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Current chemotherapy against Mycobacterium tuberculosis (Mtb), an important human pathogen, requires a multidrug regimen lasting several months. While efforts have been made to optimize therapy by exploiting drug-drug synergies, testing new drug combinations in relevant host environments remains arduous. In particular, host environments profoundly affect the bacterial metabolic state and drug efficacy, limiting the accuracy of predictions based on in vitro assays alone. In this study, we utilize conditional Mtb knockdown mutants of essential genes as an experimentally-tractable surrogate for drug treatment, and probe the relationship between Mtb carbon metabolism and chemical-genetic interactions (CGI). We examined the anti-tubercular drugs isoniazid, rifampicin and moxifloxacin, and found that CGI are differentially responsive to the metabolic state, defining both environment-independent and –dependent interactions. Specifically, growth on the in vivo-relevant carbon source, cholesterol, reduced rifampicin efficacy by altering mycobacterial cell surface lipid composition. We report that a variety of perturbations in cell wall synthesis pathways restore rifampicin efficacy during growth on cholesterol, and that both environment-independent and cholesterol-dependent in vitro CGI could be leveraged to enhance bacterial clearance in the mouse infection model. Our findings present an atlas of novel chemical-genetic-environmental interactions that can be used to optimize drug-drug interactions as well as provide a framework for understanding in vitro correlates of in vivo efficacy.SignificanceEfforts to improve tuberculosis therapy include optimizing multi-drug regimens to take advantage of drug-drug synergies. However, the complex host environment has a profound effect on bacterial metabolic state and drug activity, making predictions of optimal drug combinations difficult. In this study, we leverage a newly developed library of conditional knockdown Mycobacterium tuberculosis mutants in which genetic depletion of essential genes mimics the effect of drug therapy. This tractable system allowed us to assess the effect of growth condition on predicted drug-drug interactions. We found that these interactions can be differentially sensitive to the metabolic state and select in vitro-defined interactions can be leveraged to accelerate bacterial killing during infection. These findings suggest new strategies for optimizing tuberculosis therapy.

Gene rv3722c of Mycobacterium tuberculosis is essential for in vitro growth, and encodes a putative pyridoxal phosphate-binding protein of unknown function. Here we use metabolomic, genetic and structural approaches to show that Rv3722c is the primary aspartate aminotransferase of M. tuberculosis, and mediates an essential but underrecognized role in metabolism: nitrogen distribution. Rv3722c deficiency leads to virulence attenuation in macrophages and mice. Our results identify aspartate biosynthesis and nitrogen distribution as potential species-selective drug targets in M. tuberculosis., Gene rv3722c is essential for in vitro growth of Mycobacterium tuberculosis, but its function is unclear. Here, Jansen et al. show that Rv3722c is the primary aspartate aminotransferase of this pathogen, mediates nitrogen distribution, and is important for virulence during infection of macrophages and mice.

Body size varies widely among species, populations, and individuals depending on the environment. Transitioning between proliferation and differentiation is a crucial determinant of final organ size, but how the timing of this transition is established and maintained remains unknown. Using cell proliferation markers and genetic analysis, we show that CHIQUITA1 (CHIQ1) is required to maintain the timing of the transition from proliferation to differentiation in Arabidopsis thaliana. Combining kinematic and cell lineage tracking studies, we found that the number of actively dividing cells in chiquita1-1 plants decreases prematurely compared to wild type plants, suggesting CHIQ1 maintains the proliferative capacity in dividing cells and ensures that cells divide a certain number of times. CHIQ1 belongs to a plant-specific gene family of unknown molecular function and physically and genetically interacts with three close members of its family to control the timing of proliferation exit. Our work reveals the interdependency between cellular and organ-level processes underlying final organ size determination.SignificanceTiming of the transition between proliferation and differentiation is fundamental for determining the final size of organs and organisms. In agriculture, controlling organ and organism size can influence key agronomic traits such as yield and biomass. Dwarfism prevents lodging and was the trait responsible for the Green Revolution. Today, more sophisticated traits are needed for generating crops that are both resilient and sustainable. Revealing the molecular mechanisms that control the temporal transition between proliferation and differentiation will help unlock the potential of next-generation crops. Here, we report that CHIQUITA 1 in Arabidopsis thaliana is needed to maintain the proper timing of the transition between proliferation and differentiation in leaves and roots.

Phosphopantetheinyl hydrolase, PptH (Rv2795c), is a recently discovered enzyme from Mycobacterium tuberculosis that removes 4′-phosphopantetheine (Ppt) from holo-carrier proteins (CPs) and thereby opposes the action of phosphopantetheinyl transferases (PPTases). PptH is the first structurally characterized enzyme of the phosphopantetheinyl hydrolase family. However, conditions for optimal activity of PptH have not been defined, and only one substrate has been identified. Here, we provide biochemical characterization of PptH and demonstrate that the enzyme hydrolyzes Ppt in vitro from more than one M. tuberculosis holo-CP as well as holo-CPs from other organisms. PptH provided the only detectable activity in mycobacterial lysates that dephosphopantetheinylated acyl carrier protein M (AcpM), suggesting that PptH is the main Ppt hydrolase in M. tuberculosis. We could not detect a role for PptH in coenzyme A (CoA) salvage, and PptH was not required for virulence of M. tuberculosis during infection of mice. It remains to be determined why mycobacteria conserve a broadly acting phosphohydrolase that removes the Ppt prosthetic group from essential CPs. We speculate that the enzyme is critical for aspects of the life cycle of M. tuberculosis that are not routinely modeled. IMPORTANCE Tuberculosis (TB), caused by Mycobacterium tuberculosis, was the leading cause of death from an infectious disease before COVID, yet the in vivo essentiality and function of many of the protein-encoding genes expressed by M. tuberculosis are not known. We biochemically characterize M. tuberculosis’s phosphopantetheinyl hydrolase, PptH, a protein unique to mycobacteria that removes an essential posttranslational modification on proteins involved in synthesis of lipids important for the bacterium’s cell wall and virulence. We demonstrate that the enzyme has broad substrate specificity, but it does not appear to have a role in coenzyme A (CoA) salvage or virulence in a mouse model of TB.

The therapeutic efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by the development of graft-versus-host disease (GVHD). In GVHD, rigorous pre-conditioning regimen resets the immune landscape and inflammatory milieu causing immune dysregulation, characterized by an expansion of alloreactive cells and a reduction in immune regulatory cells. In acute GVHD (aGVHD), the release of damage- and pathogen- associated molecular patterns from damaged tissue caused by the conditioning regimen sets the stage for T cell priming, activation and expansion further exacerbating tissue injury and organ damage, particularly in the gastrointestinal tract. Studies have shown that donor T cells utilize multiple energetic and biosynthetic pathways to mediate GVHD that can be distinct from the pathways used by regulatory T cells for their suppressive function. In chronic GVHD (cGVHD), donor T cells may differentiate into IL-21 producing T follicular helper cells or tissue resident T helper cells that cooperate with germinal center B cells or memory B cells, respectively, to produce allo- and auto-reactive antibodies with subsequent tissue fibrosis. Alternatively, donor T cells can become IFN- γ/IL-17 cytokine expressing T cells that mediate sclerodermatous skin injury. Patients refractory to the first line standard regimens for GVHD treatment have a poor prognosis indicating an urgent need for new therapies to restore the balance between effector and regulatory immune cells while preserving the beneficial graft-versus-tumor effect. Emerging data points toward a role for metabolism in regulating these allo- and auto-immune responses. Here, we will discuss the preclinical and clinical data available on the distinct metabolic demands of acute and chronic GVHD and recent efforts in identifying therapeutic targets using metabolomics. Another dimension of this review will examine the changing microbiome after allo-HSCT and the role of microbial metabolites such as short chain fatty acids and long chain fatty acids on regulating immune responses. Lastly, we will examine the metabolic implications of coinhibitory pathway blockade and cellular therapies in allo-HSCT. In conclusion, greater understanding of metabolic pathways involved in immune cell dysregulation during allo-HSCT may pave the way to provide novel therapies to prevent and treat GVHD.

The Tuberculosis Drug Accelerator, an experiment designed to facilitate collaboration in tuberculosis drug discovery by breaking down barriers among competing labs and institutions, has reached a 10-year landmark. We review the consortium’s achievements, advantages and limitations and advocate for the application of similar models to other diseases.

Key Points Myoclonic jerks and inattentiveness may be rare neurologic complications of ATO toxicity. Clinicians must be aware of this rare toxicity given that the ATO and ATRA combination is now standard-of-care treatment of low-risk APL.

A sweetener's not-so-sweet effects Obesity increases an individual's risk of developing many types of cancer, including colorectal cancer. One of the factors driving the rise in obesity rates is thought to be the use of high-fructose corn syrup (HFCS) as a sweetener in soft drinks. Goncalves et al. found that ingestion of HFCS promotes the growth of intestinal cancer even in the absence of obesity in mouse tumor models. An enzyme in tumors (ketohexokinase) converts fructose to fructose-1-phosphate, which alters tumor cell metabolism and leads to enhanced cell growth. Whether a similar process occurs in humans remains to be seen. Science , this issue p. 1345

The World Health Organization (WHO) monitors the spread of diseases globally and maintains a list of diseases with epidemic or pandemic potential. Currently listed diseases include Chikungunya, cholera, Crimean-Congo hemorrhagic fever, Ebola virus disease, Hendra virus infection, influenza, Lassa fever, Marburg virus disease,Neisseria meningitis, MERS-CoV, monkeypox, Nipah virus infection, novel coronavirus (COVID-19), plague, Rift Valley fever, SARS, smallpox, tularemia, yellow fever, and Zika virus disease. The associated pathogens are increasingly important on the global stage. The majority of these diseases have neurological manifestations. Those with less frequent neurological manifestations may also have important consequences. This is highlighted now in particular through the ongoing COVID-19 pandemic and reinforces that pathogens with the potential to spread rapidly and widely, in spite of concerted global efforts, may affect the nervous system. We searched the scientific literature, dating from 1934 to August 2020, to compile data on the cause, epidemiology, clinical presentation, neuroimaging features, and treatment of each of the diseases of epidemic or pandemic potential as viewed through a neurologist's lens. We included articles with an abstract or full text in English in this topical and scoping review. Diseases with epidemic and pandemic potential can be spread directly from human to human, animal to human, via mosquitoes or other insects, or via environmental contamination. Manifestations include central neurologic conditions (meningitis, encephalitis, intraparenchymal hemorrhage, seizures), peripheral and cranial nerve syndromes (sensory neuropathy, sensorineural hearing loss, ophthalmoplegia), post-infectious syndromes (acute inflammatory polyneuropathy), and congenital syndromes (fetal microcephaly), among others. Some diseases have not been well-characterized from a neurological standpoint, but all have at least scattered case reports of neurological features. Some of the diseases have curative treatments available while in other cases, supportive care remains the only management option. Regardless of the pathogen, prompt, and aggressive measures to control the spread of these agents are the most important factors in lowering the overall morbidity and mortality they can cause.

Coenzyme A (CoA) is a fundamental co-factor for all life, involved in numerous metabolic pathways and cellular processes, and its biosynthetic pathway has raised substantial interest as a drug target against multiple pathogens including Mycobacterium tuberculosis. The biosynthesis of CoA is performed in five steps, with the second and third steps being catalysed in the vast majority of prokaryotes, including M. tuberculosis, by a single bifunctional protein, CoaBC. Depletion of CoaBC was found to be bactericidal in M. tuberculosis. Here we report the first structure of a full-length CoaBC, from the model organism Mycobacterium smegmatis, describe how it is organised as a dodecamer and regulated by CoA thioesters. A high-throughput biochemical screen focusing on CoaB identified two inhibitors with different chemical scaffolds. Hit expansion led to the discovery of potent and selective inhibitors of M. tuberculosis CoaB, which we show to bind to a cryptic allosteric site within CoaB., The bifunctional enzyme CoaBC catalyses the second and third step in the Coenzyme A (CoA) biosynthesis pathway and is of interest as a M. tuberculosis drug target. Here, the authors present the full-length crystal structure of Mycobacterium smegmatis CoaBC, which is regulated by CoA and CoA thioesters and forms a dodecamer and by performing a high-throughput screen they identify selective inhibitors of M. tuberculosis CoaB that bind to an allosteric site within CoaB.

BACKGROUND Control of the tuberculosis (TB) pandemic remains hindered in part by a lack of simple and accurate measures of treatment efficacy, as current gold standard markers rely on sputum-based assays that are slow and challenging to implement. However, previous work identified urinary N1, N12-diacetylspermine (DiAcSpm), neopterin, hydroxykynurenine, N-acetylhexosamine, ureidopropionic acid, sialic acid, and mass-to-charge ratio (m/z) 241.0903 as potential biomarkers of active pulmonary TB (ATB). Here, we evaluated their ability to serve as biomarkers of TB treatment response and mycobacterial load. METHODS We analyzed urine samples prospectively collected from 2 cohorts with ATB. A total of 34 study participants from African countries treated with first-line TB therapy rifampin, isoniazid, pyrazinamide, and ethambutol (HRZE) were followed for 1 year, and 35 participants from Haiti treated with either HRZE or an experimental drug were followed for 14 days. Blinded samples were analyzed by untargeted HPLC-coupled high-resolution TOF-mass spectrometry. RESULTS Urinary levels of all 7 molecules significantly decreased by week 26 of successful treatment (P = 0.01 to P < 0.0001) and positively correlated with sputum mycobacterial load (P < 0.0001). Urinary DiAcSpm levels decreased significantly in participants treated with HRZE as early as 14 days (P < 0.0001) but remained unchanged in cases of ineffective therapy (P = 0.14). CONCLUSION Urinary DiAcSpm, neopterin, hydroxykynurenine, N-acetylhexosamine, ureidopropionic acid, sialic acid, and m/z 241.0903 reductions correlated with successful anti-TB treatment and sputum mycobacterial load. Urinary DiAcSpm levels exhibited reductions capable of differentiating treatment success from failure as early as 2 weeks after the initiation of chemotherapy, advocating its further development as a potentially simple, noninvasive biomarker for assessing treatment response and bacterial load. FUNDING This work was supported by the Clinical and Translational Science Center at Weill Cornell College of Medicine (NIH/NCATS 1 UL1 TR002384-02 and KL2TR000458), the Department of Defense (PR170782), the National Institute of Allergy and Infectious Disease grants (NIAID T32AI007613-16, K24 AI098627, and K23 AI131913), the NIH Fogarty International Center grants (R24 TW007988 and TW010062), NIH grant (R01 GM135926), the Abby and Howard P. Milstein Program in Chemical Biology and Translational Medicine, and the Tuberculosis Research Units Networks (TBRU-N, AI111143)., A panel of biomarkers whose levels track with tuberculosis treatment efficacy and sputum mycobacterial load can be monitored non-invasively in urine.

Respiration is a promising target for the development of new antimycobacterial agents, with a growing number of compounds in clinical development entering this target space. However, more candidate inhibitors are needed to expand the therapeutic options available for drug-resistant Mycobacterium tuberculosis infection. Here, we characterize a putative respiratory complex III (QcrB) inhibitor, TB47: a pyrazolo[1,5- a]pyridine-3-carboxamide. TB47 is active (MIC between 0.016 and 0.500 μg/mL) against a panel of 56 M. tuberculosis clinical isolates, including 37 multi-drug-resistant and two extensively drug-resistant strains. Pharmacokinetic and toxicity studies showed promising profiles, including negligible CYP450 interactions, cytotoxicity, and hERG channel inhibition. Consistent with other reported QcrB inhibitors, TB47 inhibits oxygen consumption only when the alternative oxidase, cytochrome bd, is deleted. A point mutation in the qcrB cd2-loop (H190Y, M. smegmatis numbering) rescues the inhibitory effects of TB47. Metabolomic profiling of TB47-treated M. tuberculosis H37Rv cultures revealed accumulation of steps in the TCA cycle and pentose phosphate pathway that are linked to reducing equivalents, suggesting that TB47 causes metabolic redox stress. In mouse infection models, a TB47 monotherapy was not bactericidal. However, TB47 was strongly synergistic with pyrazinamide and rifampicin, suggesting a promising role in combination therapies. We propose that TB47 is an effective lead compound for the development of novel tuberculosis chemotherapies.

Background Tuberculosis (TB) is the leading infectious cause of death worldwide. A major barrier to control of the pandemic is a lack of clinical biomarkers with the ability to distinguish active TB from healthy and sick controls and potential for development into point-of-care diagnostics. Methods We conducted a prospective case control study to identify candidate urine-based diagnostic biomarkers of active pulmonary TB (discovery cohort) and obtained a separate blinded “validation” cohort of confirmed cases of active pulmonary TB and controls with non-tuberculous pulmonary disease for validation. Clean-catch urine samples were collected and analyzed using high performance liquid chromatography-coupled time-of-flight mass spectrometry. Results We discovered ten molecules from the discovery cohort with receiver-operator characteristic (ROC) area-under-the-curve (AUC) values >85%. These 10 molecules also significantly decreased after 60 days of treatment in a subset of 20 participants followed over time. Of these, a specific combination of diacetylspermine, neopterin, sialic acid, and N-acetylhexosamine exhibited ROC AUCs >80% in a blinded validation cohort of participants with active TB and non-tuberculous pulmonary disease. Conclusion Urinary levels of diacetylspermine, neopterin, sialic acid, and N-acetylhexosamine distinguished patients with tuberculosis from healthy controls and patients with non-tuberculous pulmonary diseases, providing a potential noninvasive biosignature of active TB. Funding This study was funded by Weill Cornell Medicine, the National Institute of Allergy and Infectious Diseases, the Clinical and Translational Science Center at Weill Cornell, the NIH Fogarty International Center grants, and the NIH Tuberculosis Research Unit (Tri-I TBRU)., Highlights • Urinary levels of small metabolites appear capable of distinguishing cases of active pulmonary tuberculosis from sick and healthy controls. • Levels of these biomarkers decrease after 60 days of treatment in a longitudinal cohort of 20 participants. • - Many of the identified biomarkers are known inflammatory intermediates that may reflect a specific immune response to tuberculosis. Urine tests are commonly used to enable non-invasive, rapid and point-of-care diagnosis of various infectious diseases. We identified diacetylspermine, neopterin, sialic acid and N-acetylhexosamine as potential urine-based biomarkers for tuberculosis from two independent patient cohorts. These metabolites are known inflammatory intermediates and appear to decrease with anti-tuberculosis therapy in a subset of participants followed over 2 months. If validated, these metabolites have potential to both improve our understanding of the immune reaction to active tuberculosis and facilitate the development of a much-needed clinical biomarker for tuberculosis.

Metabolism was once relegated to the supply of energy and biosynthetic precursors, but it has now become clear that it is a specific mediator of nearly all physiological processes. In the context of microbial pathogenesis, metabolism has expanded outside its canonical role in bacterial replication. Among human pathogens, this expansion has emerged perhaps nowhere more visibly than for Mycobacterium tuberculosis, the causative agent of tuberculosis. Unlike most pathogens, M. tuberculosis has evolved within humans, which are both host and reservoir. This makes unrestrained replication and perpetual quiescence equally incompatible strategies for survival as a species. In this Review, we summarize recent work that illustrates the diversity of metabolic functions that not only enable M. tuberculosis to establish and maintain a state of chronic infection within the host but also facilitate its survival in the face of drug pressure and, ultimately, completion of its life cycle.

The membrane protein Ankylosis homologue (ANKH, mouse orthologue: ANK) prevents mineralization of joint-space and articular cartilage. The accepted view is that ANKH mediates cellular release of inorganic pyrophosphate (PPi), a strong physiological inhibitor of mineralization. Using global metabolite profiling, we identified citrate as the most prominent metabolite leaving HEK293 cells in an ANKH-dependent manner. Although PPi levels were increased in culture medium of HEK293-ANKH cells, PPi was formed extracellularly after release of ATP and other nucleoside triphosphates.Ankank/ankmice, which lack functional ANK, had substantially reduced concentrations of citrate in plasma and urine, while citrate was undetectable in urine of a human patient lacking functional ANKH. Bone hydroxyapatite ofAnkank/ankmice also contained markedly reduced levels of citrate and PPi and displayed diminished strength. Together, our data show that ANKH is a crucial factor in extracellular citrate and PPi homeostasis that is essential for normal bone development.

Despite graft-versus-host disease (GVHD) prophylactic agents, the success and wider utilization of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by GVHD. Increasing donor graft regulatory T cell (Treg):effector T cell (Teff) ratios can substantially reduce GVHD in cancer patients, but pre-HSCT conditioning regimens and GVHD create a challenging inflammatory environment for Treg stability, persistence, and function. Metabolism plays a crucial role in T cell and Treg differentiation, and development of effector function. Although glycolysis is a main driver of allogeneic T cell-driven GVHD, oxidative phosphorylation is a main driver of Treg suppressor function. This review focuses on recent advances in our understanding of Treg metabolism in the context of GVHD, and discusses potential therapeutic applications of Tregs in the prevention or treatment of GVHD in cancer patients.

Background Human immunodeficiency virus (HIV) and certain antiretrovirals are associated with diabetes. Few studies have examined the prevalence of and factors associated with diabetes among HIV-infected individuals on combination antiretroviral therapy (cART) in sub-Saharan Africa; some report prevalence estimates between 3.5–26.5% for diabetes in Cameroon and 20.2–43.5% for prediabetes in sub-Saharan Africa. Methods In a cross-sectional study, HIV-infected individuals (16–65 years old) were screened for diabetes using haemoglobin A1c (HbA1c). We further categorized HbA1C as normoglycemia (HbA1c 28 days, body mass index, hypertension, history of hypertension, abdominal circumference and duration of HIV infection, larger abdominal circumference was associated with higher prevalence of prediabetes or diabetes (adjusted odds ratio = 1.07, 95% confidence interval: 1.03–1.11), while being on cART (adjusted odds ratio = 0.46, confidence interval: 0.22–0.99) was associated with lower prevalence. Conclusions There was a high prevalence of dysglycemia among Cameroonian HIV-infected adults. Larger abdominal circumference was associated with higher prevalence, while cART was associated with lower prevalence. Copyright © 2016 John Wiley & Sons, Ltd.

Cell wall biosynthesis inhibitors have proven highly effective for treating tuberculosis (TB). We discovered and validated members of the indazole sulfonamide class of small molecules as inhibitors of Mycobacterium tuberculosis KasA—a key component for biosynthesis of the mycolic acid layer of the bacterium’s cell wall and the same pathway as that inhibited by the first-line antitubercular drug isoniazid (INH). One lead compound, DG167, demonstrated synergistic lethality in combination with INH and a transcriptional pattern consistent with bactericidality and loss of persisters. Our results also detail a novel dual-binding mechanism for this compound as well as substantial structure-activity relationships (SAR) that may help in lead optimization activities. Together, these results suggest that KasA inhibition, specifically, that shown by the DG167 series, may be developed into a potent therapy that can synergize with existing antituberculars., We report GSK3011724A (DG167) as a binary inhibitor of β-ketoacyl-ACP synthase (KasA) in Mycobacterium tuberculosis. Genetic and biochemical studies established KasA as the primary target. The X-ray crystal structure of the KasA-DG167 complex refined to 2.0-Å resolution revealed two interacting DG167 molecules occupying nonidentical sites in the substrate-binding channel of KasA. The binding affinities of KasA to DG167 and its analog, 5g, which binds only once in the substrate-binding channel, were determined, along with the KasA-5g X-ray crystal structure. DG167 strongly augmented the in vitro activity of isoniazid (INH), leading to synergistic lethality, and also synergized in an acute mouse model of M. tuberculosis infection. Synergistic lethality correlated with a unique transcriptional signature, including upregulation of oxidoreductases and downregulation of molecular chaperones. The lead structure-activity relationships (SAR), pharmacokinetic profile, and detailed interactions with the KasA protein that we describe may be applied to evolve a next-generation therapeutic strategy for tuberculosis (TB).

Successful drug treatment for tuberculosis (TB) depends on the unique contributions of its component drugs. Drug resistance poses a threat to the efficacy of individual drugs and the regimens to which they contribute. Biologically and chemically validated targets capable of replacing individual components of current TB chemotherapy are a major unmet need in TB drug development. We demonstrate that chemical inhibition of the bacterial biotin protein ligase (BPL) with the inhibitor Bio-AMS (5′-[N-(d-biotinoyl)sulfamoyl]amino-5′-deoxyadenosine) killed Mycobacterium tuberculosis (Mtb), the bacterial pathogen causing TB. We also show that genetic silencing of BPL eliminated the pathogen efficiently from mice during acute and chronic infection with Mtb. Partial chemical inactivation of BPL increased the potency of two first-line drugs, rifampicin and ethambutol, and genetic interference with protein biotinylation accelerated clearance of Mtb from mouse lungs and spleens by rifampicin. These studies validate BPL as a potential drug target that could serve as an alternate frontline target in the development of new drugs against Mtb.

Background Although social support is important for quality of life in patients undergoing surgery for ulcerative colitis, the impact of surgery on patient relationships is not known. Objective We examined relationship parameters in patients with ulcerative colitis and their partners before and 6 months after surgery. Design This was a prospective cohort in which we performed an exploratory analysis. Settings Patients were enrolled from an academic medical center. Patients Surgical patients with ulcerative colitis and their partners were invited to participate. Interventions Patients underwent proctocolectomy in 1, 2, or 3 stages. Main outcome measures We measured quality of life and sexual function in patients, as well as relationship quality, empathy, and sexual satisfaction in patients and partners before and 6 months after surgery using validated questionnaires. Results The study sample consisted of 74 participants, including 37 patients (25 men and 12 women) and their opposite-sex partners. Quality of life improved significantly in male and female patients after surgery. Sexual function scores also improved after surgery in male and female patients; however, the changes reached statistical significance in male patients only. Sexual satisfaction scores improved significantly after surgery in female patients and their partners. There was little change in relationship quality or empathy after surgery, with the exception of slightly improved relationship quality reported by male partners. In general, patients and partners reported levels of relationship quality and empathy similar to normative populations. Limitations This study included a small, highly selected sample. Conclusions Male and female patients with ulcerative colitis have high-quality relationships that are not negatively affected by surgical treatment. Changes in sexual function do not necessarily coincide with changes in sexual satisfaction in this patient population. Future studies should evaluate the effect of high-quality relationships on surgical outcomes.

Context Factors contributing to and impeding palliative care (PC) development in Africa can provide insights into current strategies for advancing PC. Objectives To identify key factors affecting PC development in African countries from in-country PC experts' perspectives. Methods About 16 PC experts from seven African countries undertook semistructured interviews on PC development in their respective countries. An interpretive description approach was adopted, with data analyzed using constant comparison. Results Emerged themes included drivers, strengths, challenges, and aspirations for PC development in Africa. Drivers included advocates and pioneering organizations, HIV/AIDS, culture of caregiving, and the World Health Assembly PC resolution. Strengths included community health workers, the special role of nurses, diversity of services, and short training courses. Challenges included lack of PC education; lack of standardization in implementation; limited availability of and/or accessibility to morphine; poverty and disease burden; and lack of funding for PC. Aspirations included integration of PC, specialization in PC, nurse prescribing, and strong partnerships with Ministries of Health. Factors already highlighted in the literature were only briefly discussed. Conclusion The key factors underpinning PC development in the seven countries contributed to the beginnings of PC in Africa, fueled by advocates who built on existing strengths to maximize opportunities. However, the current approach is at high risk in terms of its sustainability, and strategies for maximizing existing resources and growing infrastructure support are needed moving forward.

Accumulating evidence has left little doubt about the importance of persistence or metabolism in the biology and chemotherapy of tuberculosis. However, knowledge of the intersection between these two factors has only recently begun to emerge. Here, we provide a focused review of metabolic characteristics associated with Mycobacterium tuberculosis persistence. We focus on metabolism because it is the biochemical foundation of all physiologic processes and a distinguishing hallmark of M. tuberculosis physiology and pathogenicity. In addition, it serves as the chemical interface between host and pathogen. Existing knowledge, however, derives largely from physiologic contexts in which replication is the primary biochemical objective. The goal of this review is to reframe current knowledge of M. tuberculosis metabolism in the context of persistence, where quiescence is often a key distinguishing characteristic. Such a perspective may help ongoing efforts to develop more efficient cures and inform on novel strategies to break the cycle of transmission sustaining the pandemic.

Enzymes of central carbon metabolism are essential mediators of Mycobacterium tuberculosis (Mtb) physiology and pathogenicity, but are often perceived to lack sufficient species selectivity to be pursued as potential drug targets. Fumarase (Fum) is an enzyme of the canonical tricarboxylic acid cycle and is dispensable in many organisms. Transposon mutagenesis studies in Mtb, however, indicate that Fum is required for optimal growth. Here, we report the generation and characterization of a genetically engineered Mtb strain in which Fum expression is conditionally regulated. This revealed that Fum deficiency is bactericidal in vitro and during both the acute and chronic phases of mouse infection. This essentiality is linked to marked accumulations of fumarate resulting in protein and metabolite succination, a covalent modification of cysteine thiol residues. These results identify Mtb Fum as a potentially species-specific drug target whose inactivation may kill Mtb through a covalently irreversible form of metabolic toxicity.

Once considered a crowning achievement of modern drug development, tuberculosis (TB) chemotherapy has proven increasingly unable to keep pace with the spread of the pandemic and rise of drug resistance. Efforts to revive the TB drug development pipeline have, in the meantime, faltered. Closer analysis reveals key experimental deficiencies that have hindered our ability to 'reverse engineer' knowledge of antibiotic mechanisms into rational drug development. Here, we discuss the emerging potential of metabolomics; the systems level study of small molecule metabolites, to help overcome these gaps and serve as a unique biochemical bridge between the phenotypic properties of chemical compounds and biological targets.

Background Extremely drug-resistant gram-negative bacilli (XDR-GNB) increasingly cause health care-associated infections (HAIs) in intensive care units (ICUs). Methods A matched case-control (1:2) study was conducted from February 2007 to January 2010 in 16 ICUs. Case and control subjects had HAIs caused by GNB susceptible to ≤1 antibiotic versus ≥2 antibiotics, respectively. Logistic and Cox proportional hazards regression assessed risk factors for HAIs and predictors of mortality, respectively. Results Overall, 103 case and 195 control subjects were enrolled. An immunocompromised state (odds ratio [OR], 1.55; P = .047) and exposure to amikacin (OR, 13.81; P P = .005), or trimethoprim-sulfamethoxazole (OR, 3.42; P = .009) were factors associated with XDR-GNB HAIs. Multiple factors in both case and control subjects significantly predicted increased mortality at different time intervals after HAI diagnosis. At 7 days, liver disease (hazard ratio [HR], 5.52), immunocompromised state (HR, 3.41), and bloodstream infection (HR, 2.55) predicted mortality; at 15 days, age (HR, 1.02 per year increase), liver disease (HR, 3.34), and immunocompromised state (HR, 2.03) predicted mortality; and, at 30 days, age (HR, 1.02 per 1-year increase), liver disease (HR, 3.34), immunocompromised state (HR, 2.03), and hospitalization in a medical ICU (HR, 1.85) predicted mortality. Conclusion HAIs caused by XDR-GNB were associated with potentially modifiable factors. Age, liver disease, and immunocompromised state, but not XDR-GNB HAIs, were associated with mortality.

Background Adequate control of the global tuberculosis (TB) burden is limited by a lack of accurate measures of treatment efficacy. Current gold standard relies on sputum cultures, which often lag weeks behind time of sample collection. Previous studies have identified urinary N1,N12-diacetylspermine (DiAcSpm) as a potential biomarker of active pulmonary TB (ATB). We aimed to quantify urinary DiAcSpm in participants being treated for ATB and identify its relationship to treatment response. Methods Longitudinal urine samples were obtained from two separate cohorts of participants treated for ATB. Cohort one consisted of 34 successfully treated ATB cases with urine collected at weeks 0, 2, 4, 8, 17, 26, and 52. Cohort two consisted of 35 ATB cases under two treatment arms: one arm was successfully treated with the standard therapy of rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE), and the other arm received an experimental drug, which was later found to be ineffective against ATB. Urine from cohort two was collected at days 0, 2, 4, and 14. All samples were blinded, randomized, normalized to osmolality and urinary creatinine, and analyzed using high-performance liquid chromatography-mass spectrometry. DiAcSpm concentrations were further tested using ELISA. Results Using linear-mixed modeling that adjusted for age, sex, and participant weight, we found that urinary DiAcSpm significantly decreased by week 2 of successful treatment in both cohorts (P < 0.0001). DiAcSpm levels remained unchanged in the ineffective experimental drug group (cohort two), significantly differentiating treatment success and failure by day 14 (P < 0.0001). Additionally, concentrations of urinary DiAcSpm positively correlate with sputum mycobacterial burden (P = 0.0002).These findings were consistent across both methods of detection. Conclusion Our results suggest that urinary concentrations of DiAcSpm correlate with TB treatment outcome and mycobacterial disease burden, and have the potential to serve as an early biomarker of TB treatment efficacy. Disclosures All Authors: No reported Disclosures.

Exudative retinopathy may be a manifestation of a variety of isolated ocular or systemic diseases in children. We report the case of a teenager with dyskeratosis congenita who developed a unilateral late exudative retinopathy after having previous laser treatment for threshold retinopathy of prematurity as an infant.

Antibacterial drug development suffers from a paucity of targets whose inhibition kills replicating and nonreplicating bacteria. The latter include phenotypically dormant cells, known as persisters, which are tolerant to many antibiotics and often contribute to failure in the treatment of chronic infections. This is nowhere more apparent than in tuberculosis caused by Mycobacterium tuberculosis, a pathogen that tolerates many antibiotics once it ceases to replicate. We developed a strategy to identify proteins that Mycobacterium tuberculosis requires to both grow and persist and whose inhibition has the potential to prevent drug tolerance and persister formation. This strategy is based on a tunable dual-control genetic switch that provides a regulatory range spanning three orders of magnitude, quickly depletes proteins in both replicating and nonreplicating mycobacteria, and exhibits increased robustness to phenotypic reversion. Using this switch, we demonstrated that depletion of the nicotinamide adenine dinucleotide synthetase (NadE) rapidly killed Mycobacterium tuberculosis under conditions of standard growth and nonreplicative persistence induced by oxygen and nutrient limitation as well as during the acute and chronic phases of infection in mice. These findings establish the dual-control switch as a robust tool with which to probe the essentiality of Mycobacterium tuberculosis proteins under different conditions, including those that induce antibiotic tolerance, and NadE as a target with the potential to shorten current tuberculosis chemotherapies.

Although the presence of MLH1 methylation in microsatellite-unstable colorectal cancer generally indicates involvement of the CpG island methylator phenotype (CIMP) in the development of the tumor, these two conditions do not always correlate. A minority of microsatellite-unstable colorectal cancers exhibit discordance between CIMP and MLH1 methylation statuses. However, the clinicopathological features of such microsatellite-unstable colorectal cancers with discrepant MLH1 methylation and CIMP statuses remain poorly studied. Microsatellite-unstable colorectal cancers (n=220) were analyzed for CIMP and MLH1 methylation statuses using the MethyLight assay. Based on the combinatorial CIMP and MLH1 methylation statuses, the microsatellite-unstable colorectal cancers were grouped into four subtypes (CIMP-high (CIMP-H) MLH1 methylation-positive (MLH1m+), CIMP-H MLH1 methylation-negative, CIMP-low/0 (CIMP-L/0) MLH1m+, and CIMP-L/0 MLH1 methylation-negative), which were compared in terms of their associations with clinicopathological and molecular features. The CIMP-L/0 MLH1 methylation-negative and CIMP-H MLH1m+ subtypes were predominant, comprising 63.6 and 24.1% of total microsatellite-unstable colorectal cancers, respectively. The discordant subtypes, CIMP-H MLH1 methylation-negative and CIMP-L/0 MLH1m+, were found in 5 and 7% of microsatellite-unstable colorectal cancers, respectively. The CIMP-H MLH1 methylation-negative subtype exhibited elevated incidence rates in male patients and was associated with larger tumor size, more frequent loss of MSH2 expression, increased frequency of KRAS mutation, and advanced cancer stage. The CIMP-L/0 MLH1m+ subtype was associated with onset at an earlier age, a predominance of MLH1 loss, and earlier cancer stage. None of the CIMP-L/0 MLH1m+ subtype patients succumbed to death during the follow-up. Our findings suggest that the discordant subtypes of colorectal cancers exhibit distinct clinicopathological and molecular features, although the proportion of discordant subtypes is low. The microsatellite-unstable colorectal cancers of the same CIMP status tended to exhibit different clinicopathological features depending on MLH1 methylation status.

Objective Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) is being increasingly performed despite lack of good evidence for its superiority. Other reported studies suffer from patient selection and publication bias with limited follow-up. This study is a single-center propensity score comparing early and midterm outcomes between open surgical repair (OSR) and endovascular repair of rAAA (REVAR). Methods A retrospective review from January 2001 to November 2010 identified 312 patients who underwent rAAA repairs. Thirty-one patients with antecedent AAA repair and three with incomplete records were excluded, leaving 37 REVARs and 241 OSRs. Propensity score-based matching for sex, age, preoperative hemodynamic status, surgeon's annual AAA volume, and preoperative cardiopulmonary resuscitation was performed in a 1:3 ratio to compare outcomes. Thirty-seven REVARs were matched with 111 OSRs. Late survival was estimated by Kaplan-Meier methods. Results Operative time and blood replacement were higher with OSR. Overall complication rates were similar (54% REVAR vs 66% OSR; P = .23), except for higher incidences of tracheostomies (21% vs 3%; P = .015), myocardial infarction (38% vs 18%; P = .036), and acute tubular necrosis (47% vs 21%; P = .009) with OSR. Operative mortality rates were similar (22% REVAR vs 32% OSR), with an odds ratio of 0.63 for REVAR (95% confidence interval=[0.24, 1.48]; P = .40). No differences in the incidences for secondary interventions for aneurysm- or graft-related complications were noted (22% REVAR vs 22% OSR; P = .99). Kaplan-Meier estimates of 1-, 2-, and 3-year survival rates were also similar (50%, 50%, 42% REVAR vs 54%, 52%, 47% OSR; P = .66). Conclusions REVAR for rAAA does not seem to conclusively confer either acute or late survival advantages. Routine use of REVAR should be deferred until prospective, randomized trial data become available.

Objective To review the evolution of traumatic thoracic aortic injury (TTAI) treatment at a single institution. Methods Retrospective analysis of all patients included in an institutional trauma registry and vascular surgery database who underwent treatment of TTAI between January 1999 and January 2011. Results Ninety-one patients (69 males) were treated for TTAI. The mean age was 38.5 years (range, 16-79 years). Forty-one patients underwent open repair (OR) and 50 thoracic endovascular repair (TEVAR), 37 with thoracic stent grafts (TSG) alone, 11 with infrarenal aortic extender cuffs (AEC), and two with a combination of TSG and AEC. OR was performed exclusively until 2004; the last one was performed in January 2007. All TTAIs have since been treated with TEVAR. The left subclavian artery (LSA) was fully covered in 10 patients (20%) and partially covered in eight patients, with revascularization in only two cases. The use of AEC and avoidance of LSA coverage increased after 2007. Baseline characteristics and injury severity scores were similar between groups. The mortality rate was higher in the OR group (19.5% vs 6.0%; P = .06), although it did not reach statistical significance. The overall incidence of morbidities was similar between the two groups (42% OR vs 50% TEVAR). Two patients developed paraplegia (4.4%) after OR compared with none after TEVAR. In the TEVAR group, a pseudoaneurysm, an iliac artery thrombosis, and a retroperitoneal hematoma developed in one patient each. Overall, eight patients (16%) developed stent graft-related complications (SRC), with two developing early (within 30 days) complications. All complications were related to poor apposition, requiring 10 reinterventions. Four patients underwent open conversions with no mortality. Nine out of 10 SRCs were associated with the use of thoracic stent graft malapposition. No patient treated with AEC had endoleaks or SRC. Conclusions TEVAR for TTAI has superior survival outcomes and has replaced OR. SRC requiring reintervention is associated with malapposition and the use of TSG. Until TTAI-specific endografts become available, use of AEC may minimize malapposition and reduce reinterventions. Routine overstenting of the LSA is not necessary and may increase SRC.

Objective To determine if there are any differences in outcomes between infrarenal fixation (IF) and suprarenal fixation (SF) endograft systems for the endovascular treatment (endovascular aneurysm repair [ EVAR]) of abdominal aortic aneurysms (AAAs) with short, straight proximal aortic necks ( Methods A retrospective review of 1379 EVAR procedures was performed between the years of 2002 and 2009 at a single institution. The charts and radiographic images of all patients were reviewed. Patients who underwent EVAR with AAA morphology with short proximal necks were stratified into two groups: IF, Gore Excluder (W. L. Gore, Flagstaff, Ariz) group and SF, Cook Zenith (Cook, Bloomington, Ind) group. The primary end point for the study was the presence of proximal type 1 endoleaks. Secondary end points were graft migration at 1- and 2-year follow-up and aneurysm sac regression. The groups' demographics and comorbidities were also compared. Results A total of 1379 EVARS were performed during the study period and 84 were identified as having a short proximal aortic neck. Sixty patients were in the IF group and 24 in the SF group. The average follow-up period was 18.6 months (IF) and 18.5 months (SF). There was no difference in the average proximal neck length (1.19 cm IF vs 1.14 cm SF; P = not significant [NS]) or the preoperative AAA size (5.8 cm IF vs 5.9 cm SF; P = NS). There were no significant differences in age (76.6 years IF vs 74.8 years SF; P = .32), gender (IF 66.7% vs SF 21.88% men; P = .053), or length of stay (2.2 days IF vs 1.9 days SF; P = .39). The comorbidities (diabetes, hypertension, and warfarin use) were also similar. There were five type 1a endoleaks in group IF and one in group SF ( P = .44) identified at the 1-month follow-up; however, only one patient in the IF group underwent intervention for enlargement of the AAA sac. At 1 year, there was persistence of one type 1a endoleak in both groups, but these were deemed dead-end leaks as they did not fill the sac nor lead to aneurysm growth. There were no migrations (>0.5 cm) noted in either group. Sac regression was observed at an average rate of 0.24 cm/year in the IF group and 0.26 cm/year in the SF group ( P = NS). There were no aneurysm ruptures during the study period. Conclusions There are no significant differences in endograft migration or in the incidence of early and late type 1a endoleaks between endografts that use IF (Gore Excluder) and SF (Cook Zenith) fixation for patients with short aortic necks undergoing EVAR.

ObjectiveEndovascular interventions for critical limb ischemia (CLI) continue to have variable reported results. The purpose of this study is to determine the effect of disease level and distribution on the outcomes of tibial interventions.MethodsA retrospective analysis of all tibial interventions done for CLI between 2006 and 2009 was performed. Outcomes of isolated tibial (group I) and multilevel interventions (group II) (femoropopliteal and tibial) were compared.ResultsEndovascular interventions were utilized to treat 136 limbs in 123 patients for CLI: 54 isolated tibial (85% tissue loss), and 82 multilevel (80% tissue loss). Mean age and baseline comorbidities were comparable. The mean ankle-brachial index (ABI) was significantly lower prior to intervention in group II (0.53 vs 0.74; P < .001) but was similar postintervention (0.86 vs 0.88; P = NS). Wound healing or improvement was achieved in 69% in group I and in 87% in group II (P = .05). Mean overall follow-up was 12.6 ± 5.3 months. Time to healing was significantly longer in group I: 11.5 ± 8.8 months vs 7.7 ± 6.6 months (P = .03). Limb salvage was achieved in 81% of group I and 95% of group II (P = .05). The rate of reintervention was similar (13% vs 18%, P = NS), so was the rate of late surgical conversion (0% vs 6%; P = NS). Limb loss resulted from lack of conduit or initial target vessel for bypass and high-risk systemic comorbidities. Overall mortality rates were similar among both groups. An isolated tibial intervention was a predictor of limb loss at 1 year on multivariate analysis and resulted in a lower rate of limb salvage at 1 year compared with multilevel interventions. Additionally, despite comparable primary patency rates, there was improved secondary patency with multilevel interventions compared with the isolated tibial interventions. Predictors of limb loss in patients treated with isolated tibial intervention included multiple synchronous tibial revascularization (P = .005) and advanced coronary artery disease requiring revascularization (P = .005).ConclusionsAdequate rates of limb salvage can be achieved in patients undergoing multilevel interventions for CLI, and improved patency is seen with multilevel compared to isolated tibial interventions. Patients with isolated tibial disease appear to have a higher incidence of limb loss secondary to poor initial pedal runoff, more extensive distal disease, and severe comorbidities precluding surgical bypass. Other therapeutic strategies should be considered in these patients, including primary amputation or pedal bypass when applicable.

Objective The natural history of acute carotid artery dissection is poorly characterized. The purpose of this study is to report on single institutional long-term outcomes. Methods A retrospective review of patients treated for acute spontaneous or posttraumatic carotid artery dissection over a 20-year period from August 1989 to July 2009 was performed. Results Twenty-nine patients with a mean age of 47 ± 19.6 years were identified with acute carotid dissection. Six (25%) were related to trauma, while 23 (79%) were spontaneous. Neurologic symptoms included contralateral limb weakness (55%), facial pain (35%), and Horner's syndrome (21%). Eight patients (28%) presented with an acute hemispheric stroke. Diagnostic imaging modalities used included computed tomography angiography (52%), magnetic resonance angiography (41%), and conventional angiography (48%). Twenty percent of patients had complete carotid occlusion and 25% had near occlusion. Most dissections (65%) had intracranial extension, and 35% were limited to the extracranial cervical internal carotid. The majority (96%) of patients were treated conservatively with anticoagulation or antiplatelet therapy or both. One patient underwent stenting for persistent symptoms resulting in complete recovery. There were two deaths, one from unrelated traumatic injuries and the other from unknown causes. Long-term follow-up was available for 20 patients: 14 had complete symptom resolution (70%) and five (25%) had partial clinical symptom resolution. Two patients had initial resolution of symptoms, with subsequent recurrence that was successfully managed conservatively. Follow-up imaging revealed luminal patency in 79% of patients with minimal residual stenosis. Two patients developed a small asymptomatic internal carotid aneurysm that did not require treatment. Mean follow-up was 1133.2 days. Conclusions Most cervical carotid dissections can safely be conservatively managed, with the majority achieving anatomic and symptomatic resolution, with low rates of recurrence over long-term follow-up.

Using 24-hour dietary recall data from the National Health and Nutrition Examination Survey 1999 to 2006, the possible link between fruit and vegetable intake and chronic disease risk was assessed. C-reactive protein (CRP), low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose (FPG), total cholesterol, and glycosylated hemoglobin were selected as biomarkers for chronic disease risk. It is hypothesized that individuals who consume more fruits and vegetables will have reduced chronic disease risk because of the healthful benefits of these foods. The objective of this study was to examine the relationship between fruit and vegetable consumption on selected biomarkers for chronic disease risk. Although some associations were significant for FPG, HDL-C, and low-density lipoprotein cholesterol in some of the models, no trend was present. After adjusting for demographic factors, socioeconomic factors, lifestyle factors, body mass index, total energy intake, and the presence of at least 1 of our 5 predetermined comorbidities, no associations of reduced or increased risk were observed in any quartiles of combined fruit and vegetable intake. Fruit and vegetable intakes were weakly associated with an increased HDL-C level and decreased FPG, glycosylated hemoglobin, and C-reactive protein levels in some of the models; however, no association was observed in the final model. Because selected biomarkers of future disease risk remained in reference ranges at both high and low intake and no significance was observed in the final model, no protective association was observed between fruit and vegetable intake and biomarkers for chronic disease risk. However, fruit and vegetable consumption is recommended as part of an overall healthy diet and to displace other energy-dense foods for weight maintenance, which can lead to a decrease in future disease risk.

Surfactant proteins A and D (SP-A and -D) play a role in many acute bacterial, viral, and fungal infections and in acute allergic responses. In vitro , human SPs bind Mycobacterium tuberculosis and alter human and rat macrophage-mediated functions. Here we report the roles of SP-A and SP-D in M. tuberculosis infection following aerosol challenge of SP-A-, SP-D-, and SP-A/-D-deficient mice. These studies surprisingly identified no gross defects in uptake or immune control of M. tuberculosis in SP-A-, SP-D-, and SP-A/-D-deficient mice. While both SP-A- and SP-D-deficient mice exhibited evidence of immunopathologic defects, the CD11b high CD11c high dendritic cell populations and the gamma interferon (IFN-γ)-dependent CD4 + T cell response to M. tuberculosis were unaltered in all genotypes tested. Together, these data indicate that SP-A and SP-D are dispensable for immune control of M. tuberculosis in a low-dose, aerosol challenge, murine model of tuberculosis (TB).

Metabolomics has ushered in a novel and multi-disciplinary realm in biological research. It has provided researchers with a platform to combine powerful biochemical, statistical, computational, and bioinformatics techniques to delve into the mysteries of biology and disease. The application of metabolomics to study malaria parasites represents a major advance in our approach towards gaining a more comprehensive perspective on parasite biology and disease etiology. This review attempts to highlight some of the important aspects of the field of metabolomics, and its ongoing and potential future applications to malaria research.

Background Advances in endovascular techniques have provided new options in the treatment of complex infrainguinal occlusive lesions. The purpose of this study was to evaluate outcomes of endovascular interventions on TransAtlantic InterSociety (TASC) II D femoropopliteal occlusive disease. Methods All patients undergoing endovascular interventions for femoropopliteal occlusive disease between July 2004 and July 2009 were reviewed. Patient demographics, pre- and postprocedure ankle-brachial indices (ABI) and anatomic factors were analyzed. Outcomes evaluated included primary patency, assisted-patency, secondary patency, predictors of restenosis, and wound healing. Results Five hundred eighty-five limbs were treated during the period reviewed. The study group included 79 TASC D limbs in 74 patients (mean age 76.5 ± 11.9 years, male sex: 53%). Fifty-six limbs (71%) underwent treatment for critical limb ischemia, including 42 (53%) with tissue loss. Eleven patients (15%) had previous failed bypasses. Preoperative ABIs were unobtainable for 23 patients, while the remaining 56 had a mean baseline ABI of 0.54 ± 0.28. There was one periprocedural mortality. Five patients (6.3%) had periprocedural complications. Mean increase in ABI postprocedure was 0.49 ± 0.35. Follow-up was available for 74 limbs at a mean of 10.7 months (range, 1-35). There were 18 mortalities (24.3%) during the follow-up period. No patient required a major amputation during this follow-up period. Twenty-one limbs (26.6%) experienced restenosis and nine limbs (11.4%) experienced occlusion. Twenty-nine limbs underwent reintervention during the follow-up time, including nine which underwent multiple reinterventions. Primary, assisted-primary, and secondary patency rates at 12 and 24 months were 52.2%, 88.4%, 92.6% and 27.5%, 74.2%, and 88.9%, respectively. Predictors of restenosis/occlusion included hypercholesterolemia, the presence of a popliteal artery stent, and patients who were current or former smokers. Conclusions Endovascular interventions for TASC II D lesions can be safely performed with excellent hemodynamic improvement and limb salvage rates. Restenosis is not uncommon in this population, which mandates strict follow-up. Further follow-up is necessary to determine the long-term efficacy of these interventions.

Objective Venous lysis is usually reserved for symptomatic patients with acute deep vein thrombosis (DVT) and low risk for bleeding. This study reports the use of pharmacomechanical thrombectomy (PMT) in patients with contraindications to thrombolysis. Methods A retrospective review of all patients with symptomatic DVT treated between 2007 and 2008 with PMT was performed. All patients were treated by a combination of local tissue plasminogen activator (tPA) with the Angiojet (Possis Medical, Minneapolis, Minn) or Trellis device (Bacchus Vascular, Santa Clara, Calif). Catheter-directed lysis was used sparingly. Results Forty-three patients (mean age, 48.4 ± 16.6 years) presented with symptoms averaging 13.6 ± 9.6 days in duration. Nineteen (44%) had symptoms for >14 days, and 15 (35%) had a high risk for bleeding. Symptomatic subclavian thrombosis occurred in eight (19%), and 35 (81%) presented with disabling lower extremity DVT (4 phlegmasia) despite anticoagulation. Fifteen patients had a thrombosed indwelling permanent filter. Sixty-three percent were treated in one session, but 16 patients required a lytic infusion after suboptimal PMT. Iliac stenting was required in 35% of limbs treated. Successful lysis (>50%) was achieved in 95% of patients and symptom resolution in 93%. All patients became ambulatory with no or minimal limitation. There were no major systemic bleeding complications, but access site hematoma occurred in two patients and worsening of pre-existing rectus sheath hematoma requiring transfusion occurred in another two. Limb salvage was maintained in 100% of patients who presented with phlegmasia. Mean follow-up was 5.0 ± 4.8 months. Freedom from DVT recurrence and reintervention was 95% at 9 months by life-table analysis. Conclusions PMT can be safely and effectively used for subacute iliocaval and iliofemoral DVT and in patients with contraindications for lytic therapy, resulting in improved functional outcomes relative to their debilitated state before the procedure.

Objectives Atherosclerotic occlusive disease of the femoral artery is associated with symptoms ranging from claudication to tissue loss. This study examined the clinical and hemodynamic outcomes of isolated femoral endarterectomy (FEA) as well as the predictors of symptom recurrence and need for further intervention. Methods Patients who underwent an isolated FEA between January 2001 and June 2008 were reviewed. Concurrent superficial femoral artery (SFA) disease was classified into Trans Atlantic Inter-Societal Consensus (TASC) II categories based upon angiographic findings. Hemodynamic success (HS) was defined as a postoperative ankle-brachial index (ABI) increase of ≥0.15. Clinical improvement was classified by Rutherford criteria. Multivariate analysis was used to identify predictors of clinical failure and need for additional intervention (AI). Kaplan-Meier estimates were used to determine the likelihood of both over time. Results Ninety-five patients (105 limbs) with a mean age of 68.3 ± 10.2 years were reviewed. Indications were severe claudication in 68 (64.8%) limbs and critical limb ischemia (CLI) in 37 (35.2%). Mean preprocedural ABI was 0.57 ± 0.25. The SFA-popliteal segment was classified as: normal in 34% of limbs, TASC A 23%, B 19%, C 9%, and D in 15%. One fatal myocardial infarction accounted for a procedural mortality of 0.95%. Morbidity was 6.7% (four hematomas and three wound infections) and mean hospital stay was 2.5 ± 3.1 days. Patency was 100% with a mean follow-up of 11 months (1-72). Complete resolution of symptoms was noted in 73.4% with some clinical improvement noted in 91% of limbs. HS was achieved in 85.1% with a mean ABI increase of 0.27 ± 0.20, and this correlated with ≥2 runoff vessels (odds ratio [OR] 0.20; 95% confidence interval [CI] 0.04-0.96; P = .045). Kaplan-Meier estimates revealed that 83.8% of patients with marked initial clinical improvement remained symptom free at 2 years, whereas only 28.6% in the group with mild and moderate initial response maintained their clinical status. Freedom from AI at 2 years was 61.8%. Multivariate analysis revealed that TASC C and D lesions (OR 9.3 [2.43-35.63] P = .001) and diabetes (OR 3.64 [1.01-13.15] P = .048) were predictive of recurrent symptoms while extensive endarterectomy and ≥2 vessel tibial runoff decreased the need for AI. Conclusion FEA can achieve excellent immediate clinical and hemodynamic outcome in patients with claudication and CLI; however, patients with diabetes and femoropopliteal TASC C and D lesions are likely to experience recurrent symptoms. Long-term symptomatic improvement is associated with the degree of immediate clinical success as well as the status of the run-off vessels. Limited FEA and poor tibial runoff are associated with the need for AI.

Epidemiologic studies have repeatedly identified malnutrition as a risk factor for tuberculosis (TB), which is the leading bacterial cause of deaths worldwide. The biologic basis for this association, however, remains unclear. Recent work has uncovered a large array of signaling molecules lying at the intersection of metabolic and immune signaling, among which nuclear hormone receptors (NHRs) and the insulin receptor have emerged as 2 prototypic examples. Existing knowledge indicates that the physiologic functions of many NHRs overlap with known epidemiologic risk factors for TB and that diabetes, itself, predisposes to TB. Here, we assimilate these data and identify a potential mechanism that may help to explain the long-standing clinical association between TB and host metabolism. Together, these data emphasize the underused potential of interdisciplinary dialog in current TB research efforts.

Purpose To describe the anatomic and visual outcomes of patients in whom noninfectious endophthalmitis developed after injection of intravitreal triamcinolone acetonide. Design Retrospective case series. Methods Ophthalmologic evaluations of patients in whom noninfectious endophthalmitis developed after intravitreal triamcinolone took place on the day of injection, at the time of presentation of noninfectious endophthalmitis, at the time of clearance of inflammation, and on follow-up examination. Seventeen eyes of 17 patients were identified from 2 institutions. Noninfectious endophthalmitis was identified based on history of visual loss immediately or soon after injection, lack of ocular pain, hypopyon, anterior or vitreous inflammation, and triamcinolone crystals present in the anterior or posterior chambers. Main outcome measures were Snellen visual acuity (VA) and mean foveal thickness by optical coherence tomography. Results Mean VA and mean foveal thickness on the day of injection of intravitreal triamcinolone were 20/132 (logarithm of the minimum angle of resolution [logMAR], 0.82 ± 0.45) and 432 ± 118 μm, respectively. Mean VA at time of noninfectious endophthalmitis (mean, 1.9 days after injection) was 20/4444 (logMAR, 2.35 ± 0.98). At last follow-up (mean, 57.6 days), VA and mean foveal thickness were 20/56 (logMAR, 0.44 ± 0.30) and 301 ± 71 μm, respectively. Conclusions VA and mean foveal thickness in all patients with noninfectious endophthalmitis after intravitreal triamcinolone improved to better than preinjection levels in this series. At last follow-up, no patient had sustained visual loss from noninfectious endophthalmitis. Noninfectious endophthalmitis after intravitreal triamcinolone may not exclude good visual and anatomic prognoses.

Endovascular abdominal aortic aneurysm repair (EVAR) has become the first-line approach for the treatment of abdominal aortic aneurysms. Outcomes outside of tertiary care settings remain unknown. The purpose of this study is to report the midterm outcomes of EVAR in a community hospital. A retrospective review of 75 elective, consecutive EVARs performed at a single nonacademic community hospital was performed. There were no conversions to open repair during or after endovascular repair. The mean follow-up was 18 months. There were no postoperative ruptures or aneurysm-related deaths. At 24 months, freedom from aneurysm-related death was 100%, freedom from secondary interventions was 91%, and freedom from endoleak was 69%. EVAR in the community setting is a safe and durable procedure, even in a medically high-risk population. Comparable outcomes can be achieved to tertiary care centers, in carefully selected patients with favorable anatomy.

ObjectiveThe purpose of this study is to evaluate contemporary results of ruptured aortoiliac aneurysms (RAAA) and identify the role of surgeons' annual aortic volume and other prognostic indicators for early outcome.MethodsA retrospective review identified 213 consecutive patients who presented with an atherosclerotic RAAA without thoracic extension over 6.5 years ending in June 2007. Excluded were 31 ruptures treated by endovascular repair (EVAR) or following previous EVAR, also excluded were two chronic asymptomatic hemodynamically stable ruptures. Ten patients were not treated due to either patient's refusal or prohibitive surgical risk. Demographic, preoperative, intraoperative, and postoperative variables were collected. Log rank test and Cox proportional hazard model analyses were utilized to identify factors contributing to mortality and morbidity in these patients. Survival rates were estimated by Kaplan-Meier method.ResultsOne hundred thirty-one males and 39 females with a mean age of 74.5 ± 8.1 years underwent consecutive RAAA repairs. The operative mortality rate was 38.2% (65/170), including 29 intraoperative deaths. Using multivariate analysis, surgeon's average annual AAA volume (20 average annual AAA cases/y) had a higher 30-day survival rates (78.4% vs 57.9%, P = .024). Octogenarians had a lower 30-day survival rate of 49.0% vs 70.5% (P = .012). Patients who developed postoperative intestinal ischemia had a lower 30-day survival rate compared with patients without (48.1% vs 15.3%, P = .002). Increased intraoperative fluid and blood product usage was associated with bowel ischemia (P < .05).ConclusionsRAAA remains a highly lethal problem. The improved early outcomes of surgeons with high-volume AAA have strong implications for training, emergency staffing needs and alternative treatment strategies.

Antidepressant overdose may be associated with significant cardiotoxicity, and recent data have shown that acute toxic effects are associated with impaired heart rate variability. This study was designed to examine the feasibility of non-invasive heart rate variability recording in patients that present to hospital after deliberate antidepressant ingestion. This was a prospective study of 72 consecutive patients attending the Emergency Department after deliberate antidepressant overdose and 72 age-matched patients that ingested paracetamol, as a control group. Single time-point continuous electrocardiographic recordings were used to allow spectral analyses of heart rate variability determined in low-frequency (LF) and high-frequency (HF) domains. The LF:HF ratio was used to represent overall sympathovagal cardiac activity. Antidepressant overdose was associated with reduced overall heart rate variability: 1329 vs. 2018 ms2 (P = 0.0239 by Mann–Whitney test). Variability in the LF domain was higher (64.8 vs. 49.8, P = 0.0006), whereas that in the HF domain was lower (24.3 vs. 36.4, P = 0.0001), and the LF:HF ratio was higher in the antidepressant group (2.4 vs. 1.2, P = 0.0003). Antidepressant overdose is associated with impaired heart rate variability in a pattern consistent with excess cardiac sympathetic activity. Further work is required to establish the significance of these findings and to explore whether the impairment of heart rate variability may be used to predict the development of arrhythmia in this patient group.

Objective A drawback of endovascular aneurysm repair (EVAR) is the need for ongoing surveillance. Follow-up schedules including 1-, 6-, and 12-month computed tomography (CT) established by regulatory trials have been carried into clinical practice without critical assessment. The utility of a 6-month CT, with its associated radiation exposure and contrast toxicity, obtained after a normal result at 1-month CT has not been established. Methods All EVAR patients from 1996 to 2004 at one institution with complete local 1-year follow-up were reviewed for clinically significant CT findings at 1, 6, and 12 months. Before 2000, all patients underwent 1-, 6-, and 12-month CT. In 2000, a policy of omitting the 6-month CT in patients who had a normal result on the 1-month scan was adopted. Results During the study period, 573 patients underwent EVAR, and 376 patients who had complete local 1-year follow-up were included in this review. All had a 1-month CT scan and the result was abnormal in 40 (10.6%): five had type 1 leaks (1.3%), 34 had type 2 leaks (9.0%), and one had a type 3 leak (0.3%); all were followed with 6-month CT. The 1-month CT scan result was normal for 336 (89.4%) patients. Of these, group I (130 patients, 67 treated after 2000) underwent routine 6-month CT, with only two abnormalities noted (1.5%); both were type 2 endoleaks not associated with sac growth. No 6-month CT in this group demonstrated findings warranting intervention. The 6-month CT was omitted in group II (206 patients, all treated after 2000), and follow-up was only at 1 year. In this group, no patient's management would have been altered by findings on a 6-month CT. No patient in either group experienced aneurysm sac growth by 1 year. Clinical complications occurred in three group I patients (2.3%): seroma, limb occlusion, and main body thrombosis. Only one group II patient (0.5%) experienced a complication ≤1 year, a limb occlusion at 9 months. Conclusions After EVAR, a 6-month CT after a normal 1-month CT result does not identify any clinically significant findings warranting intervention and can be omitted safely from the follow-up schedule.

Spinal cord ischemia after treatment of thoracic pathologies remains a devastating problem. A 74-year-old man with a history of infrarenal abdominal aortic aneurysm repair presented with bilateral common iliac and left femoral aneurysms as well as a thoracic aortic aneurysm. He underwent an open repair of the iliac and femoral aneurysms, followed by thoracic endovascular aneurysm repair in a staged manner without complications. Ten months later, he presented with hypotension, and permanent paraplegia developed.

Background Traumatic transection of the thoracic aorta is a highly morbid injury. Treatment may be delayed while attention focuses on concomitant injuries. Thoracic endovascular aortic repair (TEVAR) is effective but remains controversial in these often-young patients. We reviewed our experience in acute and subacute treatment of these injuries with TEVAR. Methods A retrospective analysis of five men and five women who underwent TEVAR for aortic transection from 1999 to 2007 was conducted. Procedures were performed with standard endovascular techniques. Follow-up included computed tomography at 1 month and yearly thereafter. Results Mean age was 44 years (range, 20 to 84 years). Motor vehicle accidents accounted for 7 injuries, a snowmobile accident for 1, skydiving for 1, and balloon angioplasty of a coarctation for 1. Average diameter of the proximal landing zone was 25 mm (range, 23 to 29 mm). Mean external iliac size was 10 mm (range, 7 to 15 mm), and no conduits were required. Immediate technical success was 90%, with no 30-day mortality. Seven patients underwent repair acutely (≤24 hours) and three patients subacutely (range, 4 days to 2 months) for pseudoaneurysm. Four patients had procedures for concomitant injuries before their transection was repaired (3 laparotomies and a fixation for open fracture). One endoleak was noted, which resolved by the 1-month follow-up. The lone device-related complication was an endograft collapse at 5 months managed by repeat endografting, which was complicated by aortoesophageal fistula requiring esophagectomy and open reconstruction. No iliac injuries occurred. At 20-months of mean follow-up (range, 2 to 70 months), all patients are alive and well. Conclusions TEVAR for traumatic aortic transection is feasible, with good initial success. Repair can be delayed in selected cases. Continued surveillance is necessary to ensure good long-term outcomes in these young patients. Care must be taken when performing TEVAR for this off-label indication because these devices are designed for the larger aortic diameters of aneurysm patients.

Objective The purpose of this study was to evaluate the results of open repair for ruptured descending thoracic and thoracoabdominal aortic aneurysm (RDTAA). Methods A retrospective review identified 41 consecutive cases of open surgical repair in 40 patients presenting with nontraumatic, atherosclerotic RDTAA from 1996 to 2006. Patients with traumatic injuries or complicated dissections were excluded. Patient characteristics and preoperative, intraoperative, and postoperative variables were collected from the medical record. Univariate and logistic regression were used to identify factors contributing to mortality and morbidity in these patients. Results The operative mortality rate was 26.8% (11/41). All but two deaths occurred within 24 hours of operation; seven were intraoperative. Overall actuarial survival rates at 1 and 2 years were 53.7% and 47.1%, respectively. For those who survived to hospital discharge, the respective numbers were 73.3% and 64.4%. Intraoperative hypotension and blood transfusion requirements were independent predictors of perioperative death. Octogenarians had a mortality rate equivalent to that of the younger population (25% vs 27.6%; not significant). There was a strong trend toward an improved outcome in the latter part (2003-2006) compared with the first part (1995-2002; 13.6% vs 42.1%, respectively; P = .075). Conclusions Direct open repair for RDTAA can be achieved with acceptable mortality and morbidity rates even in elderly patients. Improved outcome can be expected with increased volume and experience. This series should help establish a reference against which the results of endovascular endeavors and hybrid procedures could be compared.