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Firmansyah, I., Spiller, M., de Ruijter, F. J., Carsjens, G. J., & Zeeman, G. (2017). Assessment of nitrogen and phosphorus flows in agricultural and urban systems in a small island under limited data availability. Sci Total Environ, 574, 1521–1532.
Abstract: Nitrogen (N) and phosphorus (P) are two essential macronutrients required in agricultural production. The major share of this production relies on chemical fertilizer that requires energy and relies on limited resources (P). Since these nutrients are lost to the environment, there is a need to shift from this linear urban metabolism to a circular metabolism in which N and P from domestic waste and wastewater are reused in agriculture. A first step to facilitate a transition to more circular urban N and P management is to understand the flows of these resources in a coupled urban-agricultural system. For the first time this paper presents a Substance Flow Analysis (SFA) approach for the assessment of the coupled agricultural and urban systems under limited data availability in a small island. The developed SFA approach is used to identify intervention points that can provide N and P stocks for agricultural production. The island of St. Eustatius, a small island in the Caribbean, was used as a case study. The model developed in this study consists of eight sub-systems: agricultural and natural lands, urban lands, crop production, animal production, market, household consumption, soakage pit and open-dump landfill. A total of 26 flows were identified and quantified for a period of one year (2013). The results showed that the agricultural system is a significant source for N and P loss because of erosion/run-off and leaching. Moreover, urban sanitation systems contribute to deterioration of the island's ecosystem through N and P losses from domestic waste and wastewater by leaching and atmospheric emission. Proposed interventions are the treatment of blackwater and greywater for the recovery of N and P. In conclusion, this study allows for identification of potential N and P losses and proposes mitigation measures to improve nutrient management in a small island context.
Keywords: Nitrogen; Phosphorus; Small island system; Substance Flow Analysis (SFA); Urban metabolism; Urban-agriculture
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Mihu, M. R., Cabral, V., Pattabhi, R., Tar, M. T., Davies, K. P., Friedman, A. J., et al. (2017). Sustained Nitric Oxide-Releasing Nanoparticles Interfere with Methicillin-Resistant Staphylococcus aureus Adhesion and Biofilm Formation in a Rat Central Venous Catheter Model. Antimicrob Agents Chemother, 61(1).
Abstract: Staphylococcus aureus is frequently isolated in the setting of infections of indwelling medical devices, which are mediated by the microbe's ability to form biofilms on a variety of surfaces. Biofilm-embedded bacteria are more resistant to antimicrobial agents than their planktonic counterparts and often cause chronic infections and sepsis, particularly in patients with prolonged hospitalizations. In this study, we demonstrate that sustained nitric oxide-releasing nanoparticles (NO-np) interfere with S. aureus adhesion and prevent biofilm formation on a rat central venous catheter (CVC) model of infection. Confocal and scanning electron microscopy showed that NO-np-treated staphylococcal biofilms displayed considerably reduced thicknesses and bacterial numbers compared to those of control biofilms in vitro and in vivo, respectively. Although both phenotypes, planktonic and biofilm-associated staphylococci, of multiple clinical strains were susceptible to NO-np, bacteria within biofilms were more resistant to killing than their planktonic counterparts. Furthermore, chitosan, a biopolymer found in the exoskeleton of crustaceans and structurally integrated into the nanoparticles, seems to add considerable antimicrobial activity to the technology. Our findings suggest promising development and translational potential of NO-np for use as a prophylactic or therapeutic against bacterial biofilms on CVCs and other medical devices.
Keywords: Animals; Anti-Bacterial Agents/chemistry/*pharmacology; Bacterial Adhesion/drug effects; Biofilms/*drug effects/growth & development; Catheter-Related Infections/*drug therapy/microbiology; Central Venous Catheters; Chitosan/chemistry/pharmacology; Delayed-Action Preparations; Disease Models, Animal; Female; Glucose/chemistry; Humans; Methicillin-Resistant Staphylococcus aureus/*drug effects/growth & development/ultrastructure; Nanoparticles/*administration & dosage/chemistry; Nitric Oxide/chemical synthesis/*pharmacology; Oxidation-Reduction; Plankton/drug effects/growth & development; Rats; Rats, Sprague-Dawley; Sodium Nitrite/chemistry; Staphylococcal Infections/*drug therapy/microbiology; Staphylococcus aureus; antimicrobials; biofilms; nanoparticles; nitric oxide
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Mihu, M. R., Cabral, V., Pattabhi, R., Tar, M. T., Davies, K. P., Friedman, A. J., et al. (2017). Sustained Nitric Oxide-Releasing Nanoparticles Interfere with Methicillin-Resistant Staphylococcus aureus Adhesion and Biofilm Formation in a Rat Central Venous Catheter Model. Antimicrob Agents Chemother, 61(1).
Abstract: Staphylococcus aureus is frequently isolated in the setting of infections of indwelling medical devices, which are mediated by the microbe's ability to form biofilms on a variety of surfaces. Biofilm-embedded bacteria are more resistant to antimicrobial agents than their planktonic counterparts and often cause chronic infections and sepsis, particularly in patients with prolonged hospitalizations. In this study, we demonstrate that sustained nitric oxide-releasing nanoparticles (NO-np) interfere with S. aureus adhesion and prevent biofilm formation on a rat central venous catheter (CVC) model of infection. Confocal and scanning electron microscopy showed that NO-np-treated staphylococcal biofilms displayed considerably reduced thicknesses and bacterial numbers compared to those of control biofilms in vitro and in vivo, respectively. Although both phenotypes, planktonic and biofilm-associated staphylococci, of multiple clinical strains were susceptible to NO-np, bacteria within biofilms were more resistant to killing than their planktonic counterparts. Furthermore, chitosan, a biopolymer found in the exoskeleton of crustaceans and structurally integrated into the nanoparticles, seems to add considerable antimicrobial activity to the technology. Our findings suggest promising development and translational potential of NO-np for use as a prophylactic or therapeutic against bacterial biofilms on CVCs and other medical devices.
Keywords: Animals; Anti-Bacterial Agents/chemistry/*pharmacology; Bacterial Adhesion/drug effects; Biofilms/*drug effects/growth & development; Catheter-Related Infections/*drug therapy/microbiology; Central Venous Catheters; Chitosan/chemistry/pharmacology; Delayed-Action Preparations; Disease Models, Animal; Female; Glucose/chemistry; Humans; Methicillin-Resistant Staphylococcus aureus/*drug effects/growth & development/ultrastructure; Nanoparticles/*administration & dosage/chemistry; Nitric Oxide/chemical synthesis/*pharmacology; Oxidation-Reduction; Plankton/drug effects/growth & development; Rats; Rats, Sprague-Dawley; Sodium Nitrite/chemistry; Staphylococcal Infections/*drug therapy/microbiology; Staphylococcus aureus; antimicrobials; biofilms; nanoparticles; nitric oxide
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Alshehri, M. M., Robbins, S. M., & Senger, D. L. (2017). The Role of Neurotrophin Signaling in Gliomagenesis: A Focus on the p75 Neurotrophin Receptor (p75NTR/CD271). Vitam Horm, 104, 367–404.
Abstract: The p75 neurotrophin receptor (p75NTR, a.k.a. CD271), a transmembrane glycoprotein and a member of the tumor necrosis family (TNF) of receptors, was originally identified as a nerve growth factor receptor in the mid-1980s. While p75NTR is recognized to have important roles during neural development, its presence in both neural and nonneural tissues clearly supports the potential to mediate a broad range of functions depending on cellular context. Using an unbiased in vivo selection paradigm for genes underlying the invasive behavior of glioma, a critical characteristic that contributes to poor clinical outcome for glioma patients, we identified p75NTR as a central regulator of glioma invasion. Herein we review the expanding role that p75NTR plays in glioma progression with an emphasis on how p75NTR may contribute to the treatment refractory nature of glioma. Based on the observation that p75NTR is expressed and functional in two critical glioma disease reservoirs, namely, the highly infiltrative cells that evade surgical resection, and the radiation- and chemotherapy-resistant brain tumor-initiating cells (also referred to as brain tumor stem cells), we propose that p75NTR and its myriad of downstream signaling effectors represent rationale therapeutic targets for this devastating disease. Lastly, we provide the provocative hypothesis that, in addition to the well-documented cell autonomous signaling functions, the neurotrophins, and their respective receptors, contribute in a cell nonautonomous manner to drive the complex cellular and molecular composition of the brain tumor microenvironment, an environment that fuels tumorigenesis.
Keywords: Brain tumor; Cd271; Cancer stem cells; Glioblastoma; Glioma invasion; Nerve growth factor; Neurotrophin; p75(NTR)
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Ayash, C., Costas-Muniz, R., Badreddine, D., Ramirez, J., & Gany, F. (2017). An Investigation of Unmet Socio-Economic Needs Among Arab American Breast Cancer Patients Compared with Other Immigrant and Migrant Patients. J Community Health, .
Abstract: Although Arabs are a growing population in the United States, they are a hidden minority when compared to larger, more studied groups like Latinos and Caribbean immigrants of African descent (CIAD). There is limited research pertaining to patients' unmet socioeconomic and supportive care needs when undergoing breast cancer treatment, particularly among immigrants and migrants. This is a comparative study of a nested cohort of 36 Arabs, 145 Latinos and 128 CIAD breast cancer patients participating in the Integrated Cancer Care Access Network and their areas of needed assistance. The patients were recruited from eleven community cancer clinics in New York City and through community based organizations. Patients most commonly reported needing financial, transportation, and food assistance. Arabs were more likely than their CIAD and Latino counterparts to have health insurance and legal aid needs. Arabs also has the highest proportion of patients unaware of their own cancer stage, at odds with their report of lower information needs than the other groups. Additional culturally tailored Arabic language interventions are needed to educate Arabic speaking breast cancer patients to help facilitate access to available services.
Keywords: Arabs; Breast cancer; Immigrant health
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