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Purpose: Molecular deregulations underlying epithelioid sarcoma (ES) progression are poorly understood yet critically needed to develop new therapies. Epidermal growth factor receptor (EGFR) is overexpressed in ES; using preclinical models, we examined the ES EGFR role and assessed anti-ES EGFR blockade effects, alone and with mTOR inhibition.Experimental Design: EGFR and mTOR expression/activation was examined via tissue microarray (n = 27 human ES specimens; immunohistochemistry) and in human ES cell lines (Western blot and quantitative reverse transcriptase PCR). Cell proliferation, survival, migration, and invasion effects of EGFR and mTOR activation treated with erlotinib (anti-EGFR small-molecule inhibitor) alone and combined with rapamycin were assessed in cell culture assays. In vivo growth effects of erlotinib alone or with rapamycin were evaluated using severe combined immunodeficient mouse ES xenograft models.Results: EGFR was expressed and activated in ES specimens and cell lines. EGFR activation increased ES cell proliferation, motility, and invasion and induced cyclin D1, matrix metalloproteinase (MMP) 2, and MMP9 expression. EGFR blockade inhibited these processes and caused significant cytostatic ES growth inhibition in vivo. mTOR pathway activation at varying levels was identified in all tissue microarray–evaluable ES tissues; 88% of samples had no or reduced PTEN expression. Similarly, both ES cell lines showed enhanced mTOR activity; VAESBJ cells exhibited constitutive mTOR activation uncoupled from EGFR signaling. Most importantly, combined erlotinib/rapamycin resulted in synergistic anti-ES effects in vitro and induced superior tumor growth inhibition in vivo versus single agent administration.Conclusions: EGFR and mTOR signaling pathways are deregulated in ES. Preclinical ES model–derived insights suggest that combined inhibition of these targets might be beneficial, supporting evaluations in clinical trials. Clin Cancer Res; 17(18); 5901–12. ©2011 AACR.

Acute autoimmune hemolytic anemia requires rapid stabilization, typically through the administration of high-dose corticosteroids. However, it is important to consider reactivation of latent infection and how immune suppression can interfere with molecular screening tools. In this case report, we present a patient with Rheumatoid Arthritis/Systemic Lupus Erythematosus experiencing severe autoimmune hemolytic anemia complicated by an unknown latent tuberculosis infection.

Background Carbapenem use correlates with the development of carbapenem-resistant organisms, prompting our antimicrobial stewardship program (ASP) to develop a policy mandating infectious diseases (ID) consultation after 72 hours of meropenem use. Our objective was to evaluate the impact of this policy on meropenem utilization and associated clinical outcomes. Methods This quasi-experimental, observational study evaluated the impact of the new ASP policy in adult patients across four campuses. Administered meropenem orders were retrieved retrospectively six months before (11/2020-4/2021) and after (6/2021-11/2021) policy implementation. The primary outcome was meropenem days of therapy per 1000 patient-days (DOTs). Secondary outcomes included DOTs of select broad-spectrum antimicrobials, 30-day all-cause mortality, hospital length of stay (LOS), and Clostridioides difficile (C. difficile) infection incidence. All outcomes were assessed in pre- and post-intervention periods. Results There were 1493 and 1404 meropenem orders in the pre- and post-intervention periods, respectively. Pre-intervention group patients had slightly higher modified Charlson Comorbidity Index scores (2.1 vs 1.9, p=0.02). Pre-intervention group had more patients with penicillin allergies but less patients with sulfa allergies (p=0.007 and p=0.03, respectively). The most common meropenem indications were bloodstream, respiratory, abdominal, and urinary tract infections. The incidence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales and cefepime-resistant Pseudomonas spp. was similar in both groups (p=0.7 and p=0.1, respectively). ID consultation increased after policy implementation (44.1% vs 51.7%, p=0.001). Meropenem DOTs decreased significantly after intervention (50.3 vs 35.5, p=0.0003). We observed increases in ceftriaxone and cefepime DOTs (94 vs 103.8, p=0.006 and 39 vs 58.5, p=0.0005, respectively). An increase in C. difficile incidence was seen. Hospital LOS was similar pre- and post-intervention (mean 18.5 days, p=0.9). Conclusion The ASP policy mandating ID consultation after 72 hours of meropenem use helped decrease meropenem DOT and encouraged use of antimicrobial agents with narrower spectrum. Disclosures All Authors: No reported disclosures.

SARS-CoV-2 has caused a global pandemic of an acute respiratory illness known as COVID-19. Patients with solid organ transplants receiving chronic immunosuppressive therapy are at risk of severe disease caused by opportunistic pathogens, including cytomegalovirus (CMV). We present the case of a renal transplant recipient presenting with hypoxic respiratory failure because of severe COVID-19, whose course was complicated by ganciclovir-resistant CMV pneumonitis.

Infective endocarditis (IE) is a rare but serious disease. Coagulase-negative staphylococci (CoNS) are among the least prevalent causes of IE. Staphylococcus capitis, a species of CoNS, although described in the literature before has only been seen in a few cases. Even with such few cases, complications and mortality have still been demonstrated. In our review, we look at the epidemiology, diagnosis, management, and literature prevalence of CoNS in native and prosthetic valve IE.

In this report, we discuss how autoimmune conditions and associated immunocompromise may impact diagnostic utility of molecular screening tools for mycobacterial infection. Imaging, molecular screening, and clinical judgment are required to rule out disease in the immunocompromised, especially in an acute setting

Purpose The aim of this paper is to identify the business barriers that influence cost of implementing unmanned aerial system (UAS) and its suitability for a decentralised system. UAS, or drone, plays a role of data provider to architectural, engineering and construction professionals within a decentralised system. However, the expectations in the execution and test of the effectiveness of the UAS is often not met. The reasons for these fails are not well elaborated in the literature. Hence, the study investigates the barriers and cost analysis of UAS that can be used for a decentralised case, in which the UAS data are useful for multiple stakeholders, and provide illustration of the interactions within this approach. Design/methodology/approach This paper is part of a longitudinal project by using a qualitative method of interviewing 24 participants involved in the process of application of drones in the country of the Dominican Republic. The open-ended semi-structured interviews were composed for questions regarding the application of UAS, barriers and business implications. The data gathered were transcribed and used thematic analysis for its interpretation. Later, conclusions of the barriers of UAS implementation in the organisation were analysed and a cost model was developed to identify a viable scenario. Findings The paper provides empirical insights about the barriers and economic considerations faced in the implementation process of UAS. In this research, 16 barriers in the implementation process at the management level, 8 types of cases of business relationships and 13 business models were identified. Furthermore, recommendations were made about being the accountability of the dimensions and recurrent visits to the projects handled by the portfolio of the organisations. Research limitations/implications Blockchain system is supported by UAS data and its tests require skills and resources that were outside of the scope of the main research intend regarding UAS implementation in construction. Furthermore, as these technologies are still under development, the assessment of the decentralised system, smart contract and swarm technology was addressed conceptually and further research are encouraged in this field. Practical implications The paper includes barriers to consider before implementation, business implications, project examples and cost structure developed. Furthermore, the findings are fit theoretically into the context of a decentralised system. It was understood and contemplated that monitoring in open and outdoor spaces is the suitable approach for UAS implementations for decentralised system. The trend of decentralised autonomous organisations for transparency and efficiency of human tasks provides the foundations of human–robot interactions as well as the role of tokenisation of assets into the cyberspace. Therefore, the paper brings managers and technicians the implications for the future-proofing the implementation of UAS. Originality/value This paper provides an overview of the implications of cost and the suitable scenarios for return of investment in the UAS implementation in the current stage of the technology development. In addition, the paper makes reference to decentralised systems, smart contracts and swarm technology as options in which reality capture technologies are essential for construction projects.

Cholera is an illness caused by Vibrio cholerae; its main symptom is acute watery diarrhea. Some infections are asymptomatic or result in patients presenting with mild diarrhea, but complications, such as bacteremia, can be fatal. Being endemic in Africa, Southeast Asia, and Haiti, V. cholerae infection cases in the United States are primarily considered travel-related. Herein, we report a case of a 91 year old Caucasian man, a Texas Gulf Coast resident, who developed bacteremia due to V. cholerae despite having no international travel history. Culture workup by mass spectrometry, automated biochemical system, and 16S ribosomal RNA (rRNA) gene sequencing confirmed V. cholerae. This case conveys an important reminder to clinicians and laboratory professionals regarding potentially serious cholera illnesses due to the domestic prevalence of V. cholerae in the coastal regions of the United States.

Extremely drug-resistant (XDR) Acinetobacter baumannii causes challenging nosocomial infections. We report the case of a patient with XDR A. baumannii pneumonia and septic shock successfully treated with cefiderocol and a novel antibiotic obtained via expanded access protocol. With focused research and drug development efforts, the poor outcomes associated with these infections may be mitigated.

Diarrhea among recipients of solid organ transplants is a commonly encountered problem and is often multifactorial in etiology. Owing to the combination of perioperative antibiotic administration and the immunosuppressed status of transplant recipients, a high degree of suspicion for Clostridioides difficile (C. difficile) colitis is prudent. The purpose of this study is to demonstrate the association of an institutional integrated stewardship program with C. difficile testing practices after abdominal solid organ transplantation.Starting in July 2017, a diagnostic stewardship was enacted in our institution requiring the ordering provider to answer a series of questions within the electronic medical record before ordering a C. difficile toxin test. The charts were reviewed for all solid organ transplant recipients on whom a test was ordered between January 2016 and September 2019.Orders for C. difficile toxin per quarter significantly decreased in the postintervention era (18 vs 8.5, P = .038). Median cost of inpatient treatment and days of therapy per thousand patient days was significantly lower in the postintervention era (median cost, $2,944.55 vs $416.92; P = .01) (days of therapy per thousand patient days, 521.9 vs 300.5; P.01). Quarterly rates of negative tests were similar between the pre- and postintervention eras (65% vs 73%, P = .38).Although no orders were blocked based on the responses, this multilevel intervention was associated with a 47% decrease in C. difficile testing without effecting the rate of negative testing. These results suggest that we have achieved significant cost savings, in testing and isolation, without sacrificing critical aspects of clinical care.

In developing countries, typhoid fever is a common cause of febrile illness accompanied by abdominal pain and weakness. It is caused by Salmonella enterica serovar Typhi. Humans are the only known reservoir of infection, and typhoid fever is common in regions where access to clean water and sanitation is limited. The antimicrobials of choice for a case of typhoid fever acquired outside Pakistan are third generation cephalosporins. Lately, cases of extensively drug-resistant (XDR) Salmonella Typhi have been reported in people with a travel history to Pakistan. We present a case of XDR typhoid fever which relapsed after treatment with meropenem.

Introduction : Cardiovascular injury with SARS-CoV-2 infection is well known. Several studies have outlined baseline characteristics in patients presenting with STEMI and SARS-CoV-2. Paucity in data exists in selective coronary involvement in patients with STEMI and SARS-CoV-2 during the COVID-19 pandemic. Methods : A systematic search and meta-analysis of studies meeting the inclusion and exclusion criteria obtained from MEDLINE, Scopus, and Cochrane databases was performed utilizing PRISMA criteria. The main outcome was likelihood of coronary artery involvement among patients with STEMI and SARS-CoV-2 versus without SARS-CoV-2. The primary adverse outcome measured was in-hospital mortality. Results : The final analysis included 5 observational studies with a total of 2, 266 patients. There was no statistical significance in LM (OR 1.40; 95% CI: 0.68, 2.90), LAD (OR 1.09; 95% CI 0.83, 1.43), LCX (OR 1.17; 95% CI: 0.75, 1.85), or RCA (OR 0.59; 95% Confidence Interval 0.30, 1.17) disease among the two groups. LAD disease was the most prevalent coronary involvement among patients with STEMI and SARS-CoV-2 (49.6%). Higher in-hospital mortality was observed in the STEMI and SARS-CoV-2 group (OR 5.24; 95% Confidence Interval 3.63, 7.56). Discussion : Our analysis demonstrated no statistical significance in selective coronary involvement in patients with STEMI and SARS-CoV-2 during the COVID-19 pandemic. The higher mortality among patients with SARS-CoV-2 and STEMI has been noted in prior studies with concerns being late presentation due to fear of infection, delayed care time, and poor resource allocation. Focus should be placed on identifying and managing comorbidities to reduce mortality.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic condition associated with mucocutaneous and visceral arteriovenous malformations (AVMs), including pulmonary AVMs, which predispose patients to systemic paradoxical emboli that can lead to brain abscesses. Intraventricular rupture of brain abscess (IVROBA) is a feared complication with a high mortality rate. Here, we present a case with brain abscesses complicated by IVROBA and ventriculitis as the initial presentation of HHT in an undiagnosed patient. We also discuss the diagnostic and therapeutic approach that resulted in this patient’s clinical improvement.

Background Broad-spectrum antimicrobials, like carbapenems, are often initiated empirically and can be continued for long periods of time, which may increase rates of multi-drug resistant organisms. Antimicrobial stewardship programs (ASP) have been shown to decrease the duration of antimicrobial therapy. Since July 2017 at UTMB Health, meropenem use has been restricted to infectious diseases and intensive care unit (ICU) providers. This study evaluated the impact of an electronic medical record (EMR)-based ASP intervention on meropenem days of therapy (DOT) in patients transitioning from the ICU to the general floors. Methods Patients aged at least 18 years with an active medication order for meropenem upon transition from an ICU to a medical/surgical unit were included. Once transitioned, the active meropenem order appeared in the “review” column of the pharmacists’ queue. Pharmacists contacted the primary team, requested infectious diseases or ASP approval to continue therapy, and documented communication in the chart. Data for the pre- and post-intervention groups was collected retrospectively for the months of November 2017 to April 2018 and March 2020 to August 2020. The primary outcome of the study was meropenem DOT after transition from the ICU to the medical/surgical unit. Secondary outcomes of the study included meropenem total DOT, total number of meropenem doses after transfer to the medical unit, 30-day all-cause mortality, and 30-day readmission. Results A total of 163 patients were evaluated in both the pre-intervention (n = 87) and post-intervention groups (n = 76). Median meropenem DOT after transition of care (3 days vs. 2 days, P = 0.0004) and number of meropenem doses after transition (6 doses vs. 4 doses, P = 0.014) were significantly lower after TOC intervention implementation. However, total meropenem DOTs were not different at 5 days in both groups. Recommendations for de-escalation or discontinuation were accepted 60% of the time among providers. Conclusion An EMR-based ASP intervention did decrease meropenem DOT after patients were transitioned from the ICU to the medical/surgical floors. Results of the meropenem EMR-based ASP intervention may be used to expand to other broad-spectrum antimicrobials/antifungals in patients transitioning levels of care. Disclosures All Authors: No reported disclosures

Background Reported β-lactam allergy (BLA) is very common, yet less than 10% of these patients exhibit true hypersensitivity. When faced with reported BLAs, physicians often choose alternative antibiotics which can be associated with C. difficile infection, drug-resistance development, poorer outcomes, & increased costs. Effective identification of these patients is necessary for subsequent, appropriate BLA “de-labeling.” Here, we conducted a single-center analysis of alternative antibiotic utilization amongst patients reporting BLA and compare the frequency of drug-resistant infections and C. difficile infection in allergic & non-allergic patients. Methods This is a retrospective review of adult patients hospitalized at The University of Texas Medical Branch from 1/1/2015 to 12/31/2019. Pooled electronic medical records were filtered by antibiotic orders and reported allergies to penicillins or cephalosporins. Patients with drug-resistant and/or C. difficile infection (CDI) were identified by ICD-10 codes. Microsoft Excel & MedCalc were used for statistical calculations. Results Data were available for 118,326 patients and 9.3% (11,982) reported a BLA, with the highest rates seen in those receiving aztreonam (85.9%, 530/617) & clindamycin (33.7%, 3949/11718). Amongst patients reporting BLA, high ratios-of-consumption (relative to all patients receiving antibiotics) were seen with aztreonam (7.0), clindamycin (2.7), cephalosporin/β-lactamase inhibitors (2.4), & daptomycin (2.1). Compared to the non-BLA population, BLA patients more frequently experienced MRSA infection (3.0% vs 1.5%, OR 1.99, 95% CI 1.79–2.23, p< 0.0001), β-lactam resistance (1.2% vs 0.6%, OR 2.07, 95% CI 1.72–2.49, p< 0.0001), and CDI (1.2% vs 0.7%, OR 1.85, 95% CI 1.54–2.23, p< 0.0001). Conclusion Our measured BLA rate matches approximate expectations near 10%. Moreover, these patients experienced significantly higher frequencies of drug-resistant bacterial infections and CDI. Targeted inpatient penicillin allergy testing stands to be particularly effective in those patients receiving disproportionately utilized alternative agents (e.g. aztreonam, clindamycin, daptomycin). β-lactam allergy “de-labeling” in these patients is likely a valuable antimicrobial stewardship target. Disclosures All Authors: No reported disclosures

Background Despite widespread antimicrobial resistance, suboptimal antimicrobial use is common, particularly among surgical services. Studies show that antimicrobial stewardship programs (ASPs) effectively improve antimicrobial use and decrease adverse events. However, evidence for optimal ASP intervention in surgical departments is lacking, and some surgical services perceive ASPs negatively. This study aimed to evaluate the effect of several collaborative ASP interventions and workflow changes on the non-acceptance rate (NAR) of ASP recommendations and antimicrobial use among surgical services. Methods This was a retrospective, pre-post study of services in the department of surgery at a 681-bed, academic medical center between 12/01/2018 and 5/31/2020. Throughout 10/2019 and 11/2019, the core ASP, which consists of two infectious diseases physicians and two infectious diseases pharmacists, performed several interventions with surgical services. These included meetings with the chairman, vice chairs, and division chiefs of the surgery department, a grand rounds presentation to surgical house staff, and monthly surgeon NAR reporting to the chairman. Also, per feedback from surgeons, the ASP began to communicate recommendations directly to attending surgeons instead of residents or via ASP notes in the medical record. Data for the pre-period was collected from 12/2018 to 9/2019; data for the post-period was collected from 12/2019 to 5/2020. Wilcoxson rank sum, chi-square, and Fisher’s exact tests were used to compare outcomes. Results The ASP communicated 353 recommendations to surgical services in the pre-period, and 181 in the post-period. ASP offered most recommendations to trauma (n=244), cardiothoracic (n=60), and plastic surgery (n=54) during the study periods. NAR decreased post-intervention overall (43% vs 29%, p=0.0013) and in trauma surgery (63% vs 47%, p=0.03). Mean monthly days of therapy per 1000 patient days trended towards a decrease post-intervention (1105 vs 1044, p=0.26). Cost per 1000 patient days decreased post-intervention ($27,677.91 vs $19,766.31, p =0.0075). Conclusion A communicative and adaptive approach to ASP in surgical services improved NAR and antimicrobial costs and trended towards a reduction in antimicrobial use. Disclosures All Authors: No reported disclosures

Modelar el nicho ecológico óptimo para determinar la distribución potencial de las especies es una opción viable en la ubicación de las mejores áreas para establecer Unidades Productoras de Germoplasma Forestal (UPGF). El objetivo del presente estudio fue modelar la distribución potencial de Pinus pseudostrobus y P. oocarpa en Chiapas, México, mediante el procesamiento cartográfico de variables topográficas, climáticas, edáficas, ecológicas y modelos de nicho ecológico (MaxEnt). Se utilizaron 220 datos de presencia de P. oocarpa y 52 para P. pseudostrobus obtenidos de la Red Mundial de Información sobre Biodiversidad, Global Biodiversity Information Facility, del Missouri Botanical Garden y del Herbario Nacional de México (MEXU). La distribución potencial de la especie fue modelada con 500 y 1 000 iteraciones a través de las regresiones de tipo Logistic, Cumulative y Cloglog. La validación estadística se realizó con 28 % de los datos para cada taxón con las técnicas Crossvalidate y Bootstrap. El modelo que mejor se ajustó fue el logístico con método de remuestreo crossvalidate. Los valores del Área Bajo la Curva (AUC) para los datos estimados y validados fueron de 0.882 para P. oocarpa y 0.947 en P. pseudostrobus. La variable que más influyó en la presencia o ausencia de las especies fue la altitud con 84.5 y 97.3 % para P. oocarpa y P. pseudostrobus, respectivamente. Los resultados del modelo permitieron ubicar áreas óptimas para el establecimiento de UPGF.

A paradigm shift has occurred in the last decade from chemotherapy to targeted therapy for the management of many patients with advanced sarcoma. This work identifies a combination of targeted agents and doxorubicin that are effective against small cell sarcoma cell lines. Three small cell sarcoma cell lines were studied: RD18 (rhabdomyosarcoma), A204 (undifferentiated sarcoma) and TC 71 (Ewing's sarcoma). Each cell line was exposed to increasing concentrations of vorinostat (HDAC inhibitor), 17-DMAG (HSP90 inhibitor), abacavir (anti-telomerase) or sorafenib (tyrosine kinase inhibitor) alone, combined with one another, or combined with doxorubicin. Cell viability, cell cycle analysis and apoptosis were assessed by MTS assay, propidium iodide-Annexin V staining, and caspase 3/7 activity, respectively. The Chou and Talalay combination index (CI) was used to determine whether the effects were additive (CI = 1), synergistic (CI 1) or antagonistic (CI 1). In monotherapy, targeted agents achieved 30-90% reductions in viability, with the exception of abacavir. Dual-targeted combination therapies with vorinostat, sorafenib and 17-DMAG demonstrated synergy. Abacavir was antagonistic with every other drug and was not further studied. Both vorinostat and 17-DMAG synergized with doxorubicin, achieving 60% cell killing compared to 12% with doxorubicin alone. No synergy was observed for sorafenib with doxorubicin. The triple therapy vorinostat, 17-DMAG and doxorubicin did not show synergy, but increased the subG1 population at 24H, from 30% to 70% compared to monotherapies with an increase in apoptosis. This work provides evidence of synergy of combinations of vorinostat, 17-DMAG and sorafenib in small cell sarcoma. In addition to doxorubicin, these combinations enhance doxorubicin cytotoxicity at therapeutically relevant concentrations.

Background: Methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B) may fail to improve with standard monotherapy, particularly in patients with multifocal infection, incomplete source control, or persistent bacteremia. Synergy observed in vitro between ceftaroline (CPT) and daptomycin (DAP) or vancomycin (VAN) may translate into clinical benefit. Here, we describe our experience with DAP/CPT and VAN/CPT for complicated MRSA-B after monotherapy failure. Methods: Single-center, retrospective review of consecutive patients treated with DAP/CPT or VAN/CPT for MRSA-B after monotherapy failure from 1 January 2016 to 30 November 2018. Results: We identified 11 instances of combination therapy in 10 patients (DAP/CPT = 6, VAN/CPT = 5) with 1 patient receiving VAN/CPT followed by DAP/CPT. Rates of multifocal infection, incomplete source control, persistent bacteremia, and infective endocarditis were high (100%, 80%, 60%, and 60%, respectively). Combination therapy was initiated most commonly for persistent bacteremia (60%). When patients were persistently bacteremic, median preceding duration was 13 days and median time to clearance was 3 days. Total microbiologic cure rate was 100%. There were zero instances of bacteremia relapse at 30 days (30D) or 60 days (60D). All-cause 30D and 60D mortality rates were 11.1% and 33.3%, respectively. Conclusions: Combination therapy demonstrated success in diverse cases of refractory MRSA-B, including instances of persistent bacteremia paired with incomplete source control. Optimal timing and therapeutic cadence for combination therapy remain unclear. Our findings suggest that DAP/CPT and VAN/CPT can be considered for complicated MRSA bacteremia when other treatment options fail or are unavailable. We propose persistent bacteremia with incomplete source control to be a clinical niche particularly worthy of further investigation.

Gastrointestinal stromal tumor (GIST), the most common mesenchymal neoplasm of the GI tract and one of the most common sarcomas, is dependent on the expression of the mutated KIT or platelet-derived growth factor receptor in most cases. Imatinib mesylate potently abrogates the effects of KIT signaling by directly binding into the ATP-binding pocket of the kinase. It is becoming increasingly apparent that the binding affinity of imatinib for the receptor is dependent on the type and location of mutation. Within KIT, patients whose tumor has an exon 9 mutation are treated by many clinicians with higher doses of imatinib than those patients with mutations within exon 11. Additionally, there are over 400 unique mutations within exon 11 that may have distinctly different binding affinity for imatinib as well as other kinases. Secondary KIT mutations generally occur at a codon where imatinib binds resulting in KIT reactivation and resistance. Sunitinib malate, a second-generation KIT inhibitor is active in imatinib-resistant disease and is FDA-approved for use in this setting. In this review, we describe the biology of the genes and gene mutations responsible for GIST and discuss known and potential clinical implications.

Although imatinib mesylate has revolutionized the management of patients with gastrointestinal stromal tumor (GIST), resistance and progression almost inevitably develop with long-term monotherapy. To enhance imatinib-induced cytotoxicity and overcome imatinib-resistance in GIST cells, we examined the antitumor effects of the pro-apoptotic Bcl-2/Bcl-x(L) inhibitor ABT-737, alone and in combination with imatinib.We treated imatinib-sensitive, GIST-T1 and GIST882, and imatinib-resistant cells with ABT-737 alone and with imatinib. We determined the anti-proliferative and apoptotic effects by cell viability assay, flow cytometric apoptosis and cell cycle analysis, immunoblotting, and nuclear morphology. Synergism was determined by isobologram analysis.The IC(50) of single-agent ABT-737 at 72 h was 10 μM in imatinib-sensitive GIST-T1 and GIST882 cells, and 1 μM in imatinib-resistant GIST48IM cells. ABT-737 and imatinib combined synergistically in a time- and dose-dependent manner to inhibit the proliferation and induce apoptosis of all GIST cells, as evidenced by cell viability and apoptosis assays, caspase activation, PARP cleavage, and morphologic changes. Isobologram analyses revealed strongly synergistic drug interactions, with combination indices0.5 for most ABT-737/imatinib combinations. Thus, clinically relevant in vitro concentrations of ABT-737 have single-agent antitumor activity and are synergistic in combination with imatinib.We provide the first preclinical evidence that Bcl-2/Bcl-x(L) inhibition with ABT-737 synergistically enhances imatinib-induced cytotoxicity via apoptosis, and that direct engagement of apoptotic cell death may be an effective approach to circumvent imatinib-resistance in GIST.

PURPOSE OF REVIEW: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract and is a paradigm of targeted therapy for solid tumors. Elucidation of the biology of GIST enabled use of imatinib, which revolutionized the prognosis of advanced GIST. Whereas surgical resection continues to be the standard of care for primary GIST, judicious and individualized use of adjuvant and neoadjuvant imatinib may enhance the potential for cure in select patients. RECENT FINDINGS: Prospective trials utilizing adjuvant and neoadjuvant imatinib have established the safety and efficacy of these modalities adjunct to surgical resection. Correlative tissue studies derived from these trials have examined gene expression patterns, metabolic and radiographic response, and apoptosis during the first few days of imatinib therapy. As appropriate use of adjuvant and neoadjuvant imatinib requires proper patient selection, development of a predictive nomogram, and advances in mutational analysis represent progress toward individualized care. SUMMARY: Imatinib is well tolerated and beneficial as adjuvant and neoadjuvant therapy, but its utility in these settings continues to be refined. The greatest benefit will derive from an individualized approach that considers multiple patient, drug, and tumor characteristics to assess risk and likelihood of benefit for each patient.

Background People with HIV are at for metabolic syndrome (MetS) and fatty liver disease, but the role of Antiretroviral therapy (ART) is poorly understood. MetS and fatty liver disease been associated with changes in adiponectin, soluble ST2 (sST2), chitinase 3-like 1 (Chi3L1), hyaluronic acid (HA), tissue inhibitor of metalloproteinase-1 (TIMP-1), lysyl oxidase-like-2 (LOXL2) and transforming growth factor β (TGF-β) concentrations in HIV-uninfected populations. Protease (PI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) may contribute to these comorbidities, but the effects of switching from PI- or NNRTI to raltegravir (RAL) on these biomarkers is unknown. Methods Cryopreserved plasma was obtained from a completed, prospective trial of HIV-infected women with central adiposity on NNRTI- or PI-based ART during which they were randomized to remain on their current ART or switch to a RAL based regimen. Biomarker concentrations were quantified using ELISA and Multiplex assays at baseline and 24 weeks after randomization. Wilcoxon-signed rank test evaluated within-group changes, Spearman and linear regression models evaluated correlations between biomarkers and clinical covariates. Results Participants had a median age of 43 years, CD4+ T lymphocyte count 558 cells/mm3 and BMI 32 kg/m2; 35% met criteria for MetS. At baseline, higher adiponectin levels correlated with higher Chi3L1 levels (r = 0.42, p = 0.02), as did declines after 24 weeks (r = 0.40, p = 0.03). Changes in sST2 correlated with changes in Chi3L1 (r = 0.43, p = 0.02) and adiponectin (r = 0.40, p = 0.03). Adiponectin and Chi3L1 levels decreased significantly in women switched to RAL vs continue PI/NNRTI. Conclusion In women with HIV and central obesity, the hepatic steatosis/fibrosis marker Chi3L1 and adiponectin decrease in conjunction with sST2 decreases following switch to RAL. Whether switching from NNRTI/PI-based regimens to RAL can improve hepatic steatosis and dysmetabolism requires further study. Trial registration Clinicaltrials.gov NCT00656175

Unlike epithelial cancers that are both more homogeneous and easily categorized by their respective tissues of origin (e.g., breast or lung cancer), sarcomas represent a diverse class of molecularly distinct bone and soft-tissue mesenchymal neoplasms of more than 50 subtypes. This diversity, as well as the relative rarity of sarcomas as a whole, has presented challenges in conducting prospective randomized clinical trials to assess the value of neoadjuvant chemotherapy for any given subtype. Most clinical trials and meta-analyses have neglected the phenotypic and molecular heterogeneity differentiating one sarcoma subtype from another in favor of a simplified grouping that ensures timely trial completion. As the success of treating gastrointestinal stromal tumors (GISTs) with imatinib demonstrates, a decision to provide neoadjuvant chemotherapy must take into consideration both the subtype being treated and the effect such treatment would be expected to exert upon that subtype.

We characterized a cDNA from Phlebotomus papatasi, PpChit1, which encodes a midgut specific chitinase and show the presence of a functional, blood-induced chitinolytic system in sand flies. PpChit1 is detected only in the midgut and is regulated by blood feeding. A recombinant protein (rPpChit1) produced in HEK 293-F cells exhibited a similar activity profile to that found in the native protein against several specific substrates, including an oligomeric glycol chitin and synthetic 4-methyl-umbelliferone labelled substrates. Western blotting showed that the native protein is recognized by mouse polyclonal antibodies against rPpChit1. Additionally, the rPpChit1 and the native chitinase displayed similar retention times in a HPLC size fractionation column. When added to rPpChit1 or to midgut lysates, PpChit1 sera reduced chitinolytic activity by 65-70%.

Gastrointestinal stromal tumors (GISTs) are driven by gain-of-function mutations of KIT or PDGFRa. The introduction of imatinib has significantly extended survival for patients. However, most patients develop resistances. Notch signaling is a conserved developmental pathway known to play a critical role in the development of several cancers, functioning as a tumor promoter or a tumor suppressor. Given that the normal progenitor cell for GIST, the interstitial cell of Cajal, has characteristics similar to those of cells of neuroendocrine origin, we hypothesized that Notch pathway impacts the biology of GIST cells. In this study, we retrovirally and pharmacologically manipulated the Notch pathway in human GIST cells. We also performed a retrospective analysis of a cohort on 15 primary tumors to determine the role of Hes1, a major target gene of Notch, as a prognostic marker for GIST. Constitutively, active intracellular domain of Notch1 (ICN1) expression potently induced growth arrest and downregulated KIT expression in vitro. Additionally, treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid caused dose-dependent upregulation of Notch1 expression and a parallel decrease in viability in these cells. Retroviral silencing of downstream targets of Notch (dominant-negative Hes1) and pharmacological inhibition of Notch activation (γ-secretase inhibition) partially rescued GIST cells from suberoylanilide hydroxamic acid treatment. GIST patients with high Hes1 mRNA levels have a significantly longer relapse-free survival. These results identify a novel anti-tumor effect of Notch1 and cross talk between the Notch and KIT pathways. Thus, activation of this pathway by treatment with histone deacetylase inhibitors is an appealing potential therapeutic strategy for GISTs. Précis: This study is the first report of the tumor suppressor effects of Notch pathway in gastrointestinal stromal tumors via a negative feedback with the oncogene KIT and may lead the development of new therapeutic strategies for GISTs patients.

Purpose: Molecular deregulations underlying epithelioid sarcoma (ES) progression are poorly understood yet critically needed to develop new therapies. Epidermal growth factor receptor (EGFR) is overexpressed in ES; using preclinical models, we examined the ES EGFR role and assessed anti-ES EGFR blockade effects, alone and with mTOR inhibition. Experimental Design: EGFR and mTOR expression/activation was examined via tissue microarray (n = 27 human ES specimens; immunohistochemistry) and in human ES cell lines (Western blot and quantitative reverse transcriptase PCR). Cell proliferation, survival, migration, and invasion effects of EGFR and mTOR activation treated with erlotinib (anti-EGFR small-molecule inhibitor) alone and combined with rapamycin were assessed in cell culture assays. In vivo growth effects of erlotinib alone or with rapamycin were evaluated using severe combined immunodeficient mouse ES xenograft models. Results: EGFR was expressed and activated in ES specimens and cell lines. EGFR activation increased ES cell proliferation, motility, and invasion and induced cyclin D1, matrix metalloproteinase (MMP) 2, and MMP9 expression. EGFR blockade inhibited these processes and caused significant cytostatic ES growth inhibition in vivo. mTOR pathway activation at varying levels was identified in all tissue microarray–evaluable ES tissues; 88% of samples had no or reduced PTEN expression. Similarly, both ES cell lines showed enhanced mTOR activity; VAESBJ cells exhibited constitutive mTOR activation uncoupled from EGFR signaling. Most importantly, combined erlotinib/rapamycin resulted in synergistic anti-ES effects in vitro and induced superior tumor growth inhibition in vivo versus single agent administration. Conclusions: EGFR and mTOR signaling pathways are deregulated in ES. Preclinical ES model–derived insights suggest that combined inhibition of these targets might be beneficial, supporting evaluations in clinical trials. Clin Cancer Res; 17(18); 5901–12. ©2011 AACR.

LJM11, an abundant salivary protein from the sand fly Lutzomyia longipalpis, belongs to the insect "yellow" family of proteins. In this study, we immunized mice with 17 plasmids encoding L. longiplapis salivary proteins and demonstrated that LJM11 confers protective immunity against Leishmania major infection. This protection correlates with a strong induction of a delayed type hypersensitivity (DTH) response following exposure to L. longipalpis saliva. Additionally, splenocytes of exposed mice produce IFN-γ upon stimulation with LJM11, demonstrating the systemic induction of Th1 immunity by this protein. In contrast to LJM11, LJM111, another yellow protein from L. longipalpis saliva, does not produce a DTH response in these mice, suggesting that structural or functional features specific to LJM11 are important for the induction of a robust DTH response. To examine these features, we used calorimetric analysis to probe a possible ligand binding function for the salivary yellow proteins. LJM11, LJM111, and LJM17 all acted as high affinity binders of prohemostatic and proinflammatory biogenic amines, particularly serotonin, catecholamines, and histamine. We also determined the crystal structure of LJM11, revealing a six-bladed β-propeller fold with a single ligand binding pocket located in the central part of the propeller structure on one face of the molecule. A hypothetical model of LJM11 suggests a positive electrostatic potential on the face containing entry to the ligand binding pocket, whereas LJM111 is negative to neutral over its entire surface. This may be the reason for differences in antigenicity between the two proteins.

Although gastrointestinal stromal tumors (GISTs) harboring activating KIT or platelet-derived growth factor receptor A ( PDGFRA ) mutations respond to treatment with targeted KIT/PDGFRA inhibitors such as imatinib mesylate, these treatments are rarely curative. Most often, a sizeable tumor cell subpopulation survives and remains quiescent for years, eventually resulting in acquired resistance and treatment failure. Here, we report that imatinib induces autophagy as a survival pathway in quiescent GIST cells. Inhibiting autophagy, using RNAi-mediated silencing of autophagy regulators (ATGs) or antimalarial lysosomotrophic agents, promotes the death of GIST cells both in vitro and in vivo. Thus, combining imatinib with autophagy inhibition represents a potentially valuable strategy to promote GIST cytotoxicity and to diminish both cellular quiescence and acquired resistance in GIST patients.

p.1-23 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-08-28T14:08:47Z No. of bitstreams: 1 1471-2164-7-52.pdf: 1278771 bytes, checksum: bce26a4c87a4bb79671064aad19cb512 (MD5) Approved for entry into archive by Rodrigo Meirelles (rodrigomei@ufba.br) on 2013-10-31T17:44:53Z (GMT) No. of bitstreams: 1 1471-2164-7-52.pdf: 1278771 bytes, checksum: bce26a4c87a4bb79671064aad19cb512 (MD5) Made available in DSpace on 2013-10-31T17:44:53Z (GMT). No. of bitstreams: 1 1471-2164-7-52.pdf: 1278771 bytes, checksum: bce26a4c87a4bb79671064aad19cb512 (MD5) Previous issue date: 2006 Background: Immune responses to sandfly saliva have been shown to protect animals against Leishmania infection. Yet very little is known about the molecular characteristics of salivary proteins from different sandflies, particularly from vectors transmitting visceral leishmaniasis, the fatal form of the disease. Further knowledge of the repertoire of these salivary proteins will give us insights into the molecular evolution of these proteins and will help us select relevant antigens for the development of a vector based anti-Leishmania vaccine. Results: Two salivary gland cDNA libraries from female sandflies Phlebotomus argentipes and P. perniciosus were constructed, sequenced and proteomic analysis of the salivary proteins was performed. The majority of the sequenced transcripts from the two cDNA libraries coded for secreted proteins. In this analysis we identified transcripts coding for protein families not previously described in sandflies. A comparative sandfly salivary transcriptome analysis was performed by using these two cDNA libraries and two other sandfly salivary gland cDNA libraries from P. ariasi and Lutzomyia longipalpis, also vectors of visceral leishmaniasis. Full-length secreted proteins from each sandfly library were compared using a stand-alone version of BLAST, creating formatted protein databases of each sandfly library. Related groups of proteins from each sandfly species were combined into defined families of proteins. With this comparison, we identified families of salivary proteins common among all of the sandflies studied, proteins to be genus specific and proteins that appear to be species specific. The common proteins included apyrase, yellow-related protein, antigen-5, PpSP15 and PpSP32-related protein, a 33-kDa protein, D7-related protein, a 39- and a 16.1- kDa protein and an endonuclease-like protein. Some of these families contained multiple members, including PPSP15-like, yellow proteins and D7-related proteins suggesting gene expansion in these proteins. Conclusion: This comprehensive analysis allows us the identification of genus- specific proteins, species-specific proteins and, more importantly, proteins common among these different sandflies. These results give us insights into the repertoire of salivary proteins that are potential candidates for a vector-based vaccine.

Abdominal compartment syndrome (ACS) is a clinical entity that develops after sustained and uncontrolled intraabdominal hypertension (IAHT). The ACS is clinically characterized by a massively distended abdomen and respiratory, cardiovascular, neurologic, and renal dysfunction.The goal of this study was to demonstrate the benefit of early diagnosis of intra-abdominal hypertension and ACS and to identify risk factors associated with mortality.We used a prospective study that included all patients admitted to Hospital de Especialidades Miguel Hidalgo with known ACS risk factors between January 2002 and December 2003. All patients were submitted to systematic measurements of intra-abdominal pressure (IAP). Those patients with grade III-IV IAHT were treated with decompressive laparotomy.Included in the study were 32 patients (23 males and 9 females). Mean age was 45.0 +/- 18.34 years. Twenty three patients developed IAHT grade I-II (group I) and nine developed grade IIIIV (group II). All group II patients were treated with abdominal decompression. The most common clinical entities associated were closed abdominal trauma (28%), hernias (15%), intestinal occlusions: (12.5%), acute pancreatitis (9.4%) and mesenteric ischemia (6.3%). Grade III-IV IAHT was statistically associated with reoperation (p = 0.038), acidosis (p = 0.003), anuria (p0.001) and sustained arterial hypotension (p = 0.004). The significant variables associated to mortality were anuria (p = 0.024) and grade III-IV IAHTA (0.017).It is possible to make an early diagnosis of IAHT and ACS with an indirect measurement of IAP. The most important factors related to mortality are anuria and IAHT.