results showed that DacA was mainly a diadenylate cyclase, which resembles DisA. In addition, DacA also exhibited residual ATPase and ADPase in vitro. Among the potential substrates tested, DacA was able to utilize both ATP and ADP, but not AMP, pApA, c-di-AMP or GTP. By using gel filtration and analytical ultracentrifugation, we further demonstrated that DacA existed as an octamer, with the N-terminal domain contributing to tetramerization and the C-terminal domain providing additional dimerization. Both the N-terminal and the C-terminal domains were essential for the DacA's enzymatically active conformation. The diadenylate cyclase activity of DacA was dependent on divalent metal ions such as Mg2+, Mn2+ or Co2+. DacA was more active at a basic pH rather than at an acidic pH. The conserved RHR motif in DacA was essential for interacting with ATP, and mutation of this motif to AAA completely abolished DacA's diadenylate cyclase activity. These results provide the molecular basis for designating DacA as a diadenylate cyclase. Our future studies will explore the biological function of this enzyme in M. tuberculosis

    Extended abdominoperineal resection in women: the barbadian experience

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    BACKGROUND AND OBJECTIVES: We report our results of a selective approach to primary direct appositional vaginal repair versus transverse rectus abdominis flap repair (TRAM) in patients with extensive rectal/anal cancer or in cases with primary cancer of cervix, vagina or vulva involving the anal canal and anal sphincters. METHODS: Eighteen female patients (mean age: 62.9 years; range: 44–81 years) with a median follow-up of 14 months (range: 2–36 months) undergoing extended abdominoperineal reconstruction with total mesorectal excision between May 2002 and September 2005, were studied. RESULTS: Twelve patients underwent an extended abdominoperineal resection with hysterectomy and vaginectomy, with 6 patients undergoing primary TRAM flap reconstruction following pelvic exenteration. Exenterative procedures were performed in 2 cases of primary vaginal cancer, following Wertheim hysterectomy for carcinoma of the cervix with recurrence after radiation and in 2 further cases of anal cancer with extensive pelvic recurrence after primary chemoradiation. Fifteen cases are alive on follow-up with no evidence of disease; 2 patients who had recurrent carcinoma of the cervix and who underwent TRAM flap reconstruction, have recurrent disease after 5 and 6 months of follow-up, respectively. DISCUSSION: Our experience shows that careful primary closure of an extended abdominoperineal resection wound is effective and safe. Our one case of wound breakdown after primary repair underwent external beam and intracavitary irradiation primarily with wound breakdown of a primary repair followed by a delayed pedicled graciloplasty. TRAM flap reconstruction has been reserved in our unit for patients undergoing total pelvic extenteration. In general, we would recommend the use of TRAM flap reconstruction in younger sexually active patients where there has been external irradiation combined with brachytherapy

    Successful Shortening of Tuberculosis Treatment Using Adjuvant Host-Directed Therapy with FDA-Approved Phosphodiesterase Inhibitors in the Mouse Model

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    Global control of tuberculosis (TB), an infectious disease that claims nearly 2 million lives annually, is hindered by the long duration of chemotherapy required for curative treatment. Lack of adherence to this intense treatment regimen leads to poor patient outcomes, development of new or additional drug resistance, and continued spread of M.tb. within communities. Hence, shortening the duration of TB therapy could increase drug adherence and cure in TB patients. Here, we report that addition of the United Stated Food and Drug Administration-approved phosphodiesterase inhibitors (PDE-Is) cilostazol and sildenafil to the standard TB treatment regimen reduces tissue pathology, leads to faster bacterial clearance and shortens the time to lung sterilization by one month, compared to standard treatment alone, in a murine model of TB. Our data suggest that these PDE-Is could be repurposed for use as adjunctive drugs to shorten TB treatment in humans

    Reduction in acute filariasis morbidity during a mass drug administration trial to eliminate lymphatic filariasis in Papua New Guinea.

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    Background Acute painful swelling of the extremities and scrotum are debilitating clinical manifestations of Wuchereria bancrofti infection. The ongoing global program to eliminate filariasis using mass drug administration is expected to decrease this and other forms of filarial morbidity in the future by preventing establishment of new infections as a consequence of eliminating transmission by the mosquito vector. We examined whether mass treatment with anti-filarial drugs has a more immediate health benefit by monitoring acute filariasis morbidity in Papua New Guinean communities that participated in a 5-year mass drug administration trial. Methodology/Principal Findings Weekly active surveillance for acute filariasis morbidity defined by painful swelling of the extremities, scrotum and breast was performed 1 year before and each year after 4 annual mass administrations of anti-filarial drugs (16,480 person-years of observation). Acute morbidity events lasted <3 weeks in 92% of affected individuals and primarily involved the leg (74–79% of all annual events). The incidence for all communities considered together decreased from 0.39 per person-year in the pre-treatment year to 0.31, 0.15, 0.19 and 0.20 after each of 4 annual treatments (p<0.0001). Residents of communities with high pre-treatment transmission intensities (224–742 infective bites/person/year) experienced a greater reduction in acute morbidity (0.62 episodes per person-year pre-treatment vs. 0.30 in the 4th post-treatment year) than residents of communities with moderate pre-treatment transmission intensities (24–167 infective bites/person/year; 0.28 episodes per person-year pre-treatment vs. 0.16 in the 4th post-treatment year). Conclusions Mass administration of anti-filarial drugs results in immediate health benefit by decreasing the incidence of acute attacks of leg and arm swelling in people with pre-existing infection. Reduction in acute filariasis morbidity parallels decreased transmission intensity, suggesting that continuing exposure to infective mosquitoes is involved in the pathogenesis of acute filariasis morbidity

    The Economic Benefits Resulting from the First 8 Years of the Global Programme to Eliminate Lymphatic Filariasis (2000–2007)

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    Lymphatic filariasis (LF), commonly known as ‘elephantiasis’, is one of the world's most debilitating infectious diseases. In 83 countries worldwide, more than 1.3 billion people are at risk of infection with an estimated 120 million individuals already infected. A recent publication reviewing the health impact of the first 8 years of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) demonstrated the enormous health benefits achieved in populations receiving annual mass drug administration (MDA), as a result of infection prevented, disease progression halted, and ancillary treatment of co-infections. To date, however, no studies have estimated the economic value of these health benefits, either to the individuals or the societies afflicted with LF. Our study estimates that US21.8billionwillbegainedamongindividualsbenefittingfromjustthefirst8yearsoftheGlobalProgramme,andanadditionalUS21.8 billion will be gained among individuals benefitting from just the first 8 years of the Global Programme, and an additional US2.2 billion will be saved by the health systems of endemic countries. Treating endemic populations is possible at very low cost – particularly because of the generous drug donations from two pharmaceutical companies – but results in enormous economic benefits. Findings from this study yield a much clearer understanding the GPELF's full economic impact and strengthen the conviction that it is a ‘best buy’ in global health

    Neglected Tropical Diseases and the Millennium Development Goals-why the "other diseases" matter: reality versus rhetoric

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    Since 2004 there has been an increased recognition of the importance of Neglected Tropical Diseases (NTDs) as impediments to development. These diseases are caused by a variety of infectious agents - viruses, bacteria and parasites - which cause a diversity of clinical conditions throughout the tropics. The World Health Organisation (WHO) has defined seventeen of these conditions as core NTDs. The objectives for the control, elimination or eradication of these conditions have been defined in World Health Assembly resolutions whilst the strategies for the control or elimination of individual diseases have been defined in various WHO documents. Since 2005 there has been a drive for the expanded control of these diseases through an integrated approach of mass drug administration referred to as Preventive Chemotherapy via community-based distribution systems and through schools. This has been made possible by donations from major pharmaceutical companies of quality and efficacious drugs which have a proven track record of safety. As a result of the increased commitment of endemic countries, bilateral donors and non-governmental development organisations, there has been a considerable expansion of mass drug administration. In particular, programmes targeting lymphatic filariasis, onchocerciasis, schistosomiasis, trachoma and soil transmitted helminth infections have expanded to treat 887. 8 million people in 2009. There has been significant progress towards guinea worm eradication, and the control of leprosy and human African trypanosomiasis. This paper responds to what the authors believe are inappropriate criticisms of these programmes and counters accusations of the motives of partners made in recently published papers. We provide a detailed response and update the information on the numbers of global treatments undertaken for NTDs and list the success stories to date

    Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

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    Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone

    Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

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    Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced
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