Evaluation of the Implementation of Operations and Maintenance Programs in New Jersey Schools.

ERIC Educational Resources Information Center

Kominsky, John R.; Freyberg, Ronald W.; Gerber, Donald R.; Centifonti, Gary J.

All schools are required to develop and implement an asbestos management plan (AMP). The key component of this plan is each school's operations and maintenance (O&M) program. This report outlines the importance of such programs. It describes an O&M program as an administrative framework that prescribes specific activities and work…

Sandia National Laboratories: National Security Missions: International

Science.gov Websites

Programs Environmental Responsibility Environmental Management System Pollution Prevention History 60 ; Security Weapons Science & Technology Defense Systems & Assessments About Defense Systems & ; Development Technology Deployment Centers Working With Sandia Working With Sandia Prospective Suppliers What

78 FR 25487 - Final License Renewal Interim Staff Guidance LR-ISG-2012-01: Wall Thinning Due to Erosion Mechanisms

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-01

....'' This LR-ISG revises an NRC staff-recommended aging management program (AMP) in NUREG-1801, Revision 2, ``Generic Aging Lessons Learned (GALL) Report,'' and the NRC staff's aging management review procedure and... for piping and components within the scope of the Requirements for Renewal of Operating Licenses for...

Atmosphere, Magnetosphere and Plasmas in Space (AMPS). Spacelab payload definition study. Volume 7, book 2: AMPS phase C/D analysis and planning document

NASA Technical Reports Server (NTRS)

1976-01-01

The results are presented of the AMPS Phase C/D (Design, Development, and Operations) program analysis and planning effort. Cost and schedule estimates are included. Although the AMPS program has been specifically addressed, these task descriptions are basically adaptable to a broader-based program incorporating additional or different Spacelab/orbiter payloads.

7 CFR 772.14 - Reamortization of AMP loans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Reamortization of AMP loans. 772.14 Section 772.14... AGRICULTURE SPECIAL PROGRAMS SERVICING MINOR PROGRAM LOANS § 772.14 Reamortization of AMP loans. The Agency may approve reamortization of AMP loans provided: (a) There is no extension of the final maturity date...

7 CFR 772.10 - Transfer and assumption-AMP loans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Transfer and assumption-AMP loans. 772.10 Section 772..., DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS SERVICING MINOR PROGRAM LOANS § 772.10 Transfer and assumption—AMP loans. (a) Eligibility. The Agency may approve transfers and assumptions of AMP loans when: (1) The...

Impact of the Intensive Program of Emotional Intelligence (IPEI) on work supervisors.

PubMed

Rodríguez García, Gustavo A; López-Pérez, Belén; Férreo Cruzado, Manuel A; Fernández Carrascoso, María E; Fernández, Juan

2017-11-01

This study aimed to evaluate the effect of the Intensive Program of Emotional Intelligence (IPEI; Fernández, 2016; Férreo, 2016) on middle managers’ emotional intelligence, as this variable may have a significant impact on personal satisfaction, task performance, and the work environment. The intervention was applied to work team supervisors in a large call center, as it is an overlooked sector in this topic. Two-hundred and eighty-two supervisors from a Madrid-based, Spanish multinational (51.4% men and 48.6% women) participated in this study. Participants were assigned to the experimental group (n = 190) or the control group (n = 92) by availability, according to management decision. All supervisors filled in two questionnaires to evaluate the different components of intrapersonal emotional intelligence (i.e., attention, clarity, and repair; TMMS-24; Fernández-Berrocal, Extremera, & Ramos, 2004) and cognitive and affective empathy (i.e., perspective taking, emotion understanding, empathic joy, and personal distress; TECA; López-Pérez, Fernández, & Abad, 2008). The findings showed an increase in the studied variables for the experimental group. The results obtained support middle managers’ training in emotional competences through short, efficient, economic programs. Potential limitations and implications of the results are discussed.

Effectiveness of a Mindfulness-Based Intervention in the Management of Musculoskeletal Pain in Nursing Workers.

PubMed

Lopes, Shirlene Aparecida; Vannucchi, Bruna Pesce; Demarzo, Marcelo; Cunha, Ângelo Geraldo José; Nunes, Maria do Patrocínio Tenório

2018-05-17

Chronic pain is a prevalent disorder in nursing workers worldwide. Several studies have proposed measures to mitigate this critical scenario. Mindfulness-based interventions (MBI) have been found to have promising results in the treatment of this disorder. To quantify the effectiveness of an adapted mindfulness program (AMP) in the management of musculoskeletal pain (MSP) in nursing technicians of a Brazilian university hospital. This study was a clinical, prospective, open, repeated measures trial, with data collection between January and July 2015. Brazilian university hospital. Participants/Subjects: Sixty-four female nursing technicians with a mean age of 47.01 years (standard deviation = 9.50) with chronic pain symptoms. Sixty-four female nursing technicians with a mean age of 47.01 years (standard deviation = 9.50) and MSP participated in this prospective study. Before the intervention (T0), scores of anxiety, depression, mindfulness, musculoskeletal complaints, pain catastrophizing, self-compassion, and perception of quality of life were quantified. These scores were reevaluated after 8 weeks (T1) and 12 weeks (T2) of weekly AMP sessions (60 minutes each). The variables were evaluated by analysis of variance for repeated measures, followed by the Bonferroni test. AMP reduced the scores of musculoskeletal symptoms, anxiety, depression, and pain catastrophizing (p < .001). A significant increase was identified in self-compassion scores and perception of quality of life in the physical, psychological, and overall assessment (p ≤ .04). Positive effects of AMP occurred at T1 and remained unchanged at T2. AMP contributed to a reduction in painful symptoms and improved the quality of life of nursing workers, with a lasting effect until the 20th week of follow-up, indicating utility as an effective strategy for the management of MSP in the group studied. Copyright © 2018 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

48 CFR 1401.370 - Acquisition Managers' Partnership.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Acquisition Managers' Partnership. (a) The Acquisition Managers' Partnership (AMP) is a forum for DOI's senior... and effectiveness of its procurement services in support of DOI's mission. (b) The AMP consists of the...

AMPS/PC - AUTOMATIC MANUFACTURING PROGRAMMING SYSTEM

NASA Technical Reports Server (NTRS)

Schroer, B. J.

1994-01-01

The AMPS/PC system is a simulation tool designed to aid the user in defining the specifications of a manufacturing environment and then automatically writing code for the target simulation language, GPSS/PC. The domain of problems that AMPS/PC can simulate are manufacturing assembly lines with subassembly lines and manufacturing cells. The user defines the problem domain by responding to the questions from the interface program. Based on the responses, the interface program creates an internal problem specification file. This file includes the manufacturing process network flow and the attributes for all stations, cells, and stock points. AMPS then uses the problem specification file as input for the automatic code generator program to produce a simulation program in the target language GPSS. The output of the generator program is the source code of the corresponding GPSS/PC simulation program. The system runs entirely on an IBM PC running PC DOS Version 2.0 or higher and is written in Turbo Pascal Version 4 requiring 640K memory and one 360K disk drive. To execute the GPSS program, the PC must have resident the GPSS/PC System Version 2.0 from Minuteman Software. The AMPS/PC program was developed in 1988.

Atmospheric, Magnetospheric and Plasmas in Space (AMPS) spacelab payload definition study - program analysis and planning for phase C/D document - Volume 7

NASA Technical Reports Server (NTRS)

Keeley, J. T.

1976-01-01

Typical missions identified for AMPS flights in the arly 1980's are described. Experiment objectives and typical scientific instruments selected to accomplish these objectives are discussed along with mission requirements and shuttle and Spacelab capabilities assessed to determine any AMPS unique requirements. Preliminary design concepts for the first two AMPS flights form the basis for the Phase C/D program plan. This plan implements flights 1 and 2 and indicates how both the scientific and flight support hardware can be systematically evolved for future AMPS flights.

Asset Management Plans, Appraisal Guidance for 2003-04.

ERIC Educational Resources Information Center

Department for Education and Skills, London (England).

This document is one in a series which aims to assist Local Authorities in Britain with asset management planning (AMPs) for schools. AMPs set out the information needed, and the criteria used, to make decisions about spending on school premises. The document provides guidance on the appraisal of school AMPs in 2002 to inform 3-year formulaic…

Management of patients brought in by ambulance to the emergency department: role of the Advanced Musculoskeletal Physiotherapist.

PubMed

Kinsella, Rita; Collins, Tom; Shaw, Bridget; Sayer, James; Cary, Belinda; Walby, Andrew; Cowan, Sallie

2017-05-09

Objective The aim of the present study was to evaluate the role of the Advanced Musculoskeletal Physiotherapist (AMP) in managing patients brought in by ambulance to the emergency department (ED). Methods This study was a dual-centre observational study. Patients brought in by ambulance to two Melbourne hospitals over a 12-month period and seen by an AMP were compared with a matched group seen by other ED staff. Primary outcome measures were wait time and length of stay (LOS) in the ED. Results Data from 1441 patients within the Australasian Triage Scale (ATS) Categories 3-5 with musculoskeletal complaints were included in the analysis. Subgroup analysis of 825 patients aged ≤65 years demonstrated that for Category 4 (semi-urgent) patients, the median wait time to see the AMP was 9.5min (interquartile range (IQR) 3.25-18.00min) compared with 25min (IQR 10.00-56.00min) to see other ED staff (P ≤ 0.05). LOS analysis was undertaken on patients discharged home and demonstrated that there was a 1.20 greater probability (95% confidence interval 1.07-1.35) that ATS Category 4 patients managed by the AMP were discharged within the 4-hour public hospital target compared with patients managed by other ED staff: 87.04% (94/108) of patients managed by the AMPs met this standard compared with 72.35% (123/170) of patients managed by other ED staff (P=0.002). Conclusions Patients aged ≤65 years with musculoskeletal complaints brought in by ambulance to the ED and triaged to ATS Category 4 are likely to wait less time to be seen and are discharged home more quickly when managed by an AMP. This study has added to the evidence that AMPs improve patient flow in the ED, freeing up time for other ED staff to see higher-acuity, more complex patients. What is known about the topic? There is a growing body of evidence establishing that AMPs improve the flow of patients presenting with musculoskeletal conditions to the ED through reduced wait times and LOS and, at the same time, providing good-quality care and enhanced patient satisfaction. What does this paper add? Within their primary contact capacity, AMPs also manage patients who are brought in by ambulance presenting with musculoskeletal conditions. To the authors' knowledge, there is currently no available literature documenting the performance of AMPs in the management of this cohort of patients. What are the implications for practitioners? This study has added to the body of evidence that AMPs improve patient flow in the ED and illustrates that AMPs, by seeing patients brought in by ambulance, are able to have a positive impact on the pressures increasingly facing the Victorian Ambulance Service and emergency hospital care.

AMP: A platform for managing and mining data in the treatment of Autism Spectrum Disorder.

PubMed

Linstead, Erik; Burns, Ryan; Duy Nguyen; Tyler, David

2016-08-01

We introduce AMP (Autism Management Platform), an integrated health care information system for capturing, analyzing, and managing data associated with the diagnosis and treatment of Autism Spectrum Disorder in children. AMP's mobile application simplifies the means by which parents, guardians, and clinicians can collect and share multimedia data with one another, facilitating communication and reducing data redundancy, while simplifying retrieval. Additionally, AMP provides an intelligent web interface and analytics platform which allow physicians and specialists to aggregate and mine patient data in real-time, as well as give relevant feedback to automatically learn data filtering preferences over time. Together AMP's mobile app, web client, and analytics engine implement a rich set of features that streamline the data collection and analysis process in the context of a secure and easy-to-use system so that data may be more effectively leveraged to guide treatment.

Study Protocol--Alcohol Management Plans (AMPs) in remote indigenous communities in Queensland: their impacts on injury, violence, health and social indicators and their cost-effectiveness.

PubMed

Clough, Alan R; Fitts, Michelle S; Robertson, Jan A; Shakeshaft, Anthony; Miller, Adrian; Doran, Christopher M; Muller, Reinhold; Ypinazar, Valmae; Martin, David; McDermott, Robyn; Sanson-Fisher, Rob; Towle, Simon; Margolis, Stephen A; West, Caryn

2014-01-09

In 2002/03 the Queensland Government responded to high rates of alcohol-related harm in discrete Indigenous communities by implementing alcohol management plans (AMPs), designed to include supply and harm reduction and treatment measures. Tighter alcohol supply and carriage restrictions followed in 2008 following indications of reductions in violence and injury. Despite the plans being in place for over a decade, no comprehensive independent review has assessed to what level the designed aims were achieved and what effect the plans have had on Indigenous community residents and service providers. This study will describe the long-term impacts on important health, economic and social outcomes of Queensland's AMPs. The project has two main studies, 1) outcome evaluation using de-identified epidemiological data on injury, violence and other health and social indicators for across Queensland, including de-identified databases compiled from relevant routinely-available administrative data sets, and 2) a process evaluation to map the nature, timing and content of intervention components targeting alcohol. Process evaluation will also be used to assess the fidelity with which the designed intervention components have been implemented, their uptake and community responses to them and their perceived impacts on alcohol supply and consumption, injury, violence and community health. Interviews and focus groups with Indigenous residents and service providers will be used. The study will be conducted in all 24 of Queensland's Indigenous communities affected by alcohol management plans. This evaluation will report on the impacts of the original aims for AMPs, what impact they have had on Indigenous residents and service providers. A central outcome will be the establishment of relevant databases describing the parameters of the changes seen. This will permit comprehensive and rigorous surveillance systems to be put in place and provided to communities empowering them with the best credible evidence to judge future policy and program requirements for themselves. The project will inform impending alcohol policy and program adjustments in Queensland and other Australian jurisdictions.The project has been approved by the James Cook University Human Research Ethics Committee (approval number H4967 & H5241).

42 CFR 447.504 - Determination of AMP.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Determination of AMP. 447.504 Section 447.504 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PAYMENTS FOR SERVICES Payment for Drugs § 447.504 Determination of AMP. (a) AMP means, with respect to a covered...

Automatic programming of simulation models

NASA Technical Reports Server (NTRS)

Schroer, Bernard J.; Tseng, Fan T.; Zhang, Shou X.; Dwan, Wen S.

1990-01-01

The concepts of software engineering were used to improve the simulation modeling environment. Emphasis was placed on the application of an element of rapid prototyping, or automatic programming, to assist the modeler define the problem specification. Then, once the problem specification has been defined, an automatic code generator is used to write the simulation code. The following two domains were selected for evaluating the concepts of software engineering for discrete event simulation: manufacturing domain and a spacecraft countdown network sequence. The specific tasks were to: (1) define the software requirements for a graphical user interface to the Automatic Manufacturing Programming System (AMPS) system; (2) develop a graphical user interface for AMPS; and (3) compare the AMPS graphical interface with the AMPS interactive user interface.

United States Air Force Summer Faculty Research Program (1984). Program Management Report. Volume 3

DTIC Science & Technology

1984-12-01

Database Design 蕄 Raman Spectroscopy of Dr. Boake L. Plessy Glycosaminoglycans from -* Bovine Cornea 117 Study of Control Mixer Concept Dr. Kuldip S...simultaneously in polarized and non -polarized controls were repeated three times at 260-64, 368-70, 604-8-13, 735-7-40, 1277-80, 1760, 1775, and 1820 or four...times at S240-2-4, 1020 and 1874-8-90. Pooling replicates from the non -polarized components, six controls and two cAMP treatments, events repeating

Sharing Perspectives and Learning from One Another: Southern Paiutes, Scientists, and Policymakers in the Glen Canyon Dam Adaptive Management Program

NASA Astrophysics Data System (ADS)

Austin, D. E.; Bulletts, K.; Bulletts, C.

2017-12-01

The traditional lands of the Southern Paiute people in the United States are bounded by more than 600 miles of the Colorado River from the Kaiparowits Plateau in the north to Blythe, California in the south. According to Southern Paiute traditional knowledge, Southern Paiutes were the first inhabitants of this region and are responsible for protecting and managing this land along with the water and all that is upon and within it. In 1963, the Bureau of Reclamation completed construction of Glen Canyon Dam on the Colorado River, and in 1972, the Glen Canyon National Recreation Area was established, encompassing Lake Mead above the Dam and a world class trout fishery on the Colorado River between the Dam and Lees Ferry. Below Lees Ferry on its way to Lake Mead and Hoover Dam, the Colorado River flows through Grand Canyon National Park and the Navajo and Hualapai reservations. U.S. federal law requires that Glen Canyon Dam be operated with minimal impact to the natural, recreational, and cultural resources of the region of the Colorado River that is potentially impacted by flows from the Dam. The Grand Canyon Protection Act and the Environmental Impact Statement (EIS) for the Operation of the Glen Canyon Dam established a program of long-term research and monitoring of the effects of the Dam on these resources. In 1991, three Southern Paiute tribes - the Kaibab Band of Paiute Indians, the Paiute Indian Tribe of Utah, and the San Juan Southern Paiute Tribe - agreed to participate in studies to identify cultural resources impacted by Glen Canyon Dam and to recommend strategies for their protection, In 1995, the EIS was completed and transition to the Adaptive Management Program (AMP) called for in the Grand Canyon Protection Act was begun. At that time, Southern Paiute activities expanded to include assessing potential environmental and cultural impacts of the dam, developing monitoring procedures, and interacting with scientists, other tribal representatives, and policymakers in the AMP. This presentation summarizes an analysis of two decades of Southern Paiute participation in the AMP, highlighting key interactions and learning experiences as well as ongoing challenges for Southern Paiute participants.

GT | Government & Community Relations | Georgia Institute of Technology |

Science.gov Websites

Atlanta, GA Skip to content Georgia Tech Georgia Institute of Technology Government & Georgia Tech's Impact State Relations Capitol Jackets Advocacy Network Legislative Priorities & ; Resources Georgia Legislative Internship Program Georgia Tech's Impact 2018 PHELAP Conference Community &

Designing Higher Education Curriculum to Increase Graduate Outcomes and Work Readiness: The Assessment and Mentoring Program (AMP)

ERIC Educational Resources Information Center

Jenkinson, Kate A.; Benson, Amanda C.

2016-01-01

Pre-service teacher programs have a responsibility to equip graduating students with more than the minimum skill sets required by governing bodies. The Assessment and Mentoring Program (AMP) is a four-way collaborative mentoring learning community underpinned by social constructivism. Conducted in Victoria, Australia during the 2014-2016 academic…

ODP Legacy

Science.gov Websites

Legacy: Scientific results ODP Legacy: Engineering and science operations ODP Legacy: Samples & ; databases ODP Legacy: Outreach Overview Program Administration | Scientific Results | Engineering &

AMPS data management concepts. [Atmospheric, Magnetospheric and Plasma in Space experiment

NASA Technical Reports Server (NTRS)

Metzelaar, P. N.

1975-01-01

Five typical AMPS experiments were formulated to allow simulation studies to verify data management concepts. Design studies were conducted to analyze these experiments in terms of the applicable procedures, data processing and displaying functions. Design concepts for AMPS data management system are presented which permit both automatic repetitive measurement sequences and experimenter-controlled step-by-step procedures. Extensive use is made of a cathode ray tube display, the experimenters' alphanumeric keyboard, and the computer. The types of computer software required by the system and the possible choices of control and display procedures available to the experimenter are described for several examples. An electromagnetic wave transmission experiment illustrates the methods used to analyze data processing requirements.

Interorgan Molecular Communication Strategies of "Local" and "Systemic" Innate Immune Responses in Mosquito Anopheles stephensi.

PubMed

Das De, Tanwee; Sharma, Punita; Thomas, Tina; Singla, Deepak; Tevatiya, Sanjay; Kumari, Seena; Chauhan, Charu; Rani, Jyoti; Srivastava, Vartika; Kaur, Ramandeep; Pandey, Kailash C; Dixit, Rajnikant

2018-01-01

Mosquitoes that transmit many deadly infectious diseases also need to keep fighting against many microbial infections. Constitutive expression of multiple antimicrobial peptides (AMPs) in almost all body tissues is believed to facilitate the effective management of these local infections. When any infection breaches the local barrier, AMPs are induced rapidly in non-target tissues such as hemocytes (HCs) and establish their co-ordination with systemic immune effectors to clear off the body infection. But how interorgan immune communication is managed during local and systemic infections remain largely unknown. To understand this interorgan molecular relationship, we identified, extensively profiled and compared the expression of AMPs in three important mosquito tissues viz . midgut, fat body (FB), and HCs. dsRNA -mediated AMPs silencing suggests that mosquito tissues are able to manage an optimal expression of AMPs at the physiological level. We also examined the possible contribution of two important immune regulator genes relish (REL) and nitric oxide synthase, controlling AMPs expression in these tissues during local or systemic infections. We show that each tissue has a unique ability to respond to local/systemic challenges, but HCs are more specialized to recognize and discriminate-specific antigens than gut and FB. Our investigation also revealed that both REL and NO participate in the overall management of the interorgan immune responses, but at the same time each tissue also has its own ability to maintain the interorgan flow of signals. In our knowledge, this is the first large-scale study examining the interorgan immune relationship in the mosquito.

Assessing program efficiency: a time and motion study of the Mental Health Emergency Care - Rural Access Program in NSW Australia.

PubMed

Saurman, Emily; Lyle, David; Kirby, Sue; Roberts, Russell

2014-07-31

The Mental Health Emergency Care-Rural Access Program (MHEC-RAP) is a telehealth solution providing specialist emergency mental health care to rural and remote communities across western NSW, Australia. This is the first time and motion (T&M) study to examine program efficiency and capacity for a telepsychiatry program. Clinical services are an integral aspect of the program accounting for 6% of all activities and 50% of the time spent conducting program activities, but half of this time is spent completing clinical paperwork. This finding emphasizes the importance of these services to program efficiency and the need to address variability of service provision to impact capacity. Currently, there is no efficiency benchmark for emergency telepsychiatry programs. Findings suggest that MHEC-RAP could increase its activity without affecting program responsiveness. T&M studies not only determine activity and time expenditure, but have a wider application assessing program efficiency by understanding, defining, and calculating capacity. T&M studies can inform future program development of MHEC-RAP and similar telehealth programs, both in Australia and overseas.

The glutamate carboxypeptidase AMP1 mediates abscisic acid and abiotic stress responses in Arabidopsis.

PubMed

Shi, Yiting; Wang, Zheng; Meng, Pei; Tian, Siqi; Zhang, Xiaoyan; Yang, Shuhua

2013-07-01

ALTERED MERISTEM PROGRAM1 (AMP1) encodes a glutamate carboxypeptidase that plays an important role in shoot apical meristem development and phytohormone homeostasis. We isolated a new mutant allele of AMP1, amp1-20, from a screen for abscisic acid (ABA) hypersensitive mutants and characterized the function of AMP1 in plant stress responses. amp1 mutants displayed ABA hypersensitivity, while overexpression of AMP1 caused ABA insensitivity. Moreover, endogenous ABA concentration was increased in amp1-20- and decreased in AMP1-overexpressing plants under stress conditions. Application of ABA reduced the AMP1 protein level in plants. Interestingly, amp1 mutants accumulated excess superoxide and displayed hypersensitivity to oxidative stress. The hypersensitivity of amp1 to ABA and oxidative stress was partially rescued by reactive oxygen species (ROS) scavenging agent. Furthermore, amp1 was tolerant to freezing and drought stress. The ABA hypersensitivity and freezing tolerance of amp1 was dependent on ABA signaling. Moreover, amp1 had elevated soluble sugar content and showed hypersensitivity to high concentrations of sugar. By contrast, the contents of amino acids were changed in amp1 mutant compared to the wild-type. This study suggests that AMP1 modulates ABA, oxidative and abotic stress responses, and is involved in carbon and amino acid metabolism in Arabidopsis. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

77 FR 9265 - Glen Canyon Dam Adaptive Management Work Group

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-16

... (AMP) was implemented as a result of the Record of Decision on the Operation of Glen Canyon Dam Final.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the AMWG, a technical work group... administrative and resource issues pertaining to the AMP. To view a copy of the agenda and documents related to...

Predictors of Response to an Attention Modification Program in Generalized Social Phobia

ERIC Educational Resources Information Center

Amir, Nader; Taylor, Charles T.; Donohue, Michael C.

2011-01-01

Objective: At least 3 randomized, placebo-controlled, double-blind studies have supported the efficacy of computerized attention modification programs (AMPs) in reducing symptoms of anxiety in patients diagnosed with an anxiety disorder. In this study we examined patient characteristics that predicted response to AMP in a large sample of…

Phase 1 studies summary of major findings of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

USGS Publications Warehouse

Valoppi, Laura

2018-04-02

Executive SummaryThe South Bay Salt Pond Restoration Project (Project) is one of the largest restoration efforts in the United States. It is located in South San Francisco Bay of California. It is unique not only for its size—more than 15,000 acres—but also for its location adjacent to one of the nation’s largest urban areas, home to more than 4 million people (Alameda, Santa Clara, and San Mateo Counties). The Project is intended to restore and enhance wetlands in South San Francisco Bay while providing for flood management, wildlife-oriented public access, and recreation. Restoration goals of the project are to provide a mosaic of saltmarsh habitat to benefit marsh species and managed ponds to benefit waterbirds, throughout 3 complexes and 54 former salt ponds.Although much is known about the project area, significant uncertainties remain with a project of this geographic and temporal scale of an estimated 50 years to complete the restoration. For example, in order to convert anywhere from 50 to 90 percent of the existing managed ponds to saltmarsh habitat, conservation managers first enhance the habitat of managed ponds in order to increase use by waterbirds, and provide migratory, wintering, and nesting habitat for more than 90 species of waterbirds. Project managers have concluded that the best way to address these uncertainties is to carefully implement the project in phases and learn from the outcome of each phase. The Adaptive Management Plan (AMP) identifies specific restoration targets for multiple aspects of the Project and defines triggers that would necessitate some type of management action if a particular aspect is trending negatively. U.S. Geological Survey (USGS) biologist Laura Valoppi served as the project Lead Scientist and oversaw implementation of the AMP in coordination with other members of the Project Management Team (PMT), comprised of representatives from the California State Coastal Conservancy, California Department of Fish and Wildlife, the Santa Clara Valley Water District, the U.S. Army Corps of Engineers, and the U.S. Fish and Wildlife Service.To implement the AMP, the PMT have selected and funded applied studies and monitoring projects to address key uncertainties. This information is used by the PMT to make decisions about current management of the project area and future restoration actions in order to meet project.This document summarizes the major scientific findings from studies conducted from 2009 to 2016, as part of the science program that was conducted in conjunction with Phase 1 restoration and management actions. Additionally, this report summarizes the management response to the study results under the guidance of the AMP framework and provides a list of suggested studies to be conducted in “Phase 2–A scorecard summarizing the Project’s progress toward meeting the AMP goals for a range of Project objectives.” The scoring to date indicates that the Project is meeting or exceeding expectations for sediment accretion and western snowy plover (Charadrius alexandrinus nivosus) recovery. There is uncertainty with respect to objectives for California gulls (Larus californicus), California least tern (Sternula antillarum), steelhead trout (Oncorhynchus mykiss), and regulatory water quality objectives. Water quality and algal blooms, specifically of the managed ponds, is indicated as trending negative. However, the vast majority of objectives are trending positive, including increased abundance for a number of bird guilds, increasing marsh habitat, maintenance of mudflats, visitor experience, estuarine fish numbers, and special-status marsh species numbers.

A pilot study evaluating a one-session attention modification training to decrease overeating in obese children.

PubMed

Boutelle, Kerri N; Kuckertz, Jennie M; Carlson, Jordan; Amir, Nader

2014-05-01

There are a number of neurocognitive and behavioral mechanisms that contribute to overeating and obesity, including an attentional bias to food cues. Attention modification programs, which implicitly train attention away from specific cues, have been used in anxiety and substance abuse, and could logically be applied to food cues. The purpose of this study was to evaluate the initial efficacy of a single session attention modification training for food cues (AMP) on overeating in overweight and obese children. Twenty-four obese children who eat in the absence of hunger participated in two visits and were assigned to an attention modification program (AMP) or attentional control program (ACC). The AMP program trained attention away 100% of the time from food words to neutral words. The ACC program trained attention 50% of the time to neutral and 50% of the time to food. Outcome measures included the eating in the absence of hunger free access session, and measures of craving, liking and salivation. Results revealed significant treatment effects for EAH percent and EAH kcal (group by time interactions p<.05). Children in the ACC condition showed a significant increase over time in the number of calories consumed in the free access session (within group t=3.09, p=.009) as well as the percent of daily caloric needs consumed in free access (within group t=3.37, p=.006), whereas children in the AMP group demonstrated slight decreases in these variables (within group t=-0.75 and -0.63, respectively). There was a trend suggesting a beneficial effect of AMP as compared to ACC for attentional bias (group by time interaction p=.073). Changes in craving, liking and saliva were not significantly different between groups (ps=.178-.527). This is the first study to demonstrate that an AMP program can influence eating in obese children. Larger studies are needed to replicate and extend these results. Copyright © 2014. Published by Elsevier Ltd.

Nondestructive Examination for Nuclear Power Plant Cable Aging Management Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, Samuel W.; Fifield, Leonard S.

2016-01-01

Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. System tests verify cable function under normal loads; however, the concern is over cable performance under exceptional loads associated with design-basis events (DBEs). The cable’s ability to perform safely over the initial 40 year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found inmore » an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program (AMP) to justify cable performance under normal operation as well as accident conditions. This paper addresses various NDE technologies that constitute the essence of an acceptable aging management program.« less

Space Station Freedom NiH2 cell testing program

NASA Technical Reports Server (NTRS)

Moore, Bruce; Frate, Dave

1994-01-01

Testing for the Space Station Freedom Nickel Hydrogen Cell Test Program began in 1990 at Crave Division, Naval Surface Warfare Center. The program has included receipt inspection, random vibration, acceptance, characterization, and life cycle testing of Ni-H2 cells in accordance with the NASA LeRC Interagency Order C-31001-J. A total of 400 Ni-H2 cells have been received at NAVSURFWARCENDIV Crane from three separate manufacturers; Yardney Technical Products (Yardney), Eagle Picher Industries (Eagle Picher), and Gates Energy Products (Gates). Of those, 308 cells distributed among 39 packs have undergone life cycle testing under a test regime simulating low earth orbit conditions. As of 30 September 1993, there are 252 cells assembled into 32 packs still on life cycle test. Since the beginning of the program, failed cells have been detected in all phases of testing. The failures include the following; seven 65 AmpHr and 81 AmpHr Yardney cells were found to be leaking KOH on receipt, one 65 AmpHr Eagle Picher cell failed the acceptance test, one 65 AmpHr Gates cell failed during the characterization test, and six 65 AmpHr Gates cells failed the random vibration test. Of the 39 life cycle packs, testing on seven packs, 56 cells, has been suspended because of low end of discharge voltages. All of the failed life cycle packs were cycled at 60% depth of discharge.

Atmospheric, Magnetospheric, and Plasmas in Space (AMPS) spacelab payload definition study, appendixes

NASA Technical Reports Server (NTRS)

Keeley, J. T.

1976-01-01

An equipment list, instrument baseline data, engineering drawings, mass properties computer printouts, electrical energy management, and control and display functional analysis pertinent to the AMPS (Satellite Payload) are presented.

Automated distribution system management for multichannel space power systems

NASA Technical Reports Server (NTRS)

Fleck, G. W.; Decker, D. K.; Graves, J.

1983-01-01

A NASA sponsored study of space power distribution system technology is in progress to develop an autonomously managed power system (AMPS) for large space power platforms. The multichannel, multikilowatt, utility-type power subsystem proposed presents new survivability requirements and increased subsystem complexity. The computer controls under development for the power management system must optimize the power subsystem performance and minimize the life cycle cost of the platform. A distribution system management philosophy has been formulated which incorporates these constraints. Its implementation using a TI9900 microprocessor and FORTH as the programming language is presented. The approach offers a novel solution to the perplexing problem of determining the optimal combination of loads which should be connected to each power channel for a versatile electrical distribution concept.

Rationale, Design, and Baseline Characteristics of the EPICOR Asia Study (Long-tErm follow-uP of antithrombotic management patterns In Acute CORonary Syndrome patients in Asia).

PubMed

Huo, Yong; Lee, Stephen W-L; Sawhney, Jitendra P S; Kim, Hyo-Soo; Krittayaphong, Rungroj; Nhan, Vo T; Alonso-Garcia, Angeles; Han, Ya Ling; Ge, Junbo; Chin, Chee Tang; Ong, Tiong K; Jan, Stephen; Itoh, Yohji; Vega, Ana Maria; Pocock, Stuart

2015-09-01

In-hospital and postdischarge mortality for acute coronary syndromes (ACS) vary across Asia and remain generally poorer than globally. The relationship between real-life antithrombotic management patterns (AMPs) and ACS-related outcomes in Asia is unclear. EPICOR Asia (Long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients in Asia) (NCT01361386) is a prospective, multinational, observational study of patients discharged after hospitalization for an ACS, with 2-year follow-up. The aim is to describe short- and long-term (up to 2 years post-index event) AMPs in patients hospitalized for ACS and to record clinical outcomes, healthcare resource use, and self-reported health status. Pre- and in-hospital management, AMPs, and associated outcomes, with particular focus on ischemic and bleeding events, will be recorded during the 2-year follow up. Between June 2011 and May 2012, 13 005 patients were enrolled. From these, 12 922 patients surviving an ACS (6616 with STEMI, 2570 with NSTEMI, and 3736 with UA) were eligible for inclusion from 219 hospitals across 8 countries and regions in Asia: China (n = 8214), Hong Kong (n = 177), India (n = 2468), Malaysia (n = 100), Singapore (n = 93), South Korea (n = 705), Thailand (n = 957), and Vietnam (n = 208). EPICOR Asia will provide information regarding clinical management and AMPs for ACS patients in Asia. Impact of AMPs on clinical outcomes, healthcare resource use, and self-reported health status both during hospitalization and up to 2 years after discharge will also be described. © 2015 Wiley Periodicals, Inc.

Asset Management Plans. Sections 1-5: Framework [and] Property Information Systems and Schools Premises Data [and] condition Assessment [and] Suitability Assessment [and] Sufficiency Assessment.

ERIC Educational Resources Information Center

Department for Education and Employment, London (England).

The aim of these documents is to assist Local Authorities in Britain with asset management planning (AMPs) for schools. AMPs set out the information needed, and the criteria used, to make decisions about spending on school premises which will: raise standards of educational attainment; provide sustainable and energy-efficient buildings that are…

75 FR 24938 - City of Hamilton, Ohio American Municipal Power, Inc.; Notice of Application for Transfer of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

...) and American Municipal Power, Inc. (AMP) filed an application for a partial transfer of license of the... to Hamilton and AMP. Applicants' Contacts: City of Hamilton--Mr. Mark Brandenburger, City Manager...

Demodulation Radio Frequency Interference Effects in Operational Amplifier Circuits

NASA Astrophysics Data System (ADS)

Sutu, Yue-Hong

A series of investigations have been carried out to determine RFI effects in analog circuits using monolithic integrated operational amplifiers (op amps) as active devices. The specific RFI effect investigated is how amplitude-modulated (AM) RF signals are demodulated in op amp circuits to produce undesired low frequency responses at AM-modulation frequency. The undesired demodulation responses were shown to be characterized by a second-order nonlinear transfer function. Four representative op amp types investigated were the 741 bipolar op amp, the LM10 bipolar op amp, the LF355 JFET-Bipolar op amp, and the CA081 MOS-Bipolar op amp. Two op amp circuits were investigated. The first circuit was a noninverting unity voltage gain buffer circuit. The second circuit was an inverting op amp configuration. In the second circuit, the investigation includes the effects of an RFI suppression capacitor in the feedback path. Approximately 30 units of each op amp type were tested to determine the statistical variations of RFI demodulation effects in the two op amp circuits. The Nonlinear Circuit Analysis Program, NCAP, was used to simulate the demodulation RFI response. In the simulation, the op amp was replaced with its incremental macromodel. Values of macromodel parameters were obtained from previous investigations and manufacturer's data sheets. Some key results of this work are: (1) The RFI demodulation effects are 10 to 20 dB lower in CA081 and LF355 FET-bipolar op amp than in 741 and LM10 bipolar op amp except above 40 MHz where the LM10 RFI response begins to approach that of CA081. (2) The experimental mean values for 30 741 op amps show that RFI demodulation responses in the inverting amplifier with a 27 pF feedback capacitor were suppressed from 10 to 35 dB over the RF frequency range 0.1 to 150 MHz except at 0.15 MHz where only 3.5 dB suppression was observed. (3) The NCAP program can predict RFI demodulation responses in 741 and LF355 unity gain buffer circuits within 6 and 7 dB respectively for RF frequencies 0.1 to 400 MHz except near the resonant frequencies for the LF355 circuit. (4) The NCAP simulations suggest that the resonances of the LF355 unity gain buffer circuit are related to small parasitic capacitance values of the order of 1 to 5 pF. (5) The NCAP sensitivity analysis indicates that variations in a second-order transfer function are sensitive to some macromodel parameters.

A Proposed Operational Concept for the Defense Communications Operations Support System.

DTIC Science & Technology

1986-01-01

Artificial Intelligence AMA Automatic Message Accounting AMIE AUTODIN Management Index System AMPE Automated Message Processing Exchange ANCS AUTOVON Network...Support IMPRESS Inpact/Restoral System INFORM Information Retrieval System 1OC Initial Operational Capability IRU Intellegent Remote Unit I-S/A AMPE

Sandia National Laboratories: National Security Programs

Science.gov Websites

policy. Topics About Nuclear Weapons Safety & Security Science & Technology Defense Systems & science and technology to help defend and protect the United States. Topics About Defense Systems & . Topics Stationary Power Earth Science Transportation Energy Energy Research Global Security Birc We

Professionals' Recommended Strategies to Improve Australian Adolescents' Knowledge of Nutrition and Food Systems.

PubMed

Sadegholvad, Sanaz; Yeatman, Heather; Parrish, Anne-Maree; Worsley, Anthony

2017-08-07

Education and policy measures within schools are valuable strategies to promote health. This study explored views of experienced food-related educators, researchers and policy-makers regarding their recommended strategies to improve Australian adolescents' knowledge of nutrition and food systems (N&FS). Semi-structured interviews were conducted with twenty-one experienced food-related experts from across Australia. Interviews were conducted either by telephone or face-to-face. Recorded interviews were transcribed verbatim and analyzed thematically. Five central themes and five sub-themes were identified from food professionals' suggestions for best strategies to improve adolescents' knowledge of N&FS. The central themes included: (1) specific improvements in schools' core curricula; (2) pre-service and in-service training of school teachers about N&FS; (3) training students to develop a critical mind about N&FS issues; (4) multidisciplinary collaborations to improve school-based N&FS education; and (5) a supportive N&FS education environment for students. These findings provide a guide for curriculum developers, educational policy developers, and food educators to incorporate the suggested N&FS strategies into Australian education programs in order to improve Australian adolescents' knowledge and skills of N&FS issues. The results of this investigation also may assist the development of international N&FS curricula guides.

48 CFR 1401.370 - Acquisition Managers' Partnership.

Code of Federal Regulations, 2010 CFR

2010-10-01

... acquisition management community to work cooperatively and continuously to improve the management, efficiency... Associate Chairperson are leadership roles that will rotate annually. The AMP Chairperson determines when...

Individual and Store Characteristics Associated with Brand Choices in Select Food Category Redemptions among WIC Participants in Virginia.

PubMed

Zhang, Qi; Tang, Chuanyi; McLaughlin, Patrick W; Diggs, Leigh

2017-03-31

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) often allows participants to redeem food benefits for various brands at different costs. To aid the program's food cost containment efforts, it is important to understand the individual and store characteristics associated with brand choices. This study used the WIC Electronic Benefit Transfer (EBT) data for 239,062 Virginia WIC participants' brand choices in infant fruits and vegetables (F&Vs) and whole grain bread in May 2014-February 2015, one of the first such data sets available in the U.S. for research purposes. Mixed effects logistic regression models were used to analyze the choice of higher-priced brands over lower-priced brands. Minority participants were significantly more likely to redeem higher-priced brands of infant F&Vs, but more likely to choose lower-priced brands of bread. Participants shopping in urban stores or midsized stores (with 5-9 registers) were less likely to choose higher-priced brands compared to rural stores or large stores (with 9+ registers). Race/ethnicity and store characteristics may be significant factors in participants' brand choices. The results can help develop interventions that encourage targeted participants to redeem lower-priced but equivalently healthy brands. This may not only help contain WIC program costs, but help participants manage their own non-WIC food expenses as well.

[In search of results of technical cooperation].

PubMed

Jourdan Hidalgo, L; Manuel Sotelo, J

1999-06-01

For the Pan American Health Organization (PAHO), technical cooperation (TC) is the process by which the PAHO Member States work with the Organization, as equal partners, to identify and reach their own health goals and to promote self-sufficiency in health development, through programs that respond to those countries' needs and national priorities. Since 1978, PAHO has used the American Regional Planning, Programming, Monitoring, and Evaluation System (AMPES) to establish management procedures and to facilitate decision-making in health TC. As part of AMPES, PAHO uses a "logical approach to project management" to structure the work program of the Organization and to identify the expected results from TC activities and TC resource investments. This project management approach, which replaces the "functional approaches" system used to date, also helps establish a causative relationship between the programmed activities and the results that PAHO expects, and between the activities and the hoped-for outcomes in the countries. As part of an ongoing process of rethinking international health TC, several years ago PAHO began a four-phase study on the usefulness and validity of functional approaches and on the need to propose new ones or to modify existing ones. The results of the initial phase showed it was difficult to classify the activities because the functional-approaches categories were not mutually exclusive and the TC activities were complex. Further, the expected results did not specify the product for which the PAHO Secretariat was accountable within a certain time frame nor the Secretariat's level of responsibility. Thus, a new and more flexible classification of expected results was proposed, with the following categories: cooperation networks and alliances; surveillance and information systems; standards and guidelines; research and evaluation studies; plans, projects, and policies; methods, models, and technologies; training programs; promotional campaigns and advocacy; and direct support. In the second phase of the study, it was concluded that the proposed classification system made it possible to more precisely identify the products of PAHO technical cooperation projects, the Organization's degree of responsibility, and the bases for estimating needed resources. The new system could also facilitate monitoring and evaluation. In addition, the third phase of analyzing the functional approaches has begun. Its objective is to evaluate the effect of technical cooperation based on the changes incorporated in the programming of activities.

AMPS data management requirements study. [user manuals (computer programs)/display devices - computerized simulation/experimentation/ionosphere

NASA Technical Reports Server (NTRS)

1975-01-01

A data simulation is presented for instruments and associated control and display functions required to perform controlled active experiments of the atmosphere. A comprehensive user's guide is given for the data requirements and software developed for the following experiments: (1) electromagnetic wave transmission; (2) passive observation of ambient plasmas; (3) ionospheric measurements with a subsatellite; (4) electron accelerator beam measurements; and (5) measurement of acoustic gravity waves in the sodium layer using lasers. A complete description of each experiment is given.

An Approach Towards Structure Based Antimicrobial Peptide Design for Use in Development of Transgenic Plants: A Strategy for Plant Disease Management.

PubMed

Ilyas, Humaira; Datta, Aritreyee; Bhunia, Anirban

2017-01-01

Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), are ubiquitous and vital components of innate defense response that present themselves as potential candidates for drug design, and aim to control plant and animal diseases. Though their application for plant disease management has long been studied with natural AMPs, cytotoxicity and stability related shortcomings for the development of transgenic plants limit their usage. Newer technologies like molecular modelling, NMR spectroscopy and combinatorial chemistry allow screening for potent candidates and provide new avenues for the generation of rationally designed synthetic AMPs with multiple biological functions. Such AMPs can be used for the control of plant diseases that lead to huge yield losses of agriculturally important crop plants, via generation of transgenic plants. Such approaches have gained significant attention in the past decade as a consequence of increasing antibiotic resistance amongst plant pathogens, and the shortcomings of existing strategies that include environmental contamination and human/animal health hazards amongst others. This review summarizes the recent trends and approaches used for employing AMPs, emphasizing on designed/modified ones, and their applications toward agriculture and food technology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Phase A conceptual design study of the Atmospheric, Magnetospheric and Plasmas in Space (AMPS) payload

NASA Technical Reports Server (NTRS)

1974-01-01

The 12 month Phase A Conceptual Design Study of the Atmospheric, Magnetospheric and Plasmas in Space (AMPS) payload performed within the Program Development Directorate of the Marshall Space Flight Center is presented. The AMPS payload makes use of the Spacelab pressurized module and pallet, is launched by the space shuttle, and will have initial flight durations of 7 days. Scientific instruments including particle accelerators, high power transmitters, optical instruments, and chemical release devices are mounted externally on the Spacelab pallet and are controlled by the experimenters from within the pressurized module. The capability of real-time scientist interaction on-orbit with the experiment is a major characteristic of AMPS.

Statistics for demodulation RFI in inverting operational amplifier circuits

NASA Astrophysics Data System (ADS)

Sutu, Y.-H.; Whalen, J. J.

An investigation was conducted with the objective to determine statistical variations for RFI demodulation responses in operational amplifier (op amp) circuits. Attention is given to the experimental procedures employed, a three-stage op amp LED experiment, NCAP (Nonlinear Circuit Analysis Program) simulations of demodulation RFI in 741 op amps, and a comparison of RFI in four op amp types. Three major recommendations for future investigations are presented on the basis of the obtained results. One is concerned with the conduction of additional measurements of demodulation RFI in inverting amplifiers, while another suggests the employment of an automatic measurement system. It is also proposed to conduct additional NCAP simulations in which parasitic effects are accounted for more thoroughly.

Applications of AMPS-1D for solar cell simulation

NASA Astrophysics Data System (ADS)

Zhu, Hong; Kalkan, Ali Kaan; Hou, Jingya; Fonash, Stephen J.

1999-03-01

The AMPS-1D PC computer program is now used by over 70 groups world-wide for detector and solar cell analysis. It has proved to be a very powerful tool in understanding device operation and physics for single crystal, poly-crystalline and amorphous structures. For example, AMPS-1D has been successful in explaining the "red kink" [1] and the "transient effect" in CdS/CIGS poly-crystalline solar cells. It has been used to show that thin film poly-Si structures, with reasonable light trapping, are capable of competitive solar cell conversion efficiencies. In the case of a-Si:H structures, it has been used, for example, to settle the discrepancies in bandgap measurement, to predict the effective QE>1 phenomenon later seen in these materials [2], to determine the relative roles of interface and bulk properties, and to point the direction toward 16% triple junction structures. In general AMPS-1D is used for cell and detector design, material parameter sensitivity studies, and parameter extraction. Recently we have shown that it can be used to determine optimum structure and light and voltage biasing conditions in the material parameter extraction function. Information on AMPS can be found at www.psu.edu/dept/AMPS/amps_web/AMPS.html and at other web sites set up by user groups.

Autonomously managed electrical power systems

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1986-01-01

The electric power systems for future spacecraft such as the Space Station will necessarily be more sophisticated and will exhibit more nearly autonomous operation than earlier spacecraft. These new power systems will be more reliable and flexible than their predecessors offering greater utility to the users. Automation approaches implemented on various power system breadboards are investigated. These breadboards include the Hubble Space Telescope power system test bed, the Common Module Power Management and Distribution system breadboard, the Autonomusly Managed Power System (AMPS) breadboard, and the 20 kilohertz power system breadboard. Particular attention is given to the AMPS breadboard. Future plans for these breadboards including the employment of artificial intelligence techniques are addressed.

Clinical decision support systems: data quality management and governance.

PubMed

Liaw, Siaw-Teng

2013-01-01

This chapter examines data quality management (DQM) and information governance (IG) of electronic decision support (EDS) systems so that they are safe and fit for use by clinicians and patients and their carers. This is consistent with the ISO definition of data quality as being fit for purpose. The scope of DQM & IG should range from data creation and collection in clinical settings, through cleaning and, where obtained from multiple sources, linkage, storage, use by the EDS logic engine and algorithms, knowledge base and guidance provided, to curation and presentation. It must also include protocols and mechanisms to monitor the safety of EDS, which will feedback into DQM & IG activities. Ultimately, DQM & IG must be integrated across the data cycle to ensure that the EDS systems provide guidance that leads to safe and effective clinical decisions and care.

Measurement of cAMP in an undergraduate teaching laboratory, using ALPHAscreen technology.

PubMed

Bartho, Joseph D; Ly, Kien; Hay, Debbie L

2012-02-14

Adenosine 3',5'-monophosphate (cAMP) is a cellular second messenger with central relevance to pharmacology, cell biology, and biochemistry teaching programs. cAMP is produced from adenosine triphosphate by adenylate cyclase, and its production is reduced or enhanced upon activation of many G protein-coupled receptors. Therefore, the measurement of cAMP serves as an indicator of receptor activity. Although there are many assays available for measuring cAMP, few are suitable for large class teaching, and even fewer seem to have been adapted for this purpose. Here, we describe the use of bead-based ALPHAscreen (Amplified Luminescent Proximity Homogenous Assay) technology for teaching a class of more than 300 students the practical aspects of detecting signal transduction. This technology is applicable to the measurement of many different signaling pathways. This resource is designed to provide a practical guide for instructors and a useful model for developing other classes using similar technologies.

Atmospheric, Magnetospheric, and Plasmas in Space (AMPS) spacelab payload definition study, technical summary document

NASA Technical Reports Server (NTRS)

Keeley, J. T.

1976-01-01

Some 60 instrument candidates and 80 possible science investigations were evaluated. The early analysis emphasized the science aspect in terms of the functional requirements for each of the potential experiments identified by the AMPS science working group. These requirements were then used for the grouping of instruments into practical payloads which would fit the capabilities of the Shuttle/Spacelab. This analysis resulted in the definition of eleven different AMPS configurations. The data were then used to define a typical set of requirements for a flexible AMPS laboratory. The data gathered to this point showed that a planned sequential buildup of the laboratory would be necessary to meet both physical and funding limitations. This led to the definition of five strawman payloads by the science working group, which were used to establish a conceptual laboratory and to define preliminary design of a configuration which could satisfy AMPS needs during the early program period.

Factors affecting the matriculation of African American undergraduate students in science, mathematics, engineering, and technology

NASA Astrophysics Data System (ADS)

Hall, Alfred L., II

Previous research studies indicated that African Americans remain severely underrepresented in the field of science, mathematics, engineering, and technology (SMET), making up only 3% of that workforce, while representing 11.1% of all professional and related workers and 12.6% of the general population. As this country moves towards a more culturally diverse population, then representation of African Americans in SMET-related fields must be addressed in order to ensure our nation's competitiveness in a global market. This research study analyzed characteristics of African American undergraduate SMET majors participating in the Alliance for Minority Participation (AMP) program in six different states located in the Southeast region of the United States. These states consisted of Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina. AMP program participants completed a survey questionnaire, which collected information about potential factors that could affect their matriculation in SMET programs of studies at their respective institutions. Follow-up interviews and focus group sessions were also conducted with AMP participants to provide supplemental information to the survey data. The results of student responses were analyzed according to the type of institution the students attended (Historically Black College or University and Majority White Institution) as well as by the statewide Alliance program in which the students were involved. The students responded to survey questions that asked for their reasons for majoring in their field of study, their level of satisfaction with their institution, their impressions of student support programs and persons, their impressions of faculty and advisors, their reasons for thinking of switching majors, and their level of high school preparation. Statistical analyses of the student responses found that African American AMP students attending Historically Black Colleges and Universities differed from those attending Majority White Institutions in terms of their means for achieving future goals, their reasons for thinking of switching majors, their impressions of faculty and advisors, their beliefs that there was too much effort/stress involved in their major field, and their level of high school preparation and achievement. Further analyses determined that the five participating Alliances only differed in student opinions about the support provided by the AMP program/director.

Object-oriented numerics with FOSS: comparing PyPy &amp; NumPy, GCC/Clang &amp; Bitz++ and Gfortran

NASA Astrophysics Data System (ADS)

Jarecka, Dorota; Arabas, Sylwester; Fijalkowski, Maciej; Jaruga, Anna; Del Vento, Davide

2013-04-01

Employment of object-oriented programming (OOP) techniques may help to improve code readability, and hence its auditability and maintainability - both being arguably crucial for scientific software. OOP offers, in particular, the possibility to reproduce in the program code the mathematical "blackboard abstractions" used in the literature. There exist a number of free and open-source tools allowing to obtain this goal without sacrificing performance. An OOP implementation of the MPDATA advection algorithm used as a core of weather, ocean and climate modelling systems will serve as an example for briefly highlighting some relevant recent FOSS developments including: - NumPy support in the PyPy just-in-time compiler of Python. - the Blitz++ library coupled with the C++11 support in GCC and Clang; - support for OOP constructs from Fortran 2003/2008 in GFortran; A brief overview of other performance-related packages for Python like Numba and Cython will be also given. This poster will describe and extends key findings presented in http://arxiv.org/abs/1301.1334

Population-production-pollution nexus based air pollution management model for alleviating the atmospheric crisis in Beijing, China.

PubMed

Zeng, X T; Tong, Y F; Cui, L; Kong, X M; Sheng, Y N; Chen, L; Li, Y P

2017-07-15

In recent years, increscent emissions in the city of Beijing due to expanded population, accelerated industrialization and inter-regional pollutant transportation have led to hazardous atmospheric pollution issues. Although a number of anthropogenic control measures have been put into use, frequent/severe haze events have still challenged regional governments. In this study, a hybrid population-production-pollution nexus model (PPP) is proposed for air pollution management and air quality planning (AMP) with the aim to coordinate human activities and environmental protection. A fuzzy-stochastic mixed quadratic programming method (FSQ) is developed and introduced into a PPP for tackling atmospheric pollution issues with uncertainties. Based on the contribution of an index of population-production-pollution, a hybrid PPP-based AMP model that considers employment structure, industrial layout pattern, production mode, pollutant purification efficiency and a pollution mitigation scheme have been applied in Beijing. Results of the adjustment of employment structure, pollution mitigation scheme, and green gross domestic product under various environmental regulation scenarios are obtained and analyzed. This study can facilitate the identification of optimized policies for alleviating population-production-emission conflict in the study region, as well as ameliorating the hazardous air pollution crisis at an urban level. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effectiveness and efficiency of disease management programs for patients with chronic diseases.

PubMed

Hisashige, Akinori

2012-11-26

Disease management (DM) approach is increasingly advocated as a means of improving effectiveness and efficiency of healthcare for chronic diseases. To evaluate the evidence on effectiveness and efficiency of DM, evidence synthesis was carried out. To locate eligible meta-analyses and systematic reviews, we searched Medline, EMBASE, the Cochrane Library, SCI-EXPANDED, SSCI, A&HCI, DARE, HTA and NHS EED from 1995 to 2010. Two reviewers independently extracted data and assessed a study quality. Twenty-eight meta-analyses and systematic reviews were included for synthesizing evidence. The proportion of articles which observed improvement with a reasonable amount of evidence was the highest at process (69%), followed by health services (63%), QOL (57%), health outcomes (51%), satisfaction (50%), costs (38%) and so on. As to mortality, statistically significant results were observed only in coronary heart disease. Important components in DM, such as a multidisciplinary approach, were identified. The evidence synthesized shows considerable evidence in the effectiveness and efficiency of DM programs in process, health services, QOL and so on. The question is no longer whether DM programs work, but rather which type or component of DM programs works best and efficiently in the context of each healthcare system or country.

Host Defense Antimicrobial Peptides as Antibiotics: Design and Application Strategies

PubMed Central

Mishra, Biswajit; Reiling, Scott; Zarena, D.; Wang, Guangshun

2017-01-01

This review deals with the design and application strategies of new antibiotics based on naturally occurring antimicrobial peptides (AMPs). The initial candidate can be designed based on three-dimensional structure or selected from a library of peptides from natural or laboratory sources followed by optimization via structure-activity relationship studies. There are also advanced application strategies such as induction of AMP expression from host cells by various factors (e.g., metals, amino acids, vitamin D and sunlight), the use of engineered probiotic bacteria to deliver peptides, the design of prodrug and peptide conjugates to improve specific targeting. In addition, combined uses of newly developed AMPs with existing antimicrobial agents may provide a practical avenue for effective management of antibiotic-resistant bacteria (superbugs, including biofilm). Finally, we highlight AMPs already in use or under clinical trials. PMID:28399505

InverPep: A database of invertebrate antimicrobial peptides.

PubMed

Gómez, Esteban A; Giraldo, Paula; Orduz, Sergio

2017-03-01

The aim of this work was to construct InverPep, a database specialised in experimentally validated antimicrobial peptides (AMPs) from invertebrates. AMP data contained in InverPep were manually curated from other databases and the scientific literature. MySQL was integrated with the development platform Laravel; this framework allows to integrate programming in PHP with HTML and was used to design the InverPep web page's interface. InverPep contains 18 separated fields, including InverPep code, phylum and species source, peptide name, sequence, peptide length, secondary structure, molar mass, charge, isoelectric point, hydrophobicity, Boman index, aliphatic index and percentage of hydrophobic amino acids. CALCAMPI, an algorithm to calculate the physicochemical properties of multiple peptides simultaneously, was programmed in PERL language. To date, InverPep contains 702 experimentally validated AMPs from invertebrate species. All of the peptides contain information associated with their source, physicochemical properties, secondary structure, biological activity and links to external literature. Most AMPs in InverPep have a length between 10 and 50 amino acids, a positive charge, a Boman index between 0 and 2 kcal/mol, and 30-50% hydrophobic amino acids. InverPep includes 33 AMPs not reported in other databases. Besides, CALCAMPI and statistical analysis of InverPep data is presented. The InverPep database is available in English and Spanish. InverPep is a useful database to study invertebrate AMPs and its information could be used for the design of new peptides. The user-friendly interface of InverPep and its information can be freely accessed via a web-based browser at http://ciencias.medellin.unal.edu.co/gruposdeinvestigacion/prospeccionydisenobiomoleculas/InverPep/public/home_en. Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Retrospective study of urinalysis for dl-amphetamine and dl-methamphetamine analysis under current Department of Defense guidelines.

PubMed

Shippee, R L; Kippenberger, D J

2000-09-01

Under current Department of Defense (DOD) directive, the laboratories certified to conduct urinalyis testing in support of the DOD Drug Deterrence Program are required to conduct dl-isomer analysis on all specimens that confirm at a concentration greater than 500 ng/mL methamphetamine (METH). Although the same cutoff concentration is required for amphetamine (AMP) reporting, there is no requirement for dl-isomer analysis of AMP-positive specimens. Of the 894,823 specimens screened by the Army Drug Testing Laboratory at Ft. Meade, MD during a 19-month period, 339 confirmed positive for METH. From this positive population, seven specimens failed to confirm at or above the DOD cutoff of > 20% d-isomer. One of the seven specimens contained 534 ng/mL l-AMP and was reported positive for AMP. Although 100% of the AMP was the l-isomer, under current DOD directive, this information was not passed along to the Medical Review Officers (MRO) to assist them during the interview process. Although this situation appears to be a rare event, consideration should be given to requiring dl-isomer analysis of AMP-positive specimens and forwarding this information to the MRO.

Fluorescent ampicillin analogues as multifunctional disguising agents against opsonization

NASA Astrophysics Data System (ADS)

Kotagiri, Nalinikanth; Sakon, Joshua; Han, Haewook; Zharov, Vladimir P.; Kim, Jin-Woo

2016-06-01

Cancer nanomedicines are opening new paradigms in cancer management and recent research points to how they can vastly improve imaging and therapy through multimodality and multifunctionality. However, challenges to achieving optimal efficacy are manifold starting from processing materials and evaluating their intended effectiveness on biological tissue, to developing new strategies aimed at improving transport of these materials through the biological milieu to the target tissue. Here, we report a fluorescent derivative of a beta-lactam antibiotic, ampicillin (termed iAmp) and its multifunctional physicobiochemical characteristics and potential as a biocompatible shielding agent and an effective dispersant. Carbon nanotubes (CNTs) were chosen to demonstrate the efficacy of iAmp. CNTs are known for their versatility and have been used extensively for cancer theranostics as photothermal and photoacoustic agents, but have limited solubility in water and biocompatibility. Traditional dispersants are associated with imaging artifacts and are not fully biocompatible. The chemical structure of iAmp is consistent with a deamination product of ampicillin. Although the four-membered lactam ring is intact, it does not retain the antibiotic properties. The iAmp is an effective dispersant and simultaneously serves as a fluorescent label for single-walled CNTs (SWNTs) with minimal photobleaching. The iAmp also enables bioconjugation of SWNTs to bio-ligands such as antibodies through functional carboxyl groups. Viability tests show that iAmp-coated SWNTs have minimal toxicity. Bio-stability tests under physiological conditions reveal that iAmp coating not only remains stable in a biologically relevant environment with high protein and salt concentrations, but also renders SWNTs transparent against nonspecific protein adsorption, also known as protein corona. Mammalian tissue culture studies with macrophages and opsonins validate that iAmp coating affords immunological resistance to SWNTs. Furthermore, iAmp coating offers protection to SWNTs against their nonspecific adsorption across disparate cell types, which has precluded a targeted strategy, and enables selective molecular targeting. The iAmp can therefore be used as an efficient dispersant, a photostable fluorescent agent, and a biocompatible disguising agent, alleviating CNTs' drawbacks and rendering them suitable for nanotheranostic and drug delivery applications.Cancer nanomedicines are opening new paradigms in cancer management and recent research points to how they can vastly improve imaging and therapy through multimodality and multifunctionality. However, challenges to achieving optimal efficacy are manifold starting from processing materials and evaluating their intended effectiveness on biological tissue, to developing new strategies aimed at improving transport of these materials through the biological milieu to the target tissue. Here, we report a fluorescent derivative of a beta-lactam antibiotic, ampicillin (termed iAmp) and its multifunctional physicobiochemical characteristics and potential as a biocompatible shielding agent and an effective dispersant. Carbon nanotubes (CNTs) were chosen to demonstrate the efficacy of iAmp. CNTs are known for their versatility and have been used extensively for cancer theranostics as photothermal and photoacoustic agents, but have limited solubility in water and biocompatibility. Traditional dispersants are associated with imaging artifacts and are not fully biocompatible. The chemical structure of iAmp is consistent with a deamination product of ampicillin. Although the four-membered lactam ring is intact, it does not retain the antibiotic properties. The iAmp is an effective dispersant and simultaneously serves as a fluorescent label for single-walled CNTs (SWNTs) with minimal photobleaching. The iAmp also enables bioconjugation of SWNTs to bio-ligands such as antibodies through functional carboxyl groups. Viability tests show that iAmp-coated SWNTs have minimal toxicity. Bio-stability tests under physiological conditions reveal that iAmp coating not only remains stable in a biologically relevant environment with high protein and salt concentrations, but also renders SWNTs transparent against nonspecific protein adsorption, also known as protein corona. Mammalian tissue culture studies with macrophages and opsonins validate that iAmp coating affords immunological resistance to SWNTs. Furthermore, iAmp coating offers protection to SWNTs against their nonspecific adsorption across disparate cell types, which has precluded a targeted strategy, and enables selective molecular targeting. The iAmp can therefore be used as an efficient dispersant, a photostable fluorescent agent, and a biocompatible disguising agent, alleviating CNTs' drawbacks and rendering them suitable for nanotheranostic and drug delivery applications. Electronic supplementary information (ESI) available: Details of quantum yield estimation and physicobiochemical analyses to assess the mechanism of iAmp synthesis and its chemical structure as well as the cytotoxicity and bio-stability of iAmp and iAmp-SWNT hybrids. See DOI: 10.1039/c5nr08686h

AMPS data management requirements study, appendix 1. [user manuals (computer programs)/display devices - computerized simulation/experimentation/ionosphere

NASA Technical Reports Server (NTRS)

1975-01-01

Flow charts and display formats for the simulation of five experiments are given. The experiments are: (1) electromagnetic wave transmission; (2) passive observations of ambient plasma; (3) ionospheric measurements with subsatellite; (4) electron accelerator beam measurements; and (5) measurement of acoustical gravity waves in the sodium layer using lasers. A detailed explanation of the simulation procedure, definition of variables, and an explanation of how the experimenter makes display choices is also presented. A functional description is included on each flow chart and the assumptions and definitions of terms and scope of the flow charts and displays are presented.

Web-based Health Educational Program in Saudi Arabia.

PubMed

Bahkali, Salwa; Almaiman, Ahmad; Alsaleh, Mahassen; Elmetwally, Ashraf; Househ, Mowafa

2014-01-01

The purpose of this exploratory study is to provide an overview of a web-based health educational site created by the King Faisal Specialist Hospital and Research Center (KFSH&RC) in the Kingdom of Saudi Arabia (KSA). Sources of data included two interviews with Saudi IT personnel, three health educators, and two medical consultants working at KFSH&RC. The interviews ranged between 45 minutes and 120 minutes. The KFSH&RC website was also searched for the type of health information content posted. Results show that the KFSH&RC web-based health educational site provides health information through a medical encyclopedia, a social networking platform, health educational links, and targeted health information for children, which includes tools such as games and coloring books. Further research is needed on the effectiveness of the KFSH&RC web-based health education site in terms of improving knowledge and changing behavior of Saudi patients. The study recommends that targeted web-based health education strategies should be developed to reach large rural populations which have inadequate computer skills and limited access to the internet.

Zinc-oxygen battery development program

NASA Technical Reports Server (NTRS)

Bourland, Deborah S.

1991-01-01

The purpose of this Zinc-Oxygen development program is to incorporate the improved air/oxygen cathode and zinc anode technology developed in recent years into relatively large cells (150-200 amp/hr, 25-100 hour rate) and smaller high rate cells (9-12 amp/hr, 3-12 hour rate). Existing commercial cells manufactured by Duracell and Rayovac are currently being utilized on the Space Shuttle Orbiter in a mini-oscilloscope, the crew radio, and other crew equipment. These applications provide a basis for other Orbiter systems that require portable, storable, electrical power as well as emergency power for the Space Station major payload systems power and for Space Station equipment applications.

Stacey Rothgeb | NREL

Science.gov Websites

Stacey Rothgeb Photo of Stacey Rothgeb Stacey Rothgeb Manager, Residential Integration & . Prior to joining NREL, Stacey worked as the energy manager at the U.S. Air Force Academy. She also owned (PE) and a Certified Energy Manager (CEM). Education B.S. Architectural Engineering, Kansas State

AMP-Activated Protein Kinase as a Reprogramming Strategy for Hypertension and Kidney Disease of Developmental Origin.

PubMed

Tain, You-Lin; Hsu, Chien-Ning

2018-06-12

Suboptimal early-life conditions affect the developing kidney, resulting in long-term programming effects, namely renal programming. Adverse renal programming increases the risk for developing hypertension and kidney disease in adulthood. Conversely, reprogramming is a strategy aimed at reversing the programming processes in early life. AMP-activated protein kinase (AMPK) plays a key role in normal renal physiology and the pathogenesis of hypertension and kidney disease. This review discusses the regulation of AMPK in the kidney and provides hypothetical mechanisms linking AMPK to renal programming. This will be followed by studies targeting AMPK activators like metformin, resveratrol, thiazolidinediones, and polyphenols as reprogramming strategies to prevent hypertension and kidney disease. Further studies that broaden our understanding of AMPK isoform- and tissue-specific effects on renal programming are needed to ultimately develop reprogramming strategies. Despite the fact that animal models have provided interesting results with regard to reprogramming strategies targeting AMPK signaling to protect against hypertension and kidney disease with developmental origins, these results await further clinical translation.

Finance and Management Services

Science.gov Websites

Pioneer Homes Behavioral Health Office of Children's Services Office of the Commissioner Office of Substance Misuse and Addiction Prevention Finance & Management Services Health Care Services Juvenile Justice Public Assistance Public Health Seniors & Disabilities Services Boards, Councils &

A Simulation Program with Latency Exploitation for the Transient Analysis of Digital Circuits.

DTIC Science & Technology

1983-08-01

PW PER) Examples: VIN 3 0 PULSE(-5 5 iNS iNS iNS 50NS lOONS) parameters default values units Vi (initial value) volts or amps V2 (pulsed value) volts...TAUl TD2 TAU2)mU Examples: VIN 3 0 EXP(-5 0 2NS 30NS 60NS 40NS) parameters default values units V1 (initial value) volts or amps V2 (pulsed value

78 FR 70076 - Aging Management of Internal Surfaces, Fire Water Systems, Atmospheric Storage Tanks, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

... Documents Access and Management System (ADAMS): You may access publicly available documents online in the... protection system piping, (d) revisions to the scope and inspection recommendations of the GALL Report AMP XI... NUCLEAR REGULATORY COMMISSION [NRC-2013-0068] Aging Management of Internal Surfaces, Fire Water...

77 FR 49775 - Beaverhead-Deerlodge National Forest, Wisdom and Wise River Ranger Districts; Montana; North and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-17

... of the North and West Big Hole Allotment Management Plans (NWBH AMP's) project is the updating of eleven domestic livestock grazing management plans. The scope of the project is limited to the specific... River Ranger Districts; Montana; North and West Big Hole Allotment Management Plans AGENCY: Forest...

Updates from the AmeriFlux Management Project Tech Team

NASA Astrophysics Data System (ADS)

Biraud, S.; Chan, S.; Dengel, S.; Polonik, P.; Hanson, C. V.; Billesbach, D. P.; Torn, M. S.

2017-12-01

The goal of AmeriFlux is to develop a network of long-term flux sites for quantifying and understanding the role of the terrestrial biosphere in global climate and environmental change. The AmeriFlux Management Program (AMP) Tech Team at LBNL strengthens the AmeriFlux Network by (1) standardizing operational practices, (2) developing calibration and maintenance routines, and (3) setting clear data quality goals. In this poster we will present results and recent progress in three areas: IRGA intercomparison experiment in cooperation with UC Davis, and main manufacturers of sensors used in the AmeriFlux network (LI-COR, Picarro, and Campbell Scientific). Gill sonic anemometers characterization in collaboration with John Frank and Bill Massman (US Forest Service) following the discovery of a significant firmware problem in commonly used Gill Sonic anemometer, Unmanned aerial systems (UAS), and sensors systematically used at AmeriFlux sites to improve site characterization.

Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 1: Project summary

NASA Technical Reports Server (NTRS)

Mckee, James W.

1990-01-01

This volume (1 of 4) gives a summary of the original AMPS software system configuration, points out some of the problem areas in the original software design that this project is to address, and in the appendix collects all the bimonthly status reports. The purpose of AMPS is to provide a self reliant system to control the generation and distribution of power in the space station. The software in the AMPS breadboard can be divided into three levels: the operating environment software, the protocol software, and the station specific software. This project deals only with the operating environment software and the protocol software. The present station specific software will not change except as necessary to conform to new data formats.

Antimicrobial susceptibilities of Proteus mirabilis: a longitudinal nationwide study from the Taiwan surveillance of antimicrobial resistance (TSAR) program.

PubMed

Wang, Jann-Tay; Chen, Pei-Chen; Chang, Shan-Chwen; Shiau, Yih-Ru; Wang, Hui-Ying; Lai, Jui-Fen; Huang, I-Wen; Tan, Mei-Chen; Lauderdale, Tsai-Ling Yang

2014-09-05

Longitudinal nationwide data on antimicrobial susceptibility in Proteus mirabilis from different sources are rare. The effects of the revised Clinical and Laboratory Standards Institute (CLSI) β-lactam breakpoints on susceptibility rates and on detecting extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase-producers in this species are also seldom evaluated. The present study analyzed data from the Taiwan Surveillance of Antimicrobial Resistance program to address these issues. Isolates were collected biennially between 2002 and 2012 from 25 to 28 hospitals in Taiwan. Minimum inhibitory concentrations (MIC) were determined by reference broth microdilution method. All isolates with aztreonam, ceftazidime, or cefotaxime MIC ≥ 2 mg/L were checked for the presence of ESBL by CLSI confirmatory test and subjected to ESBL and AmpC β-lactamases gene detection by PCR. Univariate and multivariate analyses were performed. Between 2002 and 2012, a total of 1157 P. mirabilis were studied. Susceptibility to cefotaxime, ceftazidime, and ciprofloxacin decreased significantly during the past decade, from 92.6% to 81.7%, 100% to 95.2%, and 80.1% to 53.8%, respectively (P < 0.01). The revised CLSI breakpoints had significant impact on susceptibility to cefazolin (2009 vs. current breakpoints, 71.9% vs. 0.9%) and imipenem (99.8% vs. 55.1%) (P < 0.001 for both). However, using the 2014 cefazolin breakpoints for urinary tract infections, 81.2% of the urine isolates were susceptible. Susceptibilities of isolates from different specimen types were mostly similar but outpatient isolates were more susceptible than inpatient isolates. The overall prevalence of ESBL- and AmpC- producers was 8.2% and 4.7%, respectively, but AmpC carriage increased significantly over the years (from 0 to 7.0%, P < 0.001). ESBL and AmpC β-lactamase-producers were more likely to be found in elderly and ICU patients. The predominant ESBL and AmpC β-lactamase genes were CTX-M- and CMY- types, respectively. A significant decrease in susceptibility to 3rd-generation cephalosporins and ciprofloxacin occurred in P. mirabilis from Taiwan in the past decade. The prevalence of ESBL remained stable but AmpC β-lactamase-producing P. mirabilis increased significantly. Cefotaxime was a better surrogate than ceftazidime for predicting the presence of these β-lactamases. Continuous surveillance on antimicrobial resistance and associated resistance mechanisms in P. mirabilis is warranted.

Defense ADP Acquisition Study.

DTIC Science & Technology

1981-11-30

Logistics ALS - Advanced Logistics System AMP - ADPS Master Plan ANSI - American National Standards Institute APR - Agency Procurement Request ASD(C...Computers IRM - Information Resources Management ISO - International Standards Organization L LCC - Life Cycle Costs LCM - Life Cycle Management LE...man- agement in the process * Lack of a mission orientation . Lack of systems management and life cycle perspectives * Lack of effective leadership

Drug repurposing identifies a synergistic combination therapy with imatinib mesylate for gastrointestinal stromal tumor.

PubMed

Pessetto, Ziyan Y; Ma, Yan; Hirst, Jeff J; von Mehren, Margaret; Weir, Scott J; Godwin, Andrew K

2014-10-01

Gastrointestinal stromal tumor (GIST) is a rare and therefore often neglected disease. Introduction of the kinase inhibitor imatinib mesylate radically improved the clinical response of patients with GIST; however, its effects are often short-lived, with GISTs demonstrating a median time-to-progression of approximately two years. Although many investigational drugs, approved first for other cancers, have been subsequently evaluated for the management of GIST, few have greatly affected the overall survival of patients with advanced disease. We employed a novel, focused, drug-repurposing effort for GIST, including imatinib mesylate-resistant GIST, evaluating a large library of FDA-approved drugs regardless of current indication. As a result of the drug-repurposing screen, we identified eight FDA-approved drugs, including fludarabine phosphate (F-AMP), that showed synergy with and/or overcame resistance to imatinib mesylate. F-AMP induces DNA damage, Annexin V, and caspase-3/7 activities as the cytotoxic effects on GIST cells, including imatinib mesylate-resistant GIST cells. F-AMP and imatinib mesylate combination treatment showed greater inhibition of GIST cell proliferation when compared with imatinib mesylate and F-AMP alone. Successful in vivo experiments confirmed the combination of imatinib mesylate with F-AMP enhanced the antitumor effects compared with imatinib mesylate alone. Our results identified F-AMP as a promising, repurposed drug therapy for the treatment of GISTs, with potential to be administered in combination with imatinib mesylate or for treatment of imatinib mesylate-refractory tumors. ©2014 American Association for Cancer Research.

High-power piezo drive amplifier for large stack and PFC applications

NASA Astrophysics Data System (ADS)

Clingman, Dan J.; Gamble, Mike

2001-08-01

This paper describes the continuing development of Boeing High Power Piezo Drive Amplifiers. Described is the development and testing of a 1500 Vpp, 8 amp switching amplifier. This amplifier is used to drive a piezo stack driven rotor blade trailing edge flap on a full size helicopter. Also discuss is a switching amplifier designed to drive a Piezo Fiber Composite (PFC) active twist rotor blade. This amplifier was designed to drive the PFC material at 2000 Vpp and 0.5 amps. These amplifiers recycle reactive energy, allowing for a power and weight efficient amplifier design. This work was done in conjunction with the DARPA sponsored Phase II Smart Rotor Blade program and the NASA Langley Research Center sponsored Active Twist Rotor (ATR) blade program.

7 CFR 772.13 - Delinquent account servicing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Delinquent account servicing. 772.13 Section 772.13 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS SERVICING MINOR PROGRAM LOANS § 772.13 Delinquent account servicing. (a) AMP...

Find Us | Oregon State University Extension Service

Science.gov Websites

Catalog Programs 4-H Agriculture & Natural Resources Family & Community Health Forestry & -H Youth Development State Office Agriculture and Natural Resources Family and Community Health/SNAP health, community development, food and agriculture, coastal issues, forestry, programs for young people

Conservation and divergence of the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway in two plant-pathogenic fungi: Fusarium graminearum and F. verticillioides.

PubMed

Guo, Li; Breakspear, Andrew; Zhao, Guoyi; Gao, Lixin; Kistler, H Corby; Xu, Jin-Rong; Ma, Li-Jun

2016-02-01

The cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway is a central signalling cascade that transmits extracellular stimuli and governs cell responses through the second messenger cAMP. The importance of cAMP signalling in fungal biology has been well documented and the key conserved components, adenylate cyclase (AC) and the catalytic subunit of PKA (CPKA), have been functionally characterized. However, other genes involved in this signalling pathway and their regulation are not well understood in filamentous fungi. Here, we performed a comparative transcriptomics analysis of AC and CPKA mutants in two closely related fungi: Fusarium graminearum (Fg) and F. verticillioides (Fv). Combining available Fg transcriptomics and phenomics data, we reconstructed the Fg cAMP signalling pathway. We developed a computational program that combines sequence conservation and patterns of orthologous gene expression to facilitate global transcriptomics comparisons between different organisms. We observed highly correlated expression patterns for most orthologues (80%) between Fg and Fv. We also identified a subset of 482 (6%) diverged orthologues, whose expression under all conditions was at least 50% higher in one genome than in the other. This enabled us to dissect the conserved and unique portions of the cAMP-PKA pathway. Although the conserved portions controlled essential functions, such as metabolism, the cell cycle, chromatin remodelling and the oxidative stress response, the diverged portions had species-specific roles, such as the production and detoxification of secondary metabolites unique to each species. The evolution of the cAMP-PKA signalling pathway seems to have contributed directly to fungal divergence and niche adaptation. © 2015 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.

Expanded spectrum β-lactamase producing Escherichia coli isolated from chickens with colibacillosis in Egypt.

PubMed

El-Shazly, D A; Nasef, S A; Mahmoud, F F; Jonas, Daniel

2017-07-01

Throughout the world, expanded spectrum β-lactamases (ESBL) are increasing among clinical isolates of Enterobacteriaceae, both in humans and animals. Unfortunately, there is a paucity of data on ESBL or Ampicillin class C β-lactamase (AmpC) in Egypt, although antimicrobial consumption is high in this developing country. This study aims to characterize the resistance mechanisms to expanded spectrum cephalosporins among resistant veterinary Escherichia coli isolates in Egypt. We investigated 50 clinical multi-resistant E. coli strains isolated from 20 chicken farms for production of ESBL or AmpC. Antibiotic susceptibility was tested by Clinical and Laboratory Standards Institute (CLSI) disk diffusion and ESBL confirmatory tests. PCR and sequencing were performed to screen for plasmid mediated ESBL genes and genes encoding AmpC β-lactamases. All the isolates were phylogentically classified, investigated for harboring class 1 integrons, and genotyped by amplified fragment length polymorphism (AFLP). Three strains showed ESBL and 6 strains AmpC phenotypic patterns, respectively, with confirmed ESBL genes of blaTEM-57, blaSHV-12, blaCTX-M-14, and blaCMY-2 for AmpC producing strains. All ESBL strains belonged to phylogroup D with different clones isolated from different flocks, while most of the AmpC strains belonged to phylogroup B1 (4/6) and were assigned to the same genotype distributed in 2 different farms. Class 1 integrons were disseminated in 60% of all tested strains and in 100% of ESBL and AmpC strains. These results highlight the antimicrobial resistance problem in Egypt, caused in all probability by unwise use of antimicrobials in animal husbandry. The results call for a nationwide surveillance program to monitor antimicrobial resistance. © 2017 Poultry Science Association Inc.

An Update on Asset Management Plans in the United Kingdom.

ERIC Educational Resources Information Center

Patel, Mukund

1999-01-01

Describes a current project in the United Kingdom designed to improve school buildings. The use of Asset Management Plans (AMPs) in providing the means through which likely future needs are assessed, criteria for prioritization are set, and informed decisions on local spending are made are examined. (GR)

The best marker for guiding the clinical management of patients with raised intracranial pressure-the RAP index or the mean pulse amplitude?

PubMed

Hall, Allan; O'Kane, Roddy

2016-10-01

Raised intracranial pressure is a common problem in a variety of neurosurgical conditions including traumatic brain injury, hydrocephalus and intracranial haemorrhage. The clinical management of these patients is guided by a variety of haemodynamic, biochemical and clinical factors. However to date there is no single parameter that is used to guide clinical management of patients with raised intracranial pressure (ICP). However, the role of ICP indices, specifically the mean pulse amplitude (AMP) and RAP index [correlation coefficient (R) between AMP amplitude (A) and mean ICP pressure (P); index of compensatory reserve], as an indicator of true ICP has been investigated. Whilst the RAP index has been used both as a descriptor of neurological deterioration in TBI patients and as a way of characterising the compensatory reserve in hydrocephalus, more recent studies have highlighted the limitation of the RAP index due to the influence that baseline effect errors have on the mean ICP, which is used in the calculation of the RAP index. These studies have suggested that the ICP mean pulse amplitude may be a more accurate marker of true intracranial pressure due to the fact that it is uninfluenced by the mean ICP and, therefore, the AMP may be a more reliable marker than the RAP index for guiding the clinical management of patients with raised ICP. Although further investigation needs to be undertaken in order to fully assess the role of ICP indices in guiding the clinical management of patients with raised ICP, the studies undertaken to date provide an insight into the potential role of ICP indices to treat raised ICP proactively rather than reactively and therefore help prevent or minimise secondary brain injury.

Development of a Web-Based Quality Dashboard Including a Toolbox to Improve Pain Management in Dutch Intensive Care.

PubMed

Roos-Blom, Marie-José; Gude, Wouter T; de Jonge, Evert; Spijkstra, Jan Jaap; van der Veer, Sabine N; Dongelmans, Dave A; de Keizer, Nicolette F

2017-01-01

Audit and feedback (A&F) is a common strategy to improve quality of care. Meta-analyses have indicated that A&F may be more effective in realizing desired change when baseline performance is low, it is delivered by a supervisor or colleague, it is provided frequently and in a timely manner, it is delivered in both verbal and written formats, and it includes specific targets and an action plan. However, there is little information to guide operationalization of these factors. Researchers have consequently called for A&F interventions featuring well-described and carefully justified components, with their theoretical rationale made explicit. This paper describes the rationale and development of a quality dashboard including an improvement toolbox for four previous developed pain indicators, guided by Control Theory.

Audit Trail Management System in Community Health Care Information Network.

PubMed

Nakamura, Naoki; Nakayama, Masaharu; Nakaya, Jun; Tominaga, Teiji; Suganuma, Takuo; Shiratori, Norio

2015-01-01

After the Great East Japan Earthquake we constructed a community health care information network system. Focusing on the authentication server and portal server capable of SAML&ID-WSF, we proposed an audit trail management system to look over audit events in a comprehensive manner. Through implementation and experimentation, we verified the effectiveness of our proposed audit trail management system.

S6 Kinase Inhibits Intrinsic Axon Regeneration Capacity via AMP Kinase in Caenorhabditis elegans

PubMed Central

Hubert, Thomas; Wu, Zilu; Chisholm, Andrew D.

2014-01-01

The ability of axons to regrow after injury is determined by the complex interplay of intrinsic growth programs and external cues. In Caenorhabditis elegans mechanosensory neuron, axons exhibit robust regenerative regrowth following laser axotomy. By surveying conserved metabolic signaling pathways, we have identified the ribosomal S6 kinase RSKS-1 as a new cell-autonomous inhibitor of axon regeneration. RSKS-1 is not required for axonal development but inhibits axon regrowth after injury in multiple neuron types. Loss of function in rsks-1 results in more rapid growth cone formation after injury and accelerates subsequent axon extension. The enhanced regrowth of rsks-1 mutants is partly dependent on the DLK-1 MAPK cascade. An essential output of RSKS-1 in axon regrowth is the metabolic sensor AMP kinase, AAK-2. We further show that the antidiabetic drug phenformin, which activates AMP kinase, can promote axon regrowth. Our data reveal a new function for an S6 kinase acting through an AMP kinase in regenerative growth of injured axons. PMID:24431434

7 CFR 772.16 - Liquidation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... SPECIAL PROGRAMS SERVICING MINOR PROGRAM LOANS § 772.16 Liquidation. When the Agency determines that... liquidated according to 7 CFR part 766. For AMP loans, appeal rights under 7 CFR part 11 are provided in the notice of acceleration. For IMP loans, appeal rights must be exhausted before acceleration, and the...

AMP kinase promotes glioblastoma bioenergetics and tumour growth.

PubMed

Chhipa, Rishi Raj; Fan, Qiang; Anderson, Jane; Muraleedharan, Ranjithmenon; Huang, Yan; Ciraolo, Georgianne; Chen, Xiaoting; Waclaw, Ronald; Chow, Lionel M; Khuchua, Zaza; Kofron, Matthew; Weirauch, Matthew T; Kendler, Ady; McPherson, Christopher; Ratner, Nancy; Nakano, Ichiro; Dasgupta, Nupur; Komurov, Kakajan; Dasgupta, Biplab

2018-06-18

Stress is integral to tumour evolution, and cancer cell survival depends on stress management. We found that cancer-associated stress chronically activates the bioenergetic sensor AMP kinase (AMPK) and, to survive, tumour cells hijack an AMPK-regulated stress response pathway conserved in normal cells. Analysis of The Cancer Genome Atlas data revealed that AMPK isoforms are highly expressed in the lethal human cancer glioblastoma (GBM). We show that AMPK inhibition reduces viability of patient-derived GBM stem cells (GSCs) and tumours. In stressed (exercised) skeletal muscle, AMPK is activated to cooperate with CREB1 (cAMP response element binding protein-1) and promote glucose metabolism. We demonstrate that oncogenic stress chronically activates AMPK in GSCs that coopt the AMPK-CREB1 pathway to coordinate tumour bioenergetics through the transcription factors HIF1α and GABPA. Finally, we show that adult mice tolerate systemic deletion of AMPK, supporting the use of AMPK pharmacological inhibitors in the treatment of GBM.

Depleted Uranium Uses Research and Development

Science.gov Websites

Documents News FAQs Internet Resources Glossary Home » DU Uses Depleted Uranium Uses Research & Uses | DUF6 Management | DUF6 Conversion Facility EISs | Documents News | FAQs | Internet Resources

Managing aging effects on dry cask storage systems for extended long-term storage and transportation of used fuel - rev. 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chopra, O.K.; Diercks, D.; Fabian, R.

The cancellation of the Yucca Mountain repository program in the United States raises the prospect of extended long-term storage (i.e., >120 years) and deferred transportation of used fuel at operating and decommissioned nuclear power plant sites. Under U.S. federal regulations contained in Title 10 of the Code of Federal Regulations (CFR) 72.42, the initial license term for an Independent Spent Fuel Storage Installation (ISFSI) must not exceed 40 years from the date of issuance. Licenses may be renewed by the U.S. Nuclear Regulatory Commission (NRC) at the expiration of the license term upon application by the licensee for a periodmore » not to exceed 40 years. Application for ISFSI license renewals must include the following: (1) Time-limited aging analyses (TLAAs) that demonstrate that structures, systems, and components (SSCs) important to safety will continue to perform their intended function for the requested period of extended operation; and (2) a description of the aging management program (AMP) for management of issues associated with aging that could adversely affect SSCs important to safety. In addition, the application must also include design bases information as documented in the most recent updated final safety analysis report as required by 10 CFR 72.70. Information contained in previous applications, statements, or reports filed with the Commission under the license may be incorporated by reference provided that those references are clear and specific. The NRC has recently issued the Standard Review Plan (SRP) for renewal of used-fuel dry cask storage system (DCSS) licenses and Certificates of Compliance (CoCs), NUREG-1927, under which NRC may renew a specific license or a CoC for a term not to exceed 40 years. Both the license and the CoC renewal applications must contain revised technical requirements and operating conditions (fuel storage, surveillance and maintenance, and other requirements) for the ISFSI and DCSS that address aging effects that could affect the safe storage of the used fuel. The information contained in the license and CoC renewal applications will require NRC review to verify that the aging effects on the SSCs in DCSSs/ ISFSIs are adequately managed for the period of extended operation. To date, all of the ISFSIs located across the United States with more than 1,500 dry casks loaded with used fuel have initial license terms of 20 years; three ISFSIs (Surry, H.B. Robinson and Oconee) have received their renewed licenses for 20 years, and two other ISFSIs (Calvert Cliffs and Prairie Island) have applied for license renewal for 40 years. This report examines issues related to managing aging effects on the SSCs in DCSSs/ISFSIs for extended long-term storage and transportation of used fuels, following an approach similar to that of the Generic Aging Lessons Learned (GALL) report, NUREG-1801, for the aging management and license renewal of nuclear power plants. The report contains five chapters and an appendix on quality assurance for aging management programs for used-fuel dry storage systems. Chapter I of the report provides an overview of the ISFSI license renewal process based on 10 CFR 72 and the guidance provided in NUREG-1927. Chapter II contains definitions and terms for structures and components in DCSSs, materials, environments, aging effects, and aging mechanisms. Chapter III and Chapter IV contain generic TLAAs and AMPs, respectively, that have been developed for managing aging effects on the SSCs important to safety in the dry cask storage system designs described in Chapter V. The summary descriptions and tabulations of evaluations of AMPs and TLAAs for the SSCs that are important to safety in Chapter V include DCSS designs (i.e., NUHOMS{reg_sign}, HI-STORM 100, Transnuclear (TN) metal cask, NAC International S/T storage cask, ventilated storage cask (VSC-24), and the Westinghouse MC-10 metal dry storage cask) that have been and continue to be used by utilities across the country for dry storage of used fuel to date. The goal of this report is to help establish the technical basis for extended long-term storage and transportation of used fuel.« less

Influence of Amphibian Antimicrobial Peptides and Short Lipopeptides on Bacterial Biofilms Formed on Contact Lenses

PubMed Central

Maciejewska, Magdalena; Bauer, Marta; Neubauer, Damian; Kamysz, Wojciech; Dawgul, Malgorzata

2016-01-01

The widespread use of contact lenses is associated with several complications, including ocular biofilm-related infections. They are very difficult to manage with standard antimicrobial therapies, because bacterial growth in a biofilm is associated with an increased antibiotic resistance. The principal aim of this study was to evaluate the efficacy of antimicrobial peptides (AMPs) in eradication of bacterial biofilms formed on commercially available contact lenses. AMPs were synthesized according to Fmoc/tBu chemistry using the solid-phase method. Minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of the compounds were determined. Anti-biofilm activity of the antimicrobial peptides determined at different temperatures (25 °C and 37 °C) were compared with the effectiveness of commercially available contact lens solutions. All of the tested compounds exhibited stronger anti-biofilm properties as compared to those of the tested lens solutions. The strongest activity of AMPs was noticed against Gram-positive strains at a temperature of 25 °C. Conclusions: The results of our experiments encourage us toward further studies on AMPs and their potential application in the prophylaxis of contact lens-related eye infections. PMID:28773992

Science Programs

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Using NCAP to predict RFI effects in linear bipolar integrated circuits

NASA Astrophysics Data System (ADS)

Fang, T.-F.; Whalen, J. J.; Chen, G. K. C.

1980-11-01

Applications of the Nonlinear Circuit Analysis Program (NCAP) to calculate RFI effects in electronic circuits containing discrete semiconductor devices have been reported upon previously. The objective of this paper is to demonstrate that the computer program NCAP also can be used to calcuate RFI effects in linear bipolar integrated circuits (IC's). The IC's reported upon are the microA741 operational amplifier (op amp) which is one of the most widely used IC's, and a differential pair which is a basic building block in many linear IC's. The microA741 op amp was used as the active component in a unity-gain buffer amplifier. The differential pair was used in a broad-band cascode amplifier circuit. The computer program NCAP was used to predict how amplitude-modulated RF signals are demodulated in the IC's to cause undesired low-frequency responses. The predicted and measured results for radio frequencies in the 0.050-60-MHz range are in good agreement.

Alternative Fuels Data Center: Ridesharing

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. Carsharing programs such as Zipcar, Car2Go, and Enterprise CarShare offer different plans and pricing for carsharing companies even offer alternative fuel vehicles, such as all-electric vehicles. Fuels &

PQRS Mess.

PubMed

Sorrel, Amy Lynn

2016-03-01

One-quarter of physicians who participate in the Physician Quality Reporting System and the value modifier program risked payment cuts stemming from difficulties the Centers for Medicare & Medicaid Services had with collecting and analyzing 2014 quality data.

Milrinone enhances relaxation to prostacyclin and iloprost in pulmonary arteries isolated from lambs with persistent pulmonary hypertension of the newborn

PubMed Central

Lakshminrusimha, Satyan; Porta, Nicolas F. M.; Farrow, Kathryn N.; Chen, Bernadette; Gugino, Sylvia F.; Kumar, Vasanth H.; Russell, James A.; Steinhorn, Robin H.

2009-01-01

Prostacyclin is a pulmonary vasodilator and is produced by prostacyclin synthase and stimulates adenylate cyclase (AC) via the prostacyclin receptor (IP) to produce cAMP. Forskolin is a direct stimulant of AC. Phosphodiesterase 3 hydrolyzes cAMP and is inhibited by milrinone. Objective To characterize the prostacyclin-AC-cAMP pathway in the ovine ductal ligation model of persistent pulmonary hypertension of the newborn (PPHN). Setting University-based laboratory animal facility. Subjects Lambs delivered to time-dated pregnant ewes. Interventions Fifth generation pulmonary arteries (PA) and lung parenchyma were isolated from control fetal lambs (n = 8) and fetal lambs with PPHN induced by antenatal ductal ligation (n = 9). We studied relaxation responses to various agonists (milrinone, forskolin, prostacyclin, and iloprost, a prostacyclin analog) that increase cAMP in PA after half-maximal constriction with norepinephrine and pretreatment with propranolol ± indo-methacin. Lung protein levels of prostacyclin synthase, IP, AC2, and phosphodiesterase 3A were analyzed by Western blot and cAMP by enzyme-linked immunoassay. Main Results Milrinone relaxed control and PPHN PA and pretreatment with indomethacin significantly impaired this response. Relaxation to milrinone, prostacyclin, and iloprost were significantly impaired in PA from PPHN lambs. Pretreatment with milrinone markedly enhanced relaxation to prostacyclin and iloprost in PPHN PA, similar to relaxation in control PA. Relaxation to forskolin was similar in control and PPHN PAs indicating normal AC activity. Protein levels of prostacyclin synthase and IP were decreased in PPHN lungs compared with control, but AC2, cAMP, and phosphodiesterase 3A remained unchanged. Conclusions Prostacyclin and iloprost are dilators of PAs from PPHN lambs and their effect is enhanced by milrinone. This combination therapy may be an effective strategy in the management of patients with PPHN. PMID:19057444

77 FR 6143 - Agency Information Collection Activities: Submission for the Office of Management and Budget (OMB...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

... Radiation Safety Officer (RSO), authorized medical physicist (AMP), authorized nuclear pharmacist (ANP), or...''; (3) NRC Form 313A (ANP), ``Authorized Nuclear Pharmacist Training and Experience and Preceptor...

High Heterogeneity of Escherichia coli Sequence Types Harbouring ESBL/AmpC Genes on IncI1 Plasmids in the Colombian Poultry Chain

PubMed Central

Donado-Godoy, Pilar; León, Maribel; Clavijo, Viviana; Arevalo, Alejandra; Bernal, Johan F.; Timmerman, Arjen J.; Mevius, Dik J.; Wagenaar, Jaap A.; Hordijk, Joost

2017-01-01

Background Escherichia coli producing ESBL/AmpC enzymes are unwanted in animal production chains as they may pose a risk to human and animal health. Molecular characterization of plasmids and strains carrying genes that encode these enzymes is essential to understand their local and global spread. Objectives To investigate the diversity of genes, plasmids and strains in ESBL/AmpC-producing E. coli from the Colombian poultry chain isolated within the Colombian Integrated Program for Antimicrobial Resistance Surveillance (Coipars). Methods A total of 541 non-clinical E. coli strains from epidemiologically independent samples and randomly isolated between 2008 and 2013 within the Coipars program were tested for antimicrobial susceptibility. Poultry isolates resistant to cefotaxime (MIC ≥ 4 mg/L) were screened for ESBL/AmpC genes including blaCTX-M, blaSHV, blaTEM, blaCMY and blaOXA. Plasmid and strain characterization was performed for a selection of the ESBL/AmpC-producing isolates. Plasmids were purified and transformed into E. coli DH10B cells or transferred by conjugation to E. coli W3110. When applicable, PCR Based Replicon Typing (PBRT), plasmid Multi Locus Sequence Typing (pMLST), plasmid Double Locus Sequence Typing (pDLST) and/or plasmid Replicon Sequence Typing (pRST) was performed on resulting transformants and conjugants. Multi Locus Sequence Typing (MLST) was used for strain characterization. Results In total, 132 of 541 isolates were resistant to cefotaxime and 122 were found to carry ESBL/AmpC genes. Ninety-two harboured blaCMY-2 (75%), fourteen blaSHV-12 (11%), three blaSHV-5 (2%), five blaCTX-M-2 (4%), one blaCTX-M-15 (1%), one blaCTX-M-8 (1%), four a combination of blaCMY-2 and blaSHV-12 (4%) and two a combination of blaCMY-2 and blaSHV-5 (2%). A selection of 39 ESBL/AmpC-producing isolates was characterized at the plasmid and strain level. ESBL/AmpC genes from 36 isolates were transferable by transformation or conjugation of which 22 were located on IncI1 plasmids. These IncI1 plasmids harboured predominantly blaCMY-2 (16/22), and to a lesser extend blaSHV-12 (5/22) and blaCTX-M-8 (1/22). Other plasmid families associated with ESBL/AmpC-genes were IncK (4/33), IncHI2 (3/33), IncA/C (2/33), IncΒ/O (1/33) and a non-typeable replicon (1/33). Subtyping of IncI1 and IncHI2 demonstrated IncI1/ST12 was predominantly associated with blaCMY-2 (12/16) and IncHI2/ST7 with blaCTX-M-2 (2/3). Finally, 31 different STs were detected among the 39 selected isolates. Conclusions Resistance to extended spectrum cephalosporins in E. coli from Colombian poultry is mainly caused by blaCMY-2 and blaSHV-12. The high diversity of strain Sequence Types and the dissemination of homogeneous IncI1/ST12 plasmids suggest that spread of the resistance is mainly mediated by horizontal gene transfer. PMID:28125687

High Heterogeneity of Escherichia coli Sequence Types Harbouring ESBL/AmpC Genes on IncI1 Plasmids in the Colombian Poultry Chain.

PubMed

Castellanos, Luis Ricardo; Donado-Godoy, Pilar; León, Maribel; Clavijo, Viviana; Arevalo, Alejandra; Bernal, Johan F; Timmerman, Arjen J; Mevius, Dik J; Wagenaar, Jaap A; Hordijk, Joost

2017-01-01

Escherichia coli producing ESBL/AmpC enzymes are unwanted in animal production chains as they may pose a risk to human and animal health. Molecular characterization of plasmids and strains carrying genes that encode these enzymes is essential to understand their local and global spread. To investigate the diversity of genes, plasmids and strains in ESBL/AmpC-producing E. coli from the Colombian poultry chain isolated within the Colombian Integrated Program for Antimicrobial Resistance Surveillance (Coipars). A total of 541 non-clinical E. coli strains from epidemiologically independent samples and randomly isolated between 2008 and 2013 within the Coipars program were tested for antimicrobial susceptibility. Poultry isolates resistant to cefotaxime (MIC ≥ 4 mg/L) were screened for ESBL/AmpC genes including blaCTX-M, blaSHV, blaTEM, blaCMY and blaOXA. Plasmid and strain characterization was performed for a selection of the ESBL/AmpC-producing isolates. Plasmids were purified and transformed into E. coli DH10B cells or transferred by conjugation to E. coli W3110. When applicable, PCR Based Replicon Typing (PBRT), plasmid Multi Locus Sequence Typing (pMLST), plasmid Double Locus Sequence Typing (pDLST) and/or plasmid Replicon Sequence Typing (pRST) was performed on resulting transformants and conjugants. Multi Locus Sequence Typing (MLST) was used for strain characterization. In total, 132 of 541 isolates were resistant to cefotaxime and 122 were found to carry ESBL/AmpC genes. Ninety-two harboured blaCMY-2 (75%), fourteen blaSHV-12 (11%), three blaSHV-5 (2%), five blaCTX-M-2 (4%), one blaCTX-M-15 (1%), one blaCTX-M-8 (1%), four a combination of blaCMY-2 and blaSHV-12 (4%) and two a combination of blaCMY-2 and blaSHV-5 (2%). A selection of 39 ESBL/AmpC-producing isolates was characterized at the plasmid and strain level. ESBL/AmpC genes from 36 isolates were transferable by transformation or conjugation of which 22 were located on IncI1 plasmids. These IncI1 plasmids harboured predominantly blaCMY-2 (16/22), and to a lesser extend blaSHV-12 (5/22) and blaCTX-M-8 (1/22). Other plasmid families associated with ESBL/AmpC-genes were IncK (4/33), IncHI2 (3/33), IncA/C (2/33), IncΒ/O (1/33) and a non-typeable replicon (1/33). Subtyping of IncI1 and IncHI2 demonstrated IncI1/ST12 was predominantly associated with blaCMY-2 (12/16) and IncHI2/ST7 with blaCTX-M-2 (2/3). Finally, 31 different STs were detected among the 39 selected isolates. Resistance to extended spectrum cephalosporins in E. coli from Colombian poultry is mainly caused by blaCMY-2 and blaSHV-12. The high diversity of strain Sequence Types and the dissemination of homogeneous IncI1/ST12 plasmids suggest that spread of the resistance is mainly mediated by horizontal gene transfer.

Attention Training in Individuals with Generalized Social Phobia: A Randomized Controlled Trial

PubMed Central

Amir, Nader; Beard, Courtney; Taylor, Charles T.; Klumpp, Heide; Elias, Jason; Burns, Michelle; Chen, Xi

2009-01-01

We conducted a randomized, double-blind placebo-controlled trial to examine the efficacy of an attention training procedure in reducing symptoms of social anxiety in forty-four individuals diagnosed with Generalized Social Phobia (GSP). Attention training comprised a probe detection task where pictures of faces with either a threatening or neutral emotional expression cued different locations on the computer screen. In the Attention Modification Program (AMP), participants responded to a probe that always followed neutral faces when paired with a threatening face, thereby directing attention away from threat. In the Attention Control Condition (ACC), the probe appeared with equal frequency in the position of the threat and neutral faces. Results revealed that the AMP facilitated attention disengagement from threat from pre- to post-assessment, and reduced clinician- and self-reported symptoms of social anxiety relative to the ACC. Participants no longer meeting DSM-IV criteria for GSP at post-assessment were 50% in the AMP and 14% in the ACC. Symptom reduction in the AMP group was maintained during four-month follow-up assessment. These results suggest that computerized attention training procedures may be beneficial for treating social phobia. PMID:19803575

In Vivo Cardiovascular Pharmacology of 2′,3′-cAMP, 2′-AMP, and 3′-AMP in the Rat

PubMed Central

Mi, Zaichuan

2013-01-01

The naturally occurring purine 2′,3′-cAMP is metabolized in vitro to 2′-AMP and 3′-AMP, which are subsequently metabolized to adenosine. Whether in vivo 2′,3′-cAMP, 2′-AMP, or 3′-AMP are rapidly converted to adenosine and exert rapid effects via adenosine receptors is unknown. To address this question, we compared the cardiovascular and renal effects of 2′,3′-cAMP, 2′-AMP, 3′-AMP, 3′,5′-cAMP, 5′-AMP, and adenosine in vivo in the rat. Purines were infused intravenously while monitoring mean arterial blood pressure (MABP), heart rate (HR), cardiac output, and renal and mesenteric blood flows. Total peripheral (TPR), renal vascular (RVR), and mesenteric vascular (MVR) resistances were calculated. Urine was collected for determination of urine excretion rate [urine volume (UV)]. When sufficient urine was available, the sodium excretion rate (Na+ER) and glomerular filtration rate (GFR) were determined. 2′,3′-cAMP, 2′-AMP, and 3′-AMP dose-dependently and profoundly reduced MABP, HR, TPR, and MVR with efficacy and potency similar to adenosine and 5′-AMP. These effects of 2′,3′-cAMP, 2′-AMP, and 3′-AMP were attenuated by blockade of adenosine receptors with 1,3-dipropyl-8-(p-sulfophenyl)xanthine. 2′,3′-cAMP, 2′-AMP, 3′-AMP, adenosine, and 5′-AMP variably affected RVR, but profoundly (nearly 100%) decreased UV at higher doses. GFR and Na+ER could be measured at the lower doses and were suppressed by 2′,3′-cAMP, 2′-AMP, and 3′-AMP, but not by adenosine or 5′-AMP. 2′,3′-cAMP increased urinary excretion rates of 2′-AMP, 3′-AMP, and adenosine. 3′,5′-cAMP exerted no adverse hemodynamic effects yet increased urinary adenosine as efficiently as 2′,3′-cAMP. Conclusions: In vivo 2′,3′-cAMP is rapidly converted to adenosine. Because both cAMPs increase adenosine in the urinary compartment, these agents may provide unique therapeutic opportunities. PMID:23759508

2′,3′-cAMP, 3′-AMP, and 2′-AMP inhibit human aortic and coronary vascular smooth muscle cell proliferation via A2B receptors

PubMed Central

Ren, Jin; Gillespie, Delbert G.

2011-01-01

Rat vascular smooth muscle cells (VSMCs) from renal microvessels metabolize 2′,3′-cAMP to 2′-AMP and 3′-AMP, and these AMPs are converted to adenosine that inhibits microvascular VSMC proliferation via A2B receptors. The goal of this study was to test whether this mechanism also exists in VSMCs from conduit arteries and whether it is similarly expressed in human vs. rat VSMCs. Incubation of rat and human aortic VSMCs with 2′,3′-cAMP concentration-dependently increased levels of 2′-AMP and 3′-AMP in the medium, with a similar absolute increase in 2′-AMP vs. 3′-AMP. In contrast, in human coronary VSMCs, 2′,3′-cAMP increased 2′-AMP levels yet had little effect on 3′-AMP levels. In all cell types, 2′,3′-cAMP increased levels of adenosine, but not 5′-AMP, and 2′,3′-AMP inhibited cell proliferation. Antagonism of A2B receptors (MRS-1754), but not A1 (1,3-dipropyl-8-cyclopentylxanthine), A2A (SCH-58261), or A3 (VUF-5574) receptors, attenuated the antiproliferative effects of 2′,3′-cAMP. In all cell types, 2′-AMP, 3′-AMP, and 5′-AMP increased adenosine levels, and inhibition of ecto-5′-nucleotidase blocked this effect of 5′-AMP but not that of 2′-AMP nor 3′-AMP. Also, 2′-AMP, 3′-AMP, and 5′-AMP, like 2′,3′-cAMP, exerted antiproliferative effects that were abolished by antagonism of A2B receptors with MRS-1754. In conclusion, VSMCs from conduit arteries metabolize 2′,3′-cAMP to AMPs, which are metabolized to adenosine. In rat and human aortic VSMCs, both 2′-AMP and 3′-AMP are involved in this process, whereas, in human coronary VSMCs, 2′,3′-cAMP is mainly converted to 2′-AMP. Because adenosine inhibits VSMC proliferation via A2B receptors, local vascular production of 2′,3′-cAMP may protect conduit arteries from atherosclerosis. PMID:21622827

Extracellular 2′,3′-cAMP-adenosine pathway in proximal tubular, thick ascending limb, and collecting duct epithelial cells

PubMed Central

Gillespie, Delbert G.

2013-01-01

In a previous study, we demonstrated that human proximal tubular epithelial cells obtained from a commercial source metabolized extracellular 2′,3′-cAMP to 2′-AMP and 3′-AMP and extracellular 2′-AMP and 3′-AMP to adenosine (the extracellular 2′,3′-cAMP-adenosine pathway; extracellular 2′,3′-cAMP → 2′-AMP + 3′-AMP → adenosine). The purpose of this study was to investigate the metabolism of extracellular 2′,3′-cAMP in proximal tubular vs. thick ascending limb vs. collecting duct epithelial cells freshly isolated from their corresponding nephron segments obtained from rat kidneys. In epithelial cells from all three nephron segments, 1) extracellular 2′,3′-cAMP was metabolized to 2′-AMP and 3′-AMP, with 2′-AMP > 3′-AMP, 2) the metabolism of extracellular 2′,3′-cAMP to 2′-AMP and 3′-AMP was not inhibited by either 3-isobutyl-1-methylxanthine (phosphodiesterase inhibitor) or 1,3-dipropyl-8-p-sulfophenylxanthine (ecto-phosphodiesterase inhibitor), 3) extracellular 2′,3′-cAMP increased extracellular adenosine levels, 4) 3′-AMP and 2′-AMP were metabolized to adenosine with an efficiency similar to that of 5′-AMP, and 5) the metabolism of 5′-AMP, 3′-AMP, and 2′-AMP was not inhibited by α,β-methylene-adenosine-5′-diphosphate (CD73 inhibitor). These results support the conclusion that renal epithelial cells all along the nephron can metabolize extracellular 2′,3′-cAMP to 2′-AMP and 3′-AMP and can efficiently metabolize extracellular 2′-AMP and 3′-AMP to adenosine and that the metabolic enzymes involved are not the classical phosphodiesterases nor ecto-5′-nucleotidase (CD73). Because 2′,3′-cAMP is released by injury and because previous studies demonstrate that the extracellular 2′,3′-cAMP-adenosine pathway stimulates epithelial cell proliferation via adenosine A2B receptors, the present results suggest that the extracellular 2′,3′-cAMP-adenosine pathway may help restore epithelial cells along the nephron following kidney injury. PMID:23077101

The Brain In Vivo Expresses the 2′,3′-cAMP-Adenosine Pathway

PubMed Central

Verrier, Jonathan D.; Jackson, Travis C.; Bansal, Rashmi; Kochanek, Patrick M.; Puccio, Ava M.; Okonkwo, David O.; Jackson, Edwin K.

2012-01-01

Although multiple biochemical pathways produce adenosine, studies suggest that the 2′,3′-cAMP-adenosine pathway (2′,3′-cAMP → 2′-AMP/3′-AMP → adenosine) contributes to adenosine production in some cells/tissues/organs. To determine whether the 2′,3′-cAMP-adenosine pathway exists in vivo in the brain, we delivered to the brain (gray matter and white matter separately) via the inflow perfusate of a microdialysis probe either 2′,3′-cAMP, 3′,5′-cAMP, 2′-AMP, 3′-AMP, or 5′-AMP and measured the recovered metabolites in the microdialysis outflow perfusate with mass spectrometry. In both gray and white matter, 2′,3′-cAMP increased 2′-AMP, 3′-AMP and adenosine, and 3′,5′-cAMP increased 5′-AMP and adenosine. In both brain regions, 2′-AMP, 3-AMP and 5′-AMP were converted to adenosine. Microdialysis experiments in 2′,3′-cyclic nucleotide-3′-phosphodiesterase (CNPase) wild-type mice demonstrated that traumatic brain injury (TBI; controlled cortical impact model) activated the brain 2,3′-cAMP-adenosine pathway; similar experiments in CNPase knockout mice indicated that CNPase was involved in the metabolism of endogenous 2′,3′-cAMP to 2′-AMP and to adenosine. In CSF from TBI patients, 2′,3′-cAMP was significantly increased in the initial 12 hours after injury and strongly correlated with CSF levels of 2′-AMP, 3′-AMP, adenosine and inosine. We conclude that in vivo, 2′,3′-cAMP is converted to 2′-AMP/3′-AMP, and these AMPs are metabolized to adenosine. This pathway exists endogenously in both mice and humans. PMID:22360621

Chemotaxis in Microfluidic Devices

NASA Astrophysics Data System (ADS)

Wyatt, Danica; Nadkarni, Sharvari; Song, Loling; Voeltz, Camilla; Bodenschatz, Eberhard

2004-03-01

Dictyostelium amoebae use chemical signaling to begin starvation-induced aggregation. Cells generate a complex and dynamic pattern of cyclic AMP that drives their migration toward a central point. While this phenomenon is unique to social amoebae, the signaling pathways of chemotaxis are similar in all eukaryotic cells. Dicty serves as a model organism for imaging these intracellular protein dynamics. To date, chemotaxis has been primarily studied in diffusion-generated gradients in chambers many orders of magnitude larger than a cell. To better quantify which aspects of a gradient trigger a response, we have designed a microfluidic channel that confines cells in an environment where spatiotemporal cAMP concentration can be precisely manipulated. We report results on an early event in the signaling cascade, the translocation of PH domain-containing proteins, which test current models of chemotaxis. This work was supported by the NSF Biocomplexity program and the Nanobiotechnology Center, an STC Program of the NSF under Agreement No. ECS-9876771.

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Forager bees (Apis mellifera) highly express immune and detoxification genes in tissues associated with nectar processing.

PubMed

Vannette, Rachel L; Mohamed, Abbas; Johnson, Brian R

2015-11-09

Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging.

Forager bees (Apis mellifera) highly express immune and detoxification genes in tissues associated with nectar processing

PubMed Central

Vannette, Rachel L.; Mohamed, Abbas; Johnson, Brian R.

2015-01-01

Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging. PMID:26549293

An adenylyl cyclase like-9 gene (NlAC9) influences growth and fecundity in the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae).

PubMed

Ge, LinQuan; Gu, HaoTian; Huang, Bo; Song, Qisheng; Stanley, David; Liu, Fang; Yang, Guo-Qing; Wu, Jin-Cai

2017-01-01

The cAMP/PKA intracellular signaling pathway is launched by adenylyl cyclase (AC) conversion of adenosine triphosphate (ATP) to 3', 5'-cyclic AMP (cAMP) and cAMP-dependent activation of PKA. Although this pathway is very well known in insect physiology, there is little to no information on it in some very small pest insects, such as the brown planthopper (BPH), Nilaparvata lugens Stål. BPH is a destructive pest responsible for tremendous crop losses in rice cropping systems. We are investigating the potentials of novel pest management technologies from RNA interference perspective. Based on analysis of transcriptomic data, the BPH AC like-9 gene (NlAC9) was up-regulated in post-mating females, which led us to pose the hypothesis that NlAC9 is a target gene that would lead to reduced BPH fitness and populations. Targeting NlAC9 led to substantially decreased soluble ovarian protein content, yeast-like symbiont abundance, and vitellogenin gene expression, accompanied with stunted ovarian development and body size. Eggs laid were decreased and oviposition period shortened. Taken together, our findings indicated that NlAC9 exerted pronounced effects on female fecundity, growth and longevity, which strongly supports our hypothesis.

Using large-scale flow experiments to rehabilitate Colorado River ecosystem function in Grand Canyon: Basis for an adaptive climate-resilient strategy: Chapter 17

USGS Publications Warehouse

Melis, Theodore S.; Pine, William E.; Korman, Josh; Yard, Michael D.; Jain, Shaleen; Pulwarty, Roger S.; Miller, Kathleen; Hamlet, Alan F.; Kenney, Douglas S.; Redmond, Kelly T.

2016-01-01

Adaptive management of Glen Canyon Dam is improving downstream resources of the Colorado River in Glen Canyon National Recreation Area and Grand Canyon National Park. The Glen Canyon Dam Adaptive Management Program (AMP), a federal advisory committee of 25 members with diverse special interests tasked to advise the U.S. Department of the Interior), was established in 1997 in response to the 1992 Grand Canyon Protection Act. Adaptive management assumes that ecosystem responses to management policies are inherently complex and unpredictable, but that understanding and management can be improved through monitoring. Best known for its high-flow experiments intended to benefit physical and biological resources by simulating one aspect of pre-dam conditions—floods, the AMP promotes collaboration among tribal, recreation, hydropower, environmental, water and other natural resource management interests. Monitoring has shown that high flow experiments move limited new tributary sand inputs below the dam from the bottom of the Colorado River to shorelines; rebuilding eroded sandbars that support camping areas and other natural and cultural resources. Spring-timed high flows have also been shown to stimulate aquatic productivity by disturbing the river bed below the dam in Glen Canyon. Understanding about how nonnative tailwater rainbow trout (Oncorhynchus mykiss), and downstream endangered humpback chub (Gila cypha) respond to dam operations has also increased, but this learning has mostly posed “surprise” adaptation opportunities to managers. Since reoperation of the dam to Modified Low Fluctuating Flows in 1996, rainbow trout now benefit from more stable daily flows and high spring releases, but possibly at a risk to humpback chub and other native fishes downstream. In contrast, humpback chub have so far proven robust to all flows, and native fish have increased under the combination of warmer river temperatures associated with reduced storage in Lake Powell, and a system-wide reduction in trout from 2000-06, possibly due to several years of natural reproduction under limited food supply. Uncertainties about dam operations and ecosystem responses remain, including how native and nonnative fish will interact and respond to possible increased river temperatures under drier basin conditions. Ongoing assessment of operating policies by the AMP’s diverse stakeholders represents a major commitment to the river’s valued resources, while surprise learning opportunities can also help identify a resilient climate-change strategy for co-managing nonnative and endangered native fish, sandbar habitats and other river resources in a region with already complex and ever-increasing water demands.

Activities of daily living in children with hemiparesis: influence of cognitive abilities and motor competence.

PubMed

Adler, Caroline; Rauchenzauner, Markus; Staudt, Martin; Berweck, Steffen

2014-12-01

The aim of the article is to investigate whether motor competence and cognitive abilities influence the quality of performance of activities of daily living (ADL) in children with hemiparesis. Patients and A total of 20 children with hemiparesis (age, 6-12 years; 11 congenital, 9 acquired during childhood) were studied. Motor competence was assessed with the Assisting Hand Assessment, cognitive abilities with the German version of the Wechsler Intelligence Scale for Children IV, and the quality of ADL performance with the Assessment of Motor and Process Skills (AMPS). The motor skills scale of the AMPS correlated with motor competence, and the process skills scale of the AMPS correlated with cognitive abilities. The quality of ADL performance is influenced not only by motor competence but also by the cognitive abilities of a hemiparetic child. This suggests that, in addition to motor-oriented training programs, an optimal therapy for hemiparetic children should also consider cognitive approaches. Georg Thieme Verlag KG Stuttgart · New York.

Statewide Suicide Prevention Council

Science.gov Websites

Alaska Pioneer Homes Behavioral Health Office of Children's Services Office of the Commissioner Office of Substance Misuse and Addiction Prevention Finance & Management Services Health Care Services Juvenile Justice Public Assistance Public Health Seniors & Disabilities Services Boards, Councils &

Modularized battery management for large lithium ion cells

NASA Astrophysics Data System (ADS)

Stuart, Thomas A.; Zhu, Wei

A modular electronic battery management system (BMS) is described along with important features for protecting and optimizing the performance of large lithium ion (LiIon) battery packs. Of particular interest is the use of a much improved cell equalization system that can increase or decrease individual cell voltages. Experimental results are included for a pack of six series connected 60 Ah (amp-hour) LiIon cells.

Purification, characterization, and sequencing of antimicrobial peptides, Cy-AMP1, Cy-AMP2, and Cy-AMP3, from the Cycad (Cycas revoluta) seeds.

PubMed

Yokoyama, Seiya; Kato, Kouji; Koba, Atsuko; Minami, Yuji; Watanabe, Keiichi; Yagi, Fumio

2008-12-01

Novel antimicrobial peptides (AMP), designated Cy-AMP1, Cy-AMP2, and Cy-AMP3, were purified from seeds of the cycad (Cycas revoluta) by a CM cellulofine column, ion-exchange HPLC on SP COSMOGEL, and reverse-phase HPLC. They had molecular masses of 4583.2 Da, 4568.9 Da and 9275.8 Da, respectively, by MALDI-TOF MS analysis. Half of the amino acid residues of Cy-AMP1 and Cy-AMP2 were cysteine, glycine and proline, and their sequences were similar. The sequence of Cy-AMP3 showed high homology to various lipid transfer proteins. For Cy-AMP1 and Cy-AMP2, the concentrations of peptides required for 50% inhibition (IC(50)) of the growth of plant pathogenic fungi, Gram-positive and Gram-negative bacteria were 7.0-8.9 microg/ml. The Cy-AMP3 had weak antimicrobial activity. The structural and antimicrobial characteristics of Cy-AMP1 and Cy-AMP2 indicated that they are a novel type of antimicrobial peptide belonging to a plant defensin family.

Twin plants from supernumerary egg cells in Arabidopsis.

PubMed

Kong, Jixiang; Lau, Steffen; Jürgens, Gerd

2015-01-19

Sexual reproduction of flowering plants is distinguished by double fertilization—the two sperm cells delivered by a pollen tube fuse with the two gametic cells of the female gametophyte, the egg and the central cell—inside the ovule to give rise to the embryo and the nutritive endosperm, respectively. The pollen tube is attracted by nongametic synergid cells, and how these two cells of the female gametophyte are specified is currently unclear. Here, we show that ALTERED MERISTEM PROGRAM 1 (AMP1), encoding a protein associated with the endoplasmic reticulum, is required for synergid cell fate during Arabidopsis female gametophyte development. Loss of AMP1 function leads to supernumerary egg cells at the expense of synergids, enabling the generation of dizygotic twins. However, if twin embryos are formed, endosperm formation is prevented, eventually resulting in ovule abortion. The latter can be overcome by the delivery of supernumerary sperm cells in tetraspore (tes) pollen, enabling the formation of twin plants. Thus, both primary and supernumerary egg cells are fully functional in amp1 mutant plants. Sporophytic AMP1 expression is sufficient to prevent cell-fate change of synergids, indicating that one or more AMP1-dependent mobile signals from outside the female gametophyte can contribute to its patterning, in addition to the previously reported lateral inhibition between gametophytic cells. Our results provide insight into the mechanism of synergid fate specification and emphasize the importance of specifying only one egg cell within the female gametophyte to ensure central-cell fertilization by the second sperm cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine inhibit TNF-α and CXCL10 production from activated primary murine microglia via A2A receptors.

PubMed

Newell, Elizabeth A; Exo, Jennifer L; Verrier, Jonathan D; Jackson, Travis C; Gillespie, Delbert G; Janesko-Feldman, Keri; Kochanek, Patrick M; Jackson, Edwin K

2015-01-12

Some cells, tissues and organs release 2',3'-cAMP (a positional isomer of 3',5'-cAMP) and convert extracellular 2',3'-cAMP to 2'-AMP plus 3'-AMP and convert these AMPs to adenosine (called the extracellular 2',3'-cAMP-adenosine pathway). Recent studies show that microglia have an extracellular 2',3'-cAMP-adenosine pathway. The goal of the present study was to investigate whether the extracellular 2',3'-cAMP-adenosine pathway could have functional consequences on the production of cytokines/chemokines by activated microglia. Experiments were conducted in cultures of primary murine microglia. In the first experiment, the effect of 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine on LPS-induced TNF-α and CXCL10 production was determined. In the next experiment, the first protocol was replicated but with the addition of 1,3-dipropyl-8-p-sulfophenylxanthine (DPSPX) (0.1 μM; antagonist of adenosine receptors). The last experiment compared the ability of 2-chloro-N(6)-cyclopentyladenosine (CCPA) (10 μM; selective A1 agonist), 5'-N-ethylcarboxamide adenosine (NECA) (10 μM; agonist for all adenosine receptor subtypes) and CGS21680 (10 μM; selective A2A agonist) to inhibit LPS-induced TNF-α and CXCL10 production. (1) 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine similarly inhibited LPS-induced TNF-α and CXCL10 production; (2) DPSPX nearly eliminated the inhibitory effects of 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine on LPS-induced TNF-α and CXCL10 production; (3) CCPA did not affect LPS-induced TNF-α and CXCL10; (4) NECA and CGS21680 similarly inhibited LPS-induced TNF-α and CXCL10 production. 2',3'-cAMP and its metabolites (3'-AMP, 2'-AMP and adenosine) inhibit LPS-induced TNF-α and CXCL10 production via A2A-receptor activation. Adenosine and its precursors, via A2A receptors, likely suppress TNF-α and CXCL10 production by activated microglia in brain diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification and functional characterization of an uncharacterized antimicrobial peptide from a ciliate Paramecium caudatum.

PubMed

Cui, Pengfei; Dong, Yuan; Li, Zhijian; Zhang, Yubo; Zhang, Shicui

2016-07-01

The global ever-growing concerns about multi-drug resistant (MDR) microbes leads to urgent demands for exploration of new antibiotics including antimicrobial peptides (AMPs). Here we demonstrated that a cDNA from Ciliata Paramecium caudatum, designated Pcamp1, coded for a protein with features characteristic of AMPs, which is not homologous to any AMPs currently known. Both the C-terminal 91 amino acid residues of PcAMP1, cPcAMP1, expressed in Escherichia coli and the C-terminal 26 amino acid residues (predicted mature AMP), cPcAMP1/26, synthesized, underwent a coil-to-helix transition in the presence of TFE, SDS or DPC. Functional assays revealed that cPcAMP1 and cPcAMP1/26 were both able to kill Aeromonas hydrophila and Staphylococcus aureus. ELISA showed that cPcAMP1 and cPcAMP1/26 were able to bind to microbe-associated molecular pattern molecules LPS and LTA, which was further corroborated by the observations that cPcAMP1 could deposit onto the bacterial membranes. Importantly, both cPcAMP1 and cPcAMP1/26 were able to induce bacterial membrane permeabilization and depolarization, and to increase intracellular ROS levels. Additionally, cPcAMP1 and cPcAMP1/26 were not cytotoxic to mammalian cells. Taken together, our results show that PcAMP1 is a potential AMP with a membrane selectivity towards bacterial cells, which renders it a promising template for the design of novel peptide antibiotics against MDR microbes. It also shows that use of signal conserved sequence of AMPs can be an effective tool to identify potential AMPs across different animal classes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intracellular tortuosity underlies slow cAMP diffusion in adult ventricular myocytes.

PubMed

Richards, Mark; Lomas, Oliver; Jalink, Kees; Ford, Kerrie L; Vaughan-Jones, Richard D; Lefkimmiatis, Konstantinos; Swietach, Pawel

2016-06-01

3',5'-Cyclic adenosine monophosphate (cAMP) signals in the heart are often confined to concentration microdomains shaped by cAMP diffusion and enzymatic degradation. While the importance of phosphodiesterases (degradative enzymes) in sculpting cAMP microdomains is well established in cardiomyocytes, less is known about cAMP diffusivity (DcAMP) and factors affecting it. Many earlier studies have reported fast diffusivity, which argues against sharply defined microdomains. [cAMP] dynamics in the cytoplasm of adult rat ventricular myocytes were imaged using a fourth generation genetically encoded FRET-based sensor. The [cAMP]-response to the addition and removal of isoproterenol (β-adrenoceptor agonist) quantified the rates of cAMP synthesis and degradation. To obtain a read out of DcAMP, a stable [cAMP] gradient was generated using a microfluidic device which delivered agonist to one half of the myocyte only. After accounting for phosphodiesterase activity, DcAMP was calculated to be 32 µm(2)/s; an order of magnitude lower than in water. Diffusivity was independent of the amount of cAMP produced. Saturating cAMP-binding sites with the analogue 6-Bnz-cAMP did not accelerate DcAMP, arguing against a role of buffering in restricting cAMP mobility. cAMP diffused at a comparable rate to chemically unrelated but similar sized molecules, arguing for a common physical cause of restricted diffusivity. Lower mitochondrial density and order in neonatal cardiac myocytes allowed for faster diffusion, demonstrating the importance of mitochondria as physical barriers to cAMP mobility. In adult cardiac myocytes, tortuosity due to physical barriers, notably mitochondria, restricts cAMP diffusion to levels that are more compatible with microdomain signalling. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Metformin and phenformin activate AMP-activated protein kinase in the heart by increasing cytosolic AMP concentration.

PubMed

Zhang, Li; He, Huamei; Balschi, James A

2007-07-01

AMP-activated protein kinase (AMPK) acts as a cellular energy sensor: it responds to an increase in AMP concentration ([AMP]) or the AMP-to-ATP ratio (AMP/ATP). Metformin and phenformin, which are biguanides, have been reported to increase AMPK activity without increasing AMP/ATP. This study tests the hypothesis that these biguanides increase AMPK activity in the heart by increasing cytosolic [AMP]. Groups of isolated rat hearts (n = 5-7 each) were perfused with Krebs-Henseleit buffer with or without 0.2 mM phenformin or 10 mM metformin, and (31)P-NMR-measured phosphocreatine, ATP, and intracellular pH were used to calculate cytosolic [AMP]. At various times, hearts were freeze-clamped and assayed for AMPK activity, phosphorylation of Thr(172) on AMPK-alpha, and phosphorylation of Ser(79) on acetyl-CoA carboxylase, an AMPK target. In hearts treated with phenformin for 18 min and then perfused for 20 min with Krebs-Henseleit buffer, [AMP] began to increase at 26 min and AMPK activity was elevated at 36 min. In hearts treated with metformin, [AMP] was increased at 50 min and AMPK activity, phosphorylated AMPK, and phosphorylated acetyl-CoA carboxylase were elevated at 61 min. In metformin-treated hearts, HPLC-measured total AMP content and total AMP/ATP did not increase. In summary, phenformin and metformin increase AMPK activity and phosphorylation in the isolated heart. The increase in AMPK activity was always preceded by and correlated with increased cytosolic [AMP]. Total AMP content and total AMP/ATP did not change. Cytosolic [AMP] reported metabolically active AMP, which triggered increased AMPK activity, but measures of total AMP did not.

Schwann Cells Metabolize Extracellular 2′,3′-cAMP to 2′-AMP

PubMed Central

Verrier, Jonathan D.; Kochanek, Patrick M.

2015-01-01

The 3′,5′-cAMP–adenosine pathway (3′,5′-cAMP→5′-AMP→adenosine) and the 2′,3′-cAMP–adenosine pathway (2′,3′-cAMP→2′-AMP/3′-AMP→adenosine) are active in the brain. Oligodendrocytes participate in the brain 2′,3′-cAMP–adenosine pathway via their robust expression of 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase; converts 2′,3′-cAMP to 2′-AMP). Because Schwann cells also express CNPase, it is conceivable that the 2′,3′-cAMP–adenosine pathway exists in the peripheral nervous system. To test this and to compare the 2′,3′-cAMP–adenosine pathway to the 3′,5′-cAMP–adenosine pathway in Schwann cells, we examined the metabolism of 2′,3′-cAMP, 2′-AMP, 3′-AMP, 3′,5′-cAMP, and 5′-AMP in primary rat Schwann cells in culture. Addition of 2′,3′-cAMP (3, 10, and 30 µM) to Schwann cells increased levels of 2′-AMP in the medium from 0.006 ± 0.002 to 21 ± 2, 70 ± 3, and 187 ± 10 nM/µg protein, respectively; in contrast, Schwann cells had little ability to convert 2′,3′-cAMP to 3′-AMP or 3′,5′-cAMP to either 3′-AMP or 5′-AMP. Although Schwann cells slightly converted 2′,3′-cAMP and 2′-AMP to adenosine, they did so at very modest rates (e.g., 5- and 3-fold, respectively, more slowly compared with our previously reported studies in oligodendrocytes). Using transected myelinated rat sciatic nerves in culture medium, we observed a time-related increase in endogenous intracellular 2′,3′-cAMP and extracellular 2′-AMP. These findings indicate that Schwann cells do not have a robust 3′,5′-cAMP–adenosine pathway but do have a 2′,3′-cAMP–adenosine pathway; however, because the pathway mostly involves 2′-AMP formation rather than 3′-AMP, and because the conversion of 2′-AMP to adenosine is slow, metabolism of 2′,3′-cAMP mostly results in the accumulation of 2′-AMP. Accumulation of 2′-AMP in peripheral nerves postinjury could have pathophysiological consequences. PMID:25998049

Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 3: Commands specification

NASA Technical Reports Server (NTRS)

Mckee, James W.

1990-01-01

This volume (3 of 4) contains the specification for the command language for the AMPS system. The volume contains a requirements specification for the operating system and commands and a design specification for the operating system and command. The operating system and commands sits on top of the protocol. The commands are an extension of the present set of AMPS commands in that the commands are more compact, allow multiple sub-commands to be bundled into one command, and have provisions for identifying the sender and the intended receiver. The commands make no change to the actual software that implement the commands.

Standardized Modular Power Interfaces for Future Space Explorations Missions

NASA Technical Reports Server (NTRS)

Oeftering, Richard

2015-01-01

Earlier studies show that future human explorations missions are composed of multi-vehicle assemblies with interconnected electric power systems. Some vehicles are often intended to serve as flexible multi-purpose or multi-mission platforms. This drives the need for power architectures that can be reconfigured to support this level of flexibility. Power system developmental costs can be reduced, program wide, by utilizing a common set of modular building blocks. Further, there are mission operational and logistics cost benefits of using a common set of modular spares. These benefits are the goals of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project. A common set of modular blocks requires a substantial level of standardization in terms of the Electrical, Data System, and Mechanical interfaces. The AMPS project is developing a set of proposed interface standards that will provide useful guidance for modular hardware developers but not needlessly constrain technology options, or limit future growth in capability. In 2015 the AMPS project focused on standardizing the interfaces between the elements of spacecraft power distribution and energy storage. The development of the modular power standard starts with establishing mission assumptions and ground rules to define design application space. The standards are defined in terms of AMPS objectives including Commonality, Reliability-Availability, Flexibility-Configurability and Supportability-Reusability. The proposed standards are aimed at assembly and sub-assembly level building blocks. AMPS plans to adopt existing standards for spacecraft command and data, software, network interfaces, and electrical power interfaces where applicable. Other standards including structural encapsulation, heat transfer, and fluid transfer, are governed by launch and spacecraft environments and bound by practical limitations of weight and volume. Developing these mechanical interface standards is more difficult but an essential part of defining physical building blocks of modular power. This presentation describes the AMPS projects progress towards standardized modular power interfaces.

Role of CNPase in the Oligodendrocytic Extracellular 2′,3′-cAMP-Adenosine Pathway

PubMed Central

Verrier, Jonathan D.; Jackson, Travis C.; Gillespie, Delbert G.; Janesko-Feldman, Keri; Bansal, Rashmi; Goebbels, Sandra; Nave, Klaus-Armin; Kochanek, Patrick M.; Jackson, Edwin K.

2014-01-01

Extracellular adenosine 3′,5′-cyclic monophosphate (3′,5′-cAMP) is an endogenous source of localized adenosine production in many organs. Recent studies suggest that extracellular 2′,3′-cAMP (positional isomer of 3′,5′-cAMP) is also a source of adenosine, particularly in the brain in vivo post-injury. Moreover, in vitro studies show that both microglia and astrocytes can convert extracellular 2′,3′-cAMP to adenosine. Here we examined the ability of primary mouse oligodendrocytes and neurons to metabolize extracellular 2′,3′-cAMP and their respective adenosine monophosphates (2′-AMP and 3′-AMP). Cells were also isolated from mice deficient in 2′,3′-cyclic nucleotide-3′-phosphodiesterase (CNPase). Oligodendrocytes metabolized 2′,3′-cAMP to 2′-AMP with 10-fold greater efficiency than did neurons (and also more than previously examined microglia and astrocytes); whereas, the production of 3′-AMP was minimal in both oligodendrocytes and neurons. The production of 2′-AMP from 2′,3′-cAMP was reduced by 65% in CNPase -/- versus CNPase +/+ oligodendrocytes. Oligodendrocytes also converted 2′-AMP to adenosine, and this was also attenuated in CNPase -/- oligodendrocytes. Inhibition of classic 3′,5′-cAMP-3′-phosphodiesterases with 3-isobutyl-1-methylxanthine did not block metabolism of 2′,3′-cAMP to 2′-AMP and inhibition of classic ecto-5′-nucleotidase (CD73) with α,β-methylene-adenosine-5′-diphosphate did not attenuate the conversion of 2′-AMP to adenosine. These studies demonstrate that oligodendrocytes express the extracellular 2′,3′-cAMP-adenosine pathway (2′,3′-cAMP → 2′-AMP → adenosine). This pathway is more robustly expressed in oligodendrocytes than in all other CNS cell types because CNPase is the predominant enzyme that metabolizes 2′,3′-cAMP to 2-AMP in CNS cells. By reducing levels of 2′,3′-cAMP (a mitochondrial toxin) and increasing levels of adenosine (a neuroprotectant), oligodendrocytes may protect axons from injury. PMID:23922219

2’,3’-cAMP, 3’-AMP, 2’-AMP and Adenosine Inhibit TNF-α and CXCL10 Production From Activated Primary Murine Microglia via A2A Receptors

PubMed Central

Newell, Elizabeth A.; Exo, Jennifer L.; Verrier, Jonathan D.; Jackson, Travis C.; Gillespie, Delbert G.; Janesko-Feldman, Keri; Kochanek, Patrick M.

2014-01-01

Background Some cells, tissues and organs release 2’,3’-cAMP (a positional isomer of 3’,5’-cAMP) and convert extracellular 2’,3’-cAMP to 2’-AMP plus 3’-AMP and convert these AMPs to adenosine (called the extracellular 2’,3’-cAMP-adenosine pathway). Recent studies show that microglia have an extracellular 2’,3’-cAMP-adenosine pathway. The goal of the present study was to investigate whether the extracellular 2’,3’-cAMP-adenosine pathway could have functional consequences on the production of cytokines/chemokines by activated microglia. Methods Experiments were conducted in cultures of primary murine microglia. In the first experiment, the effect of 2’,3’-cAMP, 3’-AMP, 2’-AMP and adenosine on LPS-induced TNF-α and CXCL10 production was determined. In the next experiment, the first protocol was replicated but with the addition of 1,3-dipropyl-8-p-sulfophenylxanthine (DPSPX) (0.1 µM; antagonist of adenosine receptors). The last experiment compared the ability of 2-chloro-N6-cyclopentyladenosine (CCPA) (10 µM; selective A1 agonist), 5’-N-ethylcarboxamide adenosine (NECA) (10 µM; agonist for all adenosine receptor subtypes) and CGS21680 (10 µM; selective A2A agonist) to inhibit LPS-induced TNF-α and CXCL10 production. Results 1) 2’,3’-cAMP, 3’-AMP, 2’-AMP and adenosine similarly inhibited LPS-induced TNF-α and CXCL10 production; 2) DPSPX nearly eliminated the inhibitory effects of 2’,3’-cAMP, 3’-AMP, 2’-AMP and adenosine on LPS-induced TNF-α and CXCL10 production; 3) CCPA did not affect LPS-induced TNF-α and CXCL10; 4) NECA and CGS21680 similarly inhibited LPS-induced TNF-α and CXCL10 production. Conclusions 2’,3’-cAMP and its metabolites (3’-AMP, 2’-AMP and adenosine) inhibit LPS-induced TNF-α and CXCL10 production via A2A-receptor activation. Adenosine and its precursors, via A2A receptors, likely suppress TNF-α and CXCL10 production by activated microglia in brain diseases. PMID:25451117

The 2′,3′-cAMP-adenosine pathway

PubMed Central

2011-01-01

Our recent studies employing HPLC-tandem mass spectrometry to analyze venous perfusate from isolated, perfused kidneys demonstrate that intact kidneys produce and release into the extracellular compartment 2′,3′-cAMP, a positional isomer of the second messenger 3′,5′-cAMP. To our knowledge, this represents the first detection of 2′,3′-cAMP in any cell/tissue/organ/organism. Nuclear magnetic resonance experiments with isolated RNases and experiments in isolated, perfused kidneys suggest that 2′,3′-cAMP likely arises from RNase-mediated transphosphorylation of mRNA. Both in vitro and in vivo kidney experiments demonstrate that extracellular 2′,3′-cAMP is efficiently metabolized to 2′-AMP and 3′-AMP, both of which can be further metabolized to adenosine. This sequence of reactions is called the 2′,3′-cAMP-adenosine pathway (2′,3′-cAMP → 2′-AMP/3′-AMP → adenosine). Experiments in rat and mouse kidneys show that metabolic poisons increase extracellular levels of 2′,3′-cAMP, 2′-AMP, 3′-AMP, and adenosine; however, little is known regarding the pharmacology of 2′,3′-cAMP, 2′-AMP, and 3′-AMP. What is known is that 2′,3′-cAMP facilitates activation of mitochondrial permeability transition pores, a process that can lead to apoptosis and necrosis, and inhibits proliferation of vascular smooth muscle cells and glomerular mesangial cells. In summary, there is mounting evidence that at least some types of cellular injury, by triggering mRNA degradation, engage the 2′,3′-cAMP-adenosine pathway, and therefore this pathway should be added to the list of biochemical pathways that produce adenosine. Although speculative, it is possible that the 2′,3′-cAMP-adenosine pathway may protect against some forms of acute organ injury, for example acute kidney injury, by both removing an intracellular toxin (2′,3′-cAMP) and increasing an extracellular renoprotectant (adenosine). PMID:21937608

IMPROVING HYDROLOGIC SUSTAINABILITY OF TEXAS A&M UNIVERSITY CAMPUS

EPA Science Inventory

For small to mid-sized rain events, LID scenarios, including permeable pavements, rainwater harvesting, green roofs, and riparian buffer strips perform similarly to a conventional Best Management Practice, a detention pond, with respect to peak flows and HFR. For large rain ev...

Multivariate and Naive Bayes Text Classification Approach to Cost Growth Risk in Department of Defense Acquisition Programs

DTIC Science & Technology

2013-03-01

alerts 0.00011 3.26E-06 alternative 0.000161 0.000426 amp 5.25E-05 0.003127 amplifier 0.001501 0.000277 angular 0.000103 3.26E-06 anticipate 0.000755...0.000217 0.00056 amp 4.07E-05 0.004884 amplifier 0.002158 0.00043 angular 0.000109 4.48E-06 anticipation 0.000136 0.000453 aperture 0.000624...0.000215 instructed 0.00057 4.93E-05 java 0.000258 4.48E-05 refactoring 0.00019 2.69E-05 strike 0.000271 5.83E-05 touches 1.36E-05 9.86E-05

Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

NASA Technical Reports Server (NTRS)

Shamma, Mohammed A.

2004-01-01

The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

Dietary effects of adenosine monophosphate to enhance growth, digestibility, innate immune responses and stress resistance of juvenile red sea bream, Pagrus major.

PubMed

Hossain, Md Sakhawat; Koshio, Shunsuke; Ishikawa, Manabu; Yokoyama, Saichiro; Sony, Nadia Mahjabin

2016-09-01

Our study explored the dietary effects of adenosine monophosphate (AMP) to enhance growth, digestibility, innate immune responses and stress resistance of juvenile red sea bream. A semi-purified basal diet supplemented with 0% (Control), 0.1% (AMP-0.1), 0.2% (AMP-0.2), 0.4% (AMP-0.4) and 0.8% (AMP-0.8) purified AMP to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish (mean initial weight 3.4 g) for 56 days. The results indicated that dietary AMP supplements tended to improve growth performances. One of the best ones was found in diet group AMP-0.2, followed by diet groups AMP-0.1, AMP-0.4 and AMP-0.8. The Apparent digestibility coefficients (dry matter, protein and lipid) also improved by AMP supplementation and the significantly highest dry matter digestibility was observed in diet group AMP-0.2. Fish fed diet groups AMP-0.2 and AMP-0.4 had significantly higher peroxidase and bactericidal activities than fish fed the control diet. Nitro-blue-tetrazolium (NBT) activity was found to be significantly (P < 0.05) greater in fish fed diet groups AMP-0.4 and AMP-0.8. Total serum protein, lysozyme activity and agglutination antibody titer were also increased (P > 0.05) by dietary supplementation. In contrast, catalase activity decreased with AMP supplementation. Moreover, the fish fed AMP supplemented diets had better improvement (P < 0.05) in body lipid contents, condition factor, hematocrit content and glutamyl oxaloacetic transaminase (GOT) level than the control group. Supplementation also improved both freshwater and oxidative stress resistances. Interestingly, the fish fed diet groups AMP-0.2 and AMP-0.4 showed the least oxidative stress condition. Finally it is concluded that, dietary AMP supplementation enhanced the growth, digestibility, immune response and stress resistance of red sea bream. The regression analysis revealed that a dietary AMP supplementation between 0.2 and 0.4% supported weight gain and lysozyme activity as a marker of immune functions for red sea bream, which is also inline with the most of the growth and health performance parameters of fish under present experimental conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pulse amplitude of intracranial pressure waveform in hydrocephalus.

PubMed

Czosnyka, Z; Keong, N; Kim, D J; Radolovich, D; Smielewski, P; Lavinio, A; Schmidt, E A; Momjian, S; Owler, B; Pickard, J D; Czosnyka, M

2008-01-01

There is increasing interest in evaluation of the pulse amplitude of intracranial pressure (AMP) in explaining dynamic aspects of hydrocephalus. We reviewed a large number of ICP recordings in a group of hydrocephalic patients to assess utility of AMP. From a database including approximately 2,100 cases of infusion studies (either lumbar or intraventricular) and overnight ICP monitoring in patients suffering from hydrocephalus of various types (both communicating and non-communicating), etiology and stage of management (non-shunted or shunted) pressure recordings were evaluated. For subgroup analysis we selected 60 patients with idiopathic NPH with full follow-up after shunting. In 29 patients we compared pulse amplitude during an infusion study performed before and after shunting with a properly functioning shunt. Amplitude was calculated from ICP waveforms using spectral analysis methodology. A large amplitude was associated with good outcome after shunting (positive predictive value of clinical improvement for AMP above 2.5 mmHg was 95%). However, low amplitude did not predict poor outcome (for AMP below 2.5 mmHg 52% of patients improved). Correlations of AMP with ICP and Rcsf were positive and statistically significant (N = 131 with idiopathic NPH; R = 0.21 for correlation with mean ICP and 0.22 with Rcsf; p< 0.01). Correlation with the brain elastance coefficient (or PVI) was not significant. There was also no significant correlation between pulse amplitude and width of the ventricles. The pulse amplitude decreased (p < 0.005) after shunting. Interpretation of the ICP pulse waveform may be clinically useful in patients suffering from hydrocephalus. Elevated amplitude seems to be a positive predictor for clinical improvement after shunting. A properly functioning shunt reduces the pulse amplitude.

Automating a spacecraft electrical power system using expert systems

NASA Technical Reports Server (NTRS)

Lollar, L. F.

1991-01-01

Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

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Multi-junction Thin-film Solar Cells on Flexible Substrates for Space Power

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Smith, Mark; Scofield, John H.; Dickman, John E.; Lush, Gregory B.; Morel, Donald L.; Ferekides, Christos; Dhere, Neelkanth G.

2002-01-01

The ultimate objective of the thin-film program at NASA GRC is development of a 20 percent AM0 thin-film device technology with high power/weight ratio. Several approaches are outlined to improve overall device efficiency and power/weight ratio. One approach involves the use of very lightweight flexible substrates such as polyimides (i.e., Kapton(Trademark)) or metal foil. Also, a compound semiconductor tandem device structure that can meet this objective is proposed and simulated using Analysis of Microelectronic and Photonic Structures (AMPS). AMPS modeling of current devices in tandem format indicate that AM0 efficiencies near 20 percent can be achieved. And with improvements in materials, efficiencies approaching 25 percent are achievable. Several important technical issues need to be resolved to realize these complex devices: development of a wide bandgap material with good electronic properties, development of transparent contacts, and targeting a 2-terminal device structure (with more complicated processing and tunnel junction) or 4-terminal device. Recent progress in the NASA GRC program is outlined.

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Forskolin and derivatives as tools for studying the role of cAMP.

PubMed

Alasbahi, R H; Melzig, M F

2012-01-01

Forskolin (7beta-acetoxy-1alpha,6beta,9alpha-trihydroxy-8,13-epoxy-labd-14-en-11-one) is the first main labdane diterpenoid isolated from the roots of the Indian Plectranthus barbatus ANDREWS and one of the most extensively studied constituents of this plant. The unique character of forskolin as a general direct, rapid and reversible activator of adenylyl cyclase not only underlies its wide range of pharmacological effects but also renders it as a valuable tool in the study of the role of cAMP. The purpose of this review is to provide data presenting the utility of forskolin--as a cAMP activator--for studying the function of cAMP from different biological viewpoints as follows: 1) Investigation on the role of cAMP in various cellular processes in different organs such as gastrointestinal tract, respiratory tract, reproductive organs, endocrine system, urinary system, olfactory system, nervous system, platelet aggregating system, skin, bones, eyes, and smooth muscles. 2) Studies on the role of cAMP activation and inhibition to understand the pathogenesis (e.g. thyroid autoimmune disorders, leukocyte signal transduction defect in depression, acute malaria infection, secretory dysfunction in inflammatory diseases) as well as its possibly beneficial role for curing diseases such as the regulation of coronary microvascular NO production after heart failure, the attenuation of the development or progression of fibrosis in the heart and lungs, the augmentation of myo-protective effects of ischemic preconditioning especially in the failing hearts after myocardial infarction, the stimulation of the regeneration of injured retinal ganglion cells, the curing of glaucoma and inflammatory diseases, the reducing of cyst formation early in the polycystic kidney disease, and the management of autoimmune disorders by enhancing Fas-mediated apoptosis. 3) Studies on the role of cAMP in the mechanism of actions of a number of drugs and substances such as the effect of the protoberberine alkaloid palmatine on the active ion transport across rat colonic epithelium, the inhibitory effect of retinoic acid on HIV-1-induced podocyte proliferation, the whitening activity of luteolin, the effect of cilostazol on nitric oxide production, an effect that is involved in capillary-like tube formation in human aortic endothelial cells, the apoptotic effect of bullatacin, the effects of paraoxon and chlorpyrifos oxon on nervous system. Moreover, cAMP was found to play a role in acute and chronic exposure to ethanol, in morphine dependence and withdrawal and in behavioral sensitization to cocaine as well as in the protection against cisplatin-induced oxidative injuries.

cAMP-dependent chloride secretion mediates tubule enlargement and cyst formation by cultured mammalian collecting duct cells.

PubMed

Montesano, Roberto; Ghzili, Hafida; Carrozzino, Fabio; Rossier, Bernard C; Féraille, Eric

2009-02-01

Polycystic kidney diseases result from disruption of the genetically defined program that controls the size and geometry of renal tubules. Cysts which frequently arise from the collecting duct (CD) result from cell proliferation and fluid secretion. From mCCD(cl1) cells, a differentiated mouse CD cell line, we isolated a clonal subpopulation (mCCD-N21) that retains morphogenetic capacity. When grown in three-dimensional gels, mCCD-N21 cells formed highly organized tubular structures consisting of a palisade of polarized epithelial cells surrounding a cylindrical lumen. Subsequent addition of cAMP-elevating agents (forskolin or cholera toxin) or of membrane-permeable cAMP analogs (CPT-cAMP) resulted in rapid and progressive dilatation of existing tubules, leading to the formation of cystlike structures. When grown on filters, mCCD-N21 cells exhibited a high transepithelial resistance as well as aldosterone- and/or vasopressin-induced amiloride-sensitive and -insensitive current. The latter was in part inhibited by Na(+)-K(+)-2Cl(-) cotransporter (bumetanide) and chloride channel (NPPB) inhibitors. Real-time PCR analysis confirmed the expression of NKCC1, the ubiquitous Na(+)-K(+)-2Cl(-) cotransporter and cystic fibrosis transmembrane regulator (CFTR) in mCCD-N21 cells. Tubule enlargement and cyst formation were prevented by inhibitors of Na(+)-K(+)-2Cl(-) cotransporters (bumetanide or ethacrynic acid) or CFTR (NPPB or CFTR inhibitor-172). These results further support the notion that cAMP signaling plays a key role in renal cyst formation, at least in part by promoting chloride-driven fluid secretion. This new in vitro model of tubule-to-cyst conversion affords a unique opportunity for investigating the molecular mechanisms that govern the architecture of epithelial tubes, as well as for dissecting the pathophysiological processes underlying cystic kidney diseases.

A Self-Organizing Map Based Evaluation of the Antarctic Mesoscale Prediction System Using Observations from a 30-m Instrumented Tower on the Ross Ice Shelf, Antarctica

NASA Astrophysics Data System (ADS)

Nigro, M. A.; Cassano, J. J.; Wille, J.; Bromwich, D. H.; Lazzara, M. A.

2015-12-01

An accurate representation of the atmospheric boundary layer in numerical weather prediction models is important for predicting turbulence and energy exchange in the atmosphere. This study uses two years of observations from a 30-m automatic weather station (AWS) installed on the Ross Ice Shelf, Antarctica to evaluate forecasts from the Antarctic Mesoscale Prediction System (AMPS), a numerical weather prediction system based on the polar version of the Weather Research and Forecasting (Polar WRF) model that uses the MYJ planetary boundary layer scheme and that primarily supports the extensive aircraft operations of the U.S. Antarctic Program. The 30-m AWS has six levels of instrumentation, providing vertical profiles of temperature, wind speed, and wind direction. The observations show the atmospheric boundary layer over the Ross Ice Shelf is stable approximately 80% of the time, indicating the influence of the permanent ice surface in this region. The observations from the AWS are further analyzed using the method of self-organizing maps (SOM) to identify the range of potential temperature profiles that occur over the Ross Ice Shelf. The SOM analysis identified 30 patterns, which range from strong inversions to slightly unstable profiles. The corresponding AMPS forecasts were evaluated for each of the 30 patterns to understand the accuracy of the AMPS near surface layer under different atmospheric conditions. The results indicate that under stable conditions AMPS with MYJ under predicts the inversion strength by as much as 7.4 K over the 30-m depth of the tower and over predicts the near surface wind speed by as much as 3.8 m s-1. Conversely, under slightly unstable conditions, AMPS predicts both the inversion strength and near surface wind speeds with reasonable accuracy.

Purification, characterization, and sequencing of novel antimicrobial peptides, Tu-AMP 1 and Tu-AMP 2, from bulbs of tulip (Tulipa gesneriana L.).

PubMed

Fujimura, Masatoshi; Ideguchi, Mineo; Minami, Yuji; Watanabe, Keiichi; Tadera, Kenjiro

2004-03-01

Novel antimicrobial peptides (AMP), designated Tu-AMP 1 and Tu-AMP 2, were purified from the bulbs of tulip (Tulipa gesneriana L.) by chitin affinity chromatography and reverse-phase high-performance liquid chromatography (HPLC). They bind to chitin in a reversible way. They were basic peptides having isoelectric points of over 12. Tu-AMP 1 and Tu-AMP 2 had molecular masses of 4,988 Da and 5,006 Da on MALDI-TOF MS analysis, and their extinction coefficients of 1% aqueous solutions at 280 nm were 3.3 and 3.4, respectively. Half of all amino acid residues of Tu-AMP 1 and Tu-AMP 2 were occupied by cysteine, arginine, lysine, and proline. The concentrations of peptides required for 50% inhibition (IC(50)) of the growth of plant pathogenic bacteria and fungi were 2 to 20 microg/ml. The structural characteristics of Tu-AMP 1 and Tu-AMP 2 indicated that they were novel thionin-like antimicrobial peptides, though Tu-AMP 2 was a heterodimer composes of two short peptides joined with disulfide bonds.

Role of 2',3'-cyclic nucleotide 3'-phosphodiesterase in the renal 2',3'-cAMP-adenosine pathway.

PubMed

Jackson, Edwin K; Gillespie, Delbert G; Mi, Zaichuan; Cheng, Dongmei; Bansal, Rashmi; Janesko-Feldman, Keri; Kochanek, Patrick M

2014-07-01

Energy depletion increases the renal production of 2',3'-cAMP (a positional isomer of 3',5'-cAMP that opens mitochondrial permeability transition pores) and 2',3'-cAMP is converted to 2'-AMP and 3'-AMP, which in turn are metabolized to adenosine. Because the enzymes involved in this "2',3'-cAMP-adenosine pathway" are unknown, we examined whether 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) participates in the renal metabolism of 2',3'-cAMP. Western blotting and real-time PCR demonstrated expression of CNPase in rat glomerular mesangial, preglomerular vascular smooth muscle and endothelial, proximal tubular, thick ascending limb and collecting duct cells. Real-time PCR established the expression of CNPase in human glomerular mesangial, proximal tubular and vascular smooth muscle cells; and the level of expression of CNPase was greater than that for phosphodiesterase 4 (major enzyme for the metabolism of 3',5'-cAMP). Overexpression of CNPase in rat preglomerular vascular smooth muscle cells increased the metabolism of exogenous 2',3'-cAMP to 2'-AMP. Infusions of 2',3'-cAMP into isolated CNPase wild-type (+/+) kidneys increased renal venous 2'-AMP, and this response was diminished by 63% in CNPase knockout (-/-) kidneys, whereas the conversion of 3',5'-cAMP to 5'-AMP was similar in CNPase +/+ vs. -/- kidneys. In CNPase +/+ kidneys, energy depletion (metabolic poisons) increased kidney tissue levels of adenosine and its metabolites (inosine, hypoxanthine, xanthine, and uric acid) without accumulation of 2',3'-cAMP. In contrast, in CNPase -/- kidneys, energy depletion increased kidney tissue levels of 2',3'-cAMP and abolished the increase in adenosine and its metabolites. In conclusion, kidneys express CNPase, and renal CNPase mediates in part the renal 2',3'-cAMP-adenosine pathway. Copyright © 2014 the American Physiological Society.

Atmosphere, Magnetosphere and Plasmas in Space (AMPS). Spacelab payload definition study. Volume 7, book 3: Supporting Research and Technology (SR and T) report

NASA Technical Reports Server (NTRS)

1976-01-01

The items identified as required to support the AMPS mission and requiring SR and T support and further work are: (1) a general purpose Experiment Pointing Mount; (2) a technique for measuring the attitude of the pallet-mounted or deployed experiments; (3) the development of a common optics cryogenically cooled interferometer spectrometer; (4) the development of a differential absorption lidar system for the measurement of ozone densitites in the earth's atmosphere; (5) the development of dc to dc power processors which are capable of converting energy stored in a capacitor system at 500 V to energy supplied to equipment operating at 40 kV and at 20 kW (eventually up to 100 kW); and (6) the development of a magnetic or possibly electrostatic deflection system capable of bending the beam of an electron accelerator. A data sheet is included for each item, briefly describing the background and need for each item, and the general objectives of the required development, and identifying the schedule requirements in support of the AMPS program.

New insight into the binding modes of TNP-AMP to human liver fructose-1,6-bisphosphatase

NASA Astrophysics Data System (ADS)

Han, Xinya; Huang, Yunyuan; Zhang, Rui; Xiao, San; Zhu, Shuaihuan; Qin, Nian; Hong, Zongqin; Wei, Lin; Feng, Jiangtao; Ren, Yanliang; Feng, Lingling; Wan, Jian

2016-08-01

Human liver fructose-1,6-bisphosphatase (FBPase) contains two binding sites, a substrate fructose-1,6-bisphosphate (FBP) active site and an adenosine monophosphate (AMP) allosteric site. The FBP active site works by stabilizing the FBPase, and the allosteric site impairs the activity of FBPase through its binding of a nonsubstrate molecule. The fluorescent AMP analogue, 2‧,3‧-O-(2,4,6-trinitrophenyl)adenosine 5‧-monophosphate (TNP-AMP) has been used as a fluorescent probe as it is able to competitively inhibit AMP binding to the AMP allosteric site and, therefore, could be used for exploring the binding modes of inhibitors targeted on the allosteric site. In this study, we have re-examined the binding modes of TNP-AMP to FBPase. However, our present enzyme kinetic assays show that AMP and FBP both can reduce the fluorescence from the bound TNP-AMP through competition for FBPase, suggesting that TNP-AMP binds not only to the AMP allosteric site but also to the FBP active site. Mutagenesis assays of K274L (located in the FBP active site) show that the residue K274 is very important for TNP-AMP to bind to the active site of FBPase. The results further prove that TNP-AMP is able to bind individually to the both sites. Our present study provides a new insight into the binding mechanism of TNP-AMP to the FBPase. The TNP-AMP fluorescent probe can be used to exam the binding site of an inhibitor (the active site or the allosteric site) using FBPase saturated by AMP and FBP, respectively, or the K247L mutant FBPase.

New insight into the binding modes of TNP-AMP to human liver fructose-1,6-bisphosphatase.

PubMed

Han, Xinya; Huang, Yunyuan; Zhang, Rui; Xiao, San; Zhu, Shuaihuan; Qin, Nian; Hong, Zongqin; Wei, Lin; Feng, Jiangtao; Ren, Yanliang; Feng, Lingling; Wan, Jian

2016-08-05

Human liver fructose-1,6-bisphosphatase (FBPase) contains two binding sites, a substrate fructose-1,6-bisphosphate (FBP) active site and an adenosine monophosphate (AMP) allosteric site. The FBP active site works by stabilizing the FBPase, and the allosteric site impairs the activity of FBPase through its binding of a nonsubstrate molecule. The fluorescent AMP analogue, 2',3'-O-(2,4,6-trinitrophenyl)adenosine 5'-monophosphate (TNP-AMP) has been used as a fluorescent probe as it is able to competitively inhibit AMP binding to the AMP allosteric site and, therefore, could be used for exploring the binding modes of inhibitors targeted on the allosteric site. In this study, we have re-examined the binding modes of TNP-AMP to FBPase. However, our present enzyme kinetic assays show that AMP and FBP both can reduce the fluorescence from the bound TNP-AMP through competition for FBPase, suggesting that TNP-AMP binds not only to the AMP allosteric site but also to the FBP active site. Mutagenesis assays of K274L (located in the FBP active site) show that the residue K274 is very important for TNP-AMP to bind to the active site of FBPase. The results further prove that TNP-AMP is able to bind individually to the both sites. Our present study provides a new insight into the binding mechanism of TNP-AMP to the FBPase. The TNP-AMP fluorescent probe can be used to exam the binding site of an inhibitor (the active site or the allosteric site) using FBPase saturated by AMP and FBP, respectively, or the K247L mutant FBPase. Copyright © 2016 Elsevier B.V. All rights reserved.

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Sensitivity of GBM cells to cAMP agonist-mediated apoptosis correlates with CD44 expression and agonist resistance with MAPK signaling.

PubMed

Daniel, Paul M; Filiz, Gulay; Mantamadiotis, Theo

2016-12-01

In some cell types, activation of the second messenger cAMP leads to increased expression of proapoptotic Bim and subsequent cell death. We demonstrate that suppression of the cAMP pathway is a common event across many cancers and that pharmacological activation of cAMP in glioblastoma (GBM) cells leads to enhanced BIM expression and apoptosis in specific GBM cell types. We identified the MAPK signaling axis as the determinant of cAMP agonist sensitivity in GBM cells, with high MAPK activity corresponding to cAMP resistance and low activity corresponding to sensitization to cAMP-induced apoptosis. Sensitive cells were efficiently killed by cAMP agonists alone, while targeting both the cAMP and MAPK pathways in resistant GBM cells resulted in efficient apoptosis. We also show that CD44 is differentially expressed in cAMP agonist-sensitive and -resistant cells. We thus propose that CD44 may be a useful biomarker for distinguishing tumors that may be sensitive to cAMP agonists alone or cAMP agonists in combination with other pathway inhibitors. This suggests that using existing chemotherapeutic compounds in combination with existing FDA-approved cAMP agonists may fast track trials toward improved therapies for difficult-to-treat cancers, such as GBM.

Skeletal muscle expresses the extracellular cyclic AMP–adenosine pathway

PubMed Central

Chiavegatti, T; Costa, V L; Araújo, M S; Godinho, R O

2007-01-01

Background and purpose: cAMP is a key intracellular signalling molecule that regulates multiple processes of the vertebrate skeletal muscle. We have shown that cAMP can be actively pumped out from the skeletal muscle cell. Since in other tissues, cAMP efflux had been associated with extracellular generation of adenosine, in the present study we have assessed the fate of interstitial cAMP and the existence of an extracellular cAMP-adenosine signalling pathway in skeletal muscle. Experimental approach: cAMP efflux and/or its extracellular degradation were analysed by incubating rat cultured skeletal muscle with exogenous cAMP, forskolin or isoprenaline. cAMP and its metabolites were quantified by radioassay or HPLC, respectively. Key results: Incubation of cells with exogenous cAMP was followed by interstitial accumulation of 5′-AMP and adenosine, a phenomenon inhibited by selective inhibitors of ecto-phosphodiesterase (DPSPX) and ecto-nucleotidase (AMPCP). Activation of adenylyl cyclase (AC) in cultured cells with forskolin or isoprenaline increased cAMP efflux and extracellular generation of 5′-AMP and adenosine. Extracellular cAMP-adenosine pathway was also observed after direct and receptor-dependent stimulation of AC in rat extensor muscle ex vivo. These events were attenuated by probenecid, an inhibitor of ATP binding cassette family transporters. Conclusions and implications: Our results show the existence of an extracellular biochemical cascade that converts cAMP into adenosine. The functional relevance of this extracellular signalling system may involve a feedback modulation of cellular response initiated by several G protein-coupled receptor ligands, amplifying cAMP influence to a paracrine mode, through its metabolite, adenosine. PMID:18157164

Rp-cAMPS Prodrugs Reveal the cAMP Dependence of First-Phase Glucose-Stimulated Insulin Secretion

PubMed Central

Schwede, Frank; Chepurny, Oleg G.; Kaufholz, Melanie; Bertinetti, Daniela; Leech, Colin A.; Cabrera, Over; Zhu, Yingmin; Mei, Fang; Cheng, Xiaodong; Manning Fox, Jocelyn E.; MacDonald, Patrick E.; Genieser, Hans-G.; Herberg, Friedrich W.

2015-01-01

cAMP-elevating agents such as the incretin hormone glucagon-like peptide-1 potentiate glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. However, a debate has existed since the 1970s concerning whether or not cAMP signaling is essential for glucose alone to stimulate insulin secretion. Here, we report that the first-phase kinetic component of GSIS is cAMP-dependent, as revealed through the use of a novel highly membrane permeable para-acetoxybenzyl (pAB) ester prodrug that is a bioactivatable derivative of the cAMP antagonist adenosine-3′,5′-cyclic monophosphorothioate, Rp-isomer (Rp-cAMPS). In dynamic perifusion assays of human or rat islets, a step-wise increase of glucose concentration leads to biphasic insulin secretion, and under these conditions, 8-bromoadenosine-3′,5′-cyclic monophosphorothioate, Rp-isomer, 4-acetoxybenzyl ester (Rp-8-Br-cAMPS-pAB) inhibits first-phase GSIS by up to 80%. Surprisingly, second-phase GSIS is inhibited to a much smaller extent (≤20%). Using luciferase, fluorescence resonance energy transfer, and bioluminescence resonance energy transfer assays performed in living cells, we validate that Rp-8-Br-cAMPS-pAB does in fact block cAMP-dependent protein kinase activation. Novel effects of Rp-8-Br-cAMPS-pAB to block the activation of cAMP-regulated guanine nucleotide exchange factors (Epac1, Epac2) are also validated using genetically encoded Epac biosensors, and are independently confirmed in an in vitro Rap1 activation assay using Rp-cAMPS and Rp-8-Br-cAMPS. Thus, in addition to revealing the cAMP dependence of first-phase GSIS from human and rat islets, these findings establish a pAB-based chemistry for the synthesis of highly membrane permeable prodrug derivatives of Rp-cAMPS that act with micromolar or even nanomolar potency to inhibit cAMP signaling in living cells. PMID:26061564

Structural and Functional Characterization of Pseudomonas aeruginosa Global Regulator AmpR

PubMed Central

Caille, Olivier; Zincke, Diansy; Merighi, Massimo; Balasubramanian, Deepak; Kumari, Hansi; Kong, Kok-Fai; Silva-Herzog, Eugenia; Narasimhan, Giri; Schneper, Lisa; Lory, Stephen

2014-01-01

Pseudomonas aeruginosa is a dreaded pathogen in many clinical settings. Its inherent and acquired antibiotic resistance thwarts therapy. In particular, derepression of the AmpC β-lactamase is a common mechanism of β-lactam resistance among clinical isolates. The inducible expression of ampC is controlled by the global LysR-type transcriptional regulator (LTTR) AmpR. In the present study, we investigated the genetic and structural elements that are important for ampC induction. Specifically, the ampC (PampC) and ampR (PampR) promoters and the AmpR protein were characterized. The transcription start sites (TSSs) of the divergent transcripts were mapped using 5′ rapid amplification of cDNA ends-PCR (RACE-PCR), and strong σ54 and σ70 consensus sequences were identified at PampR and PampC, respectively. Sigma factor RpoN was found to negatively regulate ampR expression, possibly through promoter blocking. Deletion mapping revealed that the minimal PampC extends 98 bp upstream of the TSS. Gel shifts using membrane fractions showed that AmpR binds to PampC in vitro whereas in vivo binding was demonstrated using chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR). Additionally, site-directed mutagenesis of the AmpR helix-turn-helix (HTH) motif identified residues critical for binding and function (Ser38 and Lys42) and critical for function but not binding (His39). Amino acids Gly102 and Asp135, previously implicated in the repression state of AmpR in the enterobacteria, were also shown to play a structural role in P. aeruginosa AmpR. Alkaline phosphatase fusion and shaving experiments suggest that AmpR is likely to be membrane associated. Lastly, an in vivo cross-linking study shows that AmpR dimerizes. In conclusion, a potential membrane-associated AmpR dimer regulates ampC expression by direct binding. PMID:25182487

Mechanism of cAMP Partial Agonism in Protein Kinase G (PKG)*♦

PubMed Central

VanSchouwen, Bryan; Selvaratnam, Rajeevan; Giri, Rajanish; Lorenz, Robin; Herberg, Friedrich W.; Kim, Choel; Melacini, Giuseppe

2015-01-01

Protein kinase G (PKG) is a major receptor of cGMP and controls signaling pathways often distinct from those regulated by cAMP. Hence, the selective activation of PKG by cGMP versus cAMP is critical. However, the mechanism of cGMP-versus-cAMP selectivity is only limitedly understood. Although the C-terminal cyclic nucleotide-binding domain B of PKG binds cGMP with higher affinity than cAMP, the intracellular concentrations of cAMP are typically higher than those of cGMP, suggesting that the cGMP-versus-cAMP selectivity of PKG is not controlled uniquely through affinities. Here, we show that cAMP is a partial agonist for PKG, and we elucidate the mechanism for cAMP partial agonism through the comparative NMR analysis of the apo, cGMP-, and cAMP-bound forms of the PKG cyclic nucleotide-binding domain B. We show that although cGMP activation is adequately explained by a two-state conformational selection model, the partial agonism of cAMP arises from the sampling of a third, partially autoinhibited state. PMID:26370085

Role of 2′,3′-cyclic nucleotide 3′-phosphodiesterase in the renal 2′,3′-cAMP-adenosine pathway

PubMed Central

Gillespie, Delbert G.; Mi, Zaichuan; Cheng, Dongmei; Bansal, Rashmi; Janesko-Feldman, Keri; Kochanek, Patrick M.

2014-01-01

Energy depletion increases the renal production of 2′,3′-cAMP (a positional isomer of 3′,5′-cAMP that opens mitochondrial permeability transition pores) and 2′,3′-cAMP is converted to 2′-AMP and 3′-AMP, which in turn are metabolized to adenosine. Because the enzymes involved in this “2′,3′-cAMP-adenosine pathway” are unknown, we examined whether 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) participates in the renal metabolism of 2′,3′-cAMP. Western blotting and real-time PCR demonstrated expression of CNPase in rat glomerular mesangial, preglomerular vascular smooth muscle and endothelial, proximal tubular, thick ascending limb and collecting duct cells. Real-time PCR established the expression of CNPase in human glomerular mesangial, proximal tubular and vascular smooth muscle cells; and the level of expression of CNPase was greater than that for phosphodiesterase 4 (major enzyme for the metabolism of 3′,5′-cAMP). Overexpression of CNPase in rat preglomerular vascular smooth muscle cells increased the metabolism of exogenous 2′,3′-cAMP to 2′-AMP. Infusions of 2′,3′-cAMP into isolated CNPase wild-type (+/+) kidneys increased renal venous 2′-AMP, and this response was diminished by 63% in CNPase knockout (−/−) kidneys, whereas the conversion of 3′,5′-cAMP to 5′-AMP was similar in CNPase +/+ vs. −/− kidneys. In CNPase +/+ kidneys, energy depletion (metabolic poisons) increased kidney tissue levels of adenosine and its metabolites (inosine, hypoxanthine, xanthine, and uric acid) without accumulation of 2′,3′-cAMP. In contrast, in CNPase −/− kidneys, energy depletion increased kidney tissue levels of 2′,3′-cAMP and abolished the increase in adenosine and its metabolites. In conclusion, kidneys express CNPase, and renal CNPase mediates in part the renal 2′,3′-cAMP-adenosine pathway. PMID:24808540

Cyclic AMP- and (Rp)-cAMPS-induced Conformational Changes in a Complex of the Catalytic and Regulatory (RIα) Subunits of Cyclic AMP-dependent Protein Kinase*

PubMed Central

Anand, Ganesh S.; Krishnamurthy, Srinath; Bishnoi, Tanushree; Kornev, Alexandr; Taylor, Susan S.; Johnson, David A.

2010-01-01

We took a discovery approach to explore the actions of cAMP and two of its analogs, one a cAMP mimic ((Sp)-adenosine cyclic 3′:5′-monophosphorothioate ((Sp)-cAMPS)) and the other a diastereoisomeric antagonist ((Rp)-cAMPS), on a model system of the type Iα cyclic AMP-dependent protein kinase holoenzyme, RIα(91–244)·C-subunit, by using fluorescence spectroscopy and amide H/2H exchange mass spectrometry. Specifically, for the fluorescence experiments, fluorescein maleimide was conjugated to three cysteine single residue substitution mutants, R92C, T104C, and R239C, of RIα(91–244), and the effects of cAMP, (Sp)-cAMPS, and (Rp)-cAMPS on the kinetics of R-C binding and the time-resolved anisotropy of the reporter group at each conjugation site were measured. For the amide exchange experiments, ESI-TOF mass spectrometry with pepsin proteolytic fragmentation was used to assess the effects of (Rp)-cAMPS on amide exchange of the RIα(91–244)·C-subunit complex. We found that cAMP and its mimic perturbed at least parts of the C-subunit interaction Sites 2 and 3 but probably not Site 1 via reduced interactions of the linker region and αC of RIα(91–244). Surprisingly, (Rp)-cAMPS not only increased the affinity of RIα(91–244) toward the C-subunit by 5-fold but also produced long range effects that propagated through both the C- and R-subunits to produce limited unfolding and/or enhanced conformational flexibility. This combination of effects is consistent with (Rp)-cAMPS acting by enhancing the internal entropy of the R·C complex. Finally, the (Rp)-cAMPS-induced increase in affinity of RIα(91–244) toward the C-subunit indicates that (Rp)-cAMPS is better described as an inverse agonist because it decreases the fractional dissociation of the cyclic AMP-dependent protein kinase holoenzyme and in turn its basal activity. PMID:20167947

Cyclic AMP Enhances TGFβ Responses of Breast Cancer Cells by Upregulating TGFβ Receptor I Expression

PubMed Central

Oerlecke, Ilka; Bauer, Elke; Dittmer, Angela; Leyh, Benjamin; Dittmer, Jürgen

2013-01-01

Cellular functions are regulated by complex networks of many different signaling pathways. The TGFβ and cAMP pathways are of particular importance in tumor progression. We analyzed the cross-talk between these pathways in breast cancer cells in 2D and 3D cultures. We found that cAMP potentiated TGFβ-dependent gene expression by enhancing Smad3 phosphorylation. Higher levels of total Smad3, as observed in 3D-cultured cells, blocked this effect. Two Smad3 regulating proteins, YAP (Yes-associated protein) and TβRI (TGFβ receptor 1), were responsive to cAMP. While YAP had little effect on TGFβ-dependent expression and Smad3 phosphorylation, a constitutively active form of TβRI mimicked the cAMP effect on TGFβ signaling. In 3D-cultured cells, which show much higher levels of TβRI and cAMP, TβRI was unresponsive to cAMP. Upregulation of TβRI expression by cAMP was dependent on transcription. A proximal TβRI promoter fragment was moderately, but significantly activated by cAMP suggesting that cAMP increases TβRI expression at least partially by activating TβRI transcription. Neither the cAMP-responsive element binding protein (CREB) nor the TβRI-regulating transcription factor Six1 was required for the cAMP effect. An inhibitor of histone deacetylases alone or together with cAMP increased TβRI expression by a similar extent as cAMP alone suggesting that cAMP may exert its effect by interfering with histone acetylation. Along with an additive stimulatory effect of cAMP and TGFβ on p21 expression an additive inhibitory effect of these agents on proliferation was observed. Finally, we show that mesenchymal stem cells that interact with breast cancer cells can simultaneously activate the cAMP and TGFβ pathways. In summary, these data suggest that combined effects of cAMP and TGFβ, as e.g. induced by mesenchymal stem cells, involve the upregulation of TβRI expression on the transcriptional level, likely due to changes in histone acetylation. As a consequence, cancer cell functions such as proliferation are affected. PMID:23349840

Increase in Ca2+ current by sustained cAMP levels enhances proliferation rate in GH3 cells.

PubMed

Rodrigues, Andréia Laura; Brescia, Marcella; Koschinski, Andreas; Moreira, Thaís Helena; Cameron, Ryan T; Baillie, George; Beirão, Paulo S L; Zaccolo, Manuela; Cruz, Jader S

2018-01-01

Ca 2+ and cAMP are important intracellular modulators. In order to generate intracellular signals with various amplitudes, as well as different temporal and spatial properties, a tightly and precise control of these modulators in intracellular compartments is necessary. The aim of this study was to evaluate the effects of elevated and sustained cAMP levels on voltage-dependent Ca 2+ currents and proliferation in pituitary tumor GH3 cells. Effect of long-term exposure to forskolin and dibutyryl-cyclic AMP (dbcAMP) on Ca 2+ current density and cell proliferation rate were determined by using the whole-cell patch-clamp technique and real time cell monitoring system. The cAMP levels were assayed, after exposing transfected GH3 cells with the EPAC-1 cAMP sensor to forskolin and dbcAMP, by FRET analysis. Sustained forskolin treatment (24 and 48h) induced a significant increase in total Ca 2+ current density in GH3 cells. Accordingly, dibutyryl-cAMP incubation (dbcAMP) also elicited increase in Ca 2+ current density. However, the maximum effect of dbcAMP occurred only after 72h incubation, whereas forskolin showed maximal effect at 48h. FRET-experiments confirmed that the time-course to elevate intracellular cAMP was distinct between forskolin and dbcAMP. Mibefradil inhibited the fast inactivating current component selectively, indicating the recruitment of T-type Ca 2+ channels. A significant increase on cell proliferation rate, which could be related to the elevated and sustained intracellular levels of cAMP was observed. We conclude that maintaining high levels of intracellular cAMP will cause an increase in Ca 2+ current density and this phenomenon impacts proliferation rate in GH3 cells. Copyright © 2017 Elsevier Inc. All rights reserved.

5D imaging approaches reveal the formation of distinct intracellular cAMP spatial gradients

NASA Astrophysics Data System (ADS)

Rich, Thomas C.; Annamdevula, Naga; Trinh, Kenny; Britain, Andrea L.; Mayes, Samuel A.; Griswold, John R.; Deal, Joshua; Hoffman, Chase; West, Savannah; Leavesley, Silas J.

2017-02-01

Cyclic AMP (cAMP) is a ubiquitous second messenger known to differentially regulate many cellular functions. Several lines of evidence suggest that the distribution of cAMP within cells is not uniform. However, to date, no studies have measured the kinetics of 3D cAMP distributions within cells. This is largely due to the low signal-tonoise ratio of FRET-based probes. We previously reported that hyperspectral imaging improves the signal-to-noise ratio of FRET measurements. Here we utilized hyperspectral imaging approaches to measure FRET signals in five dimensions (5D) - three spatial (x, y, z), wavelength (λ), and time (t) - allowing us to visualize cAMP gradients in pulmonary endothelial cells. cAMP levels were measured using a FRET-based sensor (H188) comprised of a cAMP binding domain sandwiched between FRET donor and acceptor - Turquoise and Venus fluorescent proteins. We observed cAMP gradients in response to 0.1 or 1 μM isoproterenol, 0.1 or 1 μM PGE1, or 50 μM forskolin. Forskolin- and isoproterenol-induced cAMP gradients formed from the apical (high cAMP) to basolateral (low cAMP) face of cells. In contrast, PGE1-induced cAMP gradients originated from both the basolateral and apical faces of cells. Data suggest that 2D (x,y) studies of cAMP compartmentalization may lead to erroneous conclusions about the existence of cAMP gradients, and that 3D (x,y,z) studies are required to assess mechanisms of signaling specificity. Results demonstrate that 5D imaging technologies are powerful tools for measuring biochemical processes in discrete subcellular domains.

Inhibition of basolateral cAMP permeability in the toad urinary bladder.

PubMed

Boom, A; Golstein, P E; Frerotte, M; Sande, J V; Beauwens, R

2000-10-01

1. The effect of sulphonylurea drugs on hydrosmotic flow across toad urinary bladder epithelium was re-evaluated in the present study. Glibenclamide, added to the basolateral medium, significantly enhanced the osmotic flow induced by low doses of antidiuretic hormone (ADH) or forskolin (FK), while it inhibited the effect of exogenous cyclic adenosine monophosphate (cAMP) or its non-hydrolysable bromo derivative, 8-Br-cAMP, added to the basolateral medium. These opposite effects of glibenclamide on the transepithelial osmotic flow can be explained by a reduction of cAMP permeability across the basolateral membrane of the epithelium. The decrease in cAMP permeability leads, according to the direction of the cAMP gradient, to firstly an enhanced osmotic flow when cAMP is generated intracellularly by addition of ADH and FK, glibenclamide reducing cAMP exit from the cell, and secondly a decreased osmotic flow in response to cAMP (and 8-Br-cAMP) added to the basolateral medium, glibenclamide inhibiting, in this case, their entry into the cell. 2. The demonstration that glibenclamide actually inhibits the basolateral cAMP permeability rests on the fact that firstly it decreases the release of cAMP into the basolateral medium by about 40 %, at each concentration of ADH or forskolin tested, secondly it increases the cAMP content of paired hemibladders incubated in the presence of ADH or FK, when intracellular degradation was prevented by phosphodiesterase inhibition, and thirdly it decreases also the uptake of basolateral 8-Br-[3H]cAMP into paired toad hemibladders. 3. Taken together, the present data demonstrate that glibenclamide inhibits the toad urinary bladder basolateral membrane permeability to cAMP, most probably by a direct interaction with a membrane protein not yet indentified but distinct from the sulphonylurea receptor.

AmpA protein functions by different mechanisms to influence early cell type specification and to modulate cell adhesion and actin polymerization in Dictyostelium discoideum

PubMed Central

Cost, Hoa N.; Noratel, Elizabeth F.; Blumberg, Daphne D.

2013-01-01

The Dictyostelium discoideum ampA gene encodes a multifunctional regulator protein that modulates cell–cell and cell–substrate adhesions and actin polymerization during growth and is necessary for correct cell type specification and patterning during development. Insertional inactivation of the ampA gene results in defects that define two distinct roles for the ampA gene during development. AmpA is necessary in a non-cell autonomous manner to prevent premature expression of a prespore gene marker. It is also necessary in a cell autonomous manner for the anterior like cells, which express the ampA gene, to migrate to the upper cup during culmination. It is also necessary to prevent excessive cell–cell agglutination when cells are developed in a submerged suspension culture. Here, we demonstrate that a supernatant source of AmpA protein, added extracellularly, can prevent the premature mis-expression of the prespore marker. Synthetic oligopeptides are used to identify the domain of the AmpA protein that is important for preventing cells from mis-expressing the prespore gene. We further demonstrate that a factor capable of inducing additional cells to express the prespore gene marker accumulates extracellularly in the absence of AmpA protein. While the secreted AmpA acts extracellularly to suppress prespore gene expression, the effects of AmpA on cell agglutination and on actin polymerization in growing cells are not due to an extracellular role of secreted AmpA protein. Rather, these effects appear to reflect a distinct cell autonomous role of the ampA gene. Finally, we show that secretion of AmpA protein is brought about by elevating the levels of expression of ampA so that the protein accumulates to an excessive level. PMID:23911723

Parallel Allostery by cAMP and PDE Coordinates Activation and Termination Phases in cAMP Signaling.

PubMed

Krishnamurthy, Srinath; Tulsian, Nikhil Kumar; Chandramohan, Arun; Anand, Ganesh S

2015-09-15

The second messenger molecule cAMP regulates the activation phase of the cAMP signaling pathway through high-affinity interactions with the cytosolic cAMP receptor, the protein kinase A regulatory subunit (PKAR). Phosphodiesterases (PDEs) are enzymes responsible for catalyzing hydrolysis of cAMP to 5' AMP. It was recently shown that PDEs interact with PKAR to initiate the termination phase of the cAMP signaling pathway. While the steps in the activation phase are well understood, steps in the termination pathway are unknown. Specifically, the binding and allosteric networks that regulate the dynamic interplay between PKAR, PDE, and cAMP are unclear. In this study, PKAR and PDE from Dictyostelium discoideum (RD and RegA, respectively) were used as a model system to monitor complex formation in the presence and absence of cAMP. Amide hydrogen/deuterium exchange mass spectrometry was used to monitor slow conformational transitions in RD, using disordered regions as conformational probes. Our results reveal that RD regulates its interactions with cAMP and RegA at distinct loci by undergoing slow conformational transitions between two metastable states. In the presence of cAMP, RD and RegA form a stable ternary complex, while in the absence of cAMP they maintain transient interactions. RegA and cAMP each bind at orthogonal sites on RD with resultant contrasting effects on its dynamics through parallel allosteric relays at multiple important loci. RD thus serves as an integrative node in cAMP termination by coordinating multiple allosteric relays and governing the output signal response. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Fibroblast growth factor and cyclic AMP (cAMP) synergistically activate gene expression at a cAMP response element.

PubMed Central

Tan, Y; Low, K G; Boccia, C; Grossman, J; Comb, M J

1994-01-01

Growth factors and cyclic AMP (cAMP) are known to activate distinct intracellular signaling pathways. Fibroblast growth factor (FGF) activates ras-dependent kinase cascades, resulting in the activation of MAP kinases, whereas cAMP activates protein kinase A. In this study, we report that growth factors and cAMP act synergistically to stimulate proenkephalin gene expression. Positive synergy between growth factor- and cAMP-activated signaling pathways on gene expression has not been previously reported, and we suggest that these synergistic interactions represent a useful model for analyzing interactions between these pathways. Transfection and mutational studies indicate that both FGF-dependent gene activation and cAMP-dependent gene activation require cAMP response element 2 (CRE-2), a previously characterized cAMP-dependent regulatory element. Furthermore, multiple copies of this element are sufficient to confer FGF regulation upon a minimal promoter, indicating that FGF and cAMP signaling converge upon transcription factors acting at CRE-2. Among many different ATF/AP-1 factors tested, two factors, ATF-3 and c-Jun, stimulate proenkephalin transcription in an FGF- or Ras-dependent fashion. Finally, we show that ATF-3 and c-Jun form heterodimeric complexes in SK-N-MC cells and that the levels of both proteins are increased in response to FGF but not cAMP. Together, these results indicate that growth factor- and cAMP-dependent signaling pathways converge at CRE-2 to synergistically stimulate gene expression and that ATF-3 and c-Jun regulate proenkephalin transcription in response to both growth factor- and cAMP-dependent intracellular signaling pathways. Images PMID:7935470

The cAMP analogs have potent anti-proliferative effects on medullary thyroid cancer cell lines.

PubMed

Dicitore, Alessandra; Grassi, Elisa Stellaria; Caraglia, Michele; Borghi, Maria Orietta; Gaudenzi, Germano; Hofland, Leo J; Persani, Luca; Vitale, Giovanni

2016-01-01

The oncogenic activation of the rearranged during transfection (RET) proto-oncogene has a main role in the pathogenesis of medullary thyroid cancer (MTC). Several lines of evidence suggest that RET function could be influenced by cyclic AMP (cAMP)-dependent protein kinase A (PKA) activity. We evaluated the in vitro anti-tumor activity of 8-chloroadenosine-3',5'-cyclic monophosphate (8-Cl-cAMP) and PKA type I-selective cAMP analogs [equimolar combination of the 8-piperidinoadenosine-3',5'-cyclic monophosphate (8-PIP-cAMP) and 8-hexylaminoadenosine-3',5'-cyclic monophosphate (8-HA-cAMP) in MTC cell lines (TT and MZ-CRC-1)]. 8-Cl-cAMP and the PKA I-selective cAMP analogs showed a potent anti-proliferative effect in both cell lines. In detail, 8-Cl-cAMP blocked significantly the transition of TT cell population from G2/M to G0/G1 phase and from G0/G1 to S phase and of MZ-CRC-1 cells from G0/G1 to S phase. Moreover, 8-Cl-cAMP induced apoptosis in both cell lines, as demonstrated by FACS analysis for annexin V-FITC/propidium iodide, the activation of caspase-3 and PARP cleavage. On the other hand, the only effect induced by PKA I-selective cAMP analogs was a delay in G0/G1-S and S-G2/M progression in TT and MZ-CRC-1 cells, respectively. In conclusion, these data demonstrate that cAMP analogs, particularly 8-Cl-cAMP, significantly suppress in vitro MTC proliferation and provide rationale for a potential clinical use of cAMP analogs in the treatment of advanced MTC.

Department of Pesticide Regulation Databases

Science.gov Websites

; Safety Report an Illness | Food Safety | Risk Assessment & Mitigation | Human Health | Physicians Endangered Species Enforcement Food Safety Forms Human Health Laws Licensing Mill Assessment Permitting Pest Statewide search: Search Search Search this site: Search Search DPR California Home Programs Health &

California Department of Pesticide Regulation Home Page

Science.gov Websites

; Safety Report an Illness | Food Safety | Risk Assessment & Mitigation | Human Health | Physicians Endangered Species Enforcement Food Safety Forms Human Health Laws Licensing Mill Assessment Permitting Pest Statewide search: Search Search Search this site: Search Search DPR California Home Programs Health &

Effects of Mathematics Acceleration on Middle School Student Achievement

ERIC Educational Resources Information Center

Boysworth, Sylvia Elaine

2010-01-01

The researcher's purpose in the study was to evaluate the effectiveness of an Accelerated Mathematics Program (AMPS) for sixth and seventh grades, using the accelerative practice of curriculum telescoping in a rural school district in North Carolina. The mathematics achievement of students served in the locally developed Accelerated Mathematics…

Atmospheric, Magnetospheric and Plasmas in Space (AMPS) spacelab payload definition study. Volume 3: Interface control documents. Part 2: AMPS payload to spacelab ICD

NASA Technical Reports Server (NTRS)

1976-01-01

The AMPS to Spacelab Interface Control Document which is to be used as a guide for format and information content in generating specific AMPS Mission ICDs is presented. This document is meant to supplement the Spacelab Payload Accommodations Handbook in that it only defines interfaces which are not discussed in the handbook to the level required for design purposes. The AMPS Top Level Requirements Tree, illustrates this ICD by a shaded area and its relationship to the other AMPS technical documents. Other interface documents shown are the Level II, AMPS to Space Shuttle Vehicle ICD and the Level III, AMPS to Instruments ICD.

Regulation of Maltodextrin Phosphorylase Synthesis in Escherichia coli by Cyclic Adenosine 3′, 5′-Monophosphate and Glucose1

PubMed Central

Chao, Julie; Weathersbee, Carolyn J.

1974-01-01

Cyclic adenosine 3′, 5′-monophosphate (AMP) stimulates maltodextrin phosphorylase synthesis in Escherichia coli cells induced with maltose. A maximal effect occurs at 2 to 3 mM cyclic AMP. The action of cyclic AMP is specific, inasmuch as adenosine triphosphate, 3′-AMP, 5′-AMP, adenosine, and dibutyryl cyclic AMP are inactive. Glucose, α-methyl glucoside, 2-deoxyglucose, and pyridoxal 5′-phosphate repress maltodextrin phosphorylase synthesis. This repression is reversed by cyclic AMP. The action of cyclic AMP appears to be at the transcriptional level, since cyclic AMP fails to stimulate phosphorylase production in induced cells in which messenger ribonucleic acid synthesis has been arrested by rifampin or by inducer removal. The two other enzymes involved in the metabolism of maltose, amylomaltase and maltose permease, are also induced in this strain of E. coli and affected by glucose and cyclic AMP in a manner similar to phosphorylase. PMID:4358043

Adsorption characteristics of green 5-arylaminomethylene pyrimidine-2,4,6-triones on mild steel surface in acidic medium: Experimental and computational approach

NASA Astrophysics Data System (ADS)

Verma, Chandrabhan; Olasunkanmi, Lukman O.; Ebenso, Eno E.; Quraishi, M. A.

2018-03-01

The effect of electron withdrawing nitro (-NO2) and electron releasing hydroxyl (-OH) groups on corrosion inhibition potentials of 5-arylaminomethylenepyrimidine-2,4,6-trione (AMP) had been studied. Four AMPs tagged AMP-1, AMP-2, AMP-3 and AMP-4 were studied for their ability to inhibit mild steel corrosion in 1 M HCl using experimental and theoretical methods. Gravimetric results showed that inhibition efficiency of the studied inhibitors increases with increasing concentration. The results further revealed that that electron withdrawing nitro (-NO2) group decreases the inhibition efficiency of AMP, while electron donating hydroxyl (-OH) group increases the inhibition efficiency of AMP. SEM and AFM studies showed that the studied compounds inhibit mild steel corrosion by adsorbing at the metal/electrolyte interface and their adsorption obeyed the Temkin adsorption isotherm. Potentiodynamic polarization study revealed that studied inhibitors act as mixed type inhibitors with predominant effect on cathodic reaction. The inhibitive strength of the compounds might have direct relationship electron donating ability of the molecules as revealed by quantum chemical parameters. The order of interaction energies derived from Monte Carlo simulations is AMP-4 > AMP-3 > AMP-2 > AMP-1, which is in agreement with the order of inhibition efficiencies obtained from experimental measurements.

Gene Expression Patterns Define Key Transcriptional Events InCell-Cycle Regulation By cAMP And Protein Kinase A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zambon, Alexander C.; Zhang, Lingzhi; Minovitsky, Simon

Although a substantial number of hormones and drugs increase cellular cAMP levels, the global impact of cAMP and its major effector mechanism, protein kinase A (PKA), on gene expression is not known. Here we show that treatment of murine wild-type S49 lymphoma cells for 24 h with 8-(4-chlorophenylthio)-cAMP (8-CPTcAMP), a PKA-selective cAMP analog, alters the expression of approx equal to 4,500 of approx. equal to 13,600 unique genes. By contrast, gene expression was unaltered in Kin- S49 cells (that lack PKA) incubated with 8-CPTcAMP. Changes in mRNA and protein expression of several cell cycle regulators accompanied cAMP-induced G1-phase cell-cycle arrestmore » of wild-type S49 cells. Within 2h, 8-CPT-cAMP altered expression of 152 genes that contain evolutionarily conserved cAMP-response elements within 5 kb of transcriptional start sites, including the circadian clock gene Per1. Thus, cAMP through its activation of PKA produces extensive transcriptional regulation in eukaryotic cells. These transcriptional networks include a primary group of cAMP-response element-containing genes and secondary networks that include the circadian clock.« less

Cyclic AMP efflux inhibitors as potential therapeutic agents for leukemia.

PubMed

Perez, Dominique R; Smagley, Yelena; Garcia, Matthew; Carter, Mark B; Evangelisti, Annette; Matlawska-Wasowska, Ksenia; Winter, Stuart S; Sklar, Larry A; Chigaev, Alexandre

2016-06-07

Apoptotic evasion is a hallmark of cancer. We propose that some cancers may evade cell death by regulating 3'-5'-cyclic adenosine monophosphate (cAMP), which is associated with pro-apoptotic signaling. We hypothesize that leukemic cells possess mechanisms that efflux cAMP from the cytoplasm, thus protecting them from apoptosis. Accordingly, cAMP efflux inhibition should result in: cAMP accumulation, activation of cAMP-dependent downstream signaling, viability loss, and apoptosis. We developed a novel assay to assess cAMP efflux and performed screens to identify inhibitors. In an acute myeloid leukemia (AML) model, several identified compounds reduced cAMP efflux, appropriately modulated pathways that are responsive to cAMP elevation (cAMP-responsive element-binding protein phosphorylation, and deactivation of Very Late Antigen-4 integrin), and induced mitochondrial depolarization and caspase activation. Blocking adenylyl cyclase activity was sufficient to reduce effects of the most potent compounds. These compounds also decreased cAMP efflux and viability of B-lineage acute lymphoblastic leukemia (B-ALL) cell lines and primary patient samples, but not of normal primary peripheral blood mononuclear cells. Our data suggest that cAMP efflux is a functional feature that could be therapeutically targeted in leukemia. Furthermore, because some of the identified drugs are currently used for treating other illnesses, this work creates an opportunity for repurposing.

Dual contradictory roles of cAMP signaling pathways in hydroxyl radical production in the rat striatum.

PubMed

Hara, Shuichi; Kobayashi, Masamune; Kuriiwa, Fumi; Mukai, Toshiji; Mizukami, Hajime

2012-03-15

Studies have suggested that cAMP signaling pathways may be associated with the production of reactive oxygen species. In this study, we examined how modifications in cAMP signaling affected the production of hydroxyl radicals in rat striatum using microdialysis to measure extracellular 2,3-dihydroxybenzoic acid (2,3-DHBA), which is a hydroxyl radical adduct of salicylate. Up to 50 nmol of the cell-permeative cAMP mimetic 8-bromo-cAMP (8-Br-cAMP) increased 2,3-DHBA in a dose-dependent manner (there was no additional increase in 2,3-DHBA at 100 nmol). Another cAMP mimetic, dibutyryl cAMP (db-cAMP), caused a nonsignificant increase in 2,3-DHBA at 50 nmol and a significant decrease at 100 nmol. Up to 20 nmol of forskolin, which is a direct activator of adenylyl cyclase, increased 2,3-DHBA, similar to the effect of 8-Br-cAMP; however, forskolin resulted in a much greater increase in 2,3-DHBA. A potent inhibitor of protein kinase A (PKA), H89 (500 μM), potentiated the 8-Br-cAMP- and forskolin-induced increases in 2,3-DHBA and antagonized the inhibitory effect of 100 nmol of db-cAMP. Interestingly, the administration of 100 nmol of 8-bromo-cGMP alone or in combination with H89 had no significant effect on 2,3-DHBA levels. Doses of 100 nmol of a preferential PKA activator (6-phenyl-cAMP) or a preferential PKA inhibitor (8-bromoadenosine-3',5'-cyclic monophosphorothionate, Rp-isomer; Rp-8-Br-cAMPS), which also inhibits the cAMP-mediated activation of Epac (the exchange protein directly activated by cAMP), suppressed or enhanced, respectively, the formation of 2,3-DHBA. Up to 100 nmol of 8-(4-chlorophenylthio)-2'-O-methyladenosine-cAMP, which is a selective activator of Epac, dose-dependently stimulated the formation of 2,3-DHBA. These findings suggest that cAMP signaling plays contradictory roles (stimulation and inhibition) in the production of hydroxyl radicals in rat striatum by differential actions of Epac and PKA. These roles might contribute to the production of hydroxyl radicals concomitant with cAMP in carbon monoxide poisoning, because the formation of 2,3-DHBA was potentiated by the PKA inhibitor H89 and suppressed by Rp-8-Br-cAMPS, which inhibits PKA and Epac. Copyright © 2012 Elsevier Inc. All rights reserved.

Discovery of novel antimicrobial peptides with unusual cysteine motifs in dandelion Taraxacum officinale Wigg. flowers.

PubMed

Astafieva, A A; Rogozhin, E A; Odintsova, T I; Khadeeva, N V; Grishin, E V; Egorov, Ts A

2012-08-01

Three novel antimicrobial peptides designated ToAMP1, ToAMP2 and ToAMP3 were purified from Taraxacum officinale flowers. Their amino acid sequences were determined. The peptides are cationic and cysteine-rich and consist of 38, 44 and 42 amino acid residues for ToAMP1, ToAMP2 and ToAMP3, respectively. Importantly, according to cysteine motifs, the peptides are representatives of two novel previously unknown families of plant antimicrobial peptides. ToAMP1 and ToAMP2 share high sequence identity and belong to 6-Cys-containing antimicrobial peptides, while ToAMP3 is a member of a distinct 8-Cys family. The peptides were shown to display high antimicrobial activity both against fungal and bacterial pathogens, and therefore represent new promising molecules for biotechnological and medicinal applications. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

A continuous spectrophotometric assay for monitoring adenosine 5'-monophosphate production.

PubMed

First, Eric A

2015-08-15

A number of biologically important enzymes release adenosine 5'-monophosphate (AMP) as a product, including aminoacyl-tRNA synthetases, cyclic AMP (cAMP) phosphodiesterases, ubiquitin and ubiquitin-like ligases, DNA ligases, coenzyme A (CoA) ligases, polyA deadenylases, and ribonucleases. In contrast to the abundance of assays available for monitoring the conversion of adenosine 5'-triphosphate (ATP) to ADP, there are relatively few assays for monitoring the conversion of ATP (or cAMP) to AMP. In this article, we describe a homogeneous assay that continuously monitors the production of AMP. Specifically, we have coupled the conversion of AMP to inosine 5'-monophosphate (IMP) (by AMP deaminase) to the oxidation of IMP (by IMP dehydrogenase). This results in the reduction of oxidized nicotine adenine dinucleotide (NAD(+)) to reduced nicotine adenine dinucleotide (NADH), allowing AMP formation to be monitored by the change in the absorbance at 340 nm. Changes in AMP concentrations of 5 μM or more can be reliably detected. The ease of use and relatively low expense make the AMP assay suitable for both high-throughput screening and kinetic analyses. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel cysteine-rich antifungal peptide ToAMP4 from Taraxacum officinale Wigg. flowers.

PubMed

Astafieva, A A; Rogozhin, Eugene A; Andreev, Yaroslav A; Odintsova, T I; Kozlov, S A; Grishin, Eugene V; Egorov, Tsezi A

2013-09-01

A novel peptide named ToAMP4 was isolated from Taraxacum officinale Wigg. flowers by a combination of acetic acid extraction and different types of chromatography: affinity, size-exclusion, and RP-HPLC. The amino acid sequence of ToAMP4 was determined by automated Edman degradation. The peptide is basic, consists of 41 amino acids, and incorporates three disulphide bonds. Due to the unusual cysteine spacing pattern, ToAMP4 does not belong to any known plant AMP family, but classifies together with two other antimicrobial peptides ToAMP1 and ToAMP2 previously isolated from the dandelion flowers. To study the biological activity of ToAMP4, it was successfully produced in a prokaryotic expression system as a fusion protein with thioredoxin. The recombinant peptide was shown to be identical to the native ToAMP4 by chromatographic behavior, molecular mass, and N-terminal amino acid sequence. The peptide displays broad-spectrum antifungal activity against important phytopathogens. Two ToAMP4-mediated inhibition strategies depending on the fungus were demonstrated. The results obtained add to our knowledge on the structural and functional diversity of AMPs in plants. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

AMP Is an Adenosine A1 Receptor Agonist*

PubMed Central

Rittiner, Joseph E.; Korboukh, Ilia; Hull-Ryde, Emily A.; Jin, Jian; Janzen, William P.; Frye, Stephen V.; Zylka, Mark J.

2012-01-01

Numerous receptors for ATP, ADP, and adenosine exist; however, it is currently unknown whether a receptor for the related nucleotide adenosine 5′-monophosphate (AMP) exists. Using a novel cell-based assay to visualize adenosine receptor activation in real time, we found that AMP and a non-hydrolyzable AMP analog (deoxyadenosine 5′-monophosphonate, ACP) directly activated the adenosine A1 receptor (A1R). In contrast, AMP only activated the adenosine A2B receptor (A2BR) after hydrolysis to adenosine by ecto-5′-nucleotidase (NT5E, CD73) or prostatic acid phosphatase (PAP, ACPP). Adenosine and AMP were equipotent human A1R agonists in our real-time assay and in a cAMP accumulation assay. ACP also depressed cAMP levels in mouse cortical neurons through activation of endogenous A1R. Non-selective purinergic receptor antagonists (pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid and suramin) did not block adenosine- or AMP-evoked activation. Moreover, mutation of His-251 in the human A1R ligand binding pocket reduced AMP potency without affecting adenosine potency. In contrast, mutation of a different binding pocket residue (His-278) eliminated responses to AMP and to adenosine. Taken together, our study indicates that the physiologically relevant nucleotide AMP is a full agonist of A1R. In addition, our study suggests that some of the physiological effects of AMP may be direct, and not indirect through ectonucleotidases that hydrolyze this nucleotide to adenosine. PMID:22215671

AMP is an adenosine A1 receptor agonist.

PubMed

Rittiner, Joseph E; Korboukh, Ilia; Hull-Ryde, Emily A; Jin, Jian; Janzen, William P; Frye, Stephen V; Zylka, Mark J

2012-02-17

Numerous receptors for ATP, ADP, and adenosine exist; however, it is currently unknown whether a receptor for the related nucleotide adenosine 5'-monophosphate (AMP) exists. Using a novel cell-based assay to visualize adenosine receptor activation in real time, we found that AMP and a non-hydrolyzable AMP analog (deoxyadenosine 5'-monophosphonate, ACP) directly activated the adenosine A(1) receptor (A(1)R). In contrast, AMP only activated the adenosine A(2B) receptor (A(2B)R) after hydrolysis to adenosine by ecto-5'-nucleotidase (NT5E, CD73) or prostatic acid phosphatase (PAP, ACPP). Adenosine and AMP were equipotent human A(1)R agonists in our real-time assay and in a cAMP accumulation assay. ACP also depressed cAMP levels in mouse cortical neurons through activation of endogenous A(1)R. Non-selective purinergic receptor antagonists (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid and suramin) did not block adenosine- or AMP-evoked activation. Moreover, mutation of His-251 in the human A(1)R ligand binding pocket reduced AMP potency without affecting adenosine potency. In contrast, mutation of a different binding pocket residue (His-278) eliminated responses to AMP and to adenosine. Taken together, our study indicates that the physiologically relevant nucleotide AMP is a full agonist of A(1)R. In addition, our study suggests that some of the physiological effects of AMP may be direct, and not indirect through ectonucleotidases that hydrolyze this nucleotide to adenosine.

Human Factors in Aviation Maintenance. Phase 1

DTIC Science & Technology

1991-11-01

Aircraft Maintenance Information SystemSupyyse AMP ......... Aircraft Maintenance Personnel CRM ....... Cockpit Resource Management AMT... developments were sponsored by the Department of interchange of relevant information between system par- Defense (DoD). Fewer than twenty systems are...ofindividuals without complicating lines ofcommand andothers in the maintenance system is repeated for row "I." orthe allocation ofresponsibility

Asset Management Process (AMP) Improvement Project: Final Report of Findings and Recommendations

DTIC Science & Technology

2009-10-01

cannibalized components could no longer be sighted due to their re-use in other systems or equipment. Solution — A Rapid Improvement Event, or Kaizen , was...Property Loss Reporting domain’s lifecycle, the Green Belt recognized the opportunity for a Rapid Improvement Event (RIE), or Kaizen . A five-day RIE was

Body weight management effect of burdock (Arctium lappa L.) root is associated with the activation of AMP-activated protein kinase in human HepG2 cells.

PubMed

Kuo, Daih-Huang; Hung, Ming-Chi; Hung, Chao-Ming; Liu, Li-Min; Chen, Fu-An; Shieh, Po-Chuen; Ho, Chi-Tang; Way, Tzong-Der

2012-10-01

Burdock (Arcticum lappa L.) root is used in folk medicine and also as a vegetable in Asian countries. In the present study, burdock root treatment significantly reduced body weight in rats. To evaluate the bioactive compounds, we successively extracted the burdock root with ethanol (AL-1), and fractionated it with n-hexane (AL-2), ethyl acetate (AL-3), n-butanol (AL-4), and water (AL-5). Among these fractions, AL-2 contained components with the most effective hypolipidemic potential in human hepatoma HepG2 cells. AL-2 decreased the expression of fatty acid synthase (FASN) and inhibited the activity of acetyl-coenzyme A carboxylase (ACC) by stimulating AMP-activated protein kinase (AMPK) through the LKB1 pathway. Three active compounds were identified from the AL-2, namely α-linolenic acid, methyl α-linolenate, and methyl oleate. These results suggest that burdock root is expected to be useful for body weight management. Copyright © 2012 Elsevier Ltd. All rights reserved.

AmpC β-lactamases in nosocomial isolates of Klebsiella pneumoniae from India

PubMed Central

Gupta, Varsha; Kumarasamy, Karthikeyan; Gulati, Neelam; Garg, Ritu; Krishnan, Padma; Chander, Jagdish

2012-01-01

Background & objectives: AmpC β-lactamases are clinically significant since these confer resistance to cephalosporins in the oxyimino group, 7-α methoxycephalosporins and are not affected by available β-lactamase inhibitors. In this study we looked for both extended spectrum β-lactamases (ESBL) and AmpC β-lactamases in Klebsiella pneumoniae clinical isolates. Methods: One hundred consecutive, non-duplicate clinical isolates of K. pneumoniae collected over a period of one year (June 2008 - June 2009) were included in the study. An antibiotic susceptibility method was used with 10 antibiotics for Gram-negative infections which helped in screening for ESBL and AmpC β-lactamases and also in confirmation of ESBL production. The detection of AmpC β-lactamases was done based on screening and confirmatory tests. For screening, disc diffusion zones of cefoxitin <18 mm was taken as cefoxitin resistant. All cefoxitin resistant isolates were tested further by AmpC disk test and modified three dimensional test. Multiplex-PCR was performed for screening the presence of plasmid-mediated AmpC genes. Results: Of the 100 isolates of K. pneumoniae studied, 48 were resistant to cefoxitin on screening. AmpC disk test was positive in 32 (32%) isolates. This was also confirmed with modified three dimensional test. Indentation indicating strong AmpC producer was observed in 25 isolates whereas little distortion (weak AmpC) was observed in 7 isolates. ESBL detection was confirmed by a modification of double disk synergy test in 56 isolates. Cefepime was the best cephalosporin in synergy with tazobactam for detecting ESBL production in isolates co-producing AmpC β-lactamases. The subsets of isolates phenotypically AmpC β-lactamase positive were subjected to amplification of six different families of AmpC gene using multiplex PCR. The sequence analysis revealed 12 CMY-2 and eight DHA-1 types. Interpretation & conclusions: Tazobactam was the best β-lactamase inhibitor for detecting ESBL in presence of AmpC β-lactamase as this is a very poor inducer of AmpC gene. Amongst cephalosporins, cefepime was the best cephalosporin in detecting ESBL in presence of AmpC β-lactamase as it is least hydrolyzed by AmpC enzymes. Cefepime-tazobactam combination disk test would be a simple and best method in detection of ESBLs in Enterobacteriaceae co-producing AmpC β-lactamase in the routine diagnostic microbiology laboratories. PMID:22960890

Impact of 5'-amp-activated Protein Kinase on Male Gonad and Spermatozoa Functions.

PubMed

Nguyen, Thi Mong Diep

2017-01-01

As we already know, the male reproductive system requires less energetic investment than the female one. Nevertheless, energy balance is an important feature for spermatozoa production in the testis and for spermatozoa properties after ejaculation. The 5'-AMP-activated protein kinase, AMPK, is a sensor of cell energy, that regulates many metabolic pathways and that has been recently shown to control spermatozoa quality and functions. It is indeed involved in the regulation of spermatozoa quality through its action on the proliferation of testicular somatic cells (Sertoli and Leydig), on spermatozoa motility and acrosome reaction. It also favors spermatozoa quality through the management of lipid peroxidation and antioxidant enzymes. I review here the most recent data available on the roles of AMPK in vertebrate spermatozoa functions.

AmpH, a bifunctional DD-endopeptidase and DD-carboxypeptidase of Escherichia coli.

PubMed

González-Leiza, Silvia M; de Pedro, Miguel A; Ayala, Juan A

2011-12-01

In Escherichia coli, low-molecular-mass penicillin-binding proteins (LMM PBPs) are important for correct cell morphogenesis. These enzymes display DD-carboxypeptidase and/or dd-endopeptidase activities associated with maturation and remodeling of peptidoglycan (PG). AmpH has been classified as an AmpH-type class C LMM PBP, a group closely related to AmpC β-lactamases. AmpH has been associated with PG recycling, although its enzymatic activity remained uncharacterized until now. Construction and purification of His-tagged AmpH from E. coli permitted a detailed study of its enzymatic properties. The N-terminal export signal of AmpH is processed, but the protein remains membrane associated. The PBP nature of AmpH was demonstrated by its ability to bind the β-lactams Bocillin FL (a fluorescent penicillin) and cefmetazole. In vitro assays with AmpH and specific muropeptides demonstrated that AmpH is a bifunctional DD-endopeptidase and DD-carboxypeptidase. Indeed, the enzyme cleaved the cross-linked dimers tetrapentapeptide (D45) and tetratetrapeptide (D44) with efficiencies (k(cat)/K(m)) of 1,200 M(-1) s(-1) and 670 M(-1) s(-1), respectively, and removed the terminal D-alanine from muropeptides with a C-terminal D-Ala-D-Ala dipeptide. Both DD-peptidase activities were inhibited by 40 μM cefmetazole. AmpH also displayed a weak β-lactamase activity for nitrocefin of 1.4 × 10(-3) nmol/μg protein/min, 1/1,000 the rate obtained for AmpC under the same conditions. AmpH was also active on purified sacculi, exhibiting the bifunctional character that was seen with pure muropeptides. The wide substrate spectrum of the DD-peptidase activities associated with AmpH supports a role for this protein in PG remodeling or recycling.

AmpH, a Bifunctional dd-Endopeptidase and dd-Carboxypeptidase of Escherichia coli▿

PubMed Central

González-Leiza, Silvia M.; de Pedro, Miguel A.; Ayala, Juan A.

2011-01-01

In Escherichia coli, low-molecular-mass penicillin-binding proteins (LMM PBPs) are important for correct cell morphogenesis. These enzymes display dd-carboxypeptidase and/or dd-endopeptidase activities associated with maturation and remodeling of peptidoglycan (PG). AmpH has been classified as an AmpH-type class C LMM PBP, a group closely related to AmpC β-lactamases. AmpH has been associated with PG recycling, although its enzymatic activity remained uncharacterized until now. Construction and purification of His-tagged AmpH from E. coli permitted a detailed study of its enzymatic properties. The N-terminal export signal of AmpH is processed, but the protein remains membrane associated. The PBP nature of AmpH was demonstrated by its ability to bind the β-lactams Bocillin FL (a fluorescent penicillin) and cefmetazole. In vitro assays with AmpH and specific muropeptides demonstrated that AmpH is a bifunctional dd–endopeptidase and dd-carboxypeptidase. Indeed, the enzyme cleaved the cross-linked dimers tetrapentapeptide (D45) and tetratetrapeptide (D44) with efficiencies (kcat/Km) of 1,200 M−1 s−1 and 670 M−1 s−1, respectively, and removed the terminal d-alanine from muropeptides with a C-terminal d-Ala-d-Ala dipeptide. Both dd-peptidase activities were inhibited by 40 μM cefmetazole. AmpH also displayed a weak β-lactamase activity for nitrocefin of 1.4 × 10−3 nmol/μg protein/min, 1/1,000 the rate obtained for AmpC under the same conditions. AmpH was also active on purified sacculi, exhibiting the bifunctional character that was seen with pure muropeptides. The wide substrate spectrum of the dd-peptidase activities associated with AmpH supports a role for this protein in PG remodeling or recycling. PMID:22001512

Discovery of a cAMP Deaminase That Quenches Cyclic AMP-Dependent Regulation

PubMed Central

Goble, Alissa M.; Feng, Youjun; Raushel, Frank M.; Cronan, John E.

2013-01-01

An enzyme of unknown function within the amidohydrolase superfamily was discovered to catalyze the hydrolysis of the universal second messenger, cyclic-3’, 5’-adenosine monophosphate (cAMP). The enzyme, which we have named CadD, is encoded by the human pathogenic bacterium Leptospira interrogans. Although CadD is annotated as an adenosine deaminase, the protein specifically deaminates cAMP to cyclic-3’, 5’-inosine monophosphate (cIMP) with a kcat/Km of 2.7 ± 0.4 × 105 M−1 s−1 and has no activity on adenosine, adenine, or 5’-adenosine monophosphate (AMP). This is the first identification of a deaminase specific for cAMP. Expression of CadD in Escherichia coli mimics the loss of adenylate cyclase in that it blocks growth on carbon sources that require the cAMP-CRP transcriptional activator complex for expression of the cognate genes. The cIMP reaction product cannot replace cAMP as the ligand for CRP binding to DNA in vitro and cIMP is a very poor competitor of cAMP activation of CRP for DNA binding. Transcriptional analyses indicate that CadD expression represses expression of several cAMP-CRP dependent genes. CadD adds a new activity to the cAMP metabolic network and may be a useful tool in intracellular study of cAMP-dependent processes. PMID:24074367

Expression profiles of antimicrobial peptides (AMPs) and their regulation by Relish

NASA Astrophysics Data System (ADS)

Wang, Dongdong; Li, Fuhua; Li, Shihao; Wen, Rong; Xiang, Jianhai

2012-07-01

Antimicrobial peptides (AMPs), as key immune effectors, play important roles in the innate immune system of invertebrates. Different types of AMPs, including Penaeidin, Crustin, ALF (antilipopolysaccharide factor) have been identified in different penaeid shrimp; however, systematic analyses on the function of different AMPs in shrimp responsive to different types of bacteria are very limited. In this study, we analyzed the expression profiles of AMPs in the Chinese shrimps, Fenneropenaeus chinensis, simultaneously by real-time RT-PCR (reverse transcription-polymerase chain reaction) when shrimp were challenged with Micrococcus lysodeikticus (Gram-positive, G+) or Vibrio anguillarium (Gram-negative, G-). Different AMPs showed different expression profiles when shrimp were injected with one type of bacterium, and one AMP also showed different expression profiles when shrimp were challenged with different bacteria. Furthermore, the expression of these AMPs showed temporal expression profiles, suggesting that different AMPs function coordinately in bacteria-infected shrimp. An RNA interference approach was used to study the function of the Relish transcription factor in regulating the transcription of different AMPs. The current study showed that Relish could regulate the transcription of different AMPs in shrimp. Differential expression profiles of AMPs in shrimp injected with different types of bacteria indicated that a complicated antimicrobial response network existed in shrimp. These data contribute to our understanding of immunity in shrimp and may provide a strategy for the control of disease in shrimp.

Light Water Reactor Sustainability Program: Evaluation of Localized Cable Test Methods for Nuclear Power Plant Cable Aging Management Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, Samuel W.; Fifield, Leonard S.; Hartman, Trenton S.

This Pacific Northwest National Laboratory (PNNL) milestone report describes progress to date on the investigation of nondestructive test (NDE) methods focusing particularly on local measurements that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As NPPs consider applying for second, or subsequent, license renewal (SLR) to extend their operating period from 60 years to 80 years, it important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs (AMPs) to assure continuedmore » safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program is directed toward the more demanding challenge of assuring the cable function under accident or DBE. Most utilities already have a program associated with their first life extension from 40 to 60 years. Regrettably, there is neither a clear guideline nor a single NDE that can assure cable function and integrity for all cables. Thankfully, however, practical implementation of a broad range of tests allows utilities to develop a practical program that assures cable function to a high degree. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB is a destructive test so the test programs must apply an array of other NDE tests to assure or infer the overall set of cable’s system integrity. These cable NDE programs vary in rigor and methodology. As the industry gains experience with the efficacy of these programs, it is expected that implementation practice will converge to a more common approach. This report addresses the range of local NDE cable tests that are or could be practically implemented in a field test situation. These tests include: visual, infrared thermography, interdigital capacitance, indenter, relaxation time indenter, dynamic mechanical analyzer, infrared/near-infrared spectrometry, ultrasound, and distributed fiber optic temperature measurement.« less

Cyclic AMP Inhibits the Activity and Promotes the Acetylation of Acetyl-CoA Synthetase through Competitive Binding to the ATP/AMP Pocket.

PubMed

Han, Xiaobiao; Shen, Liqiang; Wang, Qijun; Cen, Xufeng; Wang, Jin; Wu, Meng; Li, Peng; Zhao, Wei; Zhang, Yu; Zhao, Guoping

2017-01-27

The high-affinity biosynthetic pathway for converting acetate to acetyl-coenzyme A (acetyl-CoA) is catalyzed by the central metabolic enzyme acetyl-coenzyme A synthetase (Acs), which is finely regulated both at the transcriptional level via cyclic AMP (cAMP)-driven trans-activation and at the post-translational level via acetylation inhibition. In this study, we discovered that cAMP directly binds to Salmonella enterica Acs (SeAcs) and inhibits its activity in a substrate-competitive manner. In addition, cAMP binding increases SeAcs acetylation by simultaneously promoting Pat-dependent acetylation and inhibiting CobB-dependent deacetylation, resulting in enhanced SeAcs inhibition. A crystal structure study and site-directed mutagenesis analyses confirmed that cAMP binds to the ATP/AMP pocket of SeAcs, and restrains SeAcs in an open conformation. The cAMP contact residues are well conserved from prokaryotes to eukaryotes, suggesting a general regulatory mechanism of cAMP on Acs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

cAMP enhances BMP2-signaling through PKA and MKP1-dependent mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghayor, Chafik; Ehrbar, Martin; Miguel, Blanca San

2009-04-03

Recent studies suggest that the elevation of intracellular cyclic adenosine monophosphate (cAMP) and the activation of the protein kinase A regulate BMP-induced osteogenesis. However, the precise mechanisms underlying the enhancing effect of cAMP on BMP2 signaling were not completely revealed. In this study we investigated the effect of elevated cAMP level and PKA activation on the BMP2-induced osteoblastic differentiation in pluripotent C2C12 cells. Alkaline phosphatase activity and its mRNA were consistently induced by BMP2 treatment. The pretreatment of C2C12 cells with Forskolin, a cAMP generating agent, dbcAMP, an analogue of cAMP, or IBMX (3-isobutyl 1-methyl xanthine), and a nonspecific inhibitormore » of phosphodiesterases elicited further activation of alkaline phosphatase. Furthermore, elevated intracellular cAMP level increased BMP2-induced MKP1. On the other hand, BMP2-induced Erk phosphorylation (p44/p42) and cell proliferation were suppressed in the presence of cAMP. Thus, cAMP might enhance BMP2-induced osteoblastic differentiation by a MKP1-Erk-dependent mechanism.« less

cAMP dependent and independent regulation of thyroglobulin synthesis by two clones of the OVNIS 6H thyroid cell line.

PubMed

Aouani, A; Hovsépian, S; Fayet, G

1987-07-01

The hormonal regulation of thyroglobulin synthesis has been studied using two independent clones of the OVNIS 6H cell line. Insulin, hydrocortisone and TSH were able to stimulate thyroglobulin synthesis, whereas transferrin, somatostatin and glycyl-histidyl-lysine were without effect. Insulin stimulated thyroglobulin synthesis without affecting cAMP production. Hydrocortisone, when combined with insulin was a stimulator too; this stimulation was not accompanied by an increase in cAMP. TSH alone was unable to stimulate either cAMP or thyroglobulin synthesis. The stimulatory effect of TSH on thyroglobulin synthesis took place only when combined with insulin or insulin plus hydrocortisone, and was mediated by cAMP. Consequently, insulin and hydrocortisone stimulated thyroglobulin synthesis by cAMP-independent mechanisms, whereas TSH acted via the cAMP system. Forskolin mimicked TSH effects on cAMP and thyroglobulin synthesis. Calf serum inhibited cAMP and thyroglobulin production. Optimal cAMP and thyroglobulin synthesis as well as TSH responsiveness were obtained in serum-free medium supplemented with 5 micrograms/ml insulin, 100 nM hydrocortisone and 1 mU/ml TSH.

Mechanisms Restricting Diffusion of Intracellular cAMP.

PubMed

Agarwal, Shailesh R; Clancy, Colleen E; Harvey, Robert D

2016-01-22

Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells.

Mechanisms Restricting Diffusion of Intracellular cAMP

PubMed Central

Agarwal, Shailesh R.; Clancy, Colleen E.; Harvey, Robert D.

2016-01-01

Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells. PMID:26795432

An essential complementary role of NF-kappaB pathway to microbicidal oxidants in Drosophila gut immunity.

PubMed

Ryu, Ji-Hwan; Ha, Eun-Mi; Oh, Chun-Taek; Seol, Jae-Hong; Brey, Paul T; Jin, Ingnyol; Lee, Dong Gun; Kim, Jaesang; Lee, Daekee; Lee, Won-Jae

2006-08-09

In the Drosophila gut, reactive oxygen species (ROS)-dependent immunity is critical to host survival. This is in contrast to the NF-kappaB pathway whose physiological function in the microbe-laden epithelia has yet to be convincingly demonstrated despite playing a critical role during systemic infections. We used a novel in vivo approach to reveal the physiological role of gut NF-kappaB/antimicrobial peptide (AMP) system, which has been 'masked' in the presence of the dominant intestinal ROS-dependent immunity. When fed with ROS-resistant microbes, NF-kappaB pathway mutant flies, but not wild-type flies, become highly susceptible to gut infection. This high lethality can be significantly reduced by either re-introducing Relish expression to Relish mutants or by constitutively expressing a single AMP to the NF-kappaB pathway mutants in the intestine. These results imply that the local 'NF-kappaB/AMP' system acts as an essential 'fail-safe' system, complementary to the ROS-dependent gut immunity, during gut infection with ROS-resistant pathogens. This system provides the Drosophila gut immunity the versatility necessary to manage sporadic invasion of virulent pathogens that somehow counteract or evade the ROS-dependent immunity.

AMP Affects Intracellular Ca2+ Signaling, Migration, Cytokine Secretion and T Cell Priming Capacity of Dendritic Cells

PubMed Central

Panther, Elisabeth; Dürk, Thorsten; Ferrari, Davide; Di Virgilio, Francesco; Grimm, Melanie; Sorichter, Stephan; Cicko, Sanja; Herouy, Yared; Norgauer, Johannes; Idzko, Marco; Müller, Tobias

2012-01-01

The nucleotide adenosine-5′-monophosphate (AMP) can be released by various cell types and has been shown to elicit different cellular responses. In the extracellular space AMP is dephosphorylated to the nucleoside adenosine which can then bind to adenosine receptors. However, it has been shown that AMP can also activate A1 and A2a receptors directly. Here we show that AMP is a potent modulator of mouse and human dendritic cell (DC) function. AMP increased intracellular Ca2+ concentration in a time and dose dependent manner. Furthermore, AMP stimulated actin-polymerization in human DCs and induced migration of immature human and bone marrow derived mouse DCs, both via direct activation of A1 receptors. AMP strongly inhibited secretion of TNF-α and IL-12p70, while it enhanced production of IL-10 both via activation of A2a receptors. Consequently, DCs matured in the presence of AMP and co-cultivated with naive CD4+CD45RA+ T cells inhibited IFN-γ production whereas secretion of IL-5 and IL-13 was up-regulated. An enhancement of Th2-driven immune response could also be observed when OVA-pulsed murine DCs were pretreated with AMP prior to co-culture with OVA-transgenic naïve OTII T cells. An effect due to the enzymatic degradation of AMP to adenosine could be ruled out, as AMP still elicited migration and changes in cytokine secretion in bone-marrow derived DCs generated from CD73-deficient animals and in human DCs pretreated with the ecto-nucleotidase inhibitor 5′-(alpha,beta-methylene) diphosphate (APCP). Finally, the influence of contaminating adenosine could be excluded, as AMP admixed with adenosine desaminase (ADA) was still able to influence DC function. In summary our data show that AMP when present during maturation is a potent regulator of dendritic cell function and point out the role for AMP in the pathogenesis of inflammatory disorders. PMID:22624049

c-di-AMP: An Essential Molecule in the Signaling Pathways that Regulate the Viability and Virulence of Gram-Positive Bacteria

PubMed Central

Fahmi, Tazin; Port, Gary C.

2017-01-01

Signal transduction pathways enable organisms to monitor their external environment and adjust gene regulation to appropriately modify their cellular processes. Second messenger nucleotides including cyclic adenosine monophosphate (c-AMP), cyclic guanosine monophosphate (c-GMP), cyclic di-guanosine monophosphate (c-di-GMP), and cyclic di-adenosine monophosphate (c-di-AMP) play key roles in many signal transduction pathways used by prokaryotes and/or eukaryotes. Among the various second messenger nucleotides molecules, c-di-AMP was discovered recently and has since been shown to be involved in cell growth, survival, and regulation of virulence, primarily within Gram-positive bacteria. The cellular level of c-di-AMP is maintained by a family of c-di-AMP synthesizing enzymes, diadenylate cyclases (DACs), and degradation enzymes, phosphodiesterases (PDEs). Genetic manipulation of DACs and PDEs have demonstrated that alteration of c-di-AMP levels impacts both growth and virulence of microorganisms. Unlike other second messenger molecules, c-di-AMP is essential for growth in several bacterial species as many basic cellular functions are regulated by c-di-AMP including cell wall maintenance, potassium ion homeostasis, DNA damage repair, etc. c-di-AMP follows a typical second messenger signaling pathway, beginning with binding to receptor molecules to subsequent regulation of downstream cellular processes. While c-di-AMP binds to specific proteins that regulate pathways in bacterial cells, c-di-AMP also binds to regulatory RNA molecules that control potassium ion channel expression in Bacillus subtilis. c-di-AMP signaling also occurs in eukaryotes, as bacterially produced c-di-AMP stimulates host immune responses during infection through binding of innate immune surveillance proteins. Due to its existence in diverse microorganisms, its involvement in crucial cellular activities, and its stimulating activity in host immune responses, c-di-AMP signaling pathway has become an attractive antimicrobial drug target and therefore has been the focus of intensive study in several important pathogens. PMID:28783096

cAMP-secretion coupling is impaired in diabetic GK/Par rat β-cells: a defect counteracted by GLP-1.

PubMed

Dolz, Manuel; Movassat, Jamileh; Bailbé, Danielle; Le Stunff, Hervé; Giroix, Marie-Hélène; Fradet, Magali; Kergoat, Micheline; Portha, Bernard

2011-11-01

cAMP-raising agents with glucagon-like peptide-1 (GLP-1) as the first in class, exhibit multiple actions that are beneficial for the treatment of type 2 diabetic (T2D) patients, including improvement of glucose-induced insulin secretion (GIIS). To gain additional insight into the role of cAMP in the disturbed stimulus-secretion coupling within the diabetic β-cell, we examined more thoroughly the relationship between changes in islet cAMP concentration and insulin release in the GK/Par rat model of T2D. Basal cAMP content in GK/Par islets was significantly higher, whereas their basal insulin release was not significantly different from that of Wistar (W) islets. Even in the presence of IBMX or GLP-1, their insulin release did not significantly change despite further enhanced cAMP accumulation in both cases. The high basal cAMP level most likely reflects an increased cAMP generation in GK/Par compared with W islets since 1) forskolin dose-dependently induced an exaggerated cAMP accumulation; 2) adenylyl cyclase (AC)2, AC3, and G(s)α proteins were overexpressed; 3) IBMX-activated cAMP accumulation was less efficient and PDE-3B and PDE-1C mRNA were decreased. Moreover, the GK/Par insulin release apparatus appears less sensitive to cAMP, since GK/Par islets released less insulin at submaximal cAMP levels and required five times more cAMP to reach a maximal secretion rate no longer different from W. GLP-1 was able to reactivate GK/Par insulin secretion so that GIIS became indistinguishable from that of W. The exaggerated cAMP production is instrumental, since GLP-1-induced GIIS reactivation was lost in the presence the AC blocker 2',5'-dideoxyadenosine. This GLP-1 effect takes place in the absence of any improvement of the [Ca(2+)](i) response and correlates with activation of the cAMP-dependent PKA-dependent pathway.

8-Bromo-cAMP decreases the Ca2+ sensitivity of airway smooth muscle contraction through a mechanism distinct from inhibition of Rho-kinase.

PubMed

Endou, Katsuaki; Iizuka, Kunihiko; Yoshii, Akihiro; Tsukagoshi, Hideo; Ishizuka, Tamotsu; Dobashi, Kunio; Nakazawa, Tsugio; Mori, Masatomo

2004-10-01

To clarify whether cyclic AMP (cAMP)/cAMP-dependent protein kinase (PKA) activation and Rho-kinase inhibition share a common mechanism to decrease the Ca2+ sensitivity of airway smooth muscle contraction, we examined the effects of 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), a stable cAMP analog, and (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide dihydrochloride, monohydrate (Y-27632), a Rho-kinase inhibitor, on carbachol (CCh)-, guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS)-, 4beta-phorbol 12,13-dibutyrate (PDBu)-, and leukotriene D4 (LTD4)-induced Ca2+ sensitization in alpha-toxin-permeabilized rabbit tracheal and human bronchial smooth muscle. In rabbit trachea, CCh-induced smooth muscle contraction was inhibited by 8-BrcAMP and Y-27632 to a similar extent. However, GTPgammaS-induced smooth muscle contraction was resistant to 8-BrcAMP. In the presence of a saturating concentration of Y-27632, PDBu-induced smooth muscle contraction was completely reversed by 8-BrcAMP. Conversely, PDBu-induced smooth muscle contraction was resistant to Y-27632. In the presence of a saturating concentration of 8-BrcAMP, GTPgammaS-induced Ca2+ sensitization was also reversed by Y-27632. The 8-BrcAMP had no effect on the ATP-triggered contraction of tracheal smooth muscle that had been treated with calyculin A in rigor solutions. The 8-BrcAMP and Y-27632 additively accelerated the relaxation rate of PDBu- and GTPgammaS-treated smooth muscle under myosin light chain kinase-inhibited conditions. In human bronchus, LTD4-induced smooth muscle contraction was inhibited by both 8-BrcAMP and Y-27632. We conclude that cAMP/PKA-induced Ca2+ desensitization contains at least two mechanisms: 1) inhibition of the muscarinic receptor signaling upstream from Rho activation and 2) cAMP/PKA's preferential reversal of PKC-mediated Ca2+ sensitization in airway smooth muscle.

Enzymatic Characterization of AMP Phosphorylase and Ribose-1,5-Bisphosphate Isomerase Functioning in an Archaeal AMP Metabolic Pathway

PubMed Central

Aono, Riku; Sato, Takaaki; Yano, Ayumu; Yoshida, Shosuke; Nishitani, Yuichi; Miki, Kunio; Imanaka, Tadayuki

2012-01-01

AMP phosphorylase (AMPpase), ribose-1,5-bisphosphate (R15P) isomerase, and type III ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) have been proposed to constitute a novel pathway involved in AMP metabolism in the Archaea. Here we performed a biochemical examination of AMPpase and R15P isomerase from Thermococcus kodakarensis. R15P isomerase was specific for the α-anomer of R15P and did not recognize other sugar compounds. We observed that activity was extremely low with the substrate R15P alone but was dramatically activated in the presence of AMP. Using AMP-activated R15P isomerase, we reevaluated the substrate specificity of AMPpase. AMPpase exhibited phosphorylase activity toward CMP and UMP in addition to AMP. The [S]-v plot (plot of velocity versus substrate concentration) of the enzyme toward AMP was sigmoidal, with an increase in activity observed at concentrations higher than approximately 3 mM. The behavior of the two enzymes toward AMP indicates that the pathway is intrinsically designed to prevent excess degradation of intracellular AMP. We further examined the formation of 3-phosphoglycerate from AMP, CMP, and UMP in T. kodakarensis cell extracts. 3-Phosphoglycerate generation was observed from AMP alone, and from CMP or UMP in the presence of dAMP, which also activates R15P isomerase. 3-Phosphoglycerate was not formed when 2-carboxyarabinitol 1,5-bisphosphate, a Rubisco inhibitor, was added. The results strongly suggest that these enzymes are actually involved in the conversion of nucleoside monophosphates to 3-phosphoglycerate in T. kodakarensis. PMID:23065974

Anticonvulsant effect of AMP by direct activation of adenosine A1 receptor.

PubMed

Muzzi, Mirko; Coppi, Elisabetta; Pugliese, Anna Maria; Chiarugi, Alberto

2013-12-01

Purinergic neurotransmission mediated by adenosine (Ado) type 1 receptors (A1Rs) plays pivotal roles in negative modulation of epileptic seizures, and Ado is thought to be a key endogenous anticonvulsant. Recent evidence, however, indicates that AMP, the metabolic precursor of Ado, also activate A1Rs. Here, we evaluated the antiepileptic effects of AMP adopting in vitro and in vivo models of epilepsy. We report that AMP reversed the increase in population spike (PS) amplitude and the decrease in PS latency induced by a Mg(2+)-free extracellular solution in CA1 neurons of mouse hippocampal slices. The AMP effects were inhibited by the A1R antagonist DPCPX, but not prevented by inhibiting conversion of AMP into Ado, indicating that AMP inhibited per se sustained hippocampal excitatory neurotransmission by directly activating A1Rs. AMP also reduced seizure severity and mortality in a model of audiogenic convulsion. Of note, the anticonvulsant effects of AMP were potentiated by preventing its conversion into Ado and inhibited by DPCPX. When tested in a model of kainate-induced seizure, AMP prolonged latency of convulsions but had no effects on seizure severity and mortality. Data provide the first evidence that AMP is an endogenous anticonvulsant acting at A1Rs. © 2013.

The relationship between pulsatile GnRH secretion and cAMP production in immortalized GnRH neurons.

PubMed

Frattarelli, John L; Krsmanovic, Lazar Z; Catt, Kevin J

2011-06-01

In perifused immortalized GnRH neurons (GT1-7), simultaneous measurements of GnRH and cAMP revealed that the secretory profiles for both GnRH and cAMP are pulsatile. An analysis of GnRH and cAMP pulses in 16 independent experiments revealed that 25% of pulses coincide. Inversion of the peak and nadir levels was found in 33% and random relationship between GnRH and cAMP found in 42% of analyzed pulses. The random relation between GnRH and cAMP pulse resets to synchronous after an inverse relation between pulses occurred during the major GnRH release, indicating that GnRH acts as a switching mechanism to synchronize cAMP and GnRH release in perifused GT1-7 neurons. Activation of GnRH receptors with increasing agonist concentrations caused a biphasic change in cAMP levels. Low nanomolar concentrations increased cAMP production, but at high concentrations the initial increase was followed by a rapid decline to below the basal level. Blockade of the GnRH receptors by peptide and nonpeptide antagonists generated monotonic nonpulsatile increases in both GnRH and cAMP production. These findings indicate that cAMP positively regulates GnRH secretion but does not participate in the mechanism of pulsatile GnRH release.

Exchange protein activated by cAMP (Epac) mediates cAMP-dependent but protein kinase A-insensitive modulation of vascular ATP-sensitive potassium channels

PubMed Central

Purves, Gregor I; Kamishima, Tomoko; Davies, Lowri M; Quayle, John M; Dart, Caroline

2009-01-01

Exchange proteins directly activated by cyclic AMP (Epacs or cAMP-GEF) represent a family of novel cAMP-binding effector proteins. The identification of Epacs and the recent development of pharmacological tools that discriminate between cAMP-mediated pathways have revealed previously unrecognized roles for cAMP that are independent of its traditional target cAMP-dependent protein kinase (PKA). Here we show that Epac exists in a complex with vascular ATP-sensitive potassium (KATP) channel subunits and that cAMP-mediated activation of Epac modulates KATP channel activity via a Ca2+-dependent mechanism involving the activation of Ca2+-sensitive protein phosphatase 2B (PP-2B, calcineurin). Application of the Epac-specific cAMP analogue 8-pCPT-2′-O-Me-cAMP, at concentrations that activate Epac but not PKA, caused a 41.6 ± 4.7% inhibition (mean ±s.e.m.; n= 7) of pinacidil-evoked whole-cell KATP currents recorded in isolated rat aortic smooth muscle cells. Importantly, similar results were obtained when cAMP was elevated by addition of the adenylyl cyclase activator forskolin in the presence of the structurally distinct PKA inhibitors, Rp-cAMPS or KT5720. Activation of Epac by 8-pCPT-2′-O-Me-cAMP caused a transient 171.0 ± 18.0 nm (n= 5) increase in intracellular Ca2+ in Fura-2-loaded aortic myocytes, which persisted in the absence of extracellular Ca2+. Inclusion of the Ca2+-specific chelator BAPTA in the pipette-filling solution or preincubation with the calcineurin inhibitors, cyclosporin A or ascomycin, significantly reduced the ability of 8-pCPT-2′-O-Me-cAMP to inhibit whole-cell KATP currents. These results highlight a previously undescribed cAMP-dependent regulatory mechanism that may be essential for understanding the physiological and pathophysiological roles ascribed to arterial KATP channels in the control of vascular tone and blood flow. PMID:19491242

Measuring electrically charged particle fluxes in space using a fiber optic loop sensor

NASA Technical Reports Server (NTRS)

1992-01-01

The purpose of this program was to demonstrate the potential of a fiber optic loop sensor for the measurement of electrically charged particle fluxes in space. The key elements of the sensor are a multiple turn loop of low birefringence, single mode fiber, with a laser diode light source, and a low noise optical receiver. The optical receiver is designed to be shot noise limited, with this being the limiting sensitivity factor for the sensor. The sensing element is the fiber optic loop. Under a magnetic field from an electric current flowing along the axis of the loop, there is a non-vanishing line integral along the fiber optic loop. This causes a net birefringence producing two states of polarization whose phase difference is correlated to magnetic field strength and thus, current in the optical receiver electronic processing. The objectives in this program were to develop a prototype laser diode powered fiber optic sensor. The performance specification of a minimum detectable current density of 1 (mu)amp/sq m-(radical)Hz, should be at the shot noise limit of the detection electronics. OPTRA has successfully built and tested a 3.2 m diameter loop with 137 turns of low birefringence optical fiber and achieved a minimum detectable current density of 5.4 x 10(exp-5) amps/(radical)Hz. If laboratory space considerations were not an issue, with the length of optical fiber available to us, we would have achieved a minimum detectable current density of 4 x 10(exp -7) amps/(radical)Hz.

Experiment definition studies for AMPS Spacelab

NASA Technical Reports Server (NTRS)

Liemohn, H.

1975-01-01

The electrical charging of the space shuttle orbiter is discussed in relation to the AMPS Spacelab payload along with an operations research technique for the selection of AMPS Spacelab experiments. Experiments proposed for AMPS include: hydromagnetic wave experiments; bistatic sounder of AMPS wake; and an artificial meteor gun. Experiment objectives and instrument functions are given for all experiments.

A next-generation marker genotyping platform (AmpSeq) in heterozygous crops: A case study for marker assisted selection in grapevine

USDA-ARS?s Scientific Manuscript database

Marker assisted selection (MAS) has become widely used in perennial crop breeding programs to accelerate and enhance cultivar development via selection during the juvenile phase and parental selection prior to crossing. Next generation sequencing (NGS) has been widely used for whole genome molecular...

A next-generation marker genotyping platform (AmpSeq) in heterozygous crops: a case study for marker assisted selection in grapevine

USDA-ARS?s Scientific Manuscript database

Marker assisted selection (MAS) is often employed in crop breeding programs to accelerate and enhance cultivar development, via selection during the juvenile phase and parental selection prior to crossing. Next generation sequencing (NGS) and its derivative technologies have been used for genome-wid...

40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings... primers ABP 1.55 Automotive Bumper and Trim Products ABT 1.75 Aviation or Marine Primers AMP 2.00 Aviation...

40th Combat Aviation Brigade and USS Ponce conduct interoperability

Science.gov Websites

training exercise > National Guard > Guard News - The National Guard Skip to main content Major of the ARNG State Mission Sustainability Training ARNG Distributed Learning Program Training & ; Technology Battle Lab (T3BL) Civil Support Simulation Exercises Regional Training Site Maintenance Battle

Long before smartphones, National Guard responded to nationwide muster in

Science.gov Websites

Major of the ARNG State Mission Sustainability Training ARNG Distributed Learning Program Training & ; Technology Battle Lab (T3BL) Civil Support Simulation Exercises Regional Training Site Maintenance Battle Focused Training Strategy Battle Staff Training Resources News Publications Civic Leader's Guide ARNG

Acoustic Modal Patterns and Striations (AMPS) experiment G-325, Norfolk Public Schools

NASA Technical Reports Server (NTRS)

Young, Joy W.

1995-01-01

This paper will describe how high school students with the guidance of volunteer mentors were able to successfully complete an acoustics space experiment. Some of the NORSTAR program strategies used to effectively accomplish this goal will be discussed. The experiment and present status of results will be explained.

Persons with allergy symptoms use alternative medicine more often.

PubMed

Kłak, Anna; Raciborski, Filip; Krzych-Fałta, Edyta; Opoczyńska-Świeżewska, Dagmara; Szymański, Jakub; Lipiec, Agnieszka; Piekarska, Barbara; Sybilski, Adam; Tomaszewska, Aneta; Samoliński, Bolesław

2016-01-01

The aim of the study is to indicate the relation between the use of alternative medicine and the occurrence of allergic diseases in the Polish population of adults in the age of 20-44 years. Moreover the additional aim of the study is to define the relation between the sex, age and place of living and the use of alternative medicine. The data from the project Epidemiology of Allergic Diseases in Poland (ECAP) has been used for analysis. This project was a continuation of the European Community Respiratory Health Survey II. The questions on alternative medicine were asked to the group of 4671 respondents in the age of 20-44 years. Additionally outpatient tests were performed in order to confirm the diagnosis of allergic diseases. The total of 22.2% of respondents that participated in the study have ever used alternative medicine (n = 4621). A statistically significant relation between the use of alternative medicine and declaration of allergic diseases and asthma symptoms has been demonstrated (p &amp;amp;amp;amp;amp;lt; 0.001). No statistically significant relation between the use of alternative medicine by persons diagnosed by a doctor with any form of asthma or seasonal allergic rhinitis (p &amp;amp;amp;amp;amp;gt; 0.05) has been demonstrated. The occurrence of allergic diseases and asthma influences the frequency of alternative medicine use. However the frequency of alternative medicine use does not depend on allergic disease or asthma being confirmed by a doctor.

Distinct profiling of antimicrobial peptide families

PubMed Central

Khamis, Abdullah M.; Essack, Magbubah; Gao, Xin; Bajic, Vladimir B.

2015-01-01

Motivation: The increased prevalence of multi-drug resistant (MDR) pathogens heightens the need to design new antimicrobial agents. Antimicrobial peptides (AMPs) exhibit broad-spectrum potent activity against MDR pathogens and kills rapidly, thus giving rise to AMPs being recognized as a potential substitute for conventional antibiotics. Designing new AMPs using current in-silico approaches is, however, challenging due to the absence of suitable models, large number of design parameters, testing cycles, production time and cost. To date, AMPs have merely been categorized into families according to their primary sequences, structures and functions. The ability to computationally determine the properties that discriminate AMP families from each other could help in exploring the key characteristics of these families and facilitate the in-silico design of synthetic AMPs. Results: Here we studied 14 AMP families and sub-families. We selected a specific description of AMP amino acid sequence and identified compositional and physicochemical properties of amino acids that accurately distinguish each AMP family from all other AMPs with an average sensitivity, specificity and precision of 92.88%, 99.86% and 95.96%, respectively. Many of our identified discriminative properties have been shown to be compositional or functional characteristics of the corresponding AMP family in literature. We suggest that these properties could serve as guides for in-silico methods in design of novel synthetic AMPs. The methodology we developed is generic and has a potential to be applied for characterization of any protein family. Contact: vladimir.bajic@kaust.edu.sa Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25388148

cAMP Stimulates Transepithelial Short-Circuit Current and Fluid Transport Across Porcine Ciliary Epithelium.

PubMed

Cheng, Angela King-Wah; Civan, Mortimer M; To, Chi-Ho; Do, Chi-Wai

2016-12-01

To investigate the effects of cAMP on transepithelial electrical parameters and fluid transport across porcine ciliary epithelium. Transepithelial electrical parameters were determined by mounting freshly isolated porcine ciliary epithelium in a modified Ussing chamber. Similarly, fluid movement across intact ciliary body was measured with a custom-made fluid flow chamber. Addition of 1, 10, and 100 μM 8-Br-cAMP (cAMP) to the aqueous side (nonpigmented ciliary epithelium, NPE) induced a sustained increase in short-circuit current (Isc). Addition of niflumic acid (NFA) to the aqueous surface effectively blocked the cAMP-induced Isc stimulation. The administration of cAMP to the stromal side (pigmented ciliary epithelium, PE) triggered a significant stimulation of Isc only at 100 μM. No additive effect was observed with bilateral application of cAMP. Likewise, forskolin caused a significant stimulation of Isc when applied to the aqueous side. Concomitantly, cAMP and forskolin increased fluid transport across porcine ciliary epithelium, and this stimulation was effectively inhibited by aqueous NFA. Depleting Cl- in the bathing solution abolished the baseline Isc and inhibited the subsequent stimulation by cAMP. Pretreatment with protein kinase A (PKA) blockers (H89/KT5720) significantly inhibited the cAMP- and forskolin-induced Isc responses. Our results suggest that cAMP triggers a sustained stimulation of Cl- and fluid transport across porcine ciliary epithelium; Cl- channels in the NPE cells are potentially a cellular site for this PKA-sensitive cAMP-mediated response.

Implementation of an integrated op-amp based chaotic neuron model and observation of its chaotic dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Jinwoo; Lee, Jewon; Song, Hanjung

2011-03-15

This paper presents a fully integrated circuit implementation of an operational amplifier (op-amp) based chaotic neuron model with a bipolar output function, experimental measurements, and analyses of its chaotic behavior. The proposed chaotic neuron model integrated circuit consists of several op-amps, sample and hold circuits, a nonlinear function block for chaotic signal generation, a clock generator, a nonlinear output function, etc. Based on the HSPICE (circuit program) simulation results, approximated empirical equations for analyses were formulated. Then, the chaotic dynamical responses such as bifurcation diagrams, time series, and Lyapunov exponent were calculated using these empirical equations. In addition, we performedmore » simulations about two chaotic neuron systems with four synapses to confirm neural network connections and got normal behavior of the chaotic neuron such as internal state bifurcation diagram according to the synaptic weight variation. The proposed circuit was fabricated using a 0.8-{mu}m single poly complementary metal-oxide semiconductor technology. Measurements of the fabricated single chaotic neuron with {+-}2.5 V power supplies and a 10 kHz sampling clock frequency were carried out and compared with the simulated results.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, T.; Jones, H.; Wong, K.

The Marshall Islands Environmental Characterization and Dose Assessment Program has recently implemented waste minimization measures to reduce low level radioactive (LLW) and low level mixed (LLWMIXED) waste streams at the Lawrence Livermore National Laboratory (LLNL). Several thousand environmental samples are collected annually from former US nuclear test sites in the Marshall Islands, and returned to LLNL for processing and radiometric analysis. In the past, we analyzed coconut milk directly by gamma-spectrometry after adding formaldehyde (as preservative) and sealing the fluid in metal cans. This procedure was not only tedious and time consuming but generated storage and waste disposal problems. Wemore » have now reduced the number of coconut milk samples required for analysis from 1500 per year to approximately 250, and developed a new analytical procedure which essentially eliminates the associated mixed radioactive waste stream. Coconut milk samples are mixed with a few grams of ammonium-molydophosphate (AMP) which quantitatively scavenges the target radionuclide cesium 137 in an ion-exchange process. The AMP is then separated from the mixture and sealed in a plastic container. The bulk sample material can be disposed of as a non- radioactive non-hazardous waste, and the relatively small amount of AMP conveniently counted by gamma-spectrometry, packaged and stored for future use.« less

Histone deacetylase 6 inhibition reduces cysts by decreasing cAMP and Ca2+ in knock-out mouse models of polycystic kidney disease.

PubMed

Yanda, Murali K; Liu, Qiangni; Cebotaru, Valeriu; Guggino, William B; Cebotaru, Liudmila

2017-10-27

Autosomal dominant polycystic kidney disease (ADPKD) is associated with progressive enlargement of multiple renal cysts, often leading to renal failure that cannot be prevented by a current treatment. Two proteins encoded by two genes are associated with ADPKD: PC1 ( pkd1 ), primarily a signaling molecule, and PC2 ( pkd2 ), a Ca 2+ channel. Dysregulation of cAMP signaling is central to ADPKD, but the molecular mechanism is unresolved. Here, we studied the role of histone deacetylase 6 (HDAC6) in regulating cyst growth to test the possibility that inhibiting HDAC6 might help manage ADPKD. Chemical inhibition of HDAC6 reduced cyst growth in PC1-knock-out mice. In proximal tubule-derived, PC1-knock-out cells, adenylyl cyclase 6 and 3 (AC6 and -3) are both expressed. AC6 protein expression was higher in cells lacking PC1, compared with control cells containing PC1. Intracellular Ca 2+ was higher in PC1-knock-out cells than in control cells. HDAC inhibition caused a drop in intracellular Ca 2+ and increased ATP-simulated Ca 2+ release. HDAC6 inhibition reduced the release of Ca 2+ from the endoplasmic reticulum induced by thapsigargin, an inhibitor of endoplasmic reticulum Ca 2+ -ATPase. HDAC6 inhibition and treatment of cells with the intracellular Ca 2+ chelator 1,2-bis(2-aminophenoxy)ethane- N , N , N ', N '-tetraacetic acid tetrakis(acetoxymethyl ester) reduced cAMP levels in PC1-knock-out cells. Finally, the calmodulin inhibitors W-7 and W-13 reduced cAMP levels, and W-7 reduced cyst growth, suggesting that AC3 is involved in cyst growth regulated by HDAC6. We conclude that HDAC6 inhibition reduces cell growth primarily by reducing intracellular cAMP and Ca 2+ levels. Our results provide potential therapeutic targets that may be useful as treatments for ADPKD. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Alternative Fuels Data Center: ampCNG Puts Conventional Fuels Out to

Science.gov Websites

; Steve Josephs, co-founder and director of engineering at ampCNG, Chicago, Illinois When ampCNG isn't the process. ampCNG's Cow-Powered Trucks ampCNG, a CNG station developer based in Chicago, Illinois interest in using more sustainable forms of fuel began in 2010, when the company partnered with Fair Oaks

Antimicrobial Peptides as Mediators of Innate Immunity in Teleosts

PubMed Central

Katzenback, Barbara A.

2015-01-01

Antimicrobial peptides (AMPs) have been identified throughout the metazoa suggesting their evolutionarily conserved nature and their presence in teleosts is no exception. AMPs are short (18–46 amino acids), usually cationic, amphipathic peptides. While AMPs are diverse in amino acid sequence, with no two AMPs being identical, they collectively appear to have conserved functions in the innate immunity of animals towards the pathogens they encounter in their environment. Fish AMPs are upregulated in response to pathogens and appear to have direct broad-spectrum antimicrobial activity towards both human and fish pathogens. However, an emerging role for AMPs as immunomodulatory molecules has become apparent—the ability of AMPs to activate the innate immune system sheds light onto the multifaceted capacity of these small peptides to combat pathogens through direct and indirect means. Herein, this review focuses on the role of teleost AMPs as modulators of the innate immune system and their regulation in response to pathogens or other exogenous molecules. The capacity to regulate AMP expression by exogenous factors may prove useful in modulating AMP expression in fish to prevent disease, particularly in aquaculture settings where crowded conditions and environmental stress pre-dispose these fish to infection. PMID:26426065

PKA and Epac synergistically inhibit smooth muscle cell proliferation

PubMed Central

Hewer, Richard C.; Sala-Newby, Graciela B.; Wu, Yih-Jer; Newby, Andrew C.; Bond, Mark

2011-01-01

Cyclic AMP signalling promotes VSMC quiescence in healthy vessels and during vascular healing following injury. Cyclic AMP inhibits VSMC proliferation via mechanisms that are not fully understood. We investigated the role of PKA and Epac signalling on cAMP-induced inhibition of VSMC proliferation. cAMP-mediated growth arrest was PKA-dependent. However, selective PKA activation with 6-Benzoyl-cAMP did not inhibit VSMC proliferation, indicating a requirement for additional pathways. Epac activation using the selective cAMP analogue 8-CPT-2′-O-Me-cAMP, did not affect levels of hyperphosphorylated Retinoblastoma (Rb) protein, a marker of G1-S phase transition, or BrdU incorporation, despite activation of the Epac-effector Rap1. However, 6-Benzoyl-cAMP and 8-CPT-2′-O-Me-cAMP acted synergistically to inhibit Rb-hyperphosphorylation and BrdU incorporation, indicating that both pathways are required for growth inhibition. Consistent with this, constitutively active Epac increased Rap1 activity and synergised with 6-Benzoyl-cAMP to inhibit VSMC proliferation. PKA and Epac synergised to inhibit phosphorylation of ERK and JNK. Induction of stellate morphology, previously associated with cAMP-mediated growth arrest, was also dependent on activation of both PKA and Epac. Rap1 inhibition with Rap1GAP or siRNA silencing did not negate forskolin-induced inhibition of Rb-hyperphosphorylation, BrdU incorporation or stellate morphology. This data demonstrates for the first time that Epac synergises with PKA via a Rap1-independent mechanism to mediate cAMP-induced growth arrest in VSMC. This work highlights the role of Epac as a major player in cAMP-dependent growth arrest in VSMC. PMID:20971121

Nephrogenous Cyclic Adenosine Monophosphate as a Parathyroid Function Test

PubMed Central

Broadus, Arthur E.; Mahaffey, Jane E.; Bartter, Frederic C.; Neer, Robert M.

1977-01-01

Nephrogenous cyclic AMP (NcAMP), total cyclic AMP excretion (UcAMP), and plasma immunoreactive parathyroid hormone (iPTH), determined with a multivalent antiserum, were prospectively measured in 55 control subjects, 57 patients with primary hyperparathyroidism (1°HPT), and 10 patients with chronic hypoparathyroidism. In the group with 1° HPT, NcAMP was elevated in 52 patients (91%), and similar elevations were noted in subgroups of 26 patients with mild (serum calcium ≤10.7 mg/dl) or intermittent hypercalcemia, 19 patients with mild renal insufficiency (mean glomerular filtration rate, 64 ml/min), and 10 patients with moderate renal insufficiency (mean glomerular filtration rate, 43 ml/min). Plasma iPTH was increased in 41 patients (73%). The development of a parametric expression for UcAMP was found to be critically important in the clinical interpretation of results for total cAMP excretion. Because of renal impairment in a large number of patients, the absolute excretion rate of cAMP correlated poorly with the hyperparathyroid state. Expressed as a function of creatinine excretion, UcAMP was elevated in 81% of patients with 1° HPT, but the nonparametric nature of the expression led to a number of interpretive difficulties. The expression of cAMP excretion as a function of glomerular filtration rate was developed on the basis of the unique features of cAMP clearance in man, and this expression, which provided elevated values in 51 (89%) of the patients with 1° HPT, avoided entirely the inadequacies of alternative expressions. Results for NcAMP and UcAMP in nonazotemic and azotemic patients with hypoparathyroidism confirmed the validity of the measurements and the expressions employed. PMID:197123

Cardiac Hypertrophy Is Inhibited by a Local Pool of cAMP Regulated by Phosphodiesterase 2.

PubMed

Zoccarato, Anna; Surdo, Nicoletta C; Aronsen, Jan M; Fields, Laura A; Mancuso, Luisa; Dodoni, Giuliano; Stangherlin, Alessandra; Livie, Craig; Jiang, He; Sin, Yuan Yan; Gesellchen, Frank; Terrin, Anna; Baillie, George S; Nicklin, Stuart A; Graham, Delyth; Szabo-Fresnais, Nicolas; Krall, Judith; Vandeput, Fabrice; Movsesian, Matthew; Furlan, Leonardo; Corsetti, Veronica; Hamilton, Graham; Lefkimmiatis, Konstantinos; Sjaastad, Ivar; Zaccolo, Manuela

2015-09-25

Chronic elevation of 3'-5'-cyclic adenosine monophosphate (cAMP) levels has been associated with cardiac remodeling and cardiac hypertrophy. However, enhancement of particular aspects of cAMP/protein kinase A signaling seems to be beneficial for the failing heart. cAMP is a pleiotropic second messenger with the ability to generate multiple functional outcomes in response to different extracellular stimuli with strict fidelity, a feature that relies on the spatial segregation of the cAMP pathway components in signaling microdomains. How individual cAMP microdomains affect cardiac pathophysiology remains largely to be established. The cAMP-degrading enzymes phosphodiesterases (PDEs) play a key role in shaping local changes in cAMP. Here we investigated the effect of specific inhibition of selected PDEs on cardiac myocyte hypertrophic growth. Using pharmacological and genetic manipulation of PDE activity, we found that the rise in cAMP resulting from inhibition of PDE3 and PDE4 induces hypertrophy, whereas increasing cAMP levels via PDE2 inhibition is antihypertrophic. By real-time imaging of cAMP levels in intact myocytes and selective displacement of protein kinase A isoforms, we demonstrate that the antihypertrophic effect of PDE2 inhibition involves the generation of a local pool of cAMP and activation of a protein kinase A type II subset, leading to phosphorylation of the nuclear factor of activated T cells. Different cAMP pools have opposing effects on cardiac myocyte cell size. PDE2 emerges as a novel key regulator of cardiac hypertrophy in vitro and in vivo, and its inhibition may have therapeutic applications. © 2015 American Heart Association, Inc.

Genotypic and Phenotypic Detection of AmpC β-lactamases in Enterobacter spp. Isolated from a Teaching Hospital in Malaysia.

PubMed

Mohd Khari, Fatin Izzati; Karunakaran, Rina; Rosli, Roshalina; Tee Tay, Sun

2016-01-01

The objective of this study was to determine the occurrence of chromosomal and plasmid-mediated β-lactamases (AmpC) genes in a collection of Malaysian isolates of Enterobacter species. Several phenotypic tests for detection of AmpC production of Enterobacter spp. were evaluated and the agreements between tests were determined. Antimicrobial susceptibility profiles for 117 Enterobacter clinical isolates obtained from the Medical Microbiology Diagnostic Laboratory, University Malaya Medical Centre, Malaysia, from November 2012-February 2014 were determined in accordance to CLSI guidelines. AmpC genes were detected using a multiplex PCR assay targeting the MIR/ACT gene (closely related to chromosomal EBC family gene) and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. The AmpC β-lactamase production of the isolates was assessed using cefoxitin disk screening test, D69C AmpC detection set, cefoxitin-cloxacillin double disk synergy test (CC-DDS) and AmpC induction test. Among the Enterobacter isolates in this study, 39.3% were resistant to cefotaxime and ceftriaxone and 23.9% were resistant to ceftazidime. Ten (8.5%) of the isolates were resistant to cefepime, and one isolate was resistant to meropenem. Chromosomal EBC family gene was amplified from 36 (47.4%) E. cloacae and three (25%) E. asburiae. A novel blaDHA type plasmid-mediated AmpC gene was identified for the first time from an E. cloacae isolate. AmpC β-lactamase production was detected in 99 (89.2%) of 111 potential AmpC β-lactamase producers (positive in cefoxitin disk screening) using D69C AmpC detection set. The detection rates were lower with CC-DDS (80.2%) and AmpC induction tests (50.5%). There was low agreement between the D69C AmpC detection set and the other two phenotypic tests. Of the 40 isolates with AmpC genes detected in this study, 87.5%, 77.5% and 50.0% of these isolates were positive by the D69C AmpC detection set, CC-DDS and AmpC induction tests, respectively. Besides MIR/ACT gene, a novel plasmid-mediated AmpC gene belonging to the DHA-type was identified in this study. Low agreement was noted between the D69C AmpC detection set and two other phenotypic tests for detection of AmpC production in Enterobacter spp. As plasmid-mediated genes may serve as the reservoir for the emergence of antibiotic resistance in a clinical setting, surveillance and infection control measures are necessary to limit the spread of these genes in the hospital.

Genotypic and Phenotypic Detection of AmpC β-lactamases in Enterobacter spp. Isolated from a Teaching Hospital in Malaysia

PubMed Central

Mohd Khari, Fatin Izzati; Karunakaran, Rina; Rosli, Roshalina; Tee Tay, Sun

2016-01-01

Objectives The objective of this study was to determine the occurrence of chromosomal and plasmid-mediated β-lactamases (AmpC) genes in a collection of Malaysian isolates of Enterobacter species. Several phenotypic tests for detection of AmpC production of Enterobacter spp. were evaluated and the agreements between tests were determined. Methods Antimicrobial susceptibility profiles for 117 Enterobacter clinical isolates obtained from the Medical Microbiology Diagnostic Laboratory, University Malaya Medical Centre, Malaysia, from November 2012—February 2014 were determined in accordance to CLSI guidelines. AmpC genes were detected using a multiplex PCR assay targeting the MIR/ACT gene (closely related to chromosomal EBC family gene) and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. The AmpC β-lactamase production of the isolates was assessed using cefoxitin disk screening test, D69C AmpC detection set, cefoxitin-cloxacillin double disk synergy test (CC-DDS) and AmpC induction test. Results Among the Enterobacter isolates in this study, 39.3% were resistant to cefotaxime and ceftriaxone and 23.9% were resistant to ceftazidime. Ten (8.5%) of the isolates were resistant to cefepime, and one isolate was resistant to meropenem. Chromosomal EBC family gene was amplified from 36 (47.4%) E. cloacae and three (25%) E. asburiae. A novel blaDHA type plasmid-mediated AmpC gene was identified for the first time from an E. cloacae isolate. AmpC β-lactamase production was detected in 99 (89.2%) of 111 potential AmpC β-lactamase producers (positive in cefoxitin disk screening) using D69C AmpC detection set. The detection rates were lower with CC-DDS (80.2%) and AmpC induction tests (50.5%). There was low agreement between the D69C AmpC detection set and the other two phenotypic tests. Of the 40 isolates with AmpC genes detected in this study, 87.5%, 77.5% and 50.0% of these isolates were positive by the D69C AmpC detection set, CC-DDS and AmpC induction tests, respectively. Conclusions Besides MIR/ACT gene, a novel plasmid-mediated AmpC gene belonging to the DHA-type was identified in this study. Low agreement was noted between the D69C AmpC detection set and two other phenotypic tests for detection of AmpC production in Enterobacter spp. As plasmid-mediated genes may serve as the reservoir for the emergence of antibiotic resistance in a clinical setting, surveillance and infection control measures are necessary to limit the spread of these genes in the hospital. PMID:26963619

Real-Time Monitoring and Evaluation of a Visual-Based Cervical Cancer Screening Program Using a Decision Support Job Aid.

PubMed

Peterson, Curtis W; Rose, Donny; Mink, Jonah; Levitz, David

2016-05-16

In many developing nations, cervical cancer screening is done by visual inspection with acetic acid (VIA). Monitoring and evaluation (M&E) of such screening programs is challenging. An enhanced visual assessment (EVA) system was developed to augment VIA procedures in low-resource settings. The EVA System consists of a mobile colposcope built around a smartphone, and an online image portal for storing and annotating images. A smartphone app is used to control the mobile colposcope, and upload pictures to the image portal. In this paper, a new app feature that documents clinical decisions using an integrated job aid was deployed in a cervical cancer screening camp in Kenya. Six organizations conducting VIA used the EVA System to screen 824 patients over the course of a week, and providers recorded their diagnoses and treatments in the application. Real-time aggregated statistics were broadcast on a public website. Screening organizations were able to assess the number of patients screened, alongside treatment rates, and the patients who tested positive and required treatment in real time, which allowed them to make adjustments as needed. The real-time M&E enabled by "smart" diagnostic medical devices holds promise for broader use in screening programs in low-resource settings.

Off-target effect of the Epac agonist 8-pCPT-2'-O-Me-cAMP on P2Y12 receptors in blood platelets.

PubMed

Herfindal, Lars; Nygaard, Gyrid; Kopperud, Reidun; Krakstad, Camilla; Døskeland, Stein Ove; Selheim, Frode

2013-08-09

The primary target of the cAMP analogue 8-pCPT-2'-O-Me-cAMP is exchange protein directly activated by cAMP (Epac). Here we tested potential off-target effects of the Epac activator on blood platelet activation signalling. We found that the Epac analogue 8-pCPT-2'-O-Me-cAMP inhibits agonist-induced-GPCR-stimulated, but not collagen-stimulated, P-selectin surface expression on Epac1 deficient platelets. In human platelets, 8-pCPT-2'-O-Me-cAMP inhibited P-selectin expression elicited by the PKC activator PMA. This effect was abolished in the presence of the extracellular ADP scavenger system CP/CPK. In silico modelling of 8-pCPT-2'O-Me-cAMP binding into the purinergic platelet receptor P2Y12 revealed that the analogue docks similar to the P2Y12 antagonist 2MeSAMP. The 8-pCPT-2'-O-Me-cAMP analogue per se, did not provoke Rap 1 (Rap 1-GTP) activation or phosphorylation on the vasodilator-stimulated phosphoprotein (VASP) at Ser-157. In addition, the protein kinase A (PKA) antagonists Rp-cAMPS and Rp-8-Br-cAMPS failed to block the inhibitory effect of 8-pCPT-2'-O-Me-cAMP on thrombin- and TRAP-induced Rap 1 activation, thus suggesting that PKA is not involved. We conclude that the 8-pCPT-2'-O-Me-cAMP analogue is able to inhibit agonist-induced-GPCR-stimulated P-selectin independent from Epac1; the off-target effect of the analogue appears to be mediated by antagonistic P2Y12 receptor binding. This has implications when using cAMP analogues on specialised system involving such receptors. We found, however that the Epac agonist 8-Br-2'-O-Me-cAMP did not affect platelet activation at similar concentrations. Copyright © 2013 Elsevier Inc. All rights reserved.

The pro-apoptotic protein Bim is a convergence point for cAMP/protein kinase A- and glucocorticoid-promoted apoptosis of lymphoid cells.

PubMed

Zhang, Lingzhi; Insel, Paul A

2004-05-14

The mechanisms by which cAMP mediates apoptosis are not well understood. In the current studies, we used wild-type (WT) S49 T-lymphoma cells and the kin(-) variant (which lacks protein kinase A (PKA)) to examine cAMP/PKA-mediated apoptosis. The cAMP analog, 8-CPT-cAMP, increased phosphorylation of the cAMP response element-binding protein (CREB), activated caspase-3, and induced apoptosis in WT but not in kin(-) S49 cells. Using an array of 96 apoptosis-related genes, we found that treatment of WT cells with 8-CPT-cAMP for 24 h induced expression of mRNA for the pro-apoptotic gene, Bim. Real-time PCR analysis indicated that 8-CPT-cAMP increased Bim RNA in WT cells in <2 h and maintained this increase for >24 h. Bim protein expression increased in WT but not kin(-) cells treated with 8-CPT-cAMP or with the beta-adrenergic receptor agonist isoproterenol. Both apoptosis and Bim expression were reversible with removal of 8-CPT-cAMP after <6 h. The glucocorticoid dexamethasone also promoted apoptosis and Bim expression in S49 cells. In contrast, both UV light and anti-mouse Fas monoclonal antibody promoted apoptosis in S49 cells but did not induce Bim expression. 8-CPT-cAMP also induced Bim expression and enhanced dexamethasone-promoted apoptosis in human T-cell leukemia CEM-C7-14 (glucocorticoid-sensitive) and CEM-C1-15 (glucocorticoid-resistant) cells; increased Bim expression in 8-CPT-cAMP-treated CEM-C1-15 cells correlated with conversion of the cells from resistance to sensitivity to glucocorticoid-promoted apoptosis. Induction of Bim appears to be a key event in cAMP-promoted apoptosis in both murine and human T-cell lymphoma and leukemia cells and thus appears to be a convergence point for the killing of such cells by glucocorticoids and agents that elevate cAMP.

Effects of adenosine 5'-monophosphate on epidermal turnover.

PubMed

Furukawa, Fukumi; Kanehara, Shoko; Harano, Fumiki; Shinohara, Shigeo; Kamimura, Junko; Kawabata, Shigekatsu; Igarashi, Sachiyo; Kawamura, Mitsuaki; Yamamoto, Yuki; Miyachi, Yoshiki

2008-10-01

The structure and function of the epidermis is maintained by cell renewal based on epidermal turnover. Epidermal turnover is delayed by aging, and it is thought that the delay of the epidermal turnover is a cause of aging alternation of skin. The epidermal turnover is related to the energy metabolism of epidermal basal cells. Adenosine 5'-triphosphate (ATP) is needed for cell renewal: cell division, and adenosine 5'-monophosphate (AMP) increases the amount of intracellular ATP. These findings suggest that AMP accelerates the epidermal turnover delayed by aging. This study investigated whether AMP and adenosine 5'-monophosphate disodium salt (AMP2Na) accelerates the epidermal turnover. An effect of AMP2Na on cell proliferation was examined by our counting of keratinocytes. An effect of AMP2Na on cell cycle was examined by our counting of basal cells in DNA synthetic period of hairless rats. The effects of AMP2Na (or AMP) on the epidermal turnover were examined by our measuring stratum corneum transit time by use of guinea pigs, and by our measuring stratum corneum surface area by use of hairless rats and in a clinical pharmacological study. The AMP2Na showed two different profiles on the proliferation of primary cultured keratinocytes. At a low concentration it induced cell growth, whereas at a high concentration it inhibited cell growth. The number of basal cells in the DNA synthetic period of AMP2Na was significantly higher than that of the vehicle in hairless rats. The stratum corneum transit time of AMP2Na was significantly shorter than that of the vehicle in guinea pigs. The corneocyte surface area of emulsion containing AMP2Na was significantly smaller than that of the vehicle in volunteers. We conclude that AMP promotes the cell proliferation and the cell cycle progression of epidermal basal cells and accelerates epidermal turnover safely. In addition, AMP is useful for skin rejuvenation in dermatology and aesthetic dermatology.

Distinct pools of cAMP centre on different isoforms of adenylyl cyclase in pituitary-derived GH3B6 cells.

PubMed

Wachten, Sebastian; Masada, Nanako; Ayling, Laura-Jo; Ciruela, Antonio; Nikolaev, Viacheslav O; Lohse, Martin J; Cooper, Dermot M F

2010-01-01

Microdomains have been proposed to explain specificity in the myriad of possible cellular targets of cAMP. Local differences in cAMP levels can be generated by phosphodiesterases, which control the diffusion of cAMP. Here, we address the possibility that adenylyl cyclases, the source of cAMP, can be primary architects of such microdomains. Distinctly regulated adenylyl cyclases often contribute to total cAMP levels in endogenous cellular settings, making it virtually impossible to determine the contribution of a specific isoform. To investigate cAMP dynamics with high precision at the single-isoform level, we developed a targeted version of Epac2-camps, a cAMP sensor, in which the sensor was tagged to a catalytically inactive version of the Ca(2+)-stimulable adenylyl cyclase 8 (AC8). This sensor, and less stringently targeted versions of Epac2-camps, revealed opposite regulation of cAMP synthesis in response to Ca(2+) in GH(3)B(6) pituitary cells. Ca(2+) release triggered by thyrotropin-releasing hormone stimulated the minor endogenous AC8 species. cAMP levels were decreased by inhibition of AC5 and AC6, and simultaneous activation of phosphodiesterases, in different compartments of the same cell. These findings demonstrate the existence of distinct adenylyl-cyclase-centered cAMP microdomains in live cells and open the door to their molecular micro-dissection.

The Frog Skin-Derived Antimicrobial Peptide Esculentin-1a(1-21)NH2 Promotes the Migration of Human HaCaT Keratinocytes in an EGF Receptor-Dependent Manner: A Novel Promoter of Human Skin Wound Healing?

PubMed

Di Grazia, Antonio; Cappiello, Floriana; Imanishi, Akiko; Mastrofrancesco, Arianna; Picardo, Mauro; Paus, Ralf; Mangoni, Maria Luisa

2015-01-01

One of the many functions of skin is to protect the organism against a wide range of pathogens. Antimicrobial peptides (AMPs) produced by the skin epithelium provide an effective chemical shield against microbial pathogens. However, whereas antibacterial/antifungal activities of AMPs have been extensively characterized, much less is known regarding their wound healing-modulatory properties. By using an in vitro re-epithelialisation assay employing special cell-culture inserts, we detected that a derivative of the frog-skin AMP esculentin-1a, named esculentin-1a(1-21)NH2, significantly stimulates migration of immortalized human keratinocytes (HaCaT cells) over a wide range of peptide concentrations (0.025-4 μM), and this notably more efficiently than human cathelicidin (LL-37). This activity is preserved in primary human epidermal keratinocytes. By using appropriate inhibitors and an enzyme-linked immunosorbent assay we found that the peptide-induced cell migration involves activation of the epidermal growth factor receptor and STAT3 protein. These results suggest that esculentin-1a(1-21)NH2 now deserves to be tested in standard wound healing assays as a novel candidate promoter of skin re-epithelialisation. The established ability of esculentin-1a(1-21)NH2 to kill microbes without harming mammalian cells, namely its high anti-Pseudomonal activity, makes this AMP a particularly attractive candidate wound healing promoter, especially in the management of chronic, often Pseudomonas-infected, skin ulcers.

Evolutionary plasticity of insect immunity.

PubMed

Vilcinskas, Andreas

2013-02-01

Many insect genomes have been sequenced and the innate immune responses of several species have been studied by transcriptomics, inviting the comparative analysis of immunity-related genes. Such studies have demonstrated significant evolutionary plasticity, with the emergence of novel proteins and protein domains correlated with insects adapting to both abiotic and biotic environmental stresses. This review article focuses on effector molecules such as antimicrobial peptides (AMPs) and proteinase inhibitors, which display greater evolutionary dynamism than conserved components such as immunity-related signaling molecules. There is increasing evidence to support an extended role for insect AMPs beyond defense against pathogens, including the management of beneficial endosymbionts. The total number of AMPs varies among insects with completed genome sequences, providing intriguing examples of immunity gene expansion and loss. This plasticity is discussed in the context of recent developments in evolutionary ecology suggesting that the maintenance and deployment of immune responses reallocates resources from other fitness-related traits thus requiring fitness trade-offs. Based on our recent studies using both model and non-model insects, I propose that insect immunity genes can be lost when alternative defense strategies with a lower fitness penalty have evolved, such as the so-called social immunity in bees, the chemical sanitation of the microenvironment by some beetles, and the release of antimicrobial secondary metabolites in the hemolymph. Conversely, recent studies provide evidence for the expansion and functional diversification of insect AMPs and proteinase inhibitors to reflect coevolution with a changing pathosphere and/or adaptations to habitats or food associated with microbial contamination. Copyright © 2012 Elsevier Ltd. All rights reserved.

77 FR 14446 - Changes to the Generic Aging Lessons Learned (GALL) Report Revision 2 AMP XI.M41, “Buried and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-09

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0055] Changes to the Generic Aging Lessons Learned (GALL... Aging Lessons Learned (GALL) Report,'' and the NRC staff's aging management review procedure and... into ADAMS. II. Background The NRC issues LR-ISGs to communicate insights and lessons learned and to...

A Phenomenological Study of Autonomous Management Performance Schools (AMPS) in the Chicago Public Schools

ERIC Educational Resources Information Center

Moore, Forrest W.

2009-01-01

The primary objective of this qualitative study is to explore the impact of autonomy on the relationship between schools and districts of the school level across governance, operations, curriculum and instruction and the decision making that accompanies the each of these factors. More specifically, this study focuses the impact of autonomy within…

Planning Complex Projects Automatically

NASA Technical Reports Server (NTRS)

Henke, Andrea L.; Stottler, Richard H.; Maher, Timothy P.

1995-01-01

Automated Manifest Planner (AMP) computer program applies combination of artificial-intelligence techniques to assist both expert and novice planners, reducing planning time by orders of magnitude. Gives planners flexibility to modify plans and constraints easily, without need for programming expertise. Developed specifically for planning space shuttle missions 5 to 10 years ahead, with modifications, applicable in general to planning other complex projects requiring scheduling of activities depending on other activities and/or timely allocation of resources. Adaptable to variety of complex scheduling problems in manufacturing, transportation, business, architecture, and construction.

Recent Advances in the Development of Antimicrobial Peptides (AMPs): Attempts for Sustainable Medicine?

PubMed

Kokel, Anne; Torok, Marianna

2018-01-17

Since the first isolation of antimicrobial peptides (AMPs) they have attracted extensive interest in medicinal chemistry. However, only a few AMP-based drugs are currently available on the market. Despite their effectiveness, biodegradability, and versatile mode of action that is less likely to induce resistance compared to conventional antibiotics, AMPs suffer from major issues that need to be addressed to broaden their use. Notably, AMPs can lack selectivity leading to side effects and cytotoxicity, and also exhibit in vivo instability. Several strategies are being actively considered to overcome the limitations that restrain the success of AMPs. In the current work, recent strategies reported for improving AMPs in the context of drug design and delivery were surveyed, and also their possible impact on patients and the environment was assessed. As a major advantage AMPs possess an easily tunable skeleton offering opportunities to improve their properties. Strategic structural modifications and the beneficial properties of cyclic or branched AMPs in term of stability have been reported. The conjugation of AMPs with nanoparticles has also been explored to increase their in vivo stability. Other techniques such as the coupling of AMPs with specific antibodies aim to increase the selectivity of the potential drug towards the target. These strategies were evaluated for their effect on the environment highlighting green technologies. Although further research is needed taking into account both environmental and human health consequences of novel AMPs several of these compounds are promising drug candidates for use in sustainable medicine. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Actions of cAMP on calcium sensitization in human detrusor smooth muscle contraction.

PubMed

Hayashi, Maya; Kajioka, Shunichi; Itsumi, Momoe; Takahashi, Ryosuke; Shahab, Nouval; Ishigami, Takao; Takeda, Masahiro; Masuda, Noriyuki; Yamaguchi, Akito; Naito, Seiji

2016-01-01

To clarify the effect of cAMP on the Ca(2+) -sensitized smooth muscle contraction in human detrusor, as well as the role of novel exchange protein directly activated by cAMP (Epac) in cAMP-mediated relaxation. All experimental protocols to record isometric tension force were performed using α-toxin-permeabilized human detrusor smooth muscle strips. The mechanisms of cAMP-mediated suppression of Ca(2+) sensitization activated by 10 μm carbachol (CCh) and 100 μm GTP were studied using a selective rho kinase (ROK) inhibitor, Y-27632, and a selective protein kinase C (PKC) inhibitor, GF-109203X. The relaxation mechanisms were further probed using a selective protein kinase A (PKA) activator, 6-Bnz-cAMP and a selective Epac activator, 8-pCPT-2'-O-Me-cAMP. We observed that CCh-induced Ca(2+) sensitization was inhibited by cAMP in a concentration-dependent manner. GF-109203X (10 μm) but not Y-27632 (10 μm) significantly enhanced the relaxation effect induced by cAMP (100 μm). 6-Bnz-cAMP (100 μm) predominantly decreased the tension force in comparison with 8-pCPT-2'-O-Me-cAMP (100 μm). We showed that cAMP predominantly inhibited the ROK pathway but not the PKC pathway. The PKA-dependent pathway is dominant, while Epac plays a minor role in human detrusor smooth muscle Ca(2+) sensitization. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

AMP sensing by DEAD-box RNA helicases

PubMed Central

Putnam, Andrea A.; Jankowsky, Eckhard

2013-01-01

In eukaryotes, cellular levels of adenosine monophosphate (AMP) signal the metabolic state of the cell. AMP concentrations increase significantly upon metabolic stress, such as glucose deprivation in yeast. Here we show that several DEAD-box RNA helicases are sensitive to AMP, which is not produced during ATP hydrolysis by these enzymes. We find that AMP potently inhibits RNA binding and unwinding by the yeast DEAD-box helicases Ded1p, Mss116p, and eIF4A. However, the yeast DEAD-box helicases Sub2p and Dbp5p are not inhibited by AMP. Our observations identify a subset of DEAD-box helicases as enzymes with the capacity to directly link changes in AMP concentrations to RNA metabolism. PMID:23702290

AMP sensing by DEAD-box RNA helicases.

PubMed

Putnam, Andrea A; Jankowsky, Eckhard

2013-10-23

In eukaryotes, cellular levels of adenosine monophosphate (AMP) signal the metabolic state of the cell. AMP concentrations increase significantly upon metabolic stress, such as glucose deprivation in yeast. Here, we show that several DEAD-box RNA helicases are sensitive to AMP, which is not produced during ATP hydrolysis by these enzymes. We find that AMP potently inhibits RNA binding and unwinding by the yeast DEAD-box helicases Ded1p, Mss116p, and eIF4A. However, the yeast DEAD-box helicases Sub2p and Dbp5p are not inhibited by AMP. Our observations identify a subset of DEAD-box helicases as enzymes with the capacity to directly link changes in AMP concentrations to RNA metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reciprocal regulation of insulin and plasma 5'-AMP in glucose homeostasis in mice.

PubMed

Xia, Lin; Wang, Zhongqiu; Zhang, Ying; Yang, Xiao; Zhan, Yibei; Cheng, Rui; Wang, Shiming; Zhang, Jianfa

2015-03-01

A previous investigation has demonstrated that plasma 5'-AMP (pAMP) exacerbates and causes hyperglycemia in diabetic mice. However, the crosstalk between pAMP and insulin signaling to regulate glucose homeostasis has not been investigated in depth. In this study, we showed that the blood glucose level was more dependent on the ratio of insulin to pAMP than on the absolute level of these two factors. Administration of 5'-AMP significantly attenuated the insulin-stimulated insulin receptor (IR) autophosphorylation in the liver and muscle tissues, resulting in the inhibition of downstream AKT phosphorylation. A docking analysis indicated that adenosine was a potential inhibitor of IR tyrosine kinase. Moreover, the 5'-AMP treatment elevated the ATP level in the pancreas and in the isolated islets, stimulating insulin secretion and increasing the plasma level of insulin. The insulin administration decreased the 5'-AMP-induced hyper-adenosine level by the up-regulation of adenosine kinase activities. Our results indicate that blood glucose homeostasis is reciprocally regulated by pAMP and insulin. © 2015 Society for Endocrinology.

Mechanism of bacterial membrane poration by Antimicrobial Peptides

NASA Astrophysics Data System (ADS)

Arora, Ankita; Mishra, Abhijit

2015-03-01

Bacterial resistance to conventional antibiotics is a major health concern. Antimicrobial peptides (AMPs), an important component of mammalian immune system, are thought to utilize non-specific interactions to target common features on the outer membranes of pathogens; hence development of resistance to such AMPs may be less pronounced. Most AMPs are amphiphilic and cationic in nature. Most AMPs form pores in the bacterial membranes causing them to lyse, however, the exact mechanism is unknown. Here, we study the AMP CHRG01 (KSSTRGRKSSRRKK), derived from human β defensin 3 (hBD3) with all Cysteine residues substituted with Serine. Circular Dichorism studies indicate that CHRG01 shows helicity and there is change in helicity as it interacts with the lipid membrane. The AMP was effective against different species of bacteria. Leakage of cellular components from bacterial cells observed by SEM and AFM indicates AMP action by pore formation. Confocal microscopy studies on giant vesicles incubated with AMP confirm poration. The effect of this AMP on model bacterial membranes is characterized using Small Angle X-ray scattering and Fluorescence spectroscopy to elucidate the mechanism behind antimicrobial activity.

cAMP is an essential signal in the induction of antibody production by B cells but inhibits helper function of T cells.

PubMed

Gilbert, K M; Hoffmann, M K

1985-09-01

Dibutyryl cAMP and IL 1 were found to stimulate antigen-specific and polyclonal antibody production when added together to cultures of highly purified B cells. We propose that IL 1 and an elevation in cytoplasmic cAMP represent minimal signal requirements for B cell activation. In contrast to its effect on B cells, dibutyryl cAMP inhibited helper T cell activity. Cyclic AMP suppressed the production of IL 2 and T cell replacing factor (TRF) by T cells and thus abrogated the ability of helper T cells to enhance SRBC-specific antibody production by B cells. Cyclic AMP did not inhibit the generation by T cells of B cell growth factor (BCGF). BCGF, not normally detected in Con A supernatant, was found in the culture supernatant of spleen cells that were stimulated with Con A in the presence of cAMP. Our findings indicate that cAMP blocks the production of an inhibitor of BCGF activity. cAMP had no effect on the production by macrophages of IL 1.

A simple electrostatic switch important in the activation of type I protein kinase A by cyclic AMP.

PubMed

Vigil, Dominico; Lin, Jung-Hsin; Sotriffer, Christoph A; Pennypacker, Juniper K; McCammon, J Andrew; Taylor, Susan S

2006-01-01

Cyclic AMP activates protein kinase A by binding to an inhibitory regulatory (R) subunit and releasing inhibition of the catalytic (C) subunit. Even though crystal structures of regulatory and catalytic subunits have been solved, the precise molecular mechanism by which cyclic AMP activates the kinase remains unknown. The dynamic properties of the cAMP binding domain in the absence of cAMP or C-subunit are also unknown. Here we report molecular-dynamics simulations and mutational studies of the RIalpha R-subunit that identify the C-helix as a highly dynamic switch which relays cAMP binding to the helical C-subunit binding regions. Furthermore, we identify an important salt bridge which links cAMP binding directly to the C-helix that is necessary for normal activation. Additional mutations show that a hydrophobic "hinge" region is not as critical for the cross-talk in PKA as it is in the homologous EPAC protein, illustrating how cAMP can control diverse functions using the evolutionarily conserved cAMP-binding domains.

Preparation and evaluation of effect on Escherichia coli and Staphylococcus aureus of radiolabeled ampicillin-loaded graphene oxide nanoflakes.

PubMed

Yurt, Fatma; Ersöz, Onur Alp; Harputlu, Ersan; Ocakoglu, Kasim

2018-06-01

Ampicillin is a one of effective antibiotics against Gram-positive and Gram-negative bacteria. This study aimed to label ampicillin-loaded graphene oxide nanoflake (AMP-GO) with 99m Tc and evaluate of its in vitro binding to Staphylococcus aureus and Escherichia coli. Firstly, ampicillin was loaded into graphene oxide nanoflake prepared. AMP-GO was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques, and the amount of loaded ampicillin onto GO was determined by UV-Vis absorption spectroscopy. AMP and AMP-GO were labeled with 99m Tc using stannous chloride reducing agent. Labeling efficiency of 99m Tc-AMP-GO was found to be 97.66 ± 2.06%. 99m Tc-AMP-GO has higher binding efficiencies to both S. aureus and E. coli than 99m Tc-AMP. 99m Tc-AMP-GO could be promising candidate as agent infection nuclear imaging. Furthermore, in vivo studies of 99m Tc-AMP-GO with infected rats are planned to be performed. © 2018 John Wiley & Sons A/S.

Structural basis for the mutual antagonism of cAMP and TRIP8b in regulating HCN channel function

PubMed Central

Saponaro, Andrea; Pauleta, Sofia R.; Cantini, Francesca; Matzapetakis, Manolis; Hammann, Christian; Donadoni, Chiara; Hu, Lei; Thiel, Gerhard; Banci, Lucia; Santoro, Bina; Moroni, Anna

2014-01-01

cAMP signaling in the brain mediates several higher order neural processes. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels directly bind cAMP through their cytoplasmic cyclic nucleotide binding domain (CNBD), thus playing a unique role in brain function. Neuronal HCN channels are also regulated by tetratricopeptide repeat-containing Rab8b interacting protein (TRIP8b), an auxiliary subunit that antagonizes the effects of cAMP by interacting with the channel CNBD. To unravel the molecular mechanisms underlying the dual regulation of HCN channel activity by cAMP/TRIP8b, we determined the NMR solution structure of the HCN2 channel CNBD in the cAMP-free form and mapped on it the TRIP8b interaction site. We reconstruct here the full conformational changes induced by cAMP binding to the HCN channel CNBD. Our results show that TRIP8b does not compete with cAMP for the same binding region; rather, it exerts its inhibitory action through an allosteric mechanism, preventing the cAMP-induced conformational changes in the HCN channel CNBD. PMID:25197093

The therapeutic applications of antimicrobial peptides (AMPs): a patent review.

PubMed

Kang, Hee-Kyoung; Kim, Cheolmin; Seo, Chang Ho; Park, Yoonkyung

2017-01-01

Antimicrobial peptides (AMPs) are small molecules with a broad spectrum of antibiotic activities against bacteria, yeasts, fungi, and viruses and cytotoxic activity on cancer cells, in addition to anti-inflammatory and immunomodulatory activities. Therefore, AMPs have garnered interest as novel therapeutic agents. Because of the rapid increase in drug-resistant pathogenic microorganisms, AMPs from synthetic and natural sources have been developed using alternative antimicrobial strategies. This article presents a broad analysis of patents referring to the therapeutic applications of AMPs since 2009. The review focuses on the universal trends in the effective design, mechanism, and biological evolution of AMPs.

Will new generations of modified antimicrobial peptides improve their potential as pharmaceuticals?

PubMed Central

Brogden, Nicole K.; Brogden, Kim A.

2011-01-01

The concept of antimicrobial peptides (AMPs) as potent pharmaceuticals is firmly established in the literature, and most research articles on this topic conclude by stating that AMPs represent promising therapeutic agents against bacterial and fungal agents. Indeed, early research in this field showed that AMPs were diverse in nature, had high activities with low minimal inhibitory concentrations, had broad spectrums of activity against bacterial, fungal and viral pathogens, and could easily be manipulated to alter their specificities, reduce their cytotoxicities and increase their antimicrobial activities. Unfortunately, commercial development of these peptides, for even the simplest of applications, has been very limited. With some peptides there are obstacles with their manufacture, in vivo efficacy and in vivo retention. More recently, the focus has shifted. Contemporary research now uses a more sophisticated approach to develop AMPs that surmount many of these prior obstacles. AMP mimetics, hybrid AMPs, AMP congeners, cyclotides and stabilised AMPs, AMP conjugates and immobilised AMPs have all emerged with selective or ‘targeted’ antimicrobial activities, improved retention, or unique abilities that allow them to bind to medical or industrial surfaces. These groups of new peptides have creative medical and industrial application potentials to treat antibiotic-resistant bacterial infections and septic shock, to preserve food or to sanitise surfaces both in vitro and in vivo. PMID:21733662

Antimicrobial Peptides from Plants

PubMed Central

Tam, James P.; Wang, Shujing; Wong, Ka H.; Tan, Wei Liang

2015-01-01

Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

Synthesis and Release of Cyclic Adenosine 3′:5′-Monophosphate by Ochromonas malhamensis1

PubMed Central

Bressan, Ray A.; Handa, Avtar K.; Quader, Hartmut; Filner, Philip

1980-01-01

The chrysophycean alga, Ochromonas malhamensis Pringsheim, was shown to synthesize cyclic adenosine 3′:5′-monophosphate (cAMP) and to release it into the culture medium. Cells contained 3 to 3,000 picomoles per gram fresh weight; medium contained up to 20 times the amount in the cells. Putative [32P]cAMP was purified from cultures supplied [32P]phosphate. The compound was identified as [32P]cAMP by co-chromatography with authentic cAMP through 10 serial steps; by chemical deamination at the same rate as authentic cAMP, to a 32P compound with the chromatographic behavior of cIMP; and by its conversion through the action of cyclic nucleotide phosphodiesterase to a 32P compound with the chromatographic behavior of 5′-AMP. A two-step procedure involving chromatography on alumina and on Dowex 50 purified the unlabeled compound from cells or medium sufficiently for it to be assayable by competitive inhibition of binding of [3H]cAMP to cAMP-binding protein (Gilman assay) or by stimulation of cAMP-dependent protein kinase. The activity was destroyed by cyclic nucleotide phosphodiesterase with the same kinetics as authentic cAMP, provided that an endogenous inhibitor of the phosphodiesterase was first removed by an additional purification step. Images PMID:16661154

Phenotypic detection of broad-spectrum beta-lactamases in microbiological practice.

PubMed

Htoutou Sedlakova, Miroslava; Hanulik, Vojtech; Chroma, Magdalena; Hricova, Kristyna; Kolar, Milan; Latal, Tomas; Schaumann, Reiner; Rodloff, Arne C

2011-05-01

Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. A total of 106 strains of the Enterobacteriaceae family were tested, in which molecular biology methods confirmed the presence of genes encoding ESBL or AmpC. In ESBL-positive strains, the sensitivity of the ESBL Etest (AB Biodisk) and a modified double-disk synergy test (DDST) were evaluated. AmpC strains were tested by a modified AmpC disk method using 3-aminophenylboronic acid. For simultaneous detection of ESBL and AmpC, the microdilution method with a modified set of antimicrobial agents was used. The sensitivity of the ESBL Etest was 95%; the modified DDST yielded 100% sensitivity for ESBL producers and the AmpC test correctly detected 95% of AmpC-positive strains. The sensitivity of the modified microdilution method was 87% and 95% for ESBL and AmpC beta lactamases, respectively. The detection of ESBL and AmpC beta lactamases should be based on specific phenotypic methods such as the modified DDST, ESBL Etest, AmpC disk test and the modified microdilution method.

Phenotypic detection of broad-spectrum beta-lactamases in microbiological practice

PubMed Central

Sedlakova, Miroslava Htoutou; Hanulik, Vojtech; Chroma, Magdalena; Hricova, Kristyna; Kolar, Milan; Latal, Tomas; Schaumann, Reiner; Rodloff, Arne C.

2011-01-01

Summary Background Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. Material/Methods A total of 106 strains of the Enterobacteriaceae family were tested, in which molecular biology methods confirmed the presence of genes encoding ESBL or AmpC. In ESBL-positive strains, the sensitivity of the ESBL Etest (AB Biodisk) and a modified double-disk synergy test (DDST) were evaluated. AmpC strains were tested by a modified AmpC disk method using 3-aminophenylboronic acid. For simultaneous detection of ESBL and AmpC, the microdilution method with a modified set of antimicrobial agents was used. Results The sensitivity of the ESBL Etest was 95%; the modified DDST yielded 100% sensitivity for ESBL producers and the AmpC test correctly detected 95% of AmpC-positive strains. The sensitivity of the modified microdilution method was 87% and 95% for ESBL and AmpC beta lactamases, respectively. Conclusions The detection of ESBL and AmpC beta lactamases should be based on specific phenotypic methods such as the modified DDST, ESBL Etest, AmpC disk test and the modified microdilution method. PMID:21525803

cAMP inhibits inducible nitric oxide synthase expression and NF-kappaB-binding activity in cultured rat hepatocytes.

PubMed

Harbrecht, B G; Taylor, B S; Xu, Z; Ramalakshmi, S; Ganster, R W; Geller, D A

2001-08-01

The inducible nitric oxide synthase (iNOS) is strongly expressed following inflammatory stimuli. Adenosine 3',5'-cyclic monophosphate (cAMP) increases iNOS expression and activity in a number of cell types but decreases cytokine-stimulated iNOS expression in hepatocytes. The mechanisms for this effect are unknown. Rat hepatocytes were stimulated with cytokines to induce iNOS and cultured with cAMP agonists dibutyryl-cAMP (dbcAMP), 8-bromo-cAMP, and forskolin (FSK). Nitric oxide synthesis was assessed by supernatant nitrite levels and iNOS expression was measured by Northern and Western blot analyses. Nuclear factor kappaB binding was assessed by electromobility shift assay. Cyclic AMP dose dependently decreased NO synthesis in response to a combination of proinflammatory cytokines or interleukin-1beta (IL-1beta) alone. The adenylate cyclase inhibitor SQ 22,536 increased cytokine- or IL-1beta-stimulated NO synthesis. dbcAMP decreased iNOS mRNA expression and iNOS protein expression. Both dbcAMP and glucagon decreased iNOS promoter activity in rat hepatocytes transfected with the murine iNOS promoter and decreased DNA binding of the transcription factor NF-kappaB. These data suggest that cAMP is important in hepatocyte iNOS expression and agents that alter cAMP levels may profoundly alter the response of hepatocytes to inflammatory stimuli through effects onthe iNOS promoter region and NF-kappaB. Copyright 2001 Academic Press.

Nitric oxide mediates antimicrobial peptide gene expression by activating eicosanoid signaling

PubMed Central

Sadekuzzaman, Md.

2018-01-01

Nitric oxide (NO) mediates both cellular and humoral immune responses in insects. Its mediation of cellular immune responses uses eicosanoids as a downstream signal. However, the cross-talk with two immune mediators was not known in humoral immune responses. This study focuses on cross-talk between two immune mediators in inducing gene expression of anti-microbial peptides (AMPs) of a lepidopteran insect, Spodoptera exigua. Up-regulation of eight AMPs was observed in S. exigua against bacterial challenge. However, the AMP induction was suppressed by injection of an NO synthase inhibitor, L-NAME, while little expressional change was observed on injecting its enantiomer, D-NAME. The functional association between NO biosynthesis and AMP gene expression was further supported by RNA interference (RNAi) against NO synthase (SeNOS), which suppressed AMP gene expression under the immune challenge. The AMP induction was also mimicked by NO alone because injecting an NO analog, SNAP, without bacterial challenge significantly induced the AMP gene expression. Interestingly, an eicosanoid biosynthesis inhibitor, dexamethasone (DEX), suppressed the NO induction of AMP expression. The inhibitory activity of DEX was reversed by the addition of arachidonic acid, a precursor of eicosanoid biosynthesis. AMP expression of S. exigua was also controlled by the Toll/IMD signal pathway. The RNAi of Toll receptors or Relish suppressed AMP gene expression by suppressing NO levels and subsequently reducing PLA2 enzyme activity. These results suggest that eicosanoids are a downstream signal of NO mediation of AMP expression against bacterial challenge. PMID:29466449

Pulse charging of lead-acid traction cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1980-01-01

Pulse charging, as a method of rapidly and efficiently charging 300 amp-hour lead-acid traction cells for an electric vehicle application was investigated. A wide range of charge pulse current square waveforms were investigated and the results were compared to constant current charging at the time averaged pulse current values. Representative pulse current waveforms were: (1) positive waveform-peak charge pulse current of 300 amperes (amps), discharge pulse-current of zero amps, and a duty cycle of about 50%; (2) Romanov waveform-peak charge pulse current of 300 amps, peak discharge pulse current of 15 amps, and a duty of 50%; and (3) McCulloch waveform peak charge pulse current of 193 amps, peak discharge pulse current of about 575 amps, and a duty cycle of 94%. Experimental results indicate that on the basis of amp-hour efficiency, pulse charging offered no significant advantage as a method of rapidly charging 300 amp-hour lead-acid traction cells when compared to constant current charging at the time average pulse current value. There were, however, some disadvantages of pulse charging in particular a decrease in charge amp-hour and energy efficiencies and an increase in cell electrolyte temperature. The constant current charge method resulted in the best energy efficiency with no significant sacrifice of charge time or amp-hour output. Whether or not pulse charging offers an advantage over constant current charging with regard to the cell charge/discharge cycle life is unknown at this time.

Mycobacterium tuberculosis cAMP Receptor Protein (Rv3676) Differs from the Escherichia coli Paradigm in Its cAMP Binding and DNA Binding Properties and Transcription Activation Properties*

PubMed Central

Stapleton, Melanie; Haq, Ihtshamul; Hunt, Debbie M.; Arnvig, Kristine B.; Artymiuk, Peter J.; Buxton, Roger S.; Green, Jeffrey

2010-01-01

The pathogen Mycobacterium tuberculosis produces a burst of cAMP upon infection of macrophages. Bacterial cyclic AMP receptor proteins (CRP) are transcription factors that respond to cAMP by binding at target promoters when cAMP concentrations increase. Rv3676 (CRPMt) is a CRP family protein that regulates expression of genes (rpfA and whiB1) that are potentially involved in M. tuberculosis persistence and/or emergence from the dormant state. Here, the CRPMt homodimer is shown to bind two molecules of cAMP (one per protomer) at noninteracting sites. Furthermore, cAMP binding by CRPMt was relatively weak, entropy driven, and resulted in a relatively small enhancement in DNA binding. Tandem CRPMt-binding sites (CRP1 at −58.5 and CRP2 at −37.5) were identified at the whiB1 promoter (PwhiB1). In vitro transcription reactions showed that CRP1 is an activating site and that CRP2, which was only occupied in the presence of cAMP or at high CRPMt concentrations in the absence of cAMP, is a repressing site. Binding of CRPMt to CRP1 was not essential for open complex formation but was required for transcription activation. Thus, these data suggest that binding of CRPMt to the PwhiB1 CRP1 site activates transcription at a step after open complex formation. In contrast, high cAMP concentrations allowed occupation of both CRP1 and CRP2 sites, resulting in inhibition of open complex formation. Thus, M. tuberculosis CRP has evolved several distinct characteristics, compared with the Escherichia coli CRP paradigm, to allow it to regulate gene expression against a background of high concentrations of cAMP. PMID:20028978

Dibutyryl cyclic AMP induces differentiation of human neuroblastoma SH-SY5Y cells into a noradrenergic phenotype.

PubMed

Kume, Toshiaki; Kawato, Yuka; Osakada, Fumitaka; Izumi, Yasuhiko; Katsuki, Hiroshi; Nakagawa, Takayuki; Kaneko, Shuji; Niidome, Tetsuhiro; Takada-Takatori, Yuki; Akaike, Akinori

2008-10-10

Dibutyryl cyclic AMP (dbcAMP) and retinoic acid (RA) have been demonstrated to be the inducers of morphological differentiation in SH-SY5Y cells, a human catecholaminergic neuroblastoma cell line. However, it remains unclear whether morphologically differentiated SH-SY5Y cells by these compounds acquire catecholaminergic properties. We focused on the alteration of tyrosine hydroxylase (TH) expression and intracellular content of noradrenaline (NA) as the indicators of functional differentiation. Three days treatment with dbcAMP (1mM) and RA (10microM) induced morphological changes and an increase of TH-positive cells using immunocytochemical analysis in SH-SY5Y cells. The percentage of TH-expressing cells in dbcAMP (1mM) treatment was larger than that in RA (10microM) treatment. In addition, dbcAMP increased intracellular NA content, whereas RA did not. The dbcAMP-induced increase in TH-expressing cells is partially inhibited by KT5720, a protein kinase A (PKA) inhibitor. We also investigated the effect of butyrate on SH-SY5Y cells, because dbcAMP is enzymatically degraded by intracellular esterase, thereby resulting in the formation of butyrate. Butyrate induced the increase of NA content at lower concentrations than dbcAMP, although the increase in TH-expressing cells by butyrate was smaller than that by dbcAMP. The dbcAMP (1mM)- and butyrate (0.3mM)-induced increase in NA content was completely suppressed by alpha-methyl-p-tyrosine (1mM), an inhibitor of TH. These results suggest that dbcAMP induces differentiation into the noradrenergic phenotype through both PKA activation and butyrate.

New insights on the regulation of the adenine nucleotide pool of erythrocytes in mouse models

PubMed Central

O’Brien, William G.; Ling, Han Shawn; Lee, Cheng Chi

2017-01-01

The observation that induced torpor in non-hibernating mammals could result from an increased AMP concentration in circulation led our investigation to reveal that the added AMP altered oxygen transport of erythrocytes. To further study the effect of AMP in regulation of erythrocyte function and systemic metabolism, we generated mouse models deficient in key erythrocyte enzymes in AMP metabolism. We have previously reported altered erythrocyte adenine nucleotide levels corresponding to altered oxygen saturation in mice deficient in both CD73 and AMPD3. Here we further investigate how these Ampd3-/-/Cd73-/- mice respond to the administered dose of AMP in comparison with the control models of single enzyme deficiency and wild type. We found that Ampd3-/-/Cd73-/- mice are more sensitive to AMP-induced hypometabolism than mice with a single enzyme deficiency, which are more sensitive than wild type. A dose-dependent rightward shift of erythrocyte p50 values in response to increasing amounts of extracellular AMP was observed. We provide further evidence for the direct uptake of AMP by erythrocytes that is insensitive to dipyridamole, a blocker for ENT1. The uptake of AMP by the erythrocytes remained linear at the highest concentration tested, 10mM. We also observed competitive inhibition of AMP uptake by ATP and ADP but not by the other nucleotides and metabolites tested. Importantly, our studies suggest that AMP uptake is associated with an erythrocyte ATP release that is partially sensitive to inhibition by TRO19622 and Ca++ ion. Taken together, our study suggests a novel mechanism by which erythrocytes recycle and maintain their adenine nucleotide pool through AMP uptake and ATP release. PMID:28746349

Protective mechanisms of adenosine 5'-monophosphate in platelet activation and thrombus formation.

PubMed

Fuentes, E; Badimon, L; Caballero, J; Padró, T; Vilahur, G; Alarcón, M; Pérez, P; Palomo, I

2014-03-03

Platelet activation is relevant to a variety of acute thrombotic events. We sought to examine adenosine 5'-monophosphate (AMP) mechanisms of action in preventing platelet activation, thrombus formation and platelet-related inflammatory response. We assessed the effect of AMP on 1) P-selectin expression and GPIIb/IIIa activation by flow cytometry; 2) Platelet aggregation and ATP secretion induced by ADP, collagen, TRAP-6, convulxin and thrombin; 3) Platelet rolling and firm adhesion, and platelet-leukocyte interactions under flow-controlled conditions; and, 4) Platelet cAMP levels, sP-selectin, sCD40L, IL-1β, TGF-β1 and CCL5 release, PDE3A activity and PKA phosphorylation. The effect of AMP on in vivo thrombus formation was also evaluated in a murine model. The AMP docking with respect to A2 adenosine receptor was determined by homology. AMP concentration-dependently (0.1 to 3 mmol/l) inhibited P-selectin expression and GPIIb/IIIa activation, platelet secretion and aggregation induced by ADP, collagen, TRAP-6 and convulxin, and diminished platelet rolling and firm adhesion. Furthermore, AMP induced a marked increase in the rolling speed of leukocytes retained on the platelet surface. At these concentrations AMP significantly decreased inflammatory mediator from platelet, increased intraplatelet cAMP levels and inhibited PDE3A activity. Interestingly, SQ22536, ZM241385 and SCH58261 attenuated the antiplatelet effect of AMP. Docking experiments revealed that AMP had the same orientation that adenosine inside the A2 adenosine receptor binding pocket. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. Considering the successful use of combined antiplatelet therapy, AMP may be further developed as a novel antiplatelet agent.

New insights on the regulation of the adenine nucleotide pool of erythrocytes in mouse models.

PubMed

O'Brien, William G; Ling, Han Shawn; Zhao, Zhaoyang; Lee, Cheng Chi

2017-01-01

The observation that induced torpor in non-hibernating mammals could result from an increased AMP concentration in circulation led our investigation to reveal that the added AMP altered oxygen transport of erythrocytes. To further study the effect of AMP in regulation of erythrocyte function and systemic metabolism, we generated mouse models deficient in key erythrocyte enzymes in AMP metabolism. We have previously reported altered erythrocyte adenine nucleotide levels corresponding to altered oxygen saturation in mice deficient in both CD73 and AMPD3. Here we further investigate how these Ampd3-/-/Cd73-/- mice respond to the administered dose of AMP in comparison with the control models of single enzyme deficiency and wild type. We found that Ampd3-/-/Cd73-/- mice are more sensitive to AMP-induced hypometabolism than mice with a single enzyme deficiency, which are more sensitive than wild type. A dose-dependent rightward shift of erythrocyte p50 values in response to increasing amounts of extracellular AMP was observed. We provide further evidence for the direct uptake of AMP by erythrocytes that is insensitive to dipyridamole, a blocker for ENT1. The uptake of AMP by the erythrocytes remained linear at the highest concentration tested, 10mM. We also observed competitive inhibition of AMP uptake by ATP and ADP but not by the other nucleotides and metabolites tested. Importantly, our studies suggest that AMP uptake is associated with an erythrocyte ATP release that is partially sensitive to inhibition by TRO19622 and Ca++ ion. Taken together, our study suggests a novel mechanism by which erythrocytes recycle and maintain their adenine nucleotide pool through AMP uptake and ATP release.

cAMP-dependent activation of protein kinase A attenuates respiratory syncytial virus-induced human airway epithelial barrier disruption

PubMed Central

Harford, Terri J.; Linfield, Debra T.; Altawallbeh, Ghaith; Midura, Ronald J.; Ivanov, Andrei I.; Piedimonte, Giovanni

2017-01-01

Airway epithelium forms a barrier to the outside world and has a crucial role in susceptibility to viral infections. Cyclic adenosine monophosphate (cAMP) is an important second messenger acting via two intracellular signaling molecules: protein kinase A (PKA) and the guanidine nucleotide exchange factor, Epac. We sought to investigate effects of increased cAMP level on the disruption of model airway epithelial barrier caused by RSV infection and the molecular mechanisms underlying cAMP actions. Human bronchial epithelial cells were infected with RSV-A2 and treated with either cAMP releasing agent, forskolin, or cAMP analogs. Structure and functions of the Apical Junctional Complex (AJC) were evaluated by measuring transepithelial electrical resistance and permeability to FITC-dextran, and determining localization of AJC proteins by confocal microscopy. Increased intracellular cAMP level significantly attenuated RSV-induced disassembly of AJC. These barrier-protective effects of cAMP were due to the activation of PKA signaling and did not involve Epac activity. Increased cAMP level reduced RSV-induced reorganization of the actin cytoskeleton, including apical accumulation of an essential actin-binding protein, cortactin, and inhibited expression of the RSV F protein. These barrier-protective and antiviral-function of cAMP signaling were evident even when cAMP level was increased after the onset of RSV infection. Taken together, our study demonstrates that cAMP/PKA signaling attenuated RSV-induced disruption of structure and functions of the model airway epithelial barrier by mechanisms involving the stabilization of epithelial junctions and inhibition of viral biogenesis. Improving our understanding of the mechanisms involved in RSV-induced epithelial dysfunction and viral pathogenesis will help to develop novel anti-viral therapeutic approaches. PMID:28759570

cAMP-induced activation of protein kinase A and p190B RhoGAP mediates down-regulation of TC10 activity at the plasma membrane and neurite outgrowth.

PubMed

Koinuma, Shingo; Takeuchi, Kohei; Wada, Naoyuki; Nakamura, Takeshi

2017-11-01

Cyclic AMP plays a pivotal role in neurite growth. During outgrowth, a trafficking system supplies membrane at growth cones. However, the cAMP-induced signaling leading to the regulation of membrane trafficking remains unknown. TC10 is a Rho family GTPase that is essential for specific types of vesicular trafficking. Recent studies have shown a role of TC10 in neurite growth in NGF-treated PC12 cells. Here, we investigated a mechanical linkage between cAMP and TC10 in neuritogenesis. Plasmalemmal TC10 activity decreased abruptly after cAMP addition in neuronal cells. TC10 was locally inactivated at extending neurite tips in cAMP-treated PC12 cells. TC10 depletion led to a decrease in cAMP-induced neurite outgrowth. Constitutively active TC10 could not rescue this growth reduction, supporting our model for a role of GTP hydrolysis of TC10 in neuritogenesis by accelerating vesicle fusion. The cAMP-induced TC10 inactivation was mediated by PKA. Considering cAMP-induced RhoA inactivation, we found that p190B, but not p190A, mediated inactivation of TC10 and RhoA. Upon cAMP treatment, p190B was recruited to the plasma membrane. STEF depletion and Rac1-N17 expression reduced cAMP-induced TC10 inactivation. Together, the PKA-STEF-Rac1-p190B pathway leading to inactivation of TC10 and RhoA at the plasma membrane plays an important role in cAMP-induced neurite outgrowth. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Proteomic and Metabolic Analyses of S49 Lymphoma Cells Reveal Novel Regulation of Mitochondria by cAMP and Protein Kinase A*

PubMed Central

Wilderman, Andrea; Guo, Yurong; Divakaruni, Ajit S.; Perkins, Guy; Zhang, Lingzhi; Murphy, Anne N.; Taylor, Susan S.; Insel, Paul A.

2015-01-01

Cyclic AMP (cAMP), acting via protein kinase A (PKA), regulates many cellular responses, but the role of mitochondria in such responses is poorly understood. To define such roles, we used quantitative proteomic analysis of mitochondria-enriched fractions and performed functional and morphologic studies of wild-type (WT) and kin− (PKA-null) murine S49 lymphoma cells. Basally, 75 proteins significantly differed in abundance between WT and kin− S49 cells. WT, but not kin−, S49 cells incubated with the cAMP analog 8-(4-chlorophenylthio)adenosine cAMP (CPT-cAMP) for 16 h have (a) increased expression of mitochondria-related genes and proteins, including ones in pathways of branched-chain amino acid and fatty acid metabolism and (b) increased maximal capacity of respiration on branched-chain keto acids and fatty acids. CPT-cAMP also regulates the cellular rate of ATP-utilization, as the rates of both ATP-linked respiration and proton efflux are decreased in WT but not kin− cells. CPT-cAMP protected WT S49 cells from glucose or glutamine deprivation, In contrast, CPT-cAMP did not protect kin− cells or WT cells treated with the PKA inhibitor H89 from glutamine deprivation. Under basal conditions, the mitochondrial structure of WT and kin− S49 cells is similar. Treatment with CPT-cAMP produced apoptotic changes (i.e. decreased mitochondrial density and size and loss of cristae) in WT, but not kin− cells. Together, these findings show that cAMP acts via PKA to regulate multiple aspects of mitochondrial function and structure. Mitochondrial perturbation thus likely contributes to cAMP/PKA-mediated cellular responses. PMID:26203188

Differential In Vitro and In Vivo Toxicities of Antimicrobial Peptide Prodrugs for Potential Use in Cystic Fibrosis

PubMed Central

Schütte, André; Reeves, Emer; Greene, Catherine; Humphreys, Hilary; Mall, Marcus; Fitzgerald-Hughes, Deirdre; Devocelle, Marc

2016-01-01

There has been considerable interest in the use of antimicrobial peptides (AMPs) as antimicrobial agents for the treatment of many conditions, including cystic fibrosis (CF). The challenging conditions of the CF patient lung require robust AMPs that are active in an environment of high proteolytic activity but that also have low cytotoxicity and immunogenicity. Previously, we developed prodrugs of AMPs that limited the cytotoxic effects of AMP treatment by rendering the antimicrobial activity dependent on the host enzyme neutrophil elastase (NE). However, cytotoxicity remained an issue. Here, we describe the further optimization of the AMP prodrug (pro-AMP) model for CF to produce pro-WMR, a peptide with greatly reduced cytotoxicity (50% inhibitory concentration against CFBE41o- cells, >300 μM) compared to that of the previous group of pro-AMPs. The bactericidal activity of pro-WMR was increased in NE-rich bronchoalveolar lavage (BAL) fluid from CF patients (range, 8.4% ± 6.9% alone to 91.5% ± 5.8% with BAL fluid; P = 0.0004), an activity differential greater than that of previous pro-AMPs. In a murine model of lung delivery, the pro-AMP modification reduced host toxicity, with pro-WMR being less toxic than the active peptide. Previously, host toxicity issues have hampered the clinical application of AMPs. However, the development of application-specific AMPs with modifications that minimize toxicity similar to those described here can significantly advance their potential use in patients. The combination of this prodrug strategy with a highly active AMP has the potential to produce new therapeutics for the challenging conditions of the CF patient lung. PMID:26902766

Exchange protein directly activated by cAMP (epac): a multidomain cAMP mediator in the regulation of diverse biological functions.

PubMed

Schmidt, Martina; Dekker, Frank J; Maarsingh, Harm

2013-04-01

Since the discovery nearly 60 years ago, cAMP is envisioned as one of the most universal and versatile second messengers. The tremendous feature of cAMP to tightly control highly diverse physiologic processes, including calcium homeostasis, metabolism, secretion, muscle contraction, cell fate, and gene transcription, is reflected by the award of five Nobel prizes. The discovery of Epac (exchange protein directly activated by cAMP) has ignited a new surge of cAMP-related research and has depicted novel cAMP properties independent of protein kinase A and cyclic nucleotide-gated channels. The multidomain architecture of Epac determines its activity state and allows cell-type specific protein-protein and protein-lipid interactions that control fine-tuning of pivotal biologic responses through the "old" second messenger cAMP. Compartmentalization of cAMP in space and time, maintained by A-kinase anchoring proteins, phosphodiesterases, and β-arrestins, contributes to the Epac signalosome of small GTPases, phospholipases, mitogen- and lipid-activated kinases, and transcription factors. These novel cAMP sensors seem to implement certain unexpected signaling properties of cAMP and thereby to permit delicate adaptations of biologic responses. Agonists and antagonists selective for Epac are developed and will support further studies on the biologic net outcome of the activation of Epac. This will increase our current knowledge on the pathophysiology of devastating diseases, such as diabetes, cognitive impairment, renal and heart failure, (pulmonary) hypertension, asthma, and chronic obstructive pulmonary disease. Further insights into the cAMP dynamics executed by the Epac signalosome will help to optimize the pharmacological treatment of these diseases.

Dose and Chemical Modification Considerations for Continuous Cyclic AMP Analog Delivery to the Injured CNS

PubMed Central

Fouad, Karim; Ghosh, Mousumi; Vavrek, Romana; Tse, Arthur D.

2009-01-01

Abstract In this investigation, two cell-permeable synthetic analogs of cAMP, dibutyryl-cAMP (db-cAMP) and 8-bromo-cAMP, which are widely used to elevate intracellular cAMP levels under experimental conditions, were investigated for their ability to dose-dependently improve histological and functional outcomes following continuous delivery in two models of incomplete spinal cord injury (SCI). The cAMP analogs were delivered via osmotic minipumps at 1–250 mM through an indwelling cortical cannula or by intrathecal infusion for up to 4 weeks after either a T8 unilateral over-hemisection or a C2-3 dorsolateral quadrant lesion, respectively. In both SCI models, continuous db-cAMP delivery was associated with histopathological changes that included sporadic micro-hemorrhage formation and cavitation, enhanced macrophage infiltration and tissue damage at regions beyond the immediate application site; no deleterious or beneficial effect of agent delivery was observed at the spinal injury site. Furthermore, these changes were accompanied by pronounced behavioral deficits that included an absence of progressive locomotor recovery, increased extensor tone, paralysis, and sensory abnormalities. These deleterious effects were not observed in saline-treated animals, in animals in which the db-cAMP dose did not exceed 1 mM, or in those animals that received a high dose (250 mM) of the alternative cAMP analog, 8-bromo-cAMP. These results demonstrate that, for continuous intraparenchymal or intrathecal administration of cAMP analogs for the study of biological or therapeutic effects within the central nervous system (CNS), consideration of the effective concentration applied as well as the potential toxicity of chemical moieties on the parent molecule and/or their activity needs to be taken into account. PMID:19397425

cAMP and Mitochondria

PubMed Central

Valsecchi, Federica; Ramos-Espiritu, Lavoisier S.; Buck, Jochen; Levin, Lonny R.

2013-01-01

Phosphorylation of mitochondrial proteins has emerged as a major regulatory mechanism for metabolic adaptation. cAMP signaling and PKA phosphorylation of mitochondrial proteins have just started to be investigated, and the presence of cAMP-generating enzymes and PKA inside mitochondria is still controversial. Here, we discuss the role of cAMP in regulating mitochondrial bioenergetics through protein phosphorylation and the evidence for soluble adenylyl cyclase as the source of cAMP inside mitochondria. PMID:23636265

Effect of cAMP on short-circuit current in isolated human ciliary body.

PubMed

Wu, Ren-yi; Ma, Ning; Hu, Qian-qian

2013-07-01

Cyclic adenosine monophosphate (cAMP) could activate chloride channels in bovine ciliary body and trigger an increase in the ionic current (short-circuit current, Isc) across the ciliary processes in pigs. The purpose of this study was to investigate how cAMP modulates Isc in isolated human ciliary processes and the possible involvement of chloride transport across the tissue in cAMP-induced Isc change. In an Ussing-type chamber system, the Isc changes induced by the cAMP analogue 8-bromo-cAMP and an adenylyl cyclase activator forskolin in isolated human ciliary processes were assessed. The involvement of Cl(-) component in the bath solution was investigated. The effect of Cl(-) channel (10 µmol/L niflumic acid and 1 mmol/L 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)), K(+) channel (10 mmol/L tetraethylammonium chloride (TEA)), or Na(+) channel blockers (1 mmol/L amiloride) on 8-bromo-cAMP-induced Isc change was also studied. Dose-dependently, 8-bromo-cAMP (10 nmol/L-30 µmol/L) or forskolin (10 nmol/L-3 µmol/L) increased Isc across the ciliary processes with an increase in negative potential difference on the non-pigmented epithelium (NPE) side of the tissue. Isc increase induced by 8-bromo-cAMP was more pronounced when the drug was applied on the NPE side than on the pigmented epithelium side. When the tissue was bathed in low Cl(-) solutions, the Isc increase was significantly inhibited. Finally, niflumic acid and DIDS, but not TEA or amiloride, significantly prevented the Isc increase induced by 8-bromo-cAMP. cAMP stimulates stroma-to-aqueous anionic transport in isolated human ciliary processes. Chloride is likely to be among the ions, the transportation of which across the tissue is triggered by cAMP, suggesting the potential role of cAMP in the process of aqueous humor formation in human eyes.

Antibiotic resistant salmonella and Escherichia coli isolated from indigenous Gallus domesticus in Nairobi, Kenya.

PubMed

Wesonga, S M; Muluvi, G M; Okemo, P O; Kariuki, S

2010-05-01

To characterise and investigate antimicrobial resistance of Esherichia coli and salmonella strains isolated from indigenous Gallus gallus in a leading slaughterhouse/market outlet in Nairobi-Kenya. A repeated cross sectional study and based on random sampling was used. The study was carried out in a leading market outlet in Nairobi, Kenya. A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern was the single resistance to Tet (21.43%), followed by Amp Cot Tet (14%), Aug Amp Cot Tet (4.29%), Aug Amp Cot Tet Kan Chl (2.86%), Amp Cot Tet Chl, Cot Tet (2.86%) and Crx Amp Cot Tet Chl, Crx Amp Cot Chi, Amp Cot, Aug Amp, (1.43%) respectively. The highest rate of resistance was against Tet (55.7%), followed by Cot (40%). Third in line of resistance was Amp 32.86%, followed by Aug (11.43%), low or moderate resistance was against Chl (8.57%), Kan (4.29%), and Crx (2.86%) (P<0.0002). Salmonella typhimurium recovered displayed single resistance pattern to Tet (16.67%), Gen Cot Tet (8.33%), Amp Cot Tet (8.33%), Aug Amp Cot Tet (8.33%) and Amp Cot Tet Chl (16.67%). The highest resistance was against Tet (58.3%), Cot (41.7%), Amp (33.3%), Chl (16.7%), Aug and Gen (8.3%) respectively (P<0.0001). 3.0kb and 5.6kb plasmids isolated were not transferable by conjugation. Routine surveillance at slaughter/market outlets of Escherichia coli and Salmonella enterica should be done to identify infected flocks as a regulatory procedure for food safety and security programme.

Interplay among Membrane-Bound Lytic Transglycosylase D1, the CreBC Two-Component Regulatory System, the AmpNG-AmpDI-NagZ-AmpR Regulatory Circuit, and L1/L2 β-Lactamase Expression in Stenotrophomonas maltophilia

PubMed Central

Huang, Yi-Wei; Wu, Chao-Jung; Hu, Rouh-Mei; Lin, Yi-Tsung

2015-01-01

Lytic transglycosylases (LTs) are an important class of enzymes involved in peptidoglycan (PG) cleavage, with the concomitant formation of an intramolecular 1,6-anhydromuramoyl reaction product. There are six annotated LT genes in the Stenotrophomonas maltophilia genome, including genes for five membrane-bound LTs (mltA, mltB1, mltB2, mltD1, and mltD2) and a gene for soluble LT (slt). Six LTs of S. maltophilia KJ were systematically mutated, yielding the ΔmltA, ΔmltB1, ΔmltB2, ΔmltD1, ΔmltD2, and Δslt mutants. Inactivation of mltD1 conferred a phenotype of elevated uninduced β-lactamase activity. The underlying mechanism responsible for this phenotype was elucidated by the construction of several mutants and determination of β-lactamase activity. The expression of the genes assayed was assessed by quantitative reverse transcriptase PCR and a promoter transcription fusion assay. The results demonstrate that ΔmltD1 mutant-mediated L1/L2 β-lactamase expression involved the creBC two-component regulatory system (TCS) and the ampNG-ampDI-nagZ-ampR regulatory circuit. The inactivation of mltD1 resulted in mltB1 and mltD2 upexpression in a creBC- and ampNG-dependent manner. The overexpressed MltB1 and MltD2 activity contributed to the expression of the L1/L2 β-lactamase genes via the ampNG-ampDI-nagZ-ampR regulatory circuit. These findings reveal, for the first time, a linkage between LTs, the CreBC TCS, the ampNG-ampDI-nagZ-ampR regulatory circuit, and L1/L2 β-lactamase expression in S. maltophilia. PMID:26282431

Dynamics of β-adrenergic/cAMP signaling and morphological changes in cultured astrocytes.

PubMed

Vardjan, Nina; Kreft, Marko; Zorec, Robert

2014-04-01

The morphology of astrocytes, likely regulated by cAMP, determines the structural association between astrocytes and the synapse, consequently modulating synaptic function. β-Adrenergic receptors (β-AR), which increase cytosolic cAMP concentration ([cAMP]i ), may affect cell morphology. However, the real-time dynamics of β-AR-mediated cAMP signaling in single live astrocytes and its effect on cell morphology have not been studied. We used the fluorescence resonance energy transfer (FRET)-based cAMP biosensor Epac1-camps to study time-dependent changes in [cAMP]i ; morphological changes in primary rat astrocytes were monitored by real-time confocal microscopy. Stimulation of β-AR by adrenaline, noradrenaline, and isoprenaline, a specific agonist of β-AR, rapidly increased [cAMP]i (∼15 s). The FRET signal response, mediated via β-AR, was faster than in the presence of forskolin (twofold) and dibutyryl-cAMP (>35-fold), which directly activate adenylyl cyclase and Epac1-camps, respectively, likely due to slow entry of these agents into the cytosol. Oscillations in [cAMP]i have not been recorded, indicating that cAMP-dependent processes operate in a slow time domain. Most Epac1-camps expressing astrocytes revealed a morphological change upon β-AR activation and attained a stellate morphology within 1 h. The morphological changes exhibited a bell-shaped dependency on [cAMP]i . The 5-10% decrease in cell cross-sectional area and the 30-50% increase in cell perimeter are likely due to withdrawal of the cytoplasm to the perinuclear region and the appearance of protrusions on the surface of astrocytes. Because astrocyte processes ensheath neurons, β-AR/cAMP-mediated morphological changes can modify the geometry of the extracellular space, affecting synaptic, neuronal, and astrocyte functions in health and disease. Copyright © 2014 Wiley Periodicals, Inc.

The antimicrobial peptide derived from insulin-like growth factor-binding protein 5, AMP-IBP5, regulates keratinocyte functions through Mas-related gene X receptors.

PubMed

Chieosilapatham, Panjit; Niyonsaba, François; Kiatsurayanon, Chanisa; Okumura, Ko; Ikeda, Shigaku; Ogawa, Hideoki

2017-10-01

In addition to their microbicidal properties, host defense peptides (HDPs) display various immunomodulatory functions, including keratinocyte production of cytokines/chemokines, proliferation, migration and wound healing. Recently, a novel HDP named AMP-IBP5 (antimicrobial peptide derived from insulin-like growth factor-binding protein 5) was shown to exhibit antimicrobial activity against numerous pathogens, even at concentrations comparable to those of human β-defensins and LL-37. However, the immunomodulatory role of AMP-IBP5 in cutaneous tissue remains unknown. To investigate whether AMP-IBP5 triggers keratinocyte activation and to clarify its mechanism. Production of cytokines/chemokines and growth factors was determined by appropriate ELISA kits. Cell migration was assessed by in vitro wound closure assay, whereas cell proliferation was analyzed using BrdU incorporation assay complimented with XTT assay. MAPK and NF-κB activation was determined by Western blotting. Intracellular cAMP levels were assessed using cAMP enzyme immunoassay kit. Among various cytokines/chemokines and growth factors tested, AMP-IBP5 selectively increased the production of IL-8 and VEGF. Moreover, AMP-IBP5 markedly enhanced keratinocyte migration and proliferation. AMP-IBP5-induced keratinocyte activation was mediated by Mrg X1-X4 receptors with MAPK and NF-κB pathways working downstream, as evidenced by the inhibitory effects of MrgX1-X4 siRNAs and ERK-, JNK-, p38- and NF-κB-specific inhibitors. We confirmed that AMP-IBP5 indeed induced MAPK and NF-κB activation. Furthermore, AMP-IBP5-induced VEGF but not IL-8 production correlated with an increase in intracellular cAMP. Our findings suggest that in addition to its antimicrobial function, AMP-IBP5 might contribute to wound healing process through activation of keratinocytes. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Transformation of aminopyrine in the presence of free available chlorine: Kinetics, products, and reaction pathways.

PubMed

Cai, Mei-Quan; Feng, Li; Zhang, Li-Qiu

2017-03-01

Aminopyrine (AMP) has been frequently detected in the aquatic environment. In this study, the transformation mechanism of AMP by free available chlorine (FAC) oxidation was investigated. The results showed that FAC reacted with AMP rapidly, and a 74% elimination was achieved for 1.30 μM AMP after 2 min at 14.08 μM FAC dose. AMP chlorination was strongly pH-dependent, and its reaction included second- and third-order kinetic processes. Three active FAC species, including chlorine monoxide (Cl 2 O), molecular chlorine (Cl 2 ), and hypochlorous acid (HOCl), were observed to contribute to AMP degradation. The intrinsic rate constants of each FAC species with neutral (AMP 0 ) and cation (AMP + ) species were obtained by kinetic fitting. Cl 2 O exhibited the highest reactivity with AMP 0 (k AMP0, Cl2O  = (4.33 ± 1.4) × 10 9  M -1 s -1 ). In addition, Cl 2 showed high reactivity (10 6 -10 7  M -1 s -1 ) in the presence of chloride, compared with HOCl (k AMP+, HOCl  = (5.73 ± 0.23) × 10 2  M -1 s -1 , k AMP0, HOCl  = (9.68 ± 0.96) × 10 2  M -1 s -1 ). At pH 6.15 and 14.08 μM FAC dose without chloride addition, the contribution of Cl 2 O reached to the maximum (33.3%), but in the whole pH range, HOCl was the main contributor (>66.6%) for AMP degradation. The significance of Cl 2 was noticeable in water containing chloride. Moreover, 11 transformation products were identified, and the main transformation pathways included pyrazole ring breakage, hydroxylation, dehydrogenation, and halogenation. Copyright © 2016 Elsevier Ltd. All rights reserved.

SFG studies on interactions between antimicrobial peptides and supported lipid bilayers.

PubMed

Chen, Xiaoyun; Chen, Zhan

2006-09-01

The mode of action of antimicrobial peptides (AMPs) in disrupting cell membrane bilayers is of fundamental importance in understanding the efficiency of different AMPs, which is crucial to design antibiotics with improved properties. Recent developments in the field of sum frequency generation (SFG) vibrational spectroscopy have made it a powerful and unique biophysical technique in investigating the interactions between AMPs and a single substrate supported planar lipid bilayer. We will review some of the recent progress in applying SFG to study membrane lipid bilayers and discuss how SFG can provide novel information such as real-time bilayer structure change and AMP orientation during AMP-lipid bilayer interactions in a very biologically relevant manner. Several examples of applying SFG to monitor such interactions between AMPs and a dipalmitoyl phosphatidylglycerol (DPPG) bilayer are presented. Different modes of actions are observed for melittin, tachyplesin I, d-magainin 2, MSI-843, and a synthetic antibacterial oligomer, demonstrating that SFG is very effective in the study of AMPs and AMP-lipid bilayer interactions.

Multiple detector focal plane array ultraviolet spectrometer for the AMPS laboratory

NASA Technical Reports Server (NTRS)

Feldman, P. D.

1975-01-01

The possibility of meeting the requirements of the amps spectroscopic instrumentation by using a multi-element focal plane detector array in a conventional spectrograph mount was examined. The requirements of the detector array were determined from the optical design of the spectrometer which in turn depends on the desired level of resolution and sensitivity required. The choice of available detectors and their associated electronics and controls was surveyed, bearing in mind that the data collection rate from this system is so great that on-board processing and reduction of data are absolutely essential. Finally, parallel developments in instrumentation for imaging in astronomy were examined, both in the ultraviolet (for the Large Space Telescope as well as other rocket and satellite programs) and in the visible, to determine what progress in that area can have direct bearing on atmospheric spectroscopy.

Cycle life test of secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1980-01-01

The results of the life cycling program on rechargeable calls are reported. Information on required data, the use of which the data will be put, application details, including orbital description, charge control methods, load rquirements, etc., are given. Cycle tests were performed on 660 sealed, nickel cadmium cells. The cells consisted of seven sample classifications ranging form 3.0 to 20 amp. hours. Nickel cadmium, silver cadmium, and silver zinc sealed cells, excluding synchronous orbit and accelerated test packs were added. The capacities of the nickel cadmium cells, the silver cadmium and the silver zinc cells differed in range of amp hrs. The cells were cylced under different load, charge control, and temperature conditions. All cell packs are recharged by use of a pack voltage limit. All charging is constant current until the voltage limit is reached.

The Clinical Pharmacokinetics of Amphetamines Utilized in the Treatment of Attention-Deficit/Hyperactivity Disorder.

PubMed

Markowitz, John S; Patrick, Kennerly S

2017-10-01

Amphetamine (AMP), an indirectly acting psychostimulant approved for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults, is among the most long-standing therapeutic agents in all of clinical psychopharmacology. This review focuses on AMP absorption, metabolism, and elimination brought to bear on comparative pharmacokinetics in its various formulations. A comprehensive search of the published literature was conducted using MEDLINE (PubMed) and Google Scholar databases through April 2017 to retrieve all pertinent in vitro and human studies for review and synthesis. Additionally, Food and Drug Administration (FDA) databases were accessed for otherwise unavailable data when possible. Initially available as racemic (dl)-AMP, this drug was later supplanted by enantiopure (d)-AMPH or enantioenriched (75:25 dl)-AMP formulations; although racemic AMP returned as an approved drug to treat ADHD in 2014. Presently, there are several immediate-release (IR) formulations available, including d-AMP, dl-AMP, and mixed amphetamine salts, which are neither racemic nor the pure d-enantiomer (i.e., a 3:1 mixture of d-AMP and l-AMP). Furthermore, new modified-release AMP formulations, including an oral suspension and an orally disintegrating tablet, are now available. A lysine-bonded prodrug form of d-AMP also serves as a treatment option. Oral AMP is rapidly absorbed, with high absolute bioavailability, followed by extensive metabolism involving multiple enzymes. Some metabolic pathways exhibit stereoselective biotransformations favoring the l-isomer substrate. Drug exposure exhibits dose-proportional pharmacokinetics. Body weight is a fundamental determinant of differences in observed AMP plasma concentrations. IR formulations typically provide a T max from 2 to 3 hours. In replicated studies, children exhibit a shorter plasma T 1/2 (∼7 hours) relative to adults (∼10 to 12 hours). There are few documented pharmacokinetic drug interactions of clinical significance beyond influences of drug-induced alteration of urinary pH. The array of AMP formulations addressed in this review offer flexibility in dosing, drug onset, and offset to assist in individualized pharmacotherapy of ADHD.

Properties and applications of antimicrobial peptides in biodefense against biological warfare threat agents.

PubMed

Dawson, Raymond Murray; Liu, Chun-Qiang

2008-01-01

Recent advances in knowledge of the properties of antimicrobial peptides (AMPs) are reviewed. AMPs are typically small, positively charged, amphipathic peptides that interact electrostatically and non-stereospecifically with the bacterial cell membrane, resulting in its permeabilization and cell death. Classes of AMPs, their mechanisms of action, hemolytic activity, and cytotoxicity towards host cells are discussed. A particular focus is AMPs with potential for use in defense against biological warfare agents. Some AMPs cytotoxic to Bacillus anthracis have been described. Synthesis of these peptides in multivalent form leads to a synergistic increase in antibacterial activity. Strategies to enhance the potency, stability, and selectivity of AMPs are discussed.

Further studies on the effect of adenosine cyclic monophosphate derivatives on cell proliferation in the jejunal crypts of rat.

PubMed

Tutton, P J; Barkla, D H

1982-01-01

1. Cell proliferation in the jejunal crypt epithelium of rat was measured using a stathmokinetic technique. 2. Sodium butyrate was found to promote jejunal crypt cell proliferation. 3. N6, O2'-Dibutyryl cyclic adenosine monophosphate (cAMP), N6-monobutyryl-cAMP and N6-monobutyryl-8-bromo-cAMP were found to inhibit cell proliferation when compared to sodium butyrate treated tissues. 4. 8-Chlorophenylthio-cAMP was found to inhibit cell division when compared to untreated animals. 5. O2'-Monobutyryl cAMP and 8-bromo-cAMP were not found to inhibit cell proliferation.

Effect of dibutyryl cyclic AMP on the kinetics of myo-inositol transport in cultured astrocytes.

PubMed

Isaacks, R E; Bender, A S; Reuben, J S; Kim, C Y; Shi, Y F; Norenberg, M D

1999-07-01

Dibutyryl cyclic AMP (dBcAMP) is known to induce maturation and differentiation in astrocytes. As myo-inositol is an important osmoregulator in astrocytes, we examined the effects of maturation and biochemical differentiation on the kinetic properties of myo-inositol transport. Treatment of astrocytes with dBcAMP significantly decreased the Vmax of myo-inositol uptake, but the effect on Km was not significant. The myo-inositol content of astrocytes was significantly decreased in cells treated for 5 days with dBcAMP as compared with untreated controls. Maximum suppression of myo-inositol uptake occurred 7 days after exposure of astrocytes to dBcAMP; this was gradually reversible when dBcAMP was removed from the medium. After exposure to hypertonic medium for 6 h, mRNA expression of the myo-inositol co-transporter was diminished by approximately 36% in astrocytes treated with dBcAMP as compared with untreated cells. It appears that myo-inositol transporters in astrocytes treated with dBcAMP are either decreased in number or inactivated during maturation and differentiation, suggesting that the stage of differentiation and biochemical maturation of astrocytes is an important factor in osmoregulation.

Cyclic AMP regulates formation of mammary epithelial acini in vitro

PubMed Central

Nedvetsky, Pavel I.; Kwon, Sang-Ho; Debnath, Jayanta; Mostov, Keith E.

2012-01-01

Epithelial cells form tubular and acinar structures notable for a hollow lumen. In three-dimensional culture utilizing MCF10A mammary epithelial cells, acini form due to integrin-dependent polarization and survival of cells contacting extracellular matrix (ECM), and the apoptosis of inner cells of acini lacking contact with the ECM. In this paper, we report that cyclic AMP (cAMP)-dependent protein kinase A (PKA) promotes acinus formation via two mechanisms. First, cAMP accelerates redistribution of α6-integrin to the periphery of the acinus and thus facilitates the polarization of outer acinar cells. Blocking of α6-integrin function by inhibitory antibody prevents cAMP-dependent polarization. Second, cAMP promotes the death of inner cells occupying the lumen. In the absence of cAMP, apoptosis is delayed, resulting in perturbed luminal clearance. cAMP-dependent apoptosis is accompanied by a posttranscriptional PKA-dependent increase in the proapoptotic protein Bcl-2 interacting mediator of cell death. These data demonstrate that cAMP regulates lumen formation in mammary epithelial cells in vitro, both through acceleration of polarization of outer cells and apoptosis of inner cells of the acinus. PMID:22675028

Antimicrobial Peptides: An Introduction.

PubMed

Haney, Evan F; Mansour, Sarah C; Hancock, Robert E W

2017-01-01

The "golden era" of antibiotic discovery has long passed, but the need for new antibiotics has never been greater due to the emerging threat of antibiotic resistance. This urgency to develop new antibiotics has motivated researchers to find new methods to combat pathogenic microorganisms resulting in a surge of research focused around antimicrobial peptides (AMPs; also termed host defense peptides) and their potential as therapeutics. During the past few decades, more than 2000 AMPs have been identified from a diverse range of organisms (animals, fungi, plants, and bacteria). While these AMPs share a number of common features and a limited number of structural motifs; their sequences, activities, and targets differ considerably. In addition to their antimicrobial effects, AMPs can also exhibit immunomodulatory, anti-biofilm, and anticancer activities. These diverse functions have spurred tremendous interest in research aimed at understanding the activity of AMPs, and various protocols have been described to assess different aspects of AMP function including screening and evaluating the activities of natural and synthetic AMPs, measuring interactions with membranes, optimizing peptide function, and scaling up peptide production. Here, we provide a general overview of AMPs and introduce some of the methodologies that have been used to advance AMP research.

A possible signal-coupling role for cyclic AMP during endocytosis in Amoeba proteus.

PubMed

Prusch, R D; Roscoe, J C

1993-01-01

Cytoplasmic levels of cAMP in Amoeba proteus were measured utilizing radioimmunoassays under control conditions and when stimulated by inducers of either pinocytosis or phagocytosis. In control cells, cytoplasmic cAMP levels were approximately 0.39 pM/mg cells. When exposed to either chemotactic peptide or mannose which stimulate phagocytosis in the amoeba, there is a rapid doubling of the cAMP level within 45 sec of stimulation which then returns to the control level within 3-5 min. Theophylline prolongs the elevation of cytoplasmic cAMP in stimulated cells and is also capable of eliciting food vacuole formation in the amoeba. In addition isoproterenol also causes food vacuole formation in the amoeba as well as a large and prolonged increase in cytoplasmic cAMP levels. Inducers of pinocytosis (BSA and Na Cl) also elicit changes in cytoplasmic cAMP in the amoeba, but the response appears to differ from that elicited by inducers of phagocytosis in that the peak cAMP levels are broader and biphasic. It is concluded that cAMP plays a signal-coupling role during the early phases of both forms of endocytosis in Amoeba proteus.

IP{sub 3}-dependent intracellular Ca{sup 2+} release is required for cAMP-induced c-fos expression in hippocampal neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wenting; Tingare, Asmita; Ng, David Chi-Heng

2012-08-24

Highlights: Black-Right-Pointing-Pointer cAMP-induced c-fos expression in hippocampal neurons requires a submembraneous Ca{sup 2+} pool. Black-Right-Pointing-Pointer The submembraneous Ca{sup 2+} pool derives from intracellular ER stores. Black-Right-Pointing-Pointer Expression of IP{sub 3}-metabolizing enzymes inhibits cAMP-induced c-fos expression. Black-Right-Pointing-Pointer SRE-mediated and CRE-mediated gene expression is sensitive to IP{sub 3}-metabolizing enzymes. Black-Right-Pointing-Pointer Intracellular Ca{sup 2+} release is required for cAMP-induced nuclear translocation of TORC1. -- Abstract: Ca{sup 2+} and cAMP are widely used in concert by neurons to relay signals from the synapse to the nucleus, where synaptic activity modulates gene expression required for synaptic plasticity. Neurons utilize different transcriptional regulators to integrate informationmore » encoded in the spatiotemporal dynamics and magnitude of Ca{sup 2+} and cAMP signals, including some that are Ca{sup 2+}-responsive, some that are cAMP-responsive and some that detect coincident Ca{sup 2+} and cAMP signals. Because Ca{sup 2+} and cAMP can influence each other's amplitude and spatiotemporal characteristics, we investigated how cAMP acts to regulate gene expression when increases in intracellular Ca{sup 2+} are buffered. We show here that cAMP-mobilizing stimuli are unable to induce expression of the immediate early gene c-fos in hippocampal neurons in the presence of the intracellular Ca{sup 2+} buffer BAPTA-AM. Expression of enzymes that attenuate intracellular IP{sub 3} levels also inhibited cAMP-dependent c-fos induction. Synaptic activity induces c-fos transcription through two cis regulatory DNA elements - the CRE and the SRE. We show here that in response to cAMP both CRE-mediated and SRE-mediated induction of a luciferase reporter gene is attenuated by IP{sub 3} metabolizing enzymes. Furthermore, cAMP-induced nuclear translocation of the CREB coactivator TORC1 was inhibited by depletion of intracellular Ca{sup 2+} stores. Our data indicate that Ca{sup 2+} release from IP{sub 3}-sensitive pools is required for cAMP-induced transcription in hippocampal neurons.« less

Coordinated induction of GST and MRP2 by cAMP in Caco-2 cells: Role of protein kinase A signaling pathway and toxicological relevance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arana, Maite Rocío, E-mail: arana@ifise-conicet.gov.ar; Tocchetti, Guillermo Nicolás, E-mail: gtocchetti@live.com.ar; Domizi, Pablo, E-mail: domizi@ibr-conicet.gov.ar

2015-09-01

The cAMP pathway is a universal signaling pathway regulating many cellular processes including metabolic routes, growth and differentiation. However, its effects on xenobiotic biotransformation and transport systems are poorly characterized. The effect of cAMP on expression and activity of GST and MRP2 was evaluated in Caco-2 cells, a model of intestinal epithelium. Cells incubated with the cAMP permeable analog dibutyryl cyclic AMP (db-cAMP: 1,10,100 μM) for 48 h exhibited a dose–response increase in GST class α and MRP2 protein expression. Incubation with forskolin, an activator of adenylyl cyclase, confirmed the association between intracellular cAMP and upregulation of MRP2. Consistent withmore » increased expression of GSTα and MRP2, db-cAMP enhanced their activities, as well as cytoprotection against the common substrate 1-chloro-2,4-dinitrobenzene. Pretreatment with protein kinase A (PKA) inhibitors totally abolished upregulation of MRP2 and GSTα induced by db-cAMP. In silico analysis together with experiments consisting of treatment with db-cAMP of Caco-2 cells transfected with a reporter construct containing CRE and AP-1 sites evidenced participation of these sites in MRP2 upregulation. Further studies involving the transcription factors CREB and AP-1 (c-JUN, c-FOS and ATF2) demonstrated increased levels of total c-JUN and phosphorylation of c-JUN and ATF2 by db-cAMP, which were suppressed by a PKA inhibitor. Co-immunoprecipitation and ChIP assay studies demonstrated that db-cAMP increased c-JUN/ATF2 interaction, with further recruitment to the region of the MRP2 promoter containing CRE and AP-1 sites. We conclude that cAMP induces GSTα and MRP2 expression and activity in Caco-2 cells via the PKA pathway, thus regulating detoxification of specific xenobiotics. - Highlights: • cAMP positively modulates the expression and activity of GST and MRP2 in Caco-2 cells. • Such induction resulted in increased cytoprotection against chemical injury. • PKA signaling pathway is involved downstream of cAMP. • Transcriptional MRP2 regulation ultimately involved participation of c-JUN and ATF2.« less

cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharjee, Rajesh; Xiang, Wenpei; Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China

2012-06-22

Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1more » (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC complex upon the binding of TNF to TNFR1. In conclusion, our study shows that cAMP prevents TNF + ActD-induced apoptosis in rat hepatocytes by inhibiting DISC complex formation.« less

Crystal structures of RIalpha subunit of cyclic adenosine 5'-monophosphate (cAMP)-dependent protein kinase complexed with (Rp)-adenosine 3',5'-cyclic monophosphothioate and (Sp)-adenosine 3',5'-cyclic monophosphothioate, the phosphothioate analogues of cAMP.

PubMed

Wu, Jian; Jones, John M; Nguyen-Huu, Xuong; Ten Eyck, Lynn F; Taylor, Susan S

2004-06-01

Cyclic adenosine 5'-monophosphate (cAMP) is an ancient signaling molecule, and in vertebrates, a primary target for cAMP is cAMP-dependent protein kinase (PKA). (R(p))-adenosine 3',5'-cyclic monophosphothioate ((R(p))-cAMPS) and its analogues are the only known competitive inhibitors and antagonists for cAMP activation of PKA, while (S(p))-adenosine 3',5'-cyclic monophosphothioate ((S(p))-cAMPS) functions as an agonist. The crystal structures of a Delta(1-91) deletion mutant of the RIalpha regulatory subunit of PKA bound to (R(p))-cAMPS and (S(p))-cAMPS were determined at 2.4 and 2.3 A resolution, respectively. While the structures are similar to each other and to the crystal structure of RIalpha bound to cAMP, differences in the dynamical properties of the protein when (R(p))-cAMPS is bound are apparent. The structures highlight the critical importance of the exocyclic oxygen's interaction with the invariant arginine in the phosphate binding cassette (PBC) and the importance of this interaction for the dynamical properties of the interactions that radiate out from the PBC. The conformations of the phosphate binding cassettes containing two invariant arginine residues (Arg209 on domain A, and Arg333 on domain B) are somewhat different due to the sulfur interacting with this arginine. Furthermore, the B-site ligand together with the entire domain B show significant differences in their overall dynamic properties in the crystal structure of Delta(1-91) RIalpha complexed with (R(p))-cAMPS phosphothioate analogue ((R(p))-RIalpha) compared to the cAMP- and (S(p))-cAMPS-bound type I and II regulatory subunits, based on the temperature factors. In all structures, two structural solvent molecules exist within the A-site ligand binding pocket; both mediate water-bridged interactions between the ligand and the protein. No structured waters are in the B-site pocket. Owing to the higher resolution data, the N-terminal segment (109-117) of the RIalpha subunit can also be traced. This strand forms an intermolecular antiparallel beta-sheet with the same strand in an adjacent molecule and implies that the RIalpha subunit can form a weak homodimer even in the absence of its dimerization domain.

Advanced Multi-Physics (AMP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip, Bobby

2012-06-01

The Advanced Multi-Physics (AMP) code, in its present form, will allow a user to build a multi-physics application code for existing mechanics and diffusion operators and extend them with user-defined material models and new physics operators. There are examples that demonstrate mechanics, thermo-mechanics, coupled diffusion, and mechanical contact. The AMP code is designed to leverage a variety of mathematical solvers (PETSc, Trilinos, SUNDIALS, and AMP solvers) and mesh databases (LibMesh and AMP) in a consistent interchangeable approach.

Evaluation of uridine 5'-eicosylphosphate as a stimulant of cyclic AMP-dependent cellular function.

PubMed

Yutani, Masahiro; Ogita, Akira; Fujita, Ken-Ichi; Usuki, Yoshinosuke; Tanaka, Toshio

2011-03-01

Sporulation of the yeast Saccharomyces cerevisiae is negatively regulated by cyclic AMP (cAMP). This microbial cell differentiation process was applied for the screening of a substance that can elevate the intracellular cAMP level. Among nucleoside 5'-alkylphosphates, uridine 5'-eicosylphosphate (UMPC20) selectively and predominantly inhibited ascospore formation of the yeast cells. We suppose the inhibitory effect of UMPC20 could indeed reflect the elevation of the cellular cAMP level.

AMP-guided tumour-specific nanoparticle delivery via adenosine A1 receptor.

PubMed

Dai, Tongcheng; Li, Na; Han, Fajun; Zhang, Hua; Zhang, Yuanxing; Liu, Qin

2016-03-01

Active targeting-ligands have been increasingly used to functionalize nanoparticles for tumour-specific clinical applications. Here we utilize nucleotide adenosine 5'-monophosphate (AMP) as a novel ligand to functionalize polymer-based fluorescent nanoparticles (NPs) for tumour-targeted imaging. We demonstrate that AMP-conjugated NPs (NPs-AMP) efficiently bind to and are following internalized into colon cancer cell CW-2 and breast cancer cell MDA-MB-468 in vitro. RNA interference and inhibitor assays reveal that the targeting effects mainly rely on the specific binding of AMP to adenosine A1 receptor (A1R), which is greatly up-regulated in cancer cells than in matched normal cells. More importantly, NPs-AMP specifically accumulate in the tumour site of colon and breast tumour xenografts and are further internalized into the tumour cells in vivo via tail vein injection, confirming that the high in vitro specificity of AMP can be successfully translated into the in vivo efficacy. Furthermore, NPs-AMP exhibit an active tumour-targeting behaviour in various colon and breast cancer cells, which is positively related to the up-regulation level of A1R in cancer cells, suggesting that AMP potentially suits for more extensive A1R-overexpressing cancer models. This work establishes AMP to be a novel tumour-targeting ligand and provides a promising strategy for future diagnostic or therapeutic applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Will new generations of modified antimicrobial peptides improve their potential as pharmaceuticals?

PubMed

Brogden, Nicole K; Brogden, Kim A

2011-09-01

The concept of antimicrobial peptides (AMPs) as potent pharmaceuticals is firmly established in the literature, and most research articles on this topic conclude by stating that AMPs represent promising therapeutic agents against bacterial and fungal pathogens. Indeed, early research in this field showed that AMPs were diverse in nature, had high activities with low minimal inhibitory concentrations, had broad spectrums of activity against bacterial, fungal and viral pathogens, and could easily be manipulated to alter their specificities, reduce their cytotoxicities and increase their antimicrobial activities. Unfortunately, commercial development of these peptides, for even the simplest of applications, has been very limited. With some peptides there are obstacles with their manufacture, in vivo efficacy and in vivo retention. More recently, the focus has shifted. Contemporary research now uses a more sophisticated approach to develop AMPs that surmount many of these prior obstacles. AMP mimetics, hybrid AMPs, AMP congeners, cyclotides and stabilised AMPs, AMP conjugates and immobilised AMPs have all emerged with selective or 'targeted' antimicrobial activities, improved retention, or unique abilities that allow them to bind to medical or industrial surfaces. These groups of new peptides have creative medical and industrial application potentials to treat antibiotic-resistant bacterial infections and septic shock, to preserve food or to sanitise surfaces both in vitro and in vivo. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

A Rapid Phenotypic Whole Cell Screening Approach for the Identification of Small Molecule Inhibitors that Counter Beta-lactamase Resistance in Pseudomonas aeruginosa

PubMed Central

Collia, Deanna; Bannister, Thomas D.; Tan, Hao; Jin, Shouguang; Langaee, Taimour; Shumate, Justin; Scampavia, Louis; Spicer, Timothy P.

2017-01-01

Pseudomonas aeruginosa is an opportunistic human pathogen which is prevalent in hospitals and continues to develop resistance to multiple classes of antibiotics. Historically, β-lactam antibiotics have been the first line of therapeutic defense. However, the emergence of multidrug-resistant (MDR) strains of P. aeruginosa, such as AmpC β-lactamase overproducing mutants, limits the effectiveness of current antibiotics. Among AmpC hyper producing clinical isolates, inactivation of AmpG, which is essential for the expression of AmpC, increases bacterial sensitivity to β-lactam antibiotics. We hypothesize that inhibition of AmpG activity will enhance the efficacy of β-lactams against P. aeruginosa. Here, using a highly drug resistant AmpC inducible laboratory strain PAO1, we describe an ultra-high throughput whole cell turbidity assay designed to identify small molecule inhibitors of the AmpG. We screened 645K compounds to identify compounds with the ability to inhibit bacterial growth in the presence of Cefoxitin; an AmpC inducer, and identified 2,663 inhibitors which were also tested in the absence of Cefoxitin to determine AmpG specificity. The Z′ and S:B were robust at 0.87 ± 0.05 and 2.2 ± 0.2, respectively. Through a series of secondary and tertiary studies, including a novel luciferase based counterscreen, we ultimately identified 8 potential AmpG specific inhibitors. PMID:28850797

Cyclic AMP differentiates two separate but interacting pathways of phosphoinositide hydrolysis in the DDT1-MF2 smooth muscle cell line.

PubMed

Schachter, J B; Wolfe, B B

1992-03-01

The activation of adenosine A1 receptors in DDT1-MF2 smooth muscle cells resulted in both the inhibition of agonist-stimulated cAMP accumulation and the potentiation of norepinephrine-stimulated phosphoinositide hydrolysis. Pharmacological analysis indicated the involvement of an A1 adenosine receptor subtype in both of these responses. In the absence of norepinephrine, the activation of the adenosine receptor did not directly stimulate phosphoinositide hydrolysis. The adenosine receptor-mediated augmentation of norepinephrine-stimulated phosphoinositide hydrolysis was pertussis toxin sensitive and was selectively antagonized by agents that mimicked cAMP (8-bromo-cAMP) or raised cellular cAMP levels (forskolin). This initially suggested that cAMP might partially regulate the magnitude of the phospholipase C response to norepinephrine and that adenosine agonists might enhance the phospholipase C response by reducing cAMP levels. However, neither the reduction of cellular cAMP levels by other agents nor the inhibition of cAMP-dependent protein kinase was sufficient to replicate the action of adenosine receptor activation on phosphoinositide hydrolysis. Thus, in the presence of norepinephrine, adenosine receptor agonists appear to stimulate phosphoinositide hydrolysis via a pathway that is separate from, but dependent upon, that of norepinephrine. This second pathway can be distinguished from that which is stimulated by norepinephrine on the basis of its sensitivity to inhibition by both cAMP and pertussis toxin.

A Rapid Phenotypic Whole-Cell Screening Approach for the Identification of Small-Molecule Inhibitors That Counter β-Lactamase Resistance in Pseudomonas aeruginosa.

PubMed

Collia, Deanna; Bannister, Thomas D; Tan, Hao; Jin, Shouguang; Langaee, Taimour; Shumate, Justin; Scampavia, Louis; Spicer, Timothy P

2018-01-01

Pseudomonas aeruginosa is an opportunistic human pathogen that is prevalent in hospitals and continues to develop resistance to multiple classes of antibiotics. Historically, β-lactam antibiotics have been the first line of therapeutic defense. However, the emergence of multidrug-resistant (MDR) strains of P. aeruginosa, such as AmpC β-lactamase overproducing mutants, limits the effectiveness of current antibiotics. Among AmpC hyperproducing clinical isolates, inactivation of AmpG, which is essential for the expression of AmpC, increases bacterial sensitivity to β-lactam antibiotics. We hypothesize that inhibition of AmpG activity will enhance the efficacy of β-lactams against P. aeruginosa. Here, using a highly drug-resistant AmpC-inducible laboratory strain PAO1, we describe an ultra-high-throughput whole-cell turbidity assay designed to identify small-molecule inhibitors of the AmpG. We screened 645,000 compounds to identify compounds with the ability to inhibit bacterial growth in the presence of cefoxitin, an AmpC inducer, and identified 2663 inhibitors that were also tested in the absence of cefoxitin to determine AmpG specificity. The Z' and signal-to-background ratio were robust at 0.87 ± 0.05 and 2.2 ± 0.2, respectively. Through a series of secondary and tertiary studies, including a novel luciferase-based counterscreen, we ultimately identified eight potential AmpG-specific inhibitors.

Phosphodiesterase inhibitors suppress Lactobacillus casei cell-wall-induced NF-κB and MAPK activations and cell proliferation through protein kinase A--or exchange protein activated by cAMP-dependent signal pathway.

PubMed

Saito, Takekatsu; Sugimoto, Naotoshi; Ohta, Kunio; Shimizu, Tohru; Ohtani, Kaori; Nakayama, Yuko; Nakamura, Taichi; Hitomi, Yashiaki; Nakamura, Hiroyuki; Koizumi, Shoichi; Yachie, Akihiro

2012-01-01

Specific strains of Lactobacillus have been found to be beneficial in treating some types of diarrhea and vaginosis. However, a high mortality rate results from underlying immunosuppressive conditions in patients with Lactobacillus casei bacteremia. Cyclic AMP (cAMP) is a small second messenger molecule that mediates signal transduction. The onset and progression of inflammatory responses are sensitive to changes in steady-state cAMP levels. L. casei cell wall extract (LCWE) develops arteritis in mice through Toll-like receptor-2 signaling. The purpose of this study was to investigate whether intracellular cAMP affects LCWE-induced pathological signaling. LCWE was shown to induce phosphorylation of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and cell proliferation in mice fibroblast cells. Theophylline and phosphodiesterase inhibitor increased intracellular cAMP and inhibited LCWE-induced cell proliferation as well as phosphorylation of NF-κB and MAPK. Protein kinase A inhibitor H89 prevented cAMP-induced MAPK inhibition, but not cAMP-induced NF-κB inhibition. An exchange protein activated by cAMP (Epac) agonist inhibited NF-κB activation but not MAPK activation. These results indicate that an increase in intracellular cAMP prevents LCWE induction of pathological signaling pathways dependent on PKA and Epac signaling.

Antimicrobial peptides in the female reproductive tract: a critical component of the mucosal immune barrier with physiological and clinical implications.

PubMed

Yarbrough, Victoria L; Winkle, Sean; Herbst-Kralovetz, Melissa M

2015-01-01

At the interface of the external environment and the mucosal surface of the female reproductive tract (FRT) lies a first-line defense against pathogen invasion that includes antimicrobial peptides (AMP). Comprised of a unique class of multifunctional, amphipathic molecules, AMP employ a wide range of functions to limit microbial invasion and replication within host cells as well as independently modulate the immune system, dampen inflammation and maintain tissue homeostasis. The role of AMP in barrier defense at the level of the skin and gut has received much attention as of late. Given the far reaching implications for women's health, maternal and fetal morbidity and mortality, and sexually transmissible and polymicrobial diseases, we herein review the distribution and function of key AMP throughout the female reproductive mucosa and assess their role as an essential immunological barrier to microbial invasion throughout the reproductive cycle of a woman's lifetime. A comprehensive search in PubMed/Medline was conducted related to AMP general structure, function, signaling, expression, distribution and barrier function of AMP in the FRT, hormone regulation of AMP, the microbiome of the FRT, and AMP in relation to implantation, pregnancy, fertility, pelvic inflammatory disease, complications of pregnancy and assisted reproductive technology. AMP are amphipathic peptides that target microbes for destruction and have been conserved throughout all living organisms. In the FRT, several major classes of AMP are expressed constitutively and others are inducible at the mucosal epithelium and by immune cells. AMP expression is also under the influence of sex hormones, varying throughout the menstrual cycle, and dependent on the vaginal microbiome. AMP can prevent infection with sexually transmissible and opportunistic pathogens of the female reproductive tissues, although emerging understanding of vaginal dysbiosis suggests induction of a unique AMP profile with increased susceptibility to these pathogens. During pregnancy, AMP are key immune effectors of the fetal membranes and placenta and are dysregulated in states of intrauterine infection and other complications of pregnancy. At the level of the FRT, AMP serve to inhibit infection by sexually and vertically transmissible as well as by opportunistic bacteria, fungi, viruses, and protozoa and must do so throughout the hormone flux of menses and pregnancy. Guarding the exclusive site of reproduction, AMP modulate the vaginal microbiome of the lower FRT to aid in preventing ascending microbes into the upper FRT. Evolving in parallel with, and in response to, pathogenic insults, AMP are relatively immune to the resistance mechanisms employed by rapidly evolving pathogens and play a key role in barrier function and host defense throughout the FRT. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Multiple imputation for assessment of exposures to drinking water contaminants: evaluation with the Atrazine Monitoring Program.

PubMed

Jones, Rachael M; Stayner, Leslie T; Demirtas, Hakan

2014-10-01

Drinking water may contain pollutants that harm human health. The frequency of pollutant monitoring may occur quarterly, annually, or less frequently, depending upon the pollutant, the pollutant concentration, and community water system. However, birth and other health outcomes are associated with narrow time-windows of exposure. Infrequent monitoring impedes linkage between water quality and health outcomes for epidemiological analyses. To evaluate the performance of multiple imputation to fill in water quality values between measurements in community water systems (CWSs). The multiple imputation method was implemented in a simulated setting using data from the Atrazine Monitoring Program (AMP, 2006-2009 in five Midwestern states). Values were deleted from the AMP data to leave one measurement per month. Four patterns reflecting drinking water monitoring regulations were used to delete months of data in each CWS: three patterns were missing at random and one pattern was missing not at random. Synthetic health outcome data were created using a linear and a Poisson exposure-response relationship with five levels of hypothesized association, respectively. The multiple imputation method was evaluated by comparing the exposure-response relationships estimated based on multiply imputed data with the hypothesized association. The four patterns deleted 65-92% months of atrazine observations in AMP data. Even with these high rates of missing information, our procedure was able to recover most of the missing information when the synthetic health outcome was included for missing at random patterns and for missing not at random patterns with low-to-moderate exposure-response relationships. Multiple imputation appears to be an effective method for filling in water quality values between measurements. Copyright © 2014 Elsevier Inc. All rights reserved.

cap alpha. /sub 2/-Adrenergic receptor-mediated sensitization of forskolin-stimulated cyclic AMP production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, S.B.; Toews, M.L.; Turner, J.T.

1987-03-01

Preincubation of HT29 human colonic adenocarcinoma cells with ..cap alpha../sub 2/-adrenergic agonists resulted in a 10- to 20-fold increase in forskolin-stimulated cyclic AMP production as compared to cells preincubated without agonist. Similar results were obtained using either a (/sup 3/H)adenine prelabeling assay or a cyclic AMP radioimmunoassay to measure cyclic AMP levels. This phenomenon, which is termed sensitization, is ..cap alpha../sub 2/-adrenergic receptor-mediated and rapid in onset and reversal. Yohimbine, an ..cap alpha../sub 2/-adrenergic receptor-selective antagonist, blocked norepinephrine-induced sensitization, whereas prazosin (..cap alpha../sub 1/-adrenergic) and sotalol (..beta..-adrenergic) did not. The time for half-maximal sensitization was 5 min and the half-timemore » for reversal was 10 min. Only a 2-fold sensitization of cyclic AMP production stimulated by vasoactive intestinal peptide was observed, indicating that sensitization is relatively selective for forskolin. Sensitization reflects an increased production of cyclic AMP and not a decreased degradation of cyclic AMP, since incubation with a phosphodiesterase inhibitor and forskolin did not mimic sensitization. Increasing the levels of cyclic AMP during the preincubation had no effect on sensitization, indicating that sensitization is not caused by decreased cyclic AMP levels during the preincubation. This rapid and dramatic sensitization of forskolin-stimulated cyclic AMP production is a previously unreported effect that can be added to the growing list of ..cap alpha../sub 2/-adrenergic responses that are not mediated by a decrease in cyclic AMP.« less

Molecular basis for the recognition of cyclic-di-AMP by PstA, a PII-like signal transduction protein.

PubMed

Choi, Philip H; Sureka, Kamakshi; Woodward, Joshua J; Tong, Liang

2015-06-01

Cyclic-di-AMP (c-di-AMP) is a broadly conserved bacterial second messenger that is of importance in bacterial physiology. The molecular receptors mediating the cellular responses to the c-di-AMP signal are just beginning to be discovered. PstA is a previously uncharacterized PII -like protein which has been identified as a c-di-AMP receptor. PstA is widely distributed and conserved among Gram-positive bacteria in the phylum Firmicutes. Here, we report the biochemical, structural, and functional characterization of PstA from Listeria monocytogenes. We have determined the crystal structures of PstA in the c-di-AMP-bound and apo forms at 1.6 and 2.9 Å resolution, respectively, which provide the molecular basis for its specific recognition of c-di-AMP. PstA forms a homotrimer structure that has overall similarity to the PII protein family which binds ATP. However, PstA is markedly different from PII proteins in the loop regions, and these structural differences mediate the specific recognition of their respective nucleotide ligand. The residues composing the c-di-AMP binding pocket are conserved, suggesting that c-di-AMP recognition by PstA is of functional importance. Disruption of pstA in L. monocytogenes affected c-di-AMP-mediated alterations in bacterial growth and lysis. Overall, we have defined the PstA family as a conserved and specific c-di-AMP receptor in bacteria. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Intrasteric control of AMPK via the gamma1 subunit AMP allosteric regulatory site.

PubMed

Adams, Julian; Chen, Zhi-Ping; Van Denderen, Bryce J W; Morton, Craig J; Parker, Michael W; Witters, Lee A; Stapleton, David; Kemp, Bruce E

2004-01-01

AMP-activated protein kinase (AMPK) is a alphabetagamma heterotrimer that is activated in response to both hormones and intracellular metabolic stress signals. AMPK is regulated by phosphorylation on the alpha subunit and by AMP allosteric control previously thought to be mediated by both alpha and gamma subunits. Here we present evidence that adjacent gamma subunit pairs of CBS repeat sequences (after Cystathionine Beta Synthase) form an AMP binding site related to, but distinct from the classical AMP binding site in phosphorylase, that can also bind ATP. The AMP binding site of the gamma(1) CBS1/CBS2 pair, modeled on the structures of the CBS sequences present in the inosine monophosphate dehydrogenase crystal structure, contains three arginine residues 70, 152, and 171 and His151. The yeast gamma homolog, snf4 contains a His151Gly substitution, and when this is introduced into gamma(1), AMP allosteric control is substantially lost and explains why the yeast snf1p/snf4p complex is insensitive to AMP. Arg70 in gamma(1) corresponds to the site of mutation in human gamma(2) and pig gamma(3) genes previously identified to cause an unusual cardiac phenotype and glycogen storage disease, respectively. Mutation of any of AMP binding site Arg residues to Gln substantially abolishes AMP allosteric control in expressed AMPK holoenzyme. The Arg/Gln mutations also suppress the previously described inhibitory properties of ATP and render the enzyme constitutively active. We propose that ATP acts as an intrasteric inhibitor by bridging the alpha and gamma subunits and that AMP functions to derepress AMPK activity.

Multiple Facets of cAMP Signalling and Physiological Impact: cAMP Compartmentalization in the Lung

PubMed Central

Oldenburger, Anouk; Maarsingh, Harm; Schmidt, Martina

2012-01-01

Therapies involving elevation of the endogenous suppressor cyclic AMP (cAMP) are currently used in the treatment of several chronic inflammatory disorders, including chronic obstructive pulmonary disease (COPD). Characteristics of COPD are airway obstruction, airway inflammation and airway remodelling, processes encompassed by increased airway smooth muscle mass, epithelial changes, goblet cell and submucosal gland hyperplasia. In addition to inflammatory cells, airway smooth muscle cells and (myo)fibroblasts, epithelial cells underpin a variety of key responses in the airways such as inflammatory cytokine release, airway remodelling, mucus hypersecretion and airway barrier function. Cigarette smoke, being next to environmental pollution the main cause of COPD, is believed to cause epithelial hyperpermeability by disrupting the barrier function. Here we will focus on the most recent progress on compartmentalized signalling by cAMP. In addition to G protein-coupled receptors, adenylyl cyclases, cAMP-specific phospho-diesterases (PDEs) maintain compartmentalized cAMP signalling. Intriguingly, spatially discrete cAMP-sensing signalling complexes seem also to involve distinct members of the A-kinase anchoring (AKAP) superfamily and IQ motif containing GTPase activating protein (IQGAPs). In this review, we will highlight the interaction between cAMP and the epithelial barrier to retain proper lung function and to alleviate COPD symptoms and focus on the possible molecular mechanisms involved in this process. Future studies should include the development of cAMP-sensing multiprotein complex specific disruptors and/or stabilizers to orchestrate cellular functions. Compartmentalized cAMP signalling regulates important cellular processes in the lung and may serve as a therapeutic target. PMID:24281338

Sustained signalling by PTH modulates IP3 accumulation and IP3 receptors through cyclic AMP junctions

PubMed Central

Meena, Abha; Tovey, Stephen C.; Taylor, Colin W.

2015-01-01

ABSTRACT Parathyroid hormone (PTH) stimulates adenylyl cyclase through type 1 PTH receptors (PTH1R) and potentiates the Ca2+ signals evoked by carbachol, which stimulates formation of inositol 1,4,5-trisphosphate (IP3). We confirmed that in HEK cells expressing PTH1R, acute stimulation with PTH(1-34) potentiated carbachol-evoked Ca2+ release. This was mediated by locally delivered cyclic AMP (cAMP), but unaffected by inhibition of protein kinase A (PKA), exchange proteins activated by cAMP, cAMP phosphodiesterases (PDEs) or substantial inhibition of adenylyl cyclase. Sustained stimulation with PTH(1-34) causes internalization of PTH1R–adenylyl cyclase signalling complexes, but the consequences for delivery of cAMP to IP3R within cAMP signalling junctions are unknown. Here, we show that sustained stimulation with PTH(1-34) or with PTH analogues that do not evoke receptor internalization reduced the potentiated Ca2+ signals and attenuated carbachol-evoked increases in cytosolic IP3. Similar results were obtained after sustained stimulation with NKH477 to directly activate adenylyl cyclase, or with the membrane-permeant analogue of cAMP, 8-Br-cAMP. These responses were independent of PKA and unaffected by substantial inhibition of adenylyl cyclase. During prolonged stimulation with PTH(1-34), hyperactive cAMP signalling junctions, within which cAMP is delivered directly and at saturating concentrations to its targets, mediate sensitization of IP3R and a more slowly developing inhibition of IP3 accumulation. PMID:25431134

AMPS Supporting Research and Technology (SR and T) report. Atmospheric, Magnetospheric and Plasmas in Space (AMPS) definition study

NASA Technical Reports Server (NTRS)

1976-01-01

A listing of candidate technology areas that require additional study is presented. These candidate tasks, identified during the AMPS Phase B studies, are requisites to the design, development, and operation of the AMPS concept selected for preliminary design.

78 FR 1264 - CalAmp Wireless Networks Corporation, Waseca, MN; Notice of Negative Determination Regarding...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-08

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-81,646] CalAmp Wireless Networks...; CalAmp Wireless Networks Corporation, Waseca, Minnesota; expires on December 2, 2013). Conclusion Due to the eligibility of workers and former workers of CalAmp Wireless Networks Corporation, Waseca...

Genome-wide characterization and expression profiling of immune genes in the diamondback moth, Plutella xylostella (L.)

PubMed Central

Xia, Xiaofeng; Yu, Liying; Xue, Minqian; Yu, Xiaoqiang; Vasseur, Liette; Gurr, Geoff M.; Baxter, Simon W.; Lin, Hailan; Lin, Junhan; You, Minsheng

2015-01-01

The diamondback moth, Plutella xylostella (L.), is a destructive pest that attacks cruciferous crops worldwide. Immune responses are important for interactions between insects and pathogens and information on these underpins the development of strategies for biocontrol-based pest management. Little, however, is known about immune genes and their regulation patterns in P. xylostella. A total of 149 immune-related genes in 20 gene families were identified through comparison of P. xylostella genome with the genomes of other insects. Complete and conserved Toll, IMD and JAK-STAT signaling pathways were found in P. xylostella. Genes involved in pathogen recognition were expanded and more diversified than genes associated with intracellular signal transduction. Gene expression profiles showed that the IMD pathway may regulate expression of antimicrobial peptide (AMP) genes in the midgut, and be related to an observed down-regulation of AMPs in experimental lines of insecticide-resistant P. xylostella. A bacterial feeding study demonstrated that P. xylostella could activate different AMPs in response to bacterial infection. This study has established a framework of comprehensive expression profiles that highlight cues for immune regulation in a major pest. Our work provides a foundation for further studies on the functions of P. xylostella immune genes and mechanisms of innate immunity. PMID:25943446

Genome-wide characterization and expression profiling of immune genes in the diamondback moth, Plutella xylostella (L.).

PubMed

Xia, Xiaofeng; Yu, Liying; Xue, Minqian; Yu, Xiaoqiang; Vasseur, Liette; Gurr, Geoff M; Baxter, Simon W; Lin, Hailan; Lin, Junhan; You, Minsheng

2015-05-06

The diamondback moth, Plutella xylostella (L.), is a destructive pest that attacks cruciferous crops worldwide. Immune responses are important for interactions between insects and pathogens and information on these underpins the development of strategies for biocontrol-based pest management. Little, however, is known about immune genes and their regulation patterns in P. xylostella. A total of 149 immune-related genes in 20 gene families were identified through comparison of P. xylostella genome with the genomes of other insects. Complete and conserved Toll, IMD and JAK-STAT signaling pathways were found in P. xylostella. Genes involved in pathogen recognition were expanded and more diversified than genes associated with intracellular signal transduction. Gene expression profiles showed that the IMD pathway may regulate expression of antimicrobial peptide (AMP) genes in the midgut, and be related to an observed down-regulation of AMPs in experimental lines of insecticide-resistant P. xylostella. A bacterial feeding study demonstrated that P. xylostella could activate different AMPs in response to bacterial infection. This study has established a framework of comprehensive expression profiles that highlight cues for immune regulation in a major pest. Our work provides a foundation for further studies on the functions of P. xylostella immune genes and mechanisms of innate immunity.

Deployment of the National Transparent Optical Network around the San Francisco Bay Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCammon, K.; Haigh, R.; Armstrong, G.

1996-06-01

We report on the deployment and initial operation of the National Transparent Optical Network, an experimental WDM network testbed around the San Francisco Bay Area, during the Optical Fiber Conference (OFC`96) held in San Jose, CA. The deployment aspects of the physical plant, optical and SONET layers are examined along with a discussion of broadband applications which utilized the network during the OFC`96 demonstration. The network features dense WDM technology, transparent optical routing technology using acousto- optic tunable filter based switches, and network modules with add/drop, multicast, and wavelength translation capabilities. The physical layer consisted of over 300 km ofmore » Sprint and Pacific Bell conventional single mode fiber which was amplified with I I optical amplifiers deployed in pre-amp, post-amp, and line amp configurations. An out-of-band control network provided datacom channels from remote equipment sites to the SONET network manager deployed at the San Jose Convention Center for the conference. Data transport over five wavelengths was achieved in the 1550 nm window using a variety of signal formats including analog and digital signal transmission on different wavelengths on the same fiber. The network operated throughout the week of OFC`96 and is still in operation today.« less

Activation of AMP-activated protein kinase in the liver: a new strategy for the management of metabolic hepatic disorders

PubMed Central

Viollet, Benoit; Foretz, Marc; Guigas, Bruno; Horman, Sandrine; Dentin, Renaud; Bertrand, Luc; Hue, Louis; Andreelli, Fabrizio

2006-01-01

It is now becoming evident that the liver has an important role in the control of whole body metabolism of energy nutrients. In this review, we focus on recent findings showing that AMP-activated protein kinase (AMPK) plays a major role in the control of hepatic metabolism. AMPK integrates nutritional and hormonal signals to promote energy balance by switching on catabolic pathways and switching off ATP-consuming pathways, both by short-term effects on phosphorylation of regulatory proteins and by long-term effects on gene expression. Activation of AMPK in the liver leads to the stimulation of fatty acid oxidation and inhibition of lipogenesis, glucose production and protein synthesis. Medical interest in the AMPK system has recently increased with the demonstration that AMPK could mediate some of the effects of the fat cell-derived adiponectin and the antidiabetic drugs metformin and thiazolidinediones. These findings reinforce the idea that pharmacological activation of AMPK may provide, through signalling and metabolic and gene expression effects, a new strategy for the management of metabolic hepatic disorders linked to type 2 diabetes and obesity. PMID:16644802

Specific interactions between DNA and regulatory protein controlled by ligand-binding: Ab initio molecular simulation

NASA Astrophysics Data System (ADS)

Matsushita, Y.; Murakawa, T.; Shimamura, K.; Oishi, M.; Ohyama, T.; Kurita, N.

2015-02-01

The catabolite activator protein (CAP) is one of the regulatory proteins controlling the transcription mechanism of gene. Biochemical experiments elucidated that the complex of CAP with cyclic AMP (cAMP) is indispensable for controlling the mechanism, while previous molecular simulations for the monomer of CAP+cAMP complex revealed the specific interactions between CAP and cAMP. However, the effect of cAMP-binding to CAP on the specific interactions between CAP and DNA is not elucidated at atomic and electronic levels. We here considered the ternary complex of CAP, cAMP and DNA in solvating water molecules and investigated the specific interactions between them at atomic and electronic levels using ab initio molecular simulations based on classical molecular dynamics and ab initio fragment molecular orbital methods. The results highlight the important amino acid residues of CAP for the interactions between CAP and cAMP and between CAP and DNA.

Comparative Effects of Angiotensin and ACTH on Cyclic AMP and Steroidogenesis in Isolated Bovine Adrenal Cells

PubMed Central

Peytremann, Andre; Nicholson, Wendell E.; Brown, Ronald D.; Liddle, Grant W.; Hardman, Joel G.

1973-01-01

The comparative effects of angiotensin II and adrenocorticotropic hormone (ACTH) on cyclic AMP and steroidogenesis were investigated employing isolated bovine adrenal cells from the zona fasciculata. Like ACTH, angiotensin produced a prompt increase in cyclic AMP which preceded the increase in corticosteroid production. Although this increase in cyclic AMP was small when compared to that induced by ACTH, it correlated with the amount of steroidogenesis. This observation is consistent with the view that cyclic AMP is the intracellular mediator of the steroidogenic action of angiotensin. Angiotensin acted synergistically with ACTH on cyclic AMP levels. This synergism was not explained by inhibition of phosphodiesterase activity. Unlike ACTH, angiotensin failed to stimulate adenylate cyclase in broken cell preparations. The observations suggest that more than one mechanism may be involved in effects of ACTH and angiotensin on cyclic AMP levels. PMID:4348344

Proteomics assisted profiling of antimicrobial peptide signatures from black pepper (Piper nigrum L.).

PubMed

Umadevi, P; Soumya, M; George, Johnson K; Anandaraj, M

2018-05-01

Plant antimicrobial peptides are the interesting source of studies in defense response as they are essential components of innate immunity which exert rapid defense response. In spite of abundant reports on the isolation of antimicrobial peptides (AMPs) from many sources, the profile of AMPs expressed/identified from single crop species under certain stress/physiological condition is still unknown. This work describes the AMP signature profile of black pepper and their expression upon Phytophthora infection using label-free quantitative proteomics strategy. The differential expression of 24 AMPs suggests that a combinatorial strategy is working in the defense network. The 24 AMP signatures belonged to the cationic, anionic, cysteine-rich and cysteine-free group. As the first report on the possible involvement of AMP signature in Phytophthora infection, our results offer a platform for further study on regulation, evolutionary importance and exploitation of theses AMPs as next generation molecules against pathogens.

Antimicrobial Peptide Production and Purification.

PubMed

Suda, Srinivas; Field, Des; Barron, Niall

2017-01-01

Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

AMP deaminase 3 deficiency enhanced 5'-AMP induction of hypometabolism.

PubMed

Daniels, Isadora Susan; O Brien, William G; Nath, Vinay; Zhao, Zhaoyang; Lee, Cheng Chi

2013-01-01

A hypometabolic state can be induced in mice by 5'-AMP administration. Previously we proposed that an underlying mechanism for this hypometabolism is linked to reduced erythrocyte oxygen transport function due to 5'-AMP uptake altering the cellular adenylate equilibrium. To test this hypothesis, we generated mice deficient in adenosine monophosphate deaminase 3 (AMPD3), the key catabolic enzyme for 5'-AMP in erythrocytes. Mice deficient in AMPD3 maintained AMPD activities in all tissues except erythrocytes. Developmentally and morphologically, the Ampd3(-/-) mice were indistinguishable from their wild type siblings. The levels of ATP, ADP but not 5'-AMP in erythrocytes of Ampd3(-/-) mice were significantly elevated. Fasting blood glucose levels of the Ampd3(-/-) mice were comparable to wild type siblings. In comparison to wild type mice, the Ampd3(-/-) mice displayed a deeper hypometabolism with a significantly delayed average arousal time in response to 5'-AMP administration. Together, these findings demonstrate a central role of AMPD3 in the regulation of 5'-AMP mediated hypometabolism and further implicate erythrocytes in this behavioral response.

Carboxymethylated ɩ-carrageenan conjugated amphotericin B loaded gelatin nanoparticles for treating intracellular Candida glabrata infections.

PubMed

Aparna, V; Melge, Anu Rohit; Rajan, V K; Biswas, Raja; Jayakumar, R; Gopi Mohan, C

2018-04-15

Intercellular Candida glabrata infections are difficult to treat due to poor penetration of drugs into the fungal niche. Delivering amphotericin B (Amp B) into the macrophages where the pathogen inhabits is an effective solution. We are studying the macrophage targeting proficiency of ɩ-carrageenan for the delivery of Amp B using gelatin A nanoparticles (GNPs). The choice of gelatin A was the outcome of in silico inspections where the amino functionalized polymer having the best docking score with Amp B was selected. We prepared a sustained release formulation of amp B loaded carboxymethyl ɩ-carrageenan conjugated gelatin nanoparticles (CMC-Amp B-GNPs) with size 343±12nm and -25±5.3mV zeta potential. The formulations were found to be stable, biocompatible and non-haemolytic. Flow cytometry analysis showed 3 fold higher uptake of CMC-GNPs compared to the GNPs by RAW 264.7 cells. CMC-Amp B-GNPs showed enhanced antifungal activity than bare Amp B and Amp B-GNPs. Copyright © 2017 Elsevier B.V. All rights reserved.

The group migration of Dictyostelium cells is regulated by extracellular chemoattractant degradation.

PubMed

Garcia, Gene L; Rericha, Erin C; Heger, Christopher D; Goldsmith, Paul K; Parent, Carole A

2009-07-01

Starvation of Dictyostelium induces a developmental program in which cells form an aggregate that eventually differentiates into a multicellular structure. The aggregate formation is mediated by directional migration of individual cells that quickly transition to group migration in which cells align in a head-to-tail manner to form streams. Cyclic AMP acts as a chemoattractant and its production, secretion, and degradation are highly regulated. A key protein is the extracellular phosphodiesterase PdsA. In this study we examine the role and localization of PdsA during chemotaxis and streaming. We find that pdsA(-) cells respond chemotactically to a narrower range of chemoattractant concentrations compared with wild-type (WT) cells. Moreover, unlike WT cells, pdsA(-) cells do not form streams at low cell densities and form unusual thick and transient streams at high cell densities. We find that the intracellular pool of PdsA is localized to the endoplasmic reticulum, which may provide a compartment for storage and secretion of PdsA. Because we find that cAMP synthesis is normal in cells lacking PdsA, we conclude that signal degradation regulates the external cAMP gradient field generation and that the group migration behavior of these cells is compromised even though their signaling machinery is intact.

The Group Migration of Dictyostelium Cells Is Regulated by Extracellular Chemoattractant Degradation

PubMed Central

Garcia, Gene L.; Rericha, Erin C.; Heger, Christopher D.; Goldsmith, Paul K.

2009-01-01

Starvation of Dictyostelium induces a developmental program in which cells form an aggregate that eventually differentiates into a multicellular structure. The aggregate formation is mediated by directional migration of individual cells that quickly transition to group migration in which cells align in a head-to-tail manner to form streams. Cyclic AMP acts as a chemoattractant and its production, secretion, and degradation are highly regulated. A key protein is the extracellular phosphodiesterase PdsA. In this study we examine the role and localization of PdsA during chemotaxis and streaming. We find that pdsA− cells respond chemotactically to a narrower range of chemoattractant concentrations compared with wild-type (WT) cells. Moreover, unlike WT cells, pdsA− cells do not form streams at low cell densities and form unusual thick and transient streams at high cell densities. We find that the intracellular pool of PdsA is localized to the endoplasmic reticulum, which may provide a compartment for storage and secretion of PdsA. Because we find that cAMP synthesis is normal in cells lacking PdsA, we conclude that signal degradation regulates the external cAMP gradient field generation and that the group migration behavior of these cells is compromised even though their signaling machinery is intact. PMID:19477920

Cyclic AMP-dependent modification of gonad-selective TAF(II)105 in a human ovarian granulosa cell line.

PubMed

Wu, Yimin; Lu, Yunzhe; Hu, Yanfen; Li, Rong

2005-11-01

In response to gonadotropins, the elevated level of intracellular-cyclic AMP (cAMP) in ovarian granulosa cells triggers an ordered activation of multiple ovarian genes, which in turn promotes various ovarian functions including folliculogenesis and steroidogenesis. Identification and characterization of transcription factors that control ovarian gene expression are pivotal to the understanding of the molecular basis of the tissue-specific gene regulation programs. The recent discovery of the mouse TATA binding protein (TBP)-associated factor 105 (TAF(II)105) as a gonad-selective transcriptional co-activator strongly suggests that general transcription factors such as TFIID may play a key role in regulating tissue-specific gene expression. Here we show that the human TAF(II)105 protein is preferentially expressed in ovarian granulosa cells. We also identified a novel TAF(II)105 mRNA isoform that results from alternative exon inclusion and is predicted to encode a dominant negative mutant of TAF(II)105. Following stimulation by the adenylyl cyclase activator forskolin, TAF(II)105 in granulosa cells undergoes rapid and transient phosphorylation that is dependent upon protein kinase A (PKA). Thus, our work suggests that pre-mRNA processing and post-translational modification represent two important regulatory steps for the gonad-specific functions of human TAF(II)105. Copyright 2005 Wiley-Liss, Inc.

Evaluating the Impacts of Health, Social Network and Capital on Craft Efficiency and Productivity: A Case Study of Construction Workers in China.

PubMed

Yuan, Jingfeng; Yi, Wen; Miao, Mengyi; Zhang, Lei

2018-02-15

The construction industry has been recognized, for many years, as among those having a high likelihood of accidents, injuries and occupational illnesses. Such risks of construction workers can lead to low productivity and social problems. As a result, construction workers' well-being should be highly addressed to improve construction workers' efficiency and productivity. Meanwhile, the social support from a social network and capital (SNC) of construction workers has been considered as an effective approach to promote construction workers' physical and mental health (P&M health), as well as their work efficiency and productivity. Based on a comprehensive literature review, a conceptual model, which aims to improve construction workers' efficiency and productivity from the perspective of health and SNC, was proposed. A questionnaire survey was conducted to investigate the construction workers' health, SNC and work efficiency and productivity in Nanjing, China. A structural equation model (SEM) was employed to test the three hypothetical relationships among construction workers' P&M health, SNC and work efficiency and productivity. The results indicated that the direct impacts from construction workers' P&M health on work efficiency and productivity were more significant than that from the SNC. In addition, the construction workers' social capital and the network can indirectly influence the work efficiency and productivity by affecting the construction workers' P&M health. Therefore, strategies for enhancing construction workers' efficiency and productivity were proposed. Furthermore, many useable suggestions can be drawn from the research findings from the perspective of a government. The identified indicators and relationships would contribute to the construction work efficiency and productivity assessment and health management from the perspective of the construction workers.

Friends or Foes? Host defense (antimicrobial) peptides and proteins in human skin diseases.

PubMed

Niyonsaba, François; Kiatsurayanon, Chanisa; Chieosilapatham, Panjit; Ogawa, Hideoki

2017-11-01

Host defense peptides/proteins (HDPs), also known as antimicrobial peptides/proteins (AMPs), are key molecules in the cutaneous innate immune system. AMPs/HDPs historically exhibit broad-spectrum killing activity against bacteria, enveloped viruses, fungi and several parasites. Recently, AMPs/HDPs were shown to have important biological functions, including inducing cell proliferation, migration and differentiation; regulating inflammatory responses; controlling the production of various cytokines/chemokines; promoting wound healing; and improving skin barrier function. Despite the fact that AMPs/HDPs protect our body, several studies have hypothesized that these molecules actively contribute to the pathogenesis of various skin diseases. For example, AMPs/HDPs play crucial roles in the pathological processes of psoriasis, atopic dermatitis, rosacea, acne vulgaris, systemic lupus erythematosus and systemic sclerosis. Thus, AMPs/HDPs may be a double-edged sword, promoting cutaneous immunity while simultaneously initiating the pathogenesis of some skin disorders. This review will describe the most common skin-derived AMPs/HDPs (defensins, cathelicidins, S100 proteins, ribonucleases and dermcidin) and discuss the biology and both the positive and negative aspects of these AMPs/HDPs in skin inflammatory/infectious diseases. Understanding the regulation, functions and mechanisms of AMPs/HDPs may offer new therapeutic opportunities in the treatment of various skin disorders. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

cAMP modulates multiple K+ currents, increasing spike duration and excitability in Aplysia sensory neurons.

PubMed

Goldsmith, B A; Abrams, T W

1992-12-01

Enhancement of the defensive withdrawal reflex of Aplysia involves a prolongation of the action potentials of mechanosensory neurons, which contributes to facilitation of transmitter release from these cells. Recent reports have suggested that whereas cAMP-dependent modulation of K+ current increases sensory neuron excitability, a cAMP-independent decrease in K+ current may increase the action potential duration and, thus, facilitate transmitter release. We have tested this proposal using Walsh cAMP-dependent protein kinase inhibitor or activators of the cAMP cascade and found that cAMP plays a major role in the spike-broadening effects of facilitatory transmitter; however, broadening requires higher levels of activation of the cAMP-dependent kinase than does increasing excitability. A steeply voltage-dependent transient K+ current, termed IKV,early, and the slowly activating S-type K+ (S-K+) current are both reduced by activation of the cAMP cascade, although with different sensitivities to the second messenger, enabling excitability and spike duration to be regulated independently. Differences in cAMP sensitivity also suggested that the originally described S-K+ current actually consists of two independent components, a slowly activating component and a time-independent, "steady-state" current that is activated at rest.

Antimicrobial peptides of the genus Bacillus: a new era for antibiotics.

PubMed

Sumi, Chandra Datta; Yang, Byung Wook; Yeo, In-Cheol; Hahm, Young Tae

2015-02-01

The rapid onset of resistance reduces the efficacy of most conventional antimicrobial drugs and is a general cause of concern for human well-being. Thus, there is great demand for a continuous supply of novel antibiotics to combat this problem. Bacteria-derived antimicrobial peptides (AMPs) have long been used as food preservatives; moreover, prior to the development of conventional antibiotics, these AMPs served as an efficient source of antibiotics. Recently, peptides produced by members of the genus Bacillus were shown to have a broad spectrum of antimicrobial activity against pathogenic microbes. Bacillus-derived AMPs can be synthesized both ribosomally and nonribosomally and can be classified according to peptide biosynthesis, structure, and molecular weight. The precise mechanism of action of these AMPs is not yet clear; however, one proposed mechanism is that these AMPs kill bacteria by forming channels in and (or) disrupting the bacterial cell wall. Bacillus-derived AMPs have potential in the pharmaceutical industry, as well as the food and agricultural sectors. Here, we focus on Bacillus-derived AMPs as a novel alternative approach to antibacterial drug development. We also provide an overview of the biosynthesis, mechanisms of action, applications, and effectiveness of different AMPs produced by members of the Bacillus genus, including several recently identified novel AMPs.

In vitro activities and detection performances of cefmetazole and flomoxef for extended-spectrum β-lactamase and plasmid-mediated AmpC β-lactamase-producing Enterobacteriaceae.

PubMed

Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2016-04-01

To investigate the in vitro activities of cephamycins (cefmetazole and flomoxef) for extended-spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC β-lactamase (pAmpC)-producing Enterobacteriaceae, a total of 574 third-generation cephalosporin-resistant clinical isolates were collected at a Japanese multicenter study. PCR and sequencing identified 394 isolates with only ESBL genes, 63 isolates with only pAmpC genes, and 6 isolates with both ESBL and pAmpC genes. blaCTX-M types predominated 95.5% of the ESBL genes, and blaCMY-2 predominated 91.3% of the pAmpC genes. The MIC50/90 values of cefmetazole and flomoxef were ≤ 1/4 and ≤ 1/≤ 1 μg/mL for isolates with only ESBL genes, respectively, and 16/>16 and 8/16 μg/mL for isolates with only pAmpC genes, respectively. Flomoxef ≥ 4 μg/mL had the best screening performance for the detection of isolates with pAmpC genes. Flomoxef had better in vitro activities against ESBL-producing Enterobacteriaceae and provided a clearer distinction between ESBL and pAmpC-producing Enterobacteriaceae compared to cefmetazole. Copyright © 2016 Elsevier Inc. All rights reserved.

Toward More Successful Biomedical Informatics Education Programs and Ecosystems in the Arab World.

PubMed

Wageih, Mohamed A; Marcano-Cedeño, Alexis; Gómez, Enrique J; Mantas, John

2015-01-01

Biomedical & Health Informatics (BMHI) is relatively new in Arab States. However, several programs/ tracks are running, with high promises of expansion. Programs are evaluated by national authorities, not by a specialized body/association. This does not always mean that the program is of an international standard. One of the possible ways of ensuring the quality of these programs is to be evaluated by international agencies. The International Medical Informatics Association (IMIA) has the expertise in the evaluation BMHI education programs. Accredited programs staffs will have the opportunities for Internationalization and to be engaged with other top-notch organizations, which will have great impacts on the overall implementations of the BMHI in the Arab World. The goal of this document is to show to Arab Universities (pilot: Egypt) how to apply for IMIA Accreditation for their programs.

[Activation of the alternative oxidase of Yarrowia lipolytica by adenosine 5'-monophosphate].

PubMed

Medentsev, A G; Arinbasarova, A Iu; Smirnova, N M; Akimenko, V K

2004-01-01

The study of the effect of nucleoside phosphates on the activity of cyanide-resistant oxidase in the mitochondria and the submitochondrial particles of Yarrowia lipolytica showed that adenosine monophosphate (5'-AMP, AMP) did not stimulate the respiration of the intact mitochondria. The incubation of the mitochondria at room temperature (25 degrees C) for 3-5 h or their treatment with ultrasound, phospholipase A, and detergent Triton X-100 at a low temperature inactivated the cyanide-resistant alternative oxidase. The inactivated alternative oxidase could be reactivated by AMP. The reactivating effect of AMP was enhanced by azolectin. Some other nucleoside phosphates also showed reactivating ability in the following descending order. AMP = GMP > GDP > GTP > XMP > IMP. The apparent reaction rate constant Km for AMP upon the reactivation of the alternative oxidase of mitochondria treated with Triton X-100 or incubated at 25 degrees C was 12.5 and 20 microM, respectively. The Km for AMP upon the reactivation of the alternative oxidase of submitochondrial particles was 15 microM. During the incubation of yeast cells under conditions promoting the development of alternative oxidase, the content of adenine nucleotides (AMP, ADP, and ATP) in the cells and their respiration tended to decrease. The subsequent addition of cyanide to the cells activated their respiration, diminished the intracellular content of ATP three times, and augmented the content of AMP five times. These data suggest that the stimulation of cell respiration by cyanide may be due to the activation of alternative oxidase by AMP.

Interaction of 2',3'-cAMP with Rbp47b Plays a Role in Stress Granule Formation.

PubMed

Kosmacz, Monika; Luzarowski, Marcin; Kerber, Olga; Leniak, Ewa; Gutiérrez-Beltrán, Emilio; Moreno, Juan Camilo; Gorka, Michał; Szlachetko, Jagoda; Veyel, Daniel; Graf, Alexander; Skirycz, Aleksandra

2018-05-01

2',3'-cAMP is an intriguing small molecule that is conserved among different kingdoms. 2',3'-cAMP is presumably produced during RNA degradation, with increased cellular levels observed especially under stress conditions. Previously, we observed the presence of 2',3'-cAMP in Arabidopsis ( Arabidopsis thaliana ) protein complexes isolated from native lysate, suggesting that 2',3'-cAMP has potential protein partners in plants. Here, affinity purification experiments revealed that 2',3'-cAMP associates with the stress granule (SG) proteome. SGs are aggregates composed of protein and mRNA, which enable cells to selectively store mRNA for use in response to stress such as heat whereby translation initiation is impaired. Using size-exclusion chromatography and affinity purification analyses, we identified Rbp47b, the key component of SGs, as a potential interacting partner of 2',3'-cAMP. Furthermore, SG formation was promoted in 2',3'-cAMP-treated Arabidopsis seedlings, and interactions between 2',3'-cAMP and RNA-binding domains of Rbp47b, RRM2 and RRM3, were confirmed in vitro using microscale thermophoresis. Taken together, these results (1) describe novel small-molecule regulation of SG formation, (2) provide evidence for the biological role of 2',3'-cAMP, and (3) demonstrate an original biochemical pipeline for the identification of protein-metabolite interactors. © 2018 American Society of Plant Biologists. All Rights Reserved.

Interaction of 2′,3′-cAMP with Rbp47b Plays a Role in Stress Granule Formation1[OPEN

PubMed Central

Kerber, Olga; Leniak, Ewa; Szlachetko, Jagoda; Veyel, Daniel

2018-01-01

2′,3′-cAMP is an intriguing small molecule that is conserved among different kingdoms. 2′,3′-cAMP is presumably produced during RNA degradation, with increased cellular levels observed especially under stress conditions. Previously, we observed the presence of 2′,3′-cAMP in Arabidopsis (Arabidopsis thaliana) protein complexes isolated from native lysate, suggesting that 2′,3′-cAMP has potential protein partners in plants. Here, affinity purification experiments revealed that 2′,3′-cAMP associates with the stress granule (SG) proteome. SGs are aggregates composed of protein and mRNA, which enable cells to selectively store mRNA for use in response to stress such as heat whereby translation initiation is impaired. Using size-exclusion chromatography and affinity purification analyses, we identified Rbp47b, the key component of SGs, as a potential interacting partner of 2′,3′-cAMP. Furthermore, SG formation was promoted in 2′,3′-cAMP-treated Arabidopsis seedlings, and interactions between 2′,3′-cAMP and RNA-binding domains of Rbp47b, RRM2 and RRM3, were confirmed in vitro using microscale thermophoresis. Taken together, these results (1) describe novel small-molecule regulation of SG formation, (2) provide evidence for the biological role of 2′,3′-cAMP, and (3) demonstrate an original biochemical pipeline for the identification of protein-metabolite interactors. PMID:29618637

Indole-Induced Activities of β-Lactamase and Efflux Pump Confer Ampicillin Resistance in Pseudomonas putida KT2440

PubMed Central

Kim, Jisun; Shin, Bora; Park, Chulwoo; Park, Woojun

2017-01-01

Indole, which is widespread in microbial communities, has received attention because of its effects on bacterial physiology. Pseudomonas putida and Pseudomonas aeruginosa can acquire ampicillin (Amp) resistance during growth on indole-Amp agar. Transcriptome, mutant, and inhibitor studies have suggested that Amp resistance induced by indole can be attributed to increased gene expression of ttgAB encoding two genes of RND-type multidrug efflux operons and an ampC encoding β-lactamase. Expression, enzyme activities, and mutational analyses indicated that AmpC β-lactamase is important for acquiring Amp resistance of P. putida in the presence of indole. Here, we show, for the first time, that volatile indole increased Amp-resistant cells. Consistent with results of the volatile indole assay, a low concentration of indole in liquid culture promoted growth initially, but led to mutagenesis after indole was depleted, which could not be observed at high indole concentrations. Interestingly, ttgAB and ampC gene expression levels correlate with the concentration of indole, which might explain the low number of Amp-mutated cells in high indole concentrations. The expression levels of genes involved in mutagenesis, namely rpoS, recA, and mutS, were also modulated by indole. Our data indicates that indole reduces Amp-induced heterogeneity by promoting expression of TtgABC or MexAB-OprM efflux pumps and the indole-induced β-lactamase in P. putida and P. aeruginosa. PMID:28352264

The cyclic AMP cascade is altered in the fragile X nervous system.

PubMed

Kelley, Daniel J; Davidson, Richard J; Elliott, Jamie L; Lahvis, Garet P; Yin, Jerry C P; Bhattacharyya, Anita

2007-09-26

Fragile X syndrome (FX), the most common heritable cause of mental retardation and autism, is a developmental disorder characterized by physical, cognitive, and behavioral deficits. FX results from a trinucleotide expansion mutation in the fmr1 gene that reduces levels of fragile X mental retardation protein (FMRP). Although research efforts have focused on FMRP's impact on mGluR signaling, how the loss of FMRP leads to the individual symptoms of FX is not known. Previous studies on human FX blood cells revealed alterations in the cyclic adenosine 3', 5'-monophosphate (cAMP) cascade. We tested the hypothesis that cAMP signaling is altered in the FX nervous system using three different model systems. Induced levels of cAMP in platelets and in brains of fmr1 knockout mice are substantially reduced. Cyclic AMP induction is also significantly reduced in human FX neural cells. Furthermore, cAMP production is decreased in the heads of FX Drosophila and this defect can be rescued by reintroduction of the dfmr gene. Our results indicate that a robust defect in cAMP production in FX is conserved across species and suggest that cAMP metabolism may serve as a useful biomarker in the human disease population. Reduced cAMP induction has implications for the underlying causes of FX and autism spectrum disorders. Pharmacological agents known to modulate the cAMP cascade may be therapeutic in FX patients and can be tested in these models, thus supplementing current efforts centered on mGluR signaling.

Novel mechanisms and signaling pathways of esophageal ulcer healing: the role of prostaglandin EP2 receptors, cAMP, and pCREB

PubMed Central

Ahluwalia, Amrita; Baatar, Dolgor; Jones, Michael K.

2014-01-01

Clinical studies indicate that prostaglandins of E class (PGEs) may promote healing of tissue injury e.g., gastroduodenal and dermal ulcers. However, the precise roles of PGEs, their E-prostanoid (EP) receptors, signaling pathways including cAMP and cAMP response element-binding protein (CREB), and their relation to VEGF and angiogenesis in the tissue injury healing process remain unknown, forming the rationale for this study. Using an esophageal ulcer model in rats, we demonstrated that esophageal mucosa expresses predominantly EP2 receptors and that esophageal ulceration triggers an increase in expression of the EP2 receptor, activation of CREB (the downstream target of the cAMP signaling), and enhanced VEGF gene expression. Treatment of rats with misoprostol, a PGE1 analog capable of activating EP receptors, enhanced phosphorylation of CREB, stimulated VEGF expression and angiogenesis, and accelerated esophageal ulcer healing. In cultured human esophageal epithelial (HET-1A) cells, misoprostol increased intracellular cAMP levels (by 163-fold), induced phosphorylation of CREB, and stimulated VEGF expression. A cAMP analog (Sp-cAMP) mimicked, whereas an inhibitor of cAMP-dependent protein kinase A (Rp-cAMP) blocked, these effects of misoprostol. These results indicate that the EP2/cAMP/protein kinase A pathway mediates the stimulatory effect of PGEs on angiogenesis essential for tissue injury healing via the induction of CREB activity and VEGF expression. PMID:25059824

The effect of adenosine 5'-monophosphate (AMP) on tenderness, microstructure and chemical-physical index of duck breast meat.

PubMed

Wang, Daoying; Deng, Shaoying; Zhang, Muhan; Geng, Zhiming; Sun, Chong; Bian, Huan; Xu, Weimin; Zhu, Yongzhi; Liu, Fang; Wu, Haihong

2016-03-30

Adenosine 5'-monophosphate (AMP) is often used in meat and poultry soups as a flavor enhancer (flavor modifier), or as food additives for specific nutritional purposes. Our previous research as well as evidence from others showed that actomyosin could be dissociated into myosin and actin by AMP in extracted muscle solution. However, there is no report available on the application of AMP to dissociate actomyosin and to improve meat tenderness. The objectives of this study were to evaluate the effect of AMP on duck meat tenderness and other quality traits and to explore the mechanism of the action of AMP on meat tenderness. Duck breast muscle was treated with 0, 10, 20, 30, 40 mmol L(-1) AMP at 5 °C for 10 h and examined for shear force, microstructure, actomyosin dissociation, myofibril fragmentation index (MFI), pH, water content, cooking loss, CIE* color (L*, a*, b*), inosine monophosphate (IMP) and free amino acid (FAA) contents. Results showed that shear force, cooking loss, L* and b* of the muscles significantly decreased after AMP treatment (P < 0.05); actomyosin dissociation, MFI, pH, water content, fiber diameter, sarcomere length, IMP and ammonia significantly increased (P < 0.05); no significant change in a* or other FAA content was observed (P > 0.05), and muscle shrinkage in transverse and longitudinal directions were restrained after AMP treatment. The results suggest that AMP could notably improve meat tenderness, and this effect was probably mainly through increasing muscle pH, promoting actomyosin dissociation and disrupting the Z-line; meanwhile, the conversion of AMP to IMP may contribute to the flavor of meat. © 2015 Society of Chemical Industry.

ATP and AMP Mutually Influence Their Interaction with the ATP-binding Cassette (ABC) Adenylate Kinase Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) at Separate Binding Sites*

PubMed Central

Randak, Christoph O.; Dong, Qian; Ver Heul, Amanda R.; Elcock, Adrian H.; Welsh, Michael J.

2013-01-01

Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel in the ATP-binding cassette (ABC) transporter protein family. In the presence of ATP and physiologically relevant concentrations of AMP, CFTR exhibits adenylate kinase activity (ATP + AMP ⇆ 2 ADP). Previous studies suggested that the interaction of nucleotide triphosphate with CFTR at ATP-binding site 2 is required for this activity. Two other ABC proteins, Rad50 and a structural maintenance of chromosome protein, also have adenylate kinase activity. All three ABC adenylate kinases bind and hydrolyze ATP in the absence of other nucleotides. However, little is known about how an ABC adenylate kinase interacts with ATP and AMP when both are present. Based on data from non-ABC adenylate kinases, we hypothesized that ATP and AMP mutually influence their interaction with CFTR at separate binding sites. We further hypothesized that only one of the two CFTR ATP-binding sites is involved in the adenylate kinase reaction. We found that 8-azidoadenosine 5′-triphosphate (8-N3-ATP) and 8-azidoadenosine 5′-monophosphate (8-N3-AMP) photolabeled separate sites in CFTR. Labeling of the AMP-binding site with 8-N3-AMP required the presence of ATP. Conversely, AMP enhanced photolabeling with 8-N3-ATP at ATP-binding site 2. The adenylate kinase active center probe P1,P5-di(adenosine-5′) pentaphosphate interacted simultaneously with an AMP-binding site and ATP-binding site 2. These results show that ATP and AMP interact with separate binding sites but mutually influence their interaction with the ABC adenylate kinase CFTR. They further indicate that the active center of the adenylate kinase comprises ATP-binding site 2. PMID:23921386

Dibutyryl cAMP effects on thromboxane and leukotriene production in decompression-induced lung injury

NASA Technical Reports Server (NTRS)

Little, T. M.; Butler, B. D.

1997-01-01

Decompression-induced venous bubble formation has been linked to increased neutrophil counts, endothelial cell injury, release of vasoactive eicosanoids, and increased vascular membrane permeability. These actions may account for inflammatory responses and edema formation. Increasing the intracellular cAMP has been shown to decrease eicosanoid production and edema formation in various models of lung injury. Reduction of decompression-induced inflammatory responses was evaluated in decompressed rats pretreated with saline (controls) or dibutyryl cAMP (DBcAMP, an analog of cAMP). After pretreatment, rats were exposed to either 616 kPa for 120 min or 683 kPa for 60 min. The observed increases in extravascular lung water ratios (pulmonary edema), bronchoalveolar lavage, and pleural protein in the saline control group (683 kPa) were not evident with DBcAMP treatment. DBcAMP pretreatment effects were also seen with the white blood cell counts and the percent of neutrophils in the bronchoalveolar lavage. Urinary levels of thromboxane B2, 11-dehydrothromboxane B2, and leukotriene E4 were significantly increased with the 683 kPa saline control decompression exposure. DBcAMP reduced the decompression-induced leukotriene E4 production in the urine. Plasma levels of thromboxane B2, 11-dehydrothromboxane B2, and leukotriene E4 were increased with the 683-kPa exposure groups. DBcAMP treatment did not affect these changes. The 11-dehydrothromboxane B2 and leukotriene E4 levels in the bronchoalveolar lavage were increased with the 683 kPa exposure and were reduced with the DBcAMP treatment. Our results indicate that DBcAMP has the capability to reduce eicosanoid production and limit membrane permeability and subsequent edema formation in rats experiencing decompression sickness.

High glucose enhances cAMP level and extracellular signal-regulated kinase phosphorylation in Chinese hamster ovary cell: Usage of Br-cAMP in foreign protein β-galactosidase expression.

PubMed

Lin, Hsiao-Hsien; Lee, Tsung-Yih; Liu, Ting-Wei; Tseng, Ching-Ping

2017-07-01

Glucose is a carbon source for Chinese hamster ovary (CHO) cell growth, while low growth rate is considered to enhance the production of recombinant proteins. The present study reveals that glucose concentrations higher than 1 g/L reduce the growth rate and substantially increase in cAMP (∼300%) at a high glucose concentration (10 g/L). High glucose also enhances the phosphorylation of extracellular signal-regulated kinase (ERK) and p27 kip by Western blot analysis. To determine whether the phosphorylation of ERK is involved in the mechanism, a cyclic-AMP dependent protein kinase A (PKA) inhibitor (H-8) or MEK (MAPKK) inhibitor (PD98059) was added to block ERK phosphorylation. We show that both the high glucose-induced ERK phosphorylation and growth rate return to baseline levels. These results suggest that the cAMP/PKA and MAP signaling pathways are involved in the abovementioned mechanism. Interestingly, the direct addition of 8-bromo-cAMP (Br-cAMP), a membrane-permeable cAMP analog, can mimic the similar effects produced by high glucose. Subsequently Br-cAMP could induce β-galactosidase (β-Gal) recombinant protein expression by 1.6-fold. Furthermore, Br-cAMP can additionally enhance the β-Gal production (from 2.8- to 4.5-fold) when CHO cells were stimulated with glycerol, thymidine, dimethyl sulfoxide, pentanoic acid, or sodium butyrate. Thus, Br-cAMP may be used as an alternative agent in promoting foreign protein expression for CHO cells. Copyright © 2017. Published by Elsevier B.V.

Presence of AmpC beta-lactamases, CSA-1, CSA-2, CMA-1, and CMA-2 conferring an unusual resistance phenotype in Cronobacter sakazakii and Cronobacter malonaticus.

PubMed

Müller, Andrea; Hächler, Herbert; Stephan, Roger; Lehner, Angelika

2014-08-01

Here we describe the presence of two very similar but unusual variants of AmpC cephalosporinase in each Cronobacter sakazakii and C. malonaticus isolates conferring resistance exclusively to first generation cephalosporins. During a survey on the antibiotic resistance patterns of C. sakazakii and C. malonaticus strains isolated from a milk powder production facility, originally two different phenotypes regarding the susceptibility/resistance for the two beta-lactam antibiotics ampicillin (amp) and cephalothin (ceph) were observed: (i) isolates being susceptible for both antibiotics (amp(S)/ceph(S)), and (ii) strains exhibiting susceptibility to ampicillin but resistance to cephalothin (amp(S)/ceph(R)). The latter phenotype (amp(S)/ceph(R)) was observed in the majority of the environmental strains from the facility. Analysis of whole genome sequences of C. sakazakii revealed a gene putatively coding for an AmpC beta-lactamase. Consequently, the ampC genes from both species and both phenotypes were subjected to a cloning approach. Surprisingly, when expressed in Escherichia coli, all transformants exhibited the amp(S)/ceph(R) phenotype regardless of (i) the phenotypic backgrounds or (ii) the AmpC amino acid sequences of the original strains from which the clones were derived. The novel AmpC beta-lactamases were designated CSA-1 and CSA-2 (from C. sakazakii) and CMA-1 and CMA-2 (from C. malonaticus). The observed variations in the minimum inhibitory concentration (MIC) levels for cephalothin (wt compared to transformants) suggest that this feature is a target of a yet unknown regulatory mechanism present in the natural Cronobacter background but absent in the neutral E. coli host.

Elevated Cyclic AMP Levels in T Lymphocytes Transformed by Human T-Cell Lymphotropic Virus Type 1▿

PubMed Central

Kress, Andrea K.; Schneider, Grit; Pichler, Klemens; Kalmer, Martina; Fleckenstein, Bernhard; Grassmann, Ralph

2010-01-01

Human T-cell lymphotropic virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), transforms CD4+ T cells to permanent growth through its transactivator Tax. HTLV-1-transformed cells share phenotypic properties with memory and regulatory T cells (T-reg). Murine T-reg-mediated suppression employs elevated cyclic AMP (cAMP) levels as a key regulator. This led us to determine cAMP levels in HTLV-1-transformed cells. We found elevated cAMP concentrations as a consistent feature of all HTLV-1-transformed cell lines, including in vitro-HTLV-1-transformed, Tax-transformed, and patient-derived cells. In transformed cells with conditional Tax expression, high cAMP levels coincided with the presence of Tax but were lost without it. However, transient ectopic expression of Tax alone was not sufficient to induce cAMP. We found specific downregulation of the cAMP-degrading phosphodiesterase 3B (PDE3B) in HTLV-1-transformed cells, which was independent of Tax in transient expression experiments. This is in line with the notion that PDE3B transcripts and cAMP levels are inversely correlated. Overexpression of PDE3B led to a decrease of cAMP in HTLV-1-transformed cells. Decreased expression of PDE3B was associated with inhibitory histone modifications at the PDE3B promoter and the PDE3B locus. In summary, Tax transformation and its continuous expression contribute to elevated cAMP levels, which may be regulated through PDE3B suppression. This shows that HTLV-1-transformed cells assume biological features of long-lived T-cell populations that potentially contribute to viral persistence. PMID:20573814

Running-specific prostheses permit energy cost similar to nonamputees.

PubMed

Brown, Mary Beth; Millard-Stafford, Mindy L; Allison, Andrew R

2009-05-01

Improvements in prosthesis design have facilitated participation in competitive running for persons with lower limb loss (AMP). The purpose of this study was to examine the physiological responses of AMP using a run-specific prosthesis (RP) versus a traditional prosthesis (P) and cross-referenced with nonamputee controls (C) matched by training status, age, gender, and body composition during level treadmill running (TM). Twelve trained runners completed a multistage submaximal TM exercise during which HR and oxygen uptake (VO(2)) were obtained. Steady state measures at 134 m x min(-1) were compared between RP and P in AMP. AMP using RP (AMP-RP) and C also performed a continuous speed-incremented maximal TM test until volitional fatigue. RP elicited lower HR and VO(2) compared with P in AMP. Using RP, AMP achieved similar VO(2max) and peak TM speed compared with C but with higher HR(max). Relative HR (%HR(max)) and oxygen uptake (%VO(2max)), the regression intercept, slope, SEE, and Pearson's r correlation were not different between AMP-RP and C. %HR(max) calculated with the published equation, %HR(max) = 0.73(%VO(2max)) + 30, was not significantly different from actual %HR(max) for AMP-RP or C in any stage. RP permits AMP to attain peak TM speed and aerobic capacity similar to trained nonamputees and significantly attenuates HR and energy cost of submaximal running compared with a P. Use of RP confers no physiological advantage compared with nonamputee runners because energy cost at the set speed was not significantly different for AMP-RP. Current equations on the basis of the relative HR-VO(2) relationship seem appropriate to prescribe exercise intensity for persons with transtibial amputations using RP.

Effects of Coal Fly Ash Particulate Matter on the Antimicrobial Activity of Airway Surface Liquid

PubMed Central

Vargas Buonfiglio, Luis G.; Mudunkotuwa, Imali A.; Abou Alaiwa, Mahmoud H.; Vanegas Calderón, Oriana G.; Borcherding, Jennifer A.; Gerke, Alicia K.; Zabner, Joseph; Grassian, Vicki H.

2017-01-01

Background: Sustained exposure to ambient particulate matter (PM) is a global cause of mortality. Coal fly ash (CFA) is a byproduct of coal combustion and is a source of anthropogenic PM with worldwide health relevance. The airway epithelia are lined with fluid called airway surface liquid (ASL), which contains antimicrobial proteins and peptides (AMPs). Cationic AMPs bind negatively charged bacteria to exert their antimicrobial activity. PM arriving in the airways could potentially interact with AMPs in the ASL to affect their antimicrobial activity. Objectives: We hypothesized that PM can interact with ASL AMPs to impair their antimicrobial activity. Methods: We exposed pig and human airway explants, pig and human ASL, and the human cationic AMPs β-defensin-3, LL-37, and lysozyme to CFA or control. Thereafter, we assessed the antimicrobial activity of exposed airway samples using both bioluminescence and standard colony-forming unit assays. We investigated PM-AMP electrostatic interaction by attenuated total reflection Fourier-transform infrared spectroscopy and measuring the zeta potential. We also studied the adsorption of AMPs on PM. Results: We found increased bacterial survival in CFA-exposed airway explants, ASL, and AMPs. In addition, we report that PM with a negative surface charge can adsorb cationic AMPs and form negative particle–protein complexes. Conclusion: We propose that when CFA arrives at the airway, it rapidly adsorbs AMPs and creates negative complexes, thereby decreasing the functional amount of AMPs capable of killing pathogens. These results provide a novel translational insight into an early mechanism for how ambient PM increases the susceptibility of the airways to bacterial infection. https://doi.org/10.1289/EHP876 PMID:28696208

Selective inhibition of histamine-evoked Ca2+ signals by compartmentalized cAMP in human bronchial airway smooth muscle cells.

PubMed

Dale, Philippa; Head, Victoria; Dowling, Mark R; Taylor, Colin W

2018-05-01

Intracellular Ca 2+ and cAMP typically cause opposing effects on airway smooth muscle contraction. Receptors that stimulate these pathways are therapeutic targets in asthma and chronic obstructive pulmonary disease. However, the interactions between different G protein-coupled receptors (GPCRs) that evoke cAMP and Ca 2+ signals in human bronchial airway smooth muscle cells (hBASMCs) are poorly understood. We measured Ca 2+ signals in cultures of fluo-4-loaded hBASMCs alongside measurements of intracellular cAMP using mass spectrometry or [ 3 H]-adenine labeling. Interactions between the signaling pathways were examined using selective ligands of GPCRs, and inhibitors of Ca 2+ and cAMP signaling pathways. Histamine stimulated Ca 2+ release through inositol 1,4,5-trisphosphate (IP 3 ) receptors in hBASMCs. β 2 -adrenoceptors, through cAMP and protein kinase A (PKA), substantially inhibited histamine-evoked Ca 2+ signals. Responses to other Ca 2+ -mobilizing stimuli were unaffected by cAMP (carbachol and bradykinin) or minimally affected (lysophosphatidic acid). Prostaglandin E 2 (PGE 2 ), through EP 2 and EP 4 receptors, stimulated formation of cAMP and inhibited histamine-evoked Ca 2+ signals. There was no consistent relationship between the inhibition of Ca 2+ signals and the amounts of intracellular cAMP produced by different stimuli. We conclude that β-adrenoceptors, EP 2 and EP 4 receptors, through cAMP and PKA, selectively inhibit Ca 2+ signals evoked by histamine in hBASMCs, suggesting that PKA inhibits an early step in H 1 receptor signaling. Local delivery of cAMP within hyperactive signaling junctions mediates the inhibition. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evaluation of high-voltage, high-power, solid-state remote power controllers for amps

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1987-01-01

The Electrical Power Branch at Marshall Space Flight Center has a Power System Development Facility where various power circuit breadboards are tested and evaluated. This project relates to the evaluation of a particular remote power controller (RPC) energizing high power loads. The Facility equipment permits the thorough testing and evaluation of high-voltage, high-power solid-state remote power controllers. The purpose is to evaluate a Type E, 30 Ampere, 200 V dc remote power controller. Three phases of the RPC evaluation are presented. The RPC is evaluated within a low-voltage, low-power circuit to check its operational capability. The RPC is then evaluated while performing switch/circuit breaker functions within a 200 V dc, 30 Ampere power circuit. The final effort of the project relates to the recommended procedures for installing these RPC's into the existing Autonomously Managed Power System (AMPS) breadboard/test facility at MSFC.

Challenges and Limits Using Antimicrobial Peptides in Boar Semen Preservation.

PubMed

Schulze, M; Grobbel, M; Müller, K; Junkes, C; Dathe, M; Rüdiger, K; Jung, M

2015-07-01

Antibiotics are of great importance for the preservation of ejaculates for livestock breading. The use of antibiotics, however, is not an appropriate compensation for a lack of hygiene standards in artificial insemination (AI) centres. Sophisticated hygiene management and the proper identification of hygienic critical control points (HCCPs) at AI centres provide the basis for counteracting the development of antibiotic resistance in contaminant bacteria and their settlement in AI centres. In recent years, efforts have been made to use antimicrobial peptides (AMPs) in the preservation of boar semen. Investigations have included the testing of synthetic magainin derivatives and cyclic hexapeptides. One prerequisite for the application of AMPs is that they have a minor impact on eukaryotic cells. Bacterial selectivity, proteolytic stability, thermodynamic resistance, and mechanisms including synergistic interaction with conventional antibiotics have made cyclic hexapeptides highly promising candidates for potential application as peptide antibiotics for semen preservation. © 2015 Blackwell Verlag GmbH.

Solid state power controllers

NASA Technical Reports Server (NTRS)

Gibbs, R. S.

1973-01-01

The rationale, analysis, design, breadboarding and testing of the incremental functional requirements are reported that led to the development of prototype 1 and 5 Amp dc and 1 Amp ac solid state power controllers (SSPC's). The SSPC's are to be considered for use as a replacement of electro-mechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 Vdc. They have the advantage over conventional relay/circuit breaker systems in that they can be located near utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small guage wire for control, computer interface, logic, electrical multiplexing, unboard testing, and power management and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability.

Real-time monitoring of intracellular cAMP during acute ethanol exposure

PubMed Central

Gupta, Ratna; Qualls-Creekmore, Emily; Yoshimura, Masami

2013-01-01

Background In previous studies we have shown that ethanol enhances the activity of Gs-stimulated membrane-bound adenylyl cyclase (AC). The effect is AC isoform specific and the type 7 AC (AC7) is most responsive to ethanol. In this study, we employed a fluorescence resonance energy transfer (FRET) based cAMP sensor, Epac1-camps, to examine real-time temporal dynamics of ethanol effects on cAMP concentrations. To our knowledge, this is the first report on real-time detection of the ethanol effect on intracellular cAMP. Methods Hela cells were transfected with Epac1-camps, dopamine D1A receptor, and one isoform of AC (AC7 or AC3). Fluorescent images were captured using a specific filter set for cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), and FRET, respectively and FRET intensity was calculated on a pixel-by-pixel basis to examine changes in cAMP. Results During 2-minute stimulation with dopamine (DA), the cytoplasmic cAMP level quickly increased, then decreased to a plateau, where the cAMP level was higher than the level prior to stimulation with DA. Ethanol concentration dependently increased cytoplasmic cAMP in cells transfected with AC7, while ethanol did not have effect on cells transfected with AC3. Similar trends were observed for cAMP at the plasma membrane and in the nucleus during 2-minute stimulation with DA. Unexpectedly, when cells expressing AC7 were stimulated with DA or other Gs protein-coupled receptor’s ligand plus ethanol for 5 seconds, ethanol reduced cAMP concentration. Conclusion These results suggest that ethanol has two opposing effects on the cAMP generating system in an AC isoform specific manner, the enhancing effect on AC activity and the short lived inhibitory effect. Thus, ethanol may have a different effect on cAMP depending on not only AC isoform but also the duration of exposure. PMID:23731206

Adenosine receptor subtypes in the airways responses to 5'-adenosine monophosphate inhalation of sensitized guinea-pigs.

PubMed

Smith, N; Broadley, K J

2008-09-01

Endogenous adenosine levels are raised in the lungs during asthma attacks. 5'-adenosine monophosphate (5'-AMP) inhalation in asthmatics causes bronchoconstriction and in sensitized guinea-pigs induces early (EAR) and late asthmatic responses (LAR), airway hyper-reactivity (AHR) and inflammatory cell recruitment to the lungs. The aim of this study was to investigate the roles of A(1), A(2A), A(2B) and A(3) adenosine receptors in these responses to inhaled 5'-AMP in sensitized guinea-pigs. Comparisons were made with the effect of dexamethasone treatment on 5'-AMP-induced responses. Functional airways responses to inhaled 5'-AMP (3 and 300 mM) of actively sensitized, conscious guinea-pigs were determined by whole-body plethysmography following administration of selective adenosine receptor antagonists or their vehicles. AHR to inhaled histamine (1 mM) and inflammatory cell influx in bronchoalveolar lavage fluid were determined. 5'-AMP at 3 mM caused an immediate bronchoconstriction (EAR), whereas 300 mM caused bronchodilatation. Both responses were followed at 6 h by a LAR, together with inflammatory cell influx and AHR to histamine. The A(2A) receptor antagonist, ZM241385, further enhanced cell influx after 5'-AMP inhalation (3 and 300 mM), and blocked the immediate bronchodilator response to 300 mM 5'-AMP, exposing an EAR. The A(2B) receptor antagonist, MRS1706 (in the presence of ZM241385), inhibited the LAR, AHR and cell influx, following inhalation of 5'-AMP (300 mM). The A(3) receptor antagonist, MRS1220, inhibited 5'-AMP-induced inflammatory cell influx. The A(1) receptor antagonist, DPCPX (in the presence of ZM241385), inhibited the EAR following 5'-AMP inhalation (300 mM). Dexamethasone inhibited the LAR, AHR and cell influx following inhalation of 5'-AMP (300 mM). All four adenosine receptor subtypes play various roles in the airways responses to inhaled 5'-AMP in sensitized guinea-pigs.

Mechanism of N6-threonylcarbamoyladenonsine (t(6)A) biosynthesis: isolation and characterization of the intermediate threonylcarbamoyl-AMP.

PubMed

Lauhon, Charles T

2012-11-06

Genetic and biochemical studies have recently implicated four proteins required in bacteria for the biosynthesis of the universal tRNA modified base N6-threonylcarbamoyl adenosine (t(6)A). In this work, t(6)A biosynthesis in Bacillus subtilis has been reconstituted in vitro and found to indeed require the four proteins YwlC (TsaC), YdiB (TsaE), YdiC (TsaB) and YdiE (TsaD). YwlC was found to catalyze the conversion of L-threonine, bicarbonate/CO(2) and ATP to give the intermediate L-threonylcarbamoyl-AMP (TC-AMP) and pyrophosphate as products. TC-AMP was isolated by HPLC and characterized by mass spectrometry and (1)H NMR. NMR analysis showed that TC-AMP decomposes to give AMP and a nearly equimolar mixture of L-threonine and 5-methyl-2-oxazolidinone-4-carboxylate as final products. Under physiological conditions (pH 7.5, 37 °C, 2 mM MgCl(2)), the half-life of TC-AMP was measured to be 3.5 min. Both YwlC (in the presence of pyrophosphatase) and its Escherichia coli homologue YrdC catalyze the formation of TC-AMP while producing only a small molar fraction of AMP. This suggests that CO(2) and not an activated form of bicarbonate is the true substrate for these enzymes. In the presence of pyrophosphate, both enzymes catalyze clean conversion of TC-AMP back to ATP. Purified TC-AMP is efficiently processed to t(6)A by the YdiBCE proteins in the presence of tRNA substrates. This reaction is ATP independent in vitro, despite the known ATPase activity of YdiB. The estimated rate of conversion of TC-AMP by YdiBCE to t(6)A is somewhat lower than the initial rate from L-threonine, bicarbonate and ATP, which together with the stability data, is consistent with previous studies that suggest channeling of this intermediate.

Nucleoside monophosphorothioates as the new hydrogen sulfide precursors with unique properties.

PubMed

Bełtowski, Jerzy; Guranowski, Andrzej; Jamroz-Wiśniewska, Anna; Korolczuk, Agnieszka; Wojtak, Andrzej

2014-03-01

Hydrogen sulfide (H2S) is the gasotransmitter enzymatically synthesized in mammalian tissues from l-cysteine. H2S donors are considered as the potential drugs for the treatment of cardiovascular, neurological and inflammatory diseases. Recently, it has been demonstrated that synthetic nucleotide analogs, adenosine- and guanosine 5'-monophosphorothioates (AMPS and GMPS) can be converted to H2S and AMP or GMP, respectively, by purified histidine triad nucleotide-binding (Hint) proteins. We examined if AMPS and GMPS can be used as the H2S donors in intact biological systems. H2S production by isolated rat kidney glomeruli was measured by the specific polarographic sensor. H2S production was detected when glomeruli were incubated with AMPS or GMPS and ionotropic purinergic P2X7 receptor/channel agonist, BzATP. More H2S was generated from GMPS than from equimolar amount of AMPS. Nucleoside phosphorothioates together with BzATP relaxed angiotensin II-preconstricted glomeruli. In addition, infusion of AMPS or GMPS together with BzATP into the renal artery increased filtration fraction and glomerular filtration rate but had no effect on renal vascular resistance or renal blood flow. AMPS but not GMPS was converted to adenosine by isolated glomeruli, however, adenosine was not involved in AMPS-induced H2S synthesis because neither adenosine nor specific adenosine receptor agonists had any effect on H2S production. AMPS, but not GMPS, increased phosphorylation level of AMP-stimulated protein kinase (AMPK), but AMPK inhibitor, compound C, had no effect on AMPS-induced H2S production. In conclusion, nucleoside phosphorothioates are converted to H2S which relaxes isolated kidney glomeruli in vitro and increases glomerular filtration rate in vivo. AMPS and GMPS can be used as the H2S donors in experimental studies and possibly also as the H2S-releasing drugs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cyclic AMP Affects Oocyte Maturation and Embryo Development in Prepubertal and Adult Cattle

PubMed Central

Bernal-Ulloa, Sandra Milena; Heinzmann, Julia; Herrmann, Doris; Hadeler, Klaus-Gerd; Aldag, Patrick; Winkler, Sylke; Pache, Dorit; Baulain, Ulrich; Lucas-Hahn, Andrea; Niemann, Heiner

2016-01-01

High cAMP levels during in vitro maturation (IVM) have been related to improved blastocyst yields. Here, we employed the cAMP/cGMP modulators, forskolin, IBMX, and cilostamide, during IVM to unravel the role of high cAMP in early embryonic development produced from prepubertal and adult bovine oocytes. Oocytes were collected via transvaginal aspiration and randomly assigned to three experimental groups: TCM24 (24h IVM/control), cAMP30 (2h pre-IVM (forskolin-IBMX), 30h IVM-cilostamide), and DMSO30 (Dimethyl Sulfoxide/vehicle control). After IVM, oocytes were fertilized in vitro and zygotes were cultured in vitro to blastocysts. Meiotic progression, cAMP levels, mRNA abundance of selected genes and DNA methylation were evaluated in oocytes. Blastocysts were used for gene expression or DNA methylation analyses. Blastocysts from the cAMP30 groups were transferred to recipients. The cAMP elevation delayed meiotic progression, but developmental rates were not increased. In immature oocytes, mRNA abundance of PRKACA was higher for cAMP30 protocol and no differences were found for PDE3A, SMAD2, ZAR1, PRDX1 and SLC2A8. EGR1 gene was up-regulated in prepubertal cAMP30 immature oocytes and down-regulated in blastocysts from all in vitro treatments. A similar gene expression profile was observed for DNMT3b, BCL2L1, PRDX1 and SLC2A8 in blastocysts. Satellite DNA methylation profiles were different between prepubertal and adult oocytes and blastocysts derived from the TCM24 and DMSO30 groups. Blastocysts obtained from prepubertal and adult oocytes in the cAMP30 treatment displayed normal methylation profiles and produced offspring. These data indicate that cAMP regulates IVM in prepubertal and adult oocytes in a similar manner, with impact on the establishment of epigenetic marks and acquisition of full developmental competency. PMID:26926596

Protein kinase Cδ differentially regulates cAMP-dependent translocation of NTCP and MRP2 to the plasma membrane

PubMed Central

Park, Se Won; Schonhoff, Christopher M.; Webster, Cynthia R. L.

2012-01-01

Cyclic AMP stimulates translocation of Na+/taurocholate cotransporting polypeptide (NTCP) from the cytosol to the sinusoidal membrane and multidrug resistance-associated protein 2 (MRP2) to the canalicular membrane. A recent study suggested that protein kinase Cδ (PKCδ) may mediate cAMP-induced translocation of Ntcp and Mrp2. In addition, cAMP has been shown to stimulate NTCP translocation in part via Rab4. The aim of this study was to determine whether cAMP-induced translocation of NTCP and MRP2 require kinase activity of PKCδ and to test the hypothesis that cAMP-induced activation of Rab4 is mediated via PKCδ. Studies were conducted in HuH-NTCP cells (HuH-7 cells stably transfected with NTCP). Transfection of cells with wild-type PKCδ increased plasma membrane PKCδ and NTCP and increased Rab4 activity. Paradoxically, overexpression of kinase-dead dominant-negative PKCδ also increased plasma membrane PKCδ and NTCP as well as Rab4 activity. Similar results were obtained in PKCδ knockdown experiments, despite a decrease in total PKCδ. These results raised the possibility that plasma membrane localization rather than kinase activity of PKCδ is necessary for NTCP translocation and Rab4 activity. This hypothesis was supported by results showing that rottlerin, which has previously been shown to inhibit cAMP-induced membrane translocation of PKCδ and NTCP, inhibited cAMP-induced Rab4 activity. In addition, LY294002 (a phosphoinositide-3-kinase inhibitor), which has been shown to inhibit cAMP-induced NTCP translocation, also inhibited cAMP-induced PKCδ translocation. In contrast to the results with NTCP, cAMP-induced MRP2 translocation was inhibited in cells transfected with DN-PKCδ and small interfering RNA PKCδ. Taken together, these results suggest that the plasma membrane localization rather than kinase activity of PKCδ plays an important role in cAMP-induced NTCP translocation and Rab4 activity, whereas the kinase activity of PKCδ is necessary for cAMP-induced MRP2 translocation. PMID:22744337

Protein kinase Cδ differentially regulates cAMP-dependent translocation of NTCP and MRP2 to the plasma membrane.

PubMed

Park, Se Won; Schonhoff, Christopher M; Webster, Cynthia R L; Anwer, M Sawkat

2012-09-01

Cyclic AMP stimulates translocation of Na(+)/taurocholate cotransporting polypeptide (NTCP) from the cytosol to the sinusoidal membrane and multidrug resistance-associated protein 2 (MRP2) to the canalicular membrane. A recent study suggested that protein kinase Cδ (PKCδ) may mediate cAMP-induced translocation of Ntcp and Mrp2. In addition, cAMP has been shown to stimulate NTCP translocation in part via Rab4. The aim of this study was to determine whether cAMP-induced translocation of NTCP and MRP2 require kinase activity of PKCδ and to test the hypothesis that cAMP-induced activation of Rab4 is mediated via PKCδ. Studies were conducted in HuH-NTCP cells (HuH-7 cells stably transfected with NTCP). Transfection of cells with wild-type PKCδ increased plasma membrane PKCδ and NTCP and increased Rab4 activity. Paradoxically, overexpression of kinase-dead dominant-negative PKCδ also increased plasma membrane PKCδ and NTCP as well as Rab4 activity. Similar results were obtained in PKCδ knockdown experiments, despite a decrease in total PKCδ. These results raised the possibility that plasma membrane localization rather than kinase activity of PKCδ is necessary for NTCP translocation and Rab4 activity. This hypothesis was supported by results showing that rottlerin, which has previously been shown to inhibit cAMP-induced membrane translocation of PKCδ and NTCP, inhibited cAMP-induced Rab4 activity. In addition, LY294002 (a phosphoinositide-3-kinase inhibitor), which has been shown to inhibit cAMP-induced NTCP translocation, also inhibited cAMP-induced PKCδ translocation. In contrast to the results with NTCP, cAMP-induced MRP2 translocation was inhibited in cells transfected with DN-PKCδ and small interfering RNA PKCδ. Taken together, these results suggest that the plasma membrane localization rather than kinase activity of PKCδ plays an important role in cAMP-induced NTCP translocation and Rab4 activity, whereas the kinase activity of PKCδ is necessary for cAMP-induced MRP2 translocation.

Bacteraemia due to AmpC β-lactamase-producing Escherichia coli in hospitalized cancer patients: risk factors, antibiotic therapy, and outcomes.

PubMed

Zhang, Qing; Zhang, Wenfang; Li, Zheng; Bai, Changsen; Li, Ding; Zheng, Shan; Zhang, Peng; Zhang, Sihe

2017-07-01

AmpC β-lactamase-producing Escherichia coli (AmpC-EC) is one of the main antimicrobial resistant pathogens in patients with cancer. A cohort study was performed to evaluate the risk factors, antibiotic therapy, and outcomes of AmpC-EC bacteraemia in hospitalized cancer patients from September 2012 through December 2015. Two hundred forty-eight cases of E. coli bacteraemia were documented in cancer patients, 51 (20.6%) were caused by AmpC-EC and 197 (79.4%) were caused with non-AmpC-EC. Prior exposure to cephalosporins (OR 2.786; 95% CI: 1.094-7.091; P=0.032), carbapenems (OR 2.296; 95% CI: 1.054-5.004; P=0.036), and invasive procedures (OR 4.237; 95% CI: 1.731-10.37; P=0.002) were identified as independent risk factors for AmpC-EC. The time to positivity (TTP) of patients with AmpC-EC bacteraemia tended to be significantly shorter than that of non-AmpC-EC (8.33±2.18h versus 9.48±3.82h; P=0.006), and had a higher 30-day mortality rate in AmpC-EC compared with non-AmpC-EC (25.5% versus 12.2%; P=0.018). Metastasis (OR=2.778, 95% CI: 1.078-7.162; P=0.034), the presence of septic shock (OR=4.983, 95% CI: 1.761-14.10; P=0.002), and organ failure (OR=24.51 95% CI: 9.884-60.81; P<0.001) were independently associated with the overall mortality. The mortality rate showed a gradual increase when appropriate antibiotic therapy (AAT) was delayed more than 48h as determined by the trend test (P<0.001). In conclusion, this study showed that prevalence of AmpC-EC was high in hospitalized cancer patients of our area. Thus, it is necessary to apply appropriate therapeutic approaches and improve outcomes based on the analysis of risk factors for the acquisition of AmpC-EC. Copyright © 2017 Elsevier Inc. All rights reserved.

Protective features of resveratrol on human spermatozoa cryopreservation may be mediated through 5' AMP-activated protein kinase activation.

PubMed

Shabani Nashtaei, M; Amidi, F; Sedighi Gilani, M A; Aleyasin, A; Bakhshalizadeh, Sh; Naji, M; Nekoonam, S

2017-03-01

Biochemical and physical modifications during the freeze-thaw process adversely influence the restoration of energy-dependent sperm functions required for fertilization. Resveratrol, a phytoalexin, has been introduced to activate 5' AMP-activated protein kinase which is a cell energy sensor and a cell metabolism regulator. The cryoprotection of resveratrol on sperm cryoinjury via activation of AMP-activated protein kinase also remains to be elucidated. Our aim, thus, was to investigate: (i) the presence and intracellular localization of AMP-activated protein kinase protein; (ii) whether resveratrol may exert a protective effect on certain functional properties of fresh and post-thaw human spermatozoa through modulation of AMP-activated protein kinase. Spermatozoa from normozoospermic men were incubated with or without different concentrations of Compound C as an AMP-activated protein kinase inhibitor or resveratrol as an AMP-activated protein kinase activator for different lengths of time and were then cryopreserved. AMP-activated protein kinase is expressed essentially in the entire flagellum and the post-equatorial region. Viability of fresh spermatozoa was not significantly affected by the presence of Compound C or resveratrol. However, although Compound C caused a potent inhibition of spermatozoa motility parameters, resveratrol did not induce negative effect, except a significant reduction in motility at 25 μm for 1 h. Furthermore, resveratrol significantly increased AMP-activated protein kinase phosphorylation and mitochondrial membrane potential and decreased reactive oxygen species and apoptosis-like changes in frozen-thawed spermatozoa. Nevertheless, it was not able to compensate decreased sperm viability and motility parameters following cryopreservation. In contrast, Compound C showed opposite effects to resveratrol on AMP-activated protein kinase phosphorylation, reactive oxygen species, apoptosis-like changes, mitochondrial membrane potential, and motility parameters. These findings, although preliminary, suggest that resveratrol-induced improvement of cryopreserved sperm functions may be mediated through activation of AMP-activated protein kinase, indicating the importance of AMP-activated protein kinase activity for human spermatozoa functions. Further investigations are required to elucidate the mechanism by which resveratrol ameliorates oxidative stress-mediated damages in an AMP-activated protein kinase-dependent mechanism. © 2016 American Society of Andrology and European Academy of Andrology.

Molecular and clinical characterization of plasmid-mediated AmpC β-lactamase-producing Escherichia coli bacteraemia: a comparison with extended-spectrum β-lactamase-producing and non-resistant E. coli bacteraemia.

PubMed

Matsumura, Y; Nagao, M; Iguchi, M; Yagi, T; Komori, T; Fujita, N; Yamamoto, M; Matsushima, A; Takakura, S; Ichiyama, S

2013-02-01

Plasmid-mediated AmpC β-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case-control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Epidemiology and risk factors for infections due to AmpC β-lactamase-producing Escherichia coli.

PubMed

Pascual, Vanesa; Ortiz, Gabriel; Simó, Maria; Alonso, Noemí; Garcia, Maria Consol; Xercavins, Mariona; Rivera, Alba; Morera, Maria Antonia; Miró, Elisenda; Espejo, Elena; Navarro, Ferran; Gurguí, Mercè; Pérez, Josefa; Rodríguez-Carballeira, Mónica; Garau, Javier; Calbo, Esther

2015-03-01

To describe the prevalence and risk factors for infection due to AmpC β-lactamase-producing Escherichia coli (AmpC-EC). For the prevalence study, all clinical isolates of E. coli with reduced susceptibility to third-generation cephalosporins were prospectively included from June 2010 to November 2011. For risk factor analysis, a case-control study was conducted. Cases were patients with an infection due to AmpC-EC. Controls were patients infected with cephalosporin-susceptible E. coli, matched 1 : 2. Detection of blaAmpC genes was done with a multiplex AmpC-PCR, and hyperproduction of E. coli chromosomal blaAmpC by quantitative RT-PCR. Alteration of the blaAmpC promoter was studied by PCR and sequencing. We identified 243 (1.1%) AmpC-EC strains out of 21 563 clinical isolates. Three cases with strains carrying ESBLs, 18 strains that were considered due to colonization and 8 cases lost to clinical follow-up were excluded. Finally, 214 cases were included in the analysis. Ninety-one cases (42.5%) and 269 (62.8%) controls were strictly community acquired (P < 0.001). Thirty-five (16.3%) cases and 186 controls (43.5%) did not have any identifiable risk factor (P < 0.001). Among cases, 158 (73.8%) were found to harbour an acquired AmpC (73.4% CMY-2). Previous use of fluoroquinolones [OR 2.6 (95% CI 1.12-3.36); P = 0.008] was independently associated with AmpC-EC in the multivariate analysis. Prevalence of AmpC in E. coli remains low in our area. Plasmid acquisition (CMY type) represents the main mechanism of AmpC production. A high proportion of community-acquired isolates and patients with no identifiable risk factors were found. Previous use of fluoroquinolones was identified as a risk factor. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Role of Pseudomonas aeruginosa AmpR on β-lactam and non-β-lactam transient cross-resistance upon pre-exposure to subinhibitory concentrations of antibiotics

PubMed Central

Kumari, Hansi; Balasubramanian, Deepak; Zincke, Diansy

2014-01-01

Pseudomonas aeruginosa is one of the most dreaded opportunistic pathogens accounting for 10 % of hospital-acquired infections, with a 50 % mortality rate in chronically ill patients. The increased prevalence of drug-resistant isolates is a major cause of concern. Resistance in P. aeruginosa is mediated by various mechanisms, some of which are shared among different classes of antibiotics and which raise the possibility of cross-resistance. The goal of this study was to explore the effect of subinhibitory concentrations (SICs) of clinically relevant antibiotics and the role of a global antibiotic resistance and virulence regulator, AmpR, in developing cross-resistance. We investigated the induction of transient cross-resistance in P. aeruginosa PAO1 upon exposure to SICs of antibiotics. Pre-exposure to carbapenems, specifically imipenem, even at 3 ng ml−1, adversely affected the efficacy of clinically used penicillins and cephalosporins. The high β-lactam resistance was due to elevated expression of both ampC and ampR, encoding a chromosomal β-lactamase and its regulator, respectively. Differences in the susceptibility of ampR and ampC mutants suggested non-AmpC-mediated regulation of β-lactam resistance by AmpR. The increased susceptibility of P. aeruginosa in the absence of ampR to various antibiotics upon SIC exposure suggests that AmpR plays a major role in the cross-resistance. AmpR was shown previously to be involved in resistance to quinolones by regulating MexEF–OprN efflux pump. The data here further indicate the role of AmpR in cross-resistance between quinolones and aminoglycosides. This was confirmed using quantitative PCR, where expression of the mexEF efflux pump was further induced by ciprofloxacin and tobramycin, its substrate and a non-substrate, respectively, in the absence of ampR. The data presented here highlight the intricate cross-regulation of antibiotic resistance pathways at SICs of antibiotics and the need for careful assessment of the order of antibiotic regimens as this may have dire consequences. Targeting a global regulator such as AmpR that connects diverse pathways is a feasible therapeutic approach to combat P. aeruginosa pathogenesis. PMID:24464693

Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kucka, Marek; Pogrmic-Majkic, Kristina; Fa, Svetlana

2012-11-15

Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazinemore » did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward cAMP-specific PDEs was indicated by no changes in cGMP. ► Rolipram, a specific PDE4 inhibitor, also prevents stimulatory effects of atrazine. ► Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific PDE4.« less

Role of Pseudomonas aeruginosa AmpR on β-lactam and non-β-lactam transient cross-resistance upon pre-exposure to subinhibitory concentrations of antibiotics.

PubMed

Kumari, Hansi; Balasubramanian, Deepak; Zincke, Diansy; Mathee, Kalai

2014-04-01

Pseudomonas aeruginosa is one of the most dreaded opportunistic pathogens accounting for 10 % of hospital-acquired infections, with a 50 % mortality rate in chronically ill patients. The increased prevalence of drug-resistant isolates is a major cause of concern. Resistance in P. aeruginosa is mediated by various mechanisms, some of which are shared among different classes of antibiotics and which raise the possibility of cross-resistance. The goal of this study was to explore the effect of subinhibitory concentrations (SICs) of clinically relevant antibiotics and the role of a global antibiotic resistance and virulence regulator, AmpR, in developing cross-resistance. We investigated the induction of transient cross-resistance in P. aeruginosa PAO1 upon exposure to SICs of antibiotics. Pre-exposure to carbapenems, specifically imipenem, even at 3 ng ml(-1), adversely affected the efficacy of clinically used penicillins and cephalosporins. The high β-lactam resistance was due to elevated expression of both ampC and ampR, encoding a chromosomal β-lactamase and its regulator, respectively. Differences in the susceptibility of ampR and ampC mutants suggested non-AmpC-mediated regulation of β-lactam resistance by AmpR. The increased susceptibility of P. aeruginosa in the absence of ampR to various antibiotics upon SIC exposure suggests that AmpR plays a major role in the cross-resistance. AmpR was shown previously to be involved in resistance to quinolones by regulating MexEF-OprN efflux pump. The data here further indicate the role of AmpR in cross-resistance between quinolones and aminoglycosides. This was confirmed using quantitative PCR, where expression of the mexEF efflux pump was further induced by ciprofloxacin and tobramycin, its substrate and a non-substrate, respectively, in the absence of ampR. The data presented here highlight the intricate cross-regulation of antibiotic resistance pathways at SICs of antibiotics and the need for careful assessment of the order of antibiotic regimens as this may have dire consequences. Targeting a global regulator such as AmpR that connects diverse pathways is a feasible therapeutic approach to combat P. aeruginosa pathogenesis.

Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among Klebsiella pneumoniae and Escherichia Coli

PubMed Central

Zorgani, Abdulaziz; Daw, Hiyam; Sufya, Najib; Bashein, Abdullah; Elahmer, Omar; Chouchani, Chedly

2017-01-01

Introduction: Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates. Objective: The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya. Methods: All clinical isolates (76 K. pneumoniae and 75 E. coli) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR). Results: Of the K. pneumoniae and E. coli tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the E. coli isolates were multidrug resistant compared with K. pneumoniae (65.8%). K. pneumoniae ESBL producers were significantly higher (85.5%) compared with (17.3%) E. coli isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of K. pneumoniae, and 4% E. coli isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, blaCMY (n=3), bla MOX (n=1), blaDHA (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: bla CMY and blaEBC (n=1), and blaCMY and blaMOX (n=2). Neither blaFOX nor blaACC was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units. Conclusion: Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required. PMID:29151996

Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among Klebsiella pneumoniae and Escherichia Coli.

PubMed

Zorgani, Abdulaziz; Daw, Hiyam; Sufya, Najib; Bashein, Abdullah; Elahmer, Omar; Chouchani, Chedly

2017-01-01

Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates. The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya. All clinical isolates (76 K. pneumoniae and 75 E. coli ) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR). Of the K. pneumoniae and E. coli tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the E. coli isolates were multidrug resistant compared with K. pneumoniae (65.8%). K. pneumoniae ESBL producers were significantly higher (85.5%) compared with (17.3%) E. coli isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of K. pneumoniae , and 4% E. coli isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, bla CMY (n=3), bla MOX (n=1), bla DHA (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: bla CMY and bla EBC (n=1), and bla CMY and bla MOX (n=2). Neither bla FOX nor bla ACC was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units. Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.

Cellular Action of Vasopressin in Medullary Tubules of Mice with Hereditary Nephrogenic Diabetes Insipidus

PubMed Central

Jackson, Brian A.; Edwards, Richard M.; Valtin, Heinz; Dousa, Thomas P.

1980-01-01

Our previous studies (1974. J. Clin. Invest.54: 753-762.) suggested that impaired metabolism of cyclic AMP (cAMP) may be involved in the renal unresponsiveness to vasopressin (VP) in mice with hereditary nephrogenic diabetes insipidus (NDI). To localize such a defect to specific segments of the nephron, we studied the activities of VP-sensitive adenylate cyclase, cAMP phosphodiesterase (cAMP-PDIE), as well as accumulation of cAMP in medullary collecting tubules (MCT) and in medullary thick ascending limbs of Henle's loop (MAL) microdissected from control mice with normal concentrating ability and from mice with hereditary NDI. Adenylate cyclase activity stimulated by VP or by NaF was only slightly lower (−24%) in MCT from NDI mice, compared with controls. In MAL of NDI mice, basal, VP-sensitive, and NaF-sensitive adenylate cyclase was markedly (> −60%) lower compared with MAL of controls. The specific activity of cAMP-PDIE was markedly higher in MCT of NDI mice compared with controls, but was not different between MAL of control and NDI mice. Under present in vitro conditions, incubation of intact MCT from control mice with VP caused a striking increase in cAMP levels (>10), but VP failed to elicit a change in cAMP levels in MCT from NDI mice. When the cAMP-PDIE inhibitor 1-methyl-3-isobutyl xanthine (MIX) was added to the above incubation, VP caused a significant increase in cAMP levels in MCT from both NDI mice and control mice. Under all tested conditions, cAMP levels in MCT of NDI mice were lower than corresponding values in control MCT. Under the present experimental setting, VP and other stimulating factors (MIX, cholera toxin) did not change cAMP levels in MAL from either control mice or from NDI mice. The results of the present in vitro experiments suggest that the functional unresponsiveness of NDI mice to VP is perhaps mainly the result of the inability of collecting tubules to increase intracellular cAMP levels in response to VP. In turn, this inability to increase cAMP in response to VP is at least partly the result of abnormally high activity of cAMP-PDIE, a somewhat lower activity of VP-sensitive adenylate cyclase in MCT of NDI mice, and perhaps to a deficiency of some other as yet unidentified factors. The possible contribution of low VP-sensitive adenylate cyclase activity in MAL of NDI mice to the renal resistance to VP remains to be defined. PMID:6249843

Increasing the cAMP concentration during in vitro maturation of pig oocytes improves cumulus maturation and subsequent fertilization in vitro.

PubMed

Appeltant, R; Beek, J; Vandenberghe, L; Maes, D; Van Soom, A

2015-02-01

Porcine IVF faces various problems such as incomplete cytoplasmic maturation of the oocyte and polyspermy. Previous studies proved the importance of cAMP in regulating nuclear and cytoplasmic maturation of oocytes. This study investigated the effect of the cAMP-modulating agents 3-isobutyl-1-methylxanthine (IBMX) and dibutyryl cAMP sodium salt (dbcAMP) on several parameters during in vitro production of porcine embryos. First, we wanted to see if oocyte collection in IBMX could meiotically arrest oocytes and, as such, improve synchronization of nuclear and cytoplasmic maturation. To this end, cumulus-oocyte complexes (COCs) were collected from gilts in HEPES-buffered Tyrode balanced salt solution medium with 0.5-mM IBMX or without IBMX. At the end of oocyte collection, the effect of IBMX on chromatin configuration was evaluated. However, no differences could be observed in nuclear configuration between IBMX- and IBMX+ oocytes (P > 0.05). Second, we added dbcAMP during IVM to improve cytoplasmic maturation and evaluated cumulus expansion (lack of adhesion), a disintegrin and metalloproteinase with thrombospondin-like repeats (ADAMTS-1) levels in cumulus cells, fertilization, and blastocyst rates. Cumulus-oocyte complexes were matured in modified North Carolina State University medium 37 with or without 1-mM dbcAMP. Frozen-thawed, epididymal, boar spermatozoa were used for IVF. After IVF, presumed zygotes were cultured for 7 days in North Carolina State University medium 23. Penetration rate decreased in dbcAMP+ (57.3%) compared with dbcAMP- (67.8%), but the polyspermy rate also decreased (43.3% vs. 53.4%, respectively) leading to an increased normal fertilization rate (56.7% vs. 46.6%, respectively; P < 0.05). Only 7.2% of the COCs showed adhesion in dbcAMP+ which was lower than 15.7% in dbcAMP- (P < 0.05) probably because of an upregulation of the ADAMTS-1 protein by dbcAMP. When the adherent oocytes were removed during maturation, no difference could be detected between the blastocyst rate of dbcAMP- and dbcAMP+ (17.1% and 21.0% on Day 7, respectively; P > 0.05). In conclusion, the use of IBMX during collection did not cause a meiotic arrest. Using dbcAMP during IVM caused a greater normal fertilization rate, a lower rate of adherent COCs during IVM, higher levels of ADAMTS-1 in cumulus cells, and an equal blastocyst rate after screening out adherent COCs. These findings contribute to a better understanding of cAMP involvement in porcine oocyte maturation and provide a basis to develop an improved system with less polyspermy and higher blastocyst rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Multi drug resistance and Extended Spectrum Beta Lactamases in clinical isolates of Shigella: A study from New Delhi, India.

PubMed

Aggarwal, Prabhav; Uppal, Beena; Ghosh, Roumi; Krishna Prakash, S; Chakravarti, Anita; Jha, Arun Kumar; Rajeshwari, Krishnan

2016-01-01

Shigella is an important cause of gastroenteritis in local Indian population, as well as of traveler's diarrhea in the international visitors to India. These patients often require appropriate antimicrobial therapy; however, rapid development of antimicrobial resistance poses a major hurdle in achieving this goal. A prospective study was conducted during 2009-12 in New Delhi, India, including 6339 stool samples from gastroenteritis patients. 121 Shigella strains were identified on the basis of colony morphology, biochemical reactions, serotyping and ipaH gene based PCR. Antimicrobial susceptibility testing by disc diffusion, MIC determination by Vitek(®) 2 and phenotypic tests for ESBL/AmpC production were done. Nineteen percent strains (23/121) were found to be resistant to third generation cephalosporins and all were phenotypically confirmed to be ESBL producers; one strain was positive for AmpC. ESBL producing strains were also found to be significantly more resistant (p < 0.05) to several other antimicrobials agents in comparison to ESBL non-producers, [ampicillin (100% vs. 62.2%), ampicillin/sulbactam (100% vs. 30.6%), cotrimoxazole (100% vs. 77.6%), ciprofloxacin (87.0% vs. 49.0%), ofloxacin (87.0% vs. 52.0%) and gentamicin (30.4% vs. 7.1%)]. Multidrug resistance was seen in 76% strains. Inappropriate use of antimicrobial agents puts high selection pressure on the higher-end antibiotics. Multi-drug resistance and high rates of ESBL production by Shigella is a matter of concern for the local population as well as international travelers. Therefore, better national level antimicrobial management programs are the priority needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Solid polymer electrolyte water electrolysis preprototype subsystem. [oxygen production for life support systems on space stations

NASA Technical Reports Server (NTRS)

1979-01-01

Hardware and controls developed for an electrolysis demonstration unit for use with the life sciences payload program and in NASA's regenerative life support evaluation program are described. Components discussed include: the electrolysis module; power conditioner; phase separator-pump and hydrogen differential regulator; pressure regulation of O2, He, and N2; air-cooled heat exchanger; water accumulator; fluid flow sight gage assembly; catalytic O2/H2 sensor; gas flow sensors; low voltage power supply; 100 Amp DC contactor assembly; and the water purifier design.

Real-time fluorescence loop mediated isothermal amplification for the diagnosis of malaria.

PubMed

Lucchi, Naomi W; Demas, Allison; Narayanan, Jothikumar; Sumari, Deborah; Kabanywanyi, Abdunoor; Kachur, S Patrick; Barnwell, John W; Udhayakumar, Venkatachalam

2010-10-29

Molecular diagnostic methods can complement existing tools to improve the diagnosis of malaria. However, they require good laboratory infrastructure thereby restricting their use to reference laboratories and research studies. Therefore, adopting molecular tools for routine use in malaria endemic countries will require simpler molecular platforms. The recently developed loop-mediated isothermal amplification (LAMP) method is relatively simple and can be improved for better use in endemic countries. In this study, we attempted to improve this method for malaria diagnosis by using a simple and portable device capable of performing both the amplification and detection (by fluorescence) of LAMP in one platform. We refer to this as the RealAmp method. Published genus-specific primers were used to test the utility of this method. DNA derived from different species of malaria parasites was used for the initial characterization. Clinical samples of P. falciparum were used to determine the sensitivity and specificity of this system compared to microscopy and a nested PCR method. Additionally, directly boiled parasite preparations were compared with a conventional DNA isolation method. The RealAmp method was found to be simple and allowed real-time detection of DNA amplification. The time to amplification varied but was generally less than 60 minutes. All human-infecting Plasmodium species were detected. The sensitivity and specificity of RealAmp in detecting P. falciparum was 96.7% and 91.7% respectively, compared to microscopy and 98.9% and 100% respectively, compared to a standard nested PCR method. In addition, this method consistently detected P. falciparum from directly boiled blood samples. This RealAmp method has great potential as a field usable molecular tool for diagnosis of malaria. This tool can provide an alternative to conventional PCR based diagnostic methods for field use in clinical and operational programs.

Adenylyl cyclase type 9 gene polymorphisms are associated with asthma and allergy in Brazilian children.

PubMed

Teixeira, Helena M P; Alcantara-Neves, Neuza M; Barreto, Maurício; Figueiredo, Camila A; Costa, Ryan S

2017-02-01

Asthma is a chronic inflammatory disease of the respiratory tract. This heterogeneous disease is caused by the interaction of interindividual genetic variability and environmental factors. The gene adenylyl cyclase type 9 (ADCY9) encodes a protein called adenylyl cyclase (AC), responsible for producing the second messenger cyclic AMP (cAMP). cAMP is produced by T regulatory cells and is involved in the down-regulation of T effector cells. Failures in cAMP production may be related to an imbalance in the regulatory immune response, leading to immune-mediated diseases, such as allergic disorders. The aim of this study was to investigate how polymorphisms in the ADCY9 are associated with asthma and allergic markers. The study comprised 1309 subjects from the SCAALA (Social Changes Asthma and Allergy in Latin America) program. Genotyping was accomplished using the Illumina 2.5 Human Omni bead chip. Logistic regression was used to assess the association between allergy markers and ADCY9 variation in PLINK 1.07 software with adjustments for sex, age, helminth infection and ancestry markers. The ADCY9 candidate gene was associated with different phenotypes, such as asthma, specific IgE, skin prick test, and cytokine production. Among 133 markers analyzed, 29 SNPs where associated with asthma and allergic markers in silico analysis revealed the functional impact of the 6 SNPs on ADCY9 expression. It can be concluded that polymorphisms in the ADCY9 gene are significantly associated with asthma and/or allergy markers. We believe that such polymorphisms may lead to increased expression of adenylyl cyclase with a consequent increase in immunoregulatory activity. Therefore, these SNPs may offer an impact on the occurrence of these conditions in admixture population from countries such as Brazil. Copyright © 2017 Elsevier Ltd. All rights reserved.

75 FR 22043 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-27

... report of an electrical failure, an investigation revealed inadequate functioning of the 35 amperes (Amps... to replace the 35 Amps with a 50 Amps circuit breaker and replace the wires with oversized ones to... of the 35 Amps BATT BUS circuit breaker. To prevent an electrical failure, the manufacturer has...

Activation of Exchange Protein Activated by Cyclic-AMP Enhances Long-Lasting Synaptic Potentiation in the Hippocampus

ERIC Educational Resources Information Center

Gelinas, Jennifer N.; Banko, Jessica L.; Peters, Melinda M.; Klann, Eric; Weeber, Edwin J.; Nguyen, Peter V.

2008-01-01

cAMP is a critical second messenger implicated in synaptic plasticity and memory in the mammalian brain. Substantial evidence links increases in intracellular cAMP to activation of cAMP-dependent protein kinase (PKA) and subsequent phosphorylation of downstream effectors (transcription factors, receptors, protein kinases) necessary for long-term…

Expression of Antimicrobial Peptides by Uveal and Cutaneous Melanoma Cells and Investigation of Their Role in Tumor Cell Migration and Vasculogenic Mimicry.

PubMed

Manarang, Joseph C; Otteson, Deborah C; McDermott, Alison M

2017-11-01

Antimicrobial peptides (AMPs) have been implicated in the pathogenesis of several cancers, although there is also evidence suggesting potential for novel, AMP-based antitumor therapies. Discerning potential roles of AMPs in tumor pathogenesis may provide valuable insight into the mechanisms of novel AMP-based antitumor therapy. mRNA expression of the AMPs α defensin (HNP-1); cathelicidin (LL-37); and β defensins (hBD-1, hBD-2, hBD-3, hBD-4) in human uveal and cutaneous melanoma cell lines, primary human uveal melanocytes, and primary human uveal melanoma cells was determined by reverse transcriptase polymerase chain reaction. An in vitro scratch assay and custom Matlab analysis were used to determine the AMP effects on melanoma cell migration. Last, the effect of specific AMPs on vasculogenic mimicry was determined by three-dimensional (3D) culture and light and fluorescence microscopy. Low-to-moderate AMP transcript levels were detected, and these varied across the cells tested. Overall, LL-37 expression was increased while hBD-4 was decreased in most melanoma cell lines, compared to primary cultured uveal melanocytes. There was no observable influence of HNP-1 and LL-37 on tumor cell migration. Additionally, aggressive cutaneous melanoma cells grown in 3D cultures exhibited vasculogenic mimicry, although AMP exposure did not alter this process. Collectively, our data show that although AMP mRNA expression is variable between uveal and cutaneous melanoma cells, these peptides have little influence on major characteristics that contribute to tumor aggressiveness and progression.

Gαs regulates Glucagon-Like Peptide 1 Receptor-mediated cyclic AMP generation at Rab5 endosomal compartment.

PubMed

Girada, Shravan Babu; Kuna, Ramya S; Bele, Shilpak; Zhu, Zhimeng; Chakravarthi, N R; DiMarchi, Richard D; Mitra, Prasenjit

2017-10-01

Upon activation, G protein coupled receptors (GPCRs) associate with heterotrimeric G proteins at the plasma membrane to initiate second messenger signaling. Subsequently, the activated receptor experiences desensitization, internalization, and recycling back to the plasma membrane, or it undergoes lysosomal degradation. Recent reports highlight specific cases of persistent cyclic AMP generation by internalized GPCRs, although the functional significance and mechanistic details remain to be defined. Cyclic AMP generation from internalized Glucagon-Like Peptide-1 Receptor (GLP-1R) has previously been reported from our laboratory. This study aimed at deciphering the molecular mechanism by which internalized GLP-R supports sustained cyclic AMP generation upon receptor activation in pancreatic beta cells. We studied the time course of cyclic AMP generation following GLP-1R activation with particular emphasis on defining the location where cyclic AMP is generated. Detection involved a novel GLP-1 conjugate coupled with immunofluorescence using specific endosomal markers. Finally, we employed co-immunoprecipitation as well as immunofluorescence to assess the protein-protein interactions that regulate GLP-1R mediated cyclic AMP generation at endosomes. Our data reveal that prolonged association of G protein α subunit Gαs with activated GLP-1R contributed to sustained cyclic AMP generation at Rab 5 endosomal compartment. The findings provide the mechanism of endosomal cyclic AMP generation following GLP-1R activation. We identified the specific compartment that serves as an organizing center to generate endosomal cyclic AMP by internalized activated receptor complex. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Exchange protein activated by cyclic AMP (Epac)-mediated induction of suppressor of cytokine signaling 3 (SOCS-3) in vascular endothelial cells.

PubMed

Sands, William A; Woolson, Hayley D; Milne, Gillian R; Rutherford, Claire; Palmer, Timothy M

2006-09-01

Here, we demonstrate that elevation of intracellular cyclic AMP (cAMP) in vascular endothelial cells (ECs) by either a direct activator of adenylyl cyclase or endogenous cAMP-mobilizing G protein-coupled receptors inhibited the tyrosine phosphorylation of STAT proteins by an interleukin 6 (IL-6) receptor trans-signaling complex (soluble IL-6Ralpha/IL-6). This was associated with the induction of suppressor of cytokine signaling 3 (SOCS-3), a bona fide inhibitor in vivo of gp130, the signal-transducing component of the IL-6 receptor complex. Attenuation of SOCS-3 induction in either ECs or SOCS-3-null murine embryonic fibroblasts abolished the inhibitory effect of cAMP, whereas inhibition of SHP-2, another negative regulator of gp130, was without effect. Interestingly, the inhibition of STAT phosphorylation and SOCS-3 induction did not require cAMP-dependent protein kinase activity but could be recapitulated upon selective activation of the alternative cAMP sensor Epac, a guanine nucleotide exchange factor for Rap1. Consistent with this hypothesis, small interfering RNA-mediated knockdown of Epac1 was sufficient to attenuate both cAMP-mediated SOCS-3 induction and inhibition of STAT phosphorylation, suggesting that Epac activation is both necessary and sufficient to observe these effects. Together, these data argue for the existence of a novel cAMP/Epac/Rap1/SOCS-3 pathway for limiting IL-6 receptor signaling in ECs and illuminate a new mechanism by which cAMP may mediate its potent anti-inflammatory effects.

Pathogenic and commensal Escherichia coli from irrigation water show potential in transmission of extended spectrum and AmpC β-lactamases determinants to isolates from lettuce

PubMed Central

Njage, Patrick M K; Buys, Elna M

2015-01-01

There are few studies on the presence of extended-spectrum β-lactamases and AmpC β-lactamases (ESBL/AmpC) in bacteria that contaminate vegetables. The role of the production environment in ESBL/AmpC gene transmission is poorly understood. The occurrence of ESBL/AmpC in Escherichia coli (n = 46) from lettuce and irrigation water and the role of irrigation water in the transmission of resistant E. coli were studied. The presence of ESBL/AmpC, genetic similarity and phylogeny were typed using genotypic and phenotypic techniques. The frequency of β-lactamase gene transfer was studied in vitro. ESBLs/AmpC were detected in 35 isolates (76%). Fourteen isolates (30%) produced both ESBLs/AmpC. Prevalence was highest in E. coli from lettuce (90%). Twenty-two isolates (48%) were multi-resistant with between two and five ESBL/AmpC genes. The major ESBL determinant was the CTX-M type (34 isolates). DHA (33% of isolates) were the dominant AmpC β lactamases. There was a high conjugation efficiency among the isolates, ranging from 3.5 × 10−2 to 1 × 10−2 ± 1.4 × 10−1 transconjugants per recipient. Water isolates showed a significantly higher conjugation frequency than those from lettuce. A high degree of genetic relatedness between E. coli from irrigation water and lettuce indicated possible common ancestry and pathway of transmission. PMID:25488608

iAMP-2L: a two-level multi-label classifier for identifying antimicrobial peptides and their functional types.

PubMed

Xiao, Xuan; Wang, Pu; Lin, Wei-Zhong; Jia, Jian-Hua; Chou, Kuo-Chen

2013-05-15

Antimicrobial peptides (AMPs), also called host defense peptides, are an evolutionarily conserved component of the innate immune response and are found among all classes of life. According to their special functions, AMPs are generally classified into ten categories: Antibacterial Peptides, Anticancer/tumor Peptides, Antifungal Peptides, Anti-HIV Peptides, Antiviral Peptides, Antiparasital Peptides, Anti-protist Peptides, AMPs with Chemotactic Activity, Insecticidal Peptides, and Spermicidal Peptides. Given a query peptide, how can we identify whether it is an AMP or non-AMP? If it is, can we identify which functional type or types it belong to? Particularly, how can we deal with the multi-type problem since an AMP may belong to two or more functional types? To address these problems, which are obviously very important to both basic research and drug development, a multi-label classifier was developed based on the pseudo amino acid composition (PseAAC) and fuzzy K-nearest neighbor (FKNN) algorithm, where the components of PseAAC were featured by incorporating five physicochemical properties. The novel classifier is called iAMP-2L, where "2L" means that it is a 2-level predictor. The 1st-level is to answer the 1st question above, while the 2nd-level is to answer the 2nd and 3rd questions that are beyond the reach of any existing methods in this area. For the conveniences of users, a user-friendly web-server for iAMP-2L was established at http://www.jci-bioinfo.cn/iAMP-2L. Copyright © 2013 Elsevier Inc. All rights reserved.

RasC is required for optimal activation of adenylyl cyclase and Akt/PKB during aggregation

PubMed Central

Lim, Chinten James; Spiegelman, George B.; Weeks, Gerald

2001-01-01

Disruption of Dictyostelium rasC, encoding a Ras subfamily protein, generated cells incapable of aggregation. While rasC expression is enriched in a cell type-specific manner during post-aggregative development, the defect in rasC– cells is restricted to aggregation and fully corrected by application of exogenous cAMP pulses. cAMP is not produced in rasC– cells stimulated by 2′-deoxy-cAMP, but is produced in response to GTPγS in cell lysates, indicating that G-protein-coupled cAMP receptor activation of adenylyl cyclase is regulated by RasC. However, cAMP-induced ERK2 phosphorylation is unaffected in rasC– cells, indicating that RasC is not an upstream activator of the mitogen-activated protein kinase required for cAMP relay. rasC– cells also exhibit reduced chemotaxis to cAMP during early development and delayed response to periodic cAMP stimuli produced by wild-type cells in chimeric mixtures. Furthermore, cAMP-induced Akt/PKB phosphorylation through a phosphatidylinositide 3-kinase (PI3K)-dependent pathway is dramatically reduced in rasC– cells, suggesting that G-protein-coupled serpentine receptor activation of PI3K is regulated by RasC. Cells lacking the RasGEF, AleA, exhibit similar defects as rasC– cells, suggesting that AleA may activate RasC. PMID:11500376

RasC is required for optimal activation of adenylyl cyclase and Akt/PKB during aggregation.

PubMed

Lim, C J; Spiegelman, G B; Weeks, G

2001-08-15

Disruption of Dictyostelium rasC, encoding a Ras subfamily protein, generated cells incapable of aggregation. While rasC expression is enriched in a cell type-specific manner during post-aggregative development, the defect in rasC(-) cells is restricted to aggregation and fully corrected by application of exogenous cAMP pulses. cAMP is not produced in rasC(-) cells stimulated by 2'-deoxy-cAMP, but is produced in response to GTPgammaS in cell lysates, indicating that G-protein-coupled cAMP receptor activation of adenylyl cyclase is regulated by RasC. However, cAMP-induced ERK2 phosphorylation is unaffected in rasC(-) cells, indicating that RasC is not an upstream activator of the mitogen-activated protein kinase required for cAMP relay. rasC(-) cells also exhibit reduced chemotaxis to cAMP during early development and delayed response to periodic cAMP stimuli produced by wild-type cells in chimeric mixtures. Furthermore, cAMP-induced Akt/PKB phosphorylation through a phosphatidylinositide 3-kinase (PI3K)-dependent pathway is dramatically reduced in rasC(-) cells, suggesting that G-protein-coupled serpentine receptor activation of PI3K is regulated by RasC. Cells lacking the RasGEF, AleA, exhibit similar defects as rasC(-) cells, suggesting that AleA may activate RasC.

Quantitative Proteomics Analysis of the cAMP/Protein Kinase A Signaling Pathway

PubMed Central

2012-01-01

To define the proteins whose expression is regulated by cAMP and protein kinase A (PKA), we used a quantitative proteomics approach in studies of wild-type (WT) and kin- (PKA-null) S49 murine T lymphoma cells. We also compared the impact of endogenous increases in the level of cAMP [by forskolin (Fsk) and the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX)] or by a cAMP analogue (8-CPT-cAMP). We identified 1056 proteins in WT and kin- S49 cells and found that 8-CPT-cAMP and Fsk with IBMX produced differences in protein expression. WT S49 cells had a correlation coefficient of 0.41 between DNA microarray data and the proteomics analysis in cells incubated with 8-CPT-cAMP for 24 h and a correlation coefficient of 0.42 between the DNA microarray data obtained at 6 h and the changes in protein expression after incubation with 8-CPT-cAMP for 24 h. Glutathione reductase (Gsr) had a higher level of basal expression in kin- S49 cells than in WT cells. Consistent with this finding, kin- cells are less sensitive to cell killing and generation of malondialdehyde than are WT cells incubated with H2O2. Cyclic AMP acting via PKA thus has a broad impact on protein expression in mammalian cells, including in the regulation of Gsr and oxidative stress. PMID:23110364

Extracellular cyclic AMP-adenosine pathway in isolated adipocytes and adipose tissue.

PubMed

Strouch, Marci B; Jackson, Edwin K; Mi, Zaichuan; Metes, Nicole A; Carey, Gale B

2005-06-01

Our goal was to evaluate the presence and lipolytic impact of the extracellular cyclic adenosine monophosphate (AMP)-adenosine pathway in adipose tissue. Sixteen miniature Yucatan swine (Sus scrofa) were used for these in vitro and in situ experiments. Four microdialysis probes were implanted into subcutaneous adipose tissue and perfused at 2 microL/min with Ringer's solution containing no addition, varying levels of cyclic AMP, 10 microM isoproterenol, or 10 microM isoproterenol plus 1 mM alpha,beta-methylene adenosine 5'-diphosphate (AMPCP), a 5'-nucleotidase inhibitor. Dialysate was assayed for AMP, adenosine, inosine, hypoxanthine, and glycerol. Freshly isolated adipocytes were incubated with buffer, 1 microM isoproterenol, or 1 microM isoproterenol plus 0.1 mM AMPCP, and extracellular levels of AMP, adenosine, inosine, hypoxanthine, and glycerol were measured. Perfusion of adipose tissue with exogenous cyclic AMP caused a significant increase in AMP and adenosine appearance. Perfusion with AMPCP, in the presence or absence of isoproterenol, significantly increased the levels of AMP and glycerol, whereas it significantly reduced the level of adenosine and its metabolites. However, the AMPCP-provoked increase in lipolysis observed in situ and in vitro was not temporally associated with a decrease in adenosine. These data suggest the existence of a cyclic AMP-adenosine pathway in adipocytes and adipose tissue. The role of this pathway in the regulation of lipolysis remains to be clarified.

An entomopathogenic bacterium, Xenorhabdus nematophila, suppresses expression of antimicrobial peptides controlled by Toll and Imd pathways by blocking eicosanoid biosynthesis.

PubMed

Hwang, Jihyun; Park, Youngjin; Kim, Yonggyun; Hwang, Jihyun; Lee, Daeweon

2013-07-01

Immune-associated genes of the beet armyworm, Spodoptera exigua, were predicted from 454 pyrosequencing transcripts of hemocytes collected from fifth instar larvae challenged with bacteria. Out of 22,551 contigs and singletons, 36% of the transcripts had at least one significant hit (E-value cutoff of 1e-20) and used to predict immune-associated genes implicated in pattern recognition, prophenoloxidase activation, intracellular signaling, and antimicrobial peptides (AMPs). Immune signaling and AMP genes were further confirmed in their expression patterns in response to different types of microbial challenge. To discriminate the AMP expression signaling between Toll and Imd pathways, RNA interference was applied to specifically knockdown each signal pathway; the separate silencing treatments resulted in differential suppression of AMP genes. An entomopathogenic bacterium, Xenorhabdus nematophila, suppressed expression of most AMP genes controlled by Toll and Imd pathways, while challenge with heat-killed X. nematophila induced expression of all AMPs in experimental larvae. Benzylideneacetone (BZA), a metabolite of X. nematophila, suppressed the AMP gene inductions when it was co-injected with the heat-killed X. nematophila. However, arachidonic acid, a catalytic product of PLA2 , significantly reversed the inhibitory effect of BZA on the AMP gene expression. This study suggests that X. nematophila suppresses AMP production controlled by Toll and Imd pathways by inhibiting eicosanoid biosynthesis in S. exigua. © 2013 Wiley Periodicals, Inc.

Dizocilpine and reduced body temperature do not prevent methamphetamine-induced neurotoxicity in the vervet monkey: [11C]WIN 35,428 - positron emission tomography studies.

PubMed

Melega, W P; Lacan, G; Harvey, D C; Huang, S C; Phelps, M E

1998-12-11

[11C]WIN 35,428 (WIN), a cocaine analog that binds to the dopamine transporter (DAT), and positron emission tomography (PET) were used to evaluate the potential neuroprotective effects of dizocilpine (MK-801) on methamphetamine (MeAmp) induced neurotoxicity in the striatal dopamine system of the vervet monkey. MK-801 (1 mg/kg, i.m.) was administered 30 min prior to a neurotoxic MeAmp dosage for this species (2 x 2 mg/kg, 4 h apart); control subjects received MeAmp. MK-801 treated subjects were anesthetized by the drug for 6-8 h; throughout that period, a 2-3 degrees C decrease in body temperature was measured. At 1-2 weeks post-MeAmp, decreases of approximately 75% in striatal WIN binding were observed for both MK-801/MeAmp and MeAmp subjects. Thus, in this non-human primate species, the combination of MK-801 pretreatment and reduced body temperature did not provide protection from the MeAmp-induced loss of DAT. Further, the absence of an elevated body temperature during the acute MeAmp exposure period indicated that hyperthermia, per se, was not a necessary concomitant of the MeAmp neurotoxicity profile as has been previously demonstrated in rodents. These results provide evidence that different regulatory factors maintain the integrity of the rodent and primate striatal dopamine systems.

Catabolite Repression of Escherichia coli Biofilm Formation

PubMed Central

Jackson, Debra W.; Simecka, Jerry W.; Romeo, Tony

2002-01-01

Biofilm formation was repressed by glucose in several species of Enterobacteriaceae. In Escherichia coli, this effect was mediated at least in part by cyclic AMP (cAMP)-cAMP receptor protein. A temporal role for cAMP in biofilm development was indicated by the finding that glucose addition after ∼24 h failed to repress and generally activated biofilm formation. PMID:12029060

AMP Deaminase 3 Deficiency Enhanced 5′-AMP Induction of Hypometabolism

PubMed Central

Daniels, Isadora Susan; O′Brien, William G.; Nath, Vinay; Zhao, Zhaoyang; Lee, Cheng Chi

2013-01-01

A hypometabolic state can be induced in mice by 5′-AMP administration. Previously we proposed that an underlying mechanism for this hypometabolism is linked to reduced erythrocyte oxygen transport function due to 5′-AMP uptake altering the cellular adenylate equilibrium. To test this hypothesis, we generated mice deficient in adenosine monophosphate deaminase 3 (AMPD3), the key catabolic enzyme for 5′-AMP in erythrocytes. Mice deficient in AMPD3 maintained AMPD activities in all tissues except erythrocytes. Developmentally and morphologically, the Ampd3−/− mice were indistinguishable from their wild type siblings. The levels of ATP, ADP but not 5′-AMP in erythrocytes of Ampd3−/− mice were significantly elevated. Fasting blood glucose levels of the Ampd3−/− mice were comparable to wild type siblings. In comparison to wild type mice, the Ampd3−/− mice displayed a deeper hypometabolism with a significantly delayed average arousal time in response to 5′-AMP administration. Together, these findings demonstrate a central role of AMPD3 in the regulation of 5′-AMP mediated hypometabolism and further implicate erythrocytes in this behavioral response. PMID:24066180

Membrane Active Antimicrobial Peptides: Translating Mechanistic Insights to Design

PubMed Central

Li, Jianguo; Koh, Jun-Jie; Liu, Shouping; Lakshminarayanan, Rajamani; Verma, Chandra S.; Beuerman, Roger W.

2017-01-01

Antimicrobial peptides (AMPs) are promising next generation antibiotics that hold great potential for combating bacterial resistance. AMPs can be both bacteriostatic and bactericidal, induce rapid killing and display a lower propensity to develop resistance than do conventional antibiotics. Despite significant progress in the past 30 years, no peptide antibiotic has reached the clinic yet. Poor understanding of the action mechanisms and lack of rational design principles have been the two major obstacles that have slowed progress. Technological developments are now enabling multidisciplinary approaches including molecular dynamics simulations combined with biophysics and microbiology toward providing valuable insights into the interactions of AMPs with membranes at atomic level. This has led to increasingly robust models of the mechanisms of action of AMPs and has begun to contribute meaningfully toward the discovery of new AMPs. This review discusses the detailed action mechanisms that have been put forward, with detailed atomistic insights into how the AMPs interact with bacterial membranes. The review further discusses how this knowledge is exploited toward developing design principles for novel AMPs. Finally, the current status, associated challenges, and future directions for the development of AMP therapeutics are discussed. PMID:28261050

Detection of ESBL among ampc producing enterobacteriaceae using inhibitor-based method

PubMed Central

Bakthavatchalu, Sasirekha; Shakthivel, Uma; Mishra, Tannu

2013-01-01

Introduction The occurrence of multiple β-lactamases among bacteria only limits the therapeutic options but also poses a challenge. A study using boronic acid (BA), an AmpC enzyme inhibitor, was designed to detect the combined expression of AmpC β-lactamases and extended-spectrum β-lactamases (ESBLs) in bacterial isolates further different phenotypic methods are compared to detect ESBL and AmpC. Methods A total of 259 clinical isolates of Enterobacteriaceae were isolated and screened for ESBL production by (i) CLSI double-disk diffusion method (ii) cefepime- clavulanic acid method (iii) boronic disk potentiation method. AmpC production was detected using cefoxitin alone and in combination with boronic acid and confirmation was done by three dimensional disk methods. Isolates were also subjected to detailed antibiotic susceptibility test. Results Among 259 isolates, 20.46% were coproducers of ESBL and AmpC, 26.45% were ESBL and 5.40% were AmpC. All of the 53 AmpC and ESBL coproducers were accurately detected by boronic acid disk potentiation method. Conclusion The BA disk test using Clinical and Laboratory Standards Institute methodology is simple and very efficient method that accurately detects the isolates that harbor both AmpCs and ESBLs. PMID:23504148

Diversity, evolution and medical applications of insect antimicrobial peptides

PubMed Central

Mylonakis, Eleftherios; Podsiadlowski, Lars; Muhammed, Maged

2016-01-01

Antimicrobial peptides (AMPs) are short proteins with antimicrobial activity. A large portion of known AMPs originate from insects, and the number and diversity of these molecules in different species varies considerably. Insect AMPs represent a potential source of alternative antibiotics to address the limitation of current antibiotics, which has been caused by the emergence and spread of multidrug-resistant pathogens. To get more insight into AMPs, we investigated the diversity and evolution of insect AMPs by mapping their phylogenetic distribution, allowing us to predict the evolutionary origins of selected AMP families and to identify evolutionarily conserved and taxon-specific families. Furthermore, we highlight the use of the nematode Caenorhabditis elegans as a whole-animal model in high-throughput screening methods to identify AMPs with efficacy against human pathogens, including Acinetobacter baumanii and methicillin-resistant Staphylococcus aureus. We also discuss the potential medical applications of AMPs, including their use as alternatives for conventional antibiotics in ectopic therapies, their combined use with antibiotics to restore the susceptibility of multidrug-resistant pathogens, and their use as templates for the rational design of peptidomimetic drugs that overcome the disadvantages of therapeutic peptides. The article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’. PMID:27160593

Antimicrobial Activity of Cationic Antimicrobial Peptides against Gram-Positives: Current Progress Made in Understanding the Mode of Action and the Response of Bacteria.

PubMed

Omardien, Soraya; Brul, Stanley; Zaat, Sebastian A J

2016-01-01

Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs. Concerns about possible resistance that bacteria might develop to AMPs are addressed. Proteomics, transcriptomics, and other molecular techniques are reviewed in the context of explaining the response of bacteria to the presence of AMPs and to predict what resistance strategies might be. Emergent mechanisms are cell envelope stress responses as well as enzymes able to degrade and/or specifically bind (and thus inactivate) AMPs. Further studies are needed to address the broadness of the AMP resistance and stress responses observed.

Antimicrobial Activity of Cationic Antimicrobial Peptides against Gram-Positives: Current Progress Made in Understanding the Mode of Action and the Response of Bacteria

PubMed Central

Omardien, Soraya; Brul, Stanley; Zaat, Sebastian A. J.

2016-01-01

Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs. Concerns about possible resistance that bacteria might develop to AMPs are addressed. Proteomics, transcriptomics, and other molecular techniques are reviewed in the context of explaining the response of bacteria to the presence of AMPs and to predict what resistance strategies might be. Emergent mechanisms are cell envelope stress responses as well as enzymes able to degrade and/or specifically bind (and thus inactivate) AMPs. Further studies are needed to address the broadness of the AMP resistance and stress responses observed. PMID:27790614

cAMP signalling in the vasculature: the role of Epac (exchange protein directly activated by cAMP).

PubMed

Roberts, Owain Llŷr; Dart, Caroline

2014-02-01

The second messenger cAMP plays a central role in mediating vascular smooth muscle relaxation in response to vasoactive transmitters and in strengthening endothelial cell-cell junctions that regulate the movement of solutes, cells and macromolecules between the blood and the surrounding tissue. The vasculature expresses three cAMP effector proteins: PKA (protein kinase A), CNG (cyclic-nucleotide-gated) ion channels, and the most recently discovered Epacs (exchange proteins directly activated by cAMP). Epacs are a family of GEFs (guanine-nucleotide-exchange factors) for the small Ras-related GTPases Rap1 and Rap2, and are being increasingly implicated as important mediators of cAMP signalling, both in their own right and in parallel with the prototypical cAMP target PKA. In the present paper, we review what is currently known about the role of Epac within blood vessels, particularly with regard to the regulation of vascular tone, endothelial barrier function and inflammation.

Increased survival of experimentally evolved antimicrobial peptide-resistant Staphylococcus aureus in an animal host

PubMed Central

Dobson, Adam J; Purves, Joanne; Rolff, Jens

2014-01-01

Antimicrobial peptides (AMPs) have been proposed as new class of antimicrobial drugs, following the increasing prevalence of bacteria resistant to antibiotics. Synthetic AMPs are functional analogues of highly evolutionarily conserved immune effectors in animals and plants, produced in response to microbial infection. Therefore, the proposed therapeutic use of AMPs bears the risk of ‘arming the enemy’: bacteria that evolve resistance to AMPs may be cross-resistant to immune effectors (AMPs) in their hosts. We used a panel of populations of Staphylococcus aureus that were experimentally selected for resistance to a suite of individual AMPs and antibiotics to investigate the ‘arming the enemy’ hypothesis. We tested whether the selected strains showed higher survival in an insect model (Tenebrio molitor) and cross-resistance against other antimicrobials in vitro. A population selected for resistance to the antimicrobial peptide iseganan showed increased in vivo survival, but was not more virulent. We suggest that increased survival of AMP-resistant bacteria almost certainly poses problems to immune-compromised hosts. PMID:25469169

Enzymatic production of 5'-inosinic acid by AMP deaminase from a newly isolated Aspergillus oryzae.

PubMed

Li, Shubo; Chen, Leitao; Hu, Yangjun; Fang, Guohui; Zhao, Mouming; Guo, Yuan; Pang, Zongwen

2017-02-01

5'-adenylic acid deaminase (AMP deaminase), an important enzyme for the food industry, can catalyze the irreversible hydrolysis of adenosine monophosphate (AMP) to inosine monophosphate (IMP) and ammonia. In this study, a new strain was screened that efficiently produces 3191.6U/g of AMP deaminase at 32°C. After purification, the optimal temperature and pH of the AMP deaminase were found to be 40°C and 6.0, respectively, but it was partially inhibited by Fe(3+), Cu(2+), Al(3+), and Zn(2+). With amplification of the AMP deaminase production system, 6mL of crude enzyme could produce 2.00mg/g of IMP from 2.04mg/g of dried yeast with an 84.8% molar yield after 40min. These results provide a new insight into AMP deaminase production and offer a potential platform for producing 5'-IMP. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inactivation of phosphorylase b by potassium ferrate, a new reactive analogue of the phosphate group.

PubMed

Lee, Y M; Benisek, W F

1976-03-25

Rabbit muscle phosphorylase b reacts with the phosphate-like reagent potassium ferrate, K2FeO4, a potent oxidizing agent. The reaction results in inactivation of the enzyme and abolition of the ability of the enzyme to bind 5'-AMP. Activating and nonactivating nucleotides which bind at the 5'-AMP binding site such as 5'-AMP, 2'-AMP, 3'-AMP, and 5'-IMP substantially protect the enzyme from inactivation by ferrate. One to two residues of tyrosine and approximately 1 residue of cysteine are modified by ferrate under the conditions employed. Tyrosine is protected by 5-AMP, whereas cysteine is not. The tyrosine modification is suggested as the inactivating chemical reaction. The location of the inactivating reaction is suggested to be in or near the 5'-AMP binding site. The structural and chemical properties of ferrate ion are discussed and compared to those of phosphate. Ferrate ion may be a reagent useful for phosphate group binding site-directed modification of proteins.

Bacterial strategies of resistance to antimicrobial peptides.

PubMed

Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

2016-05-26

Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

TSH-induced cyclic AMP production in an ovine thyroid cell line: OVNIS 5H.

PubMed

Fayet, G; Aouani, A; Hovsépian, S

1986-01-06

The TSH-induced cyclic AMP response was studied using a 3-year-old ovine thyroid cell line TSH-independent for growth: OVNIS 5H. The kinetics of cyclic AMP production was followed both in cell layers and in cell culture media, with or without phosphodiesterase inhibitor. It is noteworthy that following the first wave in cyclic AMP obtained within minutes, we observed later a sustained exponential increase in cyclic AMP during the 5 days following TSH stimulation. A bioassay of TSH was derived allowing measurement of 1 microU/ml TSH from a crude bTSH preparation.

Reduction of extended-spectrum-β-lactamase- and AmpC-β-lactamase-producing Escherichia coli through processing in two broiler chicken slaughterhouses.

PubMed

Pacholewicz, Ewa; Liakopoulos, Apostolos; Swart, Arno; Gortemaker, Betty; Dierikx, Cindy; Havelaar, Arie; Schmitt, Heike

2015-12-23

Whilst broilers are recognised as a reservoir of extended-spectrum-β-lactamase (ESBL)- and AmpC-β-lactamase (AmpC)-producing Escherichia coli, there is currently limited knowledge on the effect of slaughtering on its concentrations on poultry meat. The aim of this study was to establish the concentration of ESBL/AmpC producing E. coli on broiler chicken carcasses through processing. In addition the changes in ESBL/AmpC producing E. coli concentrations were compared with generic E. coli and Campylobacter. In two slaughterhouses, the surface of the whole carcasses was sampled after 5 processing steps: bleeding, scalding, defeathering, evisceration and chilling. In total, 17 batches were sampled in two different slaughterhouses during the summers of 2012 and 2013. ESBL/AmpC producing E. coli was enumerated on MacConkey agar with 1mg/l cefotaxime, and the ESBL/AmpC phenotypes and genotypes were characterised. The ESBL/AmpC producing E. coli concentrations varied significantly between the incoming batches in both slaughterhouses. The concentrations on broiler chicken carcasses were significantly reduced during processing. In Slaughterhouse 1, all subsequent processing steps reduced the concentrations except evisceration which led to a slight increase that was statistically not significant. The changes in concentration between processing steps were relatively similar for all sampled batches in this slaughterhouse. In contrast, changes varied between batches in Slaughterhouse 2, and the overall reduction through processing was higher in Slaughterhouse 2. Changes in ESBL/AmpC producing E. coli along the processing line were similar to changes in generic E. coli in both slaughterhouses. The effect of defeathering differed between ESBL/AmpC producing E. coli and Campylobacter. ESBL/AmpC producing E. coli decreased after defeathering, whereas Campylobacter concentrations increased. The genotypes of ESBL/AmpC producing E. coli (blaCTX-M-1, blaSHV-12, blaCMY-2, blaTEM-52c, blaTEM-52cvar) from both slaughterhouses match typical poultry genotypes. Their distribution differed between batches and changed throughout processing for some batches. The concentration levels found after chilling were between 10(2) and 10(5)CFU/carcass. To conclude, changes in ESBL/AmpC producing E. coli concentrations on broiler chicken carcasses during processing are influenced by batch and slaughterhouse, pointing to the role of both primary production and process control for reducing ESBL/AmpC producing E. coli levels in final products. Due to similar changes upon processing, E. coli can be used as a process indicator of ESBL/AmpC producing E. coli, because the processing steps had similar impact on both organisms. Cross contamination may potentially explain shifts in genotypes within some batches through the processing. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterisation of extended-spectrum β-lactamase and AmpC β-lactamase-producing Enterobacteriaceae isolated from companion animals in New Zealand.

PubMed

Karkaba, A; Grinberg, A; Benschop, J; Pleydell, E

2017-03-01

To assess the occurrence of, and characterise, extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC)-producing Enterobacteriaceae isolated by veterinary diagnostic laboratories from infection sites in companion animals in New Zealand. Selected Enterobacteriaceae isolates were submitted by seven New Zealand veterinary diagnostic laboratories. They were isolated from infection sites in companion animals between June 2012 and June 2013, and were resistant to amoxicillin-clavulanic acid, fluoroquinolones, or any combination of two or more antimicrobials. Based on disk diffusion test results, the isolates were phenotypically categorised according to production of ESBL and AmpC. Genes for ESBL and AmpC production were amplified by PCR and sequenced. Escherichia coli isolates were also typed by multilocus sequence typing. A total of 115 isolates matching the inclusion criteria were obtained from the participating laboratories, of which 74 (64%) originated from dogs and 29 (25%) from cats. Seven bacterial species were identified, of which E. coli was the most common (87/115, 76%). Of the 115 isolates, 10 (9%) expressed the ESBL phenotype, 43 (37%) the AmpC phenotype, and seven (6%) both ESBL and AmpC phenotypes. Of the 60 ESBL and AmpC-producing isolates, 36 (60%) were E. coli. Amongst these isolates, 27/60 (45%) were classified as multidrug resistant, compared with 15/55 (27%) non-ESBL or AmpC-producing isolates (p<0.01). Ninety five isolates were resistant to amoxicillin-clavulanic acid and 58 (61%) of these were ESBL or AmpC-producing. The predominant ESBL genes were bla CTX-M-14 and bla CTX-M-15 , and the dominant plasmid-encoded AmpC gene was bla CMY-2 . Thirty-eight E. coli multilocus sequence types (ST) were identified, and the most prevalent were ST12 (12/89, 13%), ST131 (6/89, 7%) and ST648 (6/89, 7%). ESBL and AmpC-producing isolates accounted for 35/1,082 (3.2%) of the Enterobacteriaceae isolated by one laboratory network over the study period. ESBL and AmpC-producing Enterobacteriaceae were associated with clinical infections in companion animals in New Zealand, and were often multidrug resistant. In this study, these organisms accounted for <5% of all Enterobacteriaceae isolated from infection sites by one laboratory network, but their prevalence among isolates resistant to amoxicillin-clavulanic acid was 61%. Therefore routine secondary testing for ESBL and AmpC production by Enterobacteriaceae that are resistant to amoxicillin-clavulanic acid in primary testing could improve the accuracy of definitive antimicrobial therapy in companion animals in New Zealand.

The cAMP signaling system inhibits the repair of {gamma}-ray-induced DNA damage by promoting Epac1-mediated proteasomal degradation of XRCC1 protein in human lung cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Eun-Ah; Juhnn, Yong-Sung, E-mail: juhnn@snu.ac.kr

2012-06-01

Highlights: Black-Right-Pointing-Pointer cAMP signaling system inhibits repair of {gamma}-ray-induced DNA damage. Black-Right-Pointing-Pointer cAMP signaling system inhibits DNA damage repair by decreasing XRCC1 expression. Black-Right-Pointing-Pointer cAMP signaling system decreases XRCC1 expression by promoting its proteasomal degradation. Black-Right-Pointing-Pointer The promotion of XRCC1 degradation by cAMP signaling system is mediated by Epac1. -- Abstract: Cyclic AMP is involved in the regulation of metabolism, gene expression, cellular growth and proliferation. Recently, the cAMP signaling system was found to modulate DNA-damaging agent-induced apoptosis by regulating the expression of Bcl-2 family proteins and inhibitors of apoptosis. Thus, we hypothesized that the cAMP signaling may modulate DNAmore » repair activity, and we investigated the effects of the cAMP signaling system on {gamma}-ray-induced DNA damage repair in lung cancer cells. Transient expression of a constitutively active mutant of stimulatory G protein (G{alpha}sQL) or treatment with forskolin, an adenylyl cyclase activator, augmented radiation-induced DNA damage and inhibited repair of the damage in H1299 lung cancer cells. Expression of G{alpha}sQL or treatment with forskolin or isoproterenol inhibited the radiation-induced expression of the XRCC1 protein, and exogenous expression of XRCC1 abolished the DNA repair-inhibiting effect of forskolin. Forskolin treatment promoted the ubiquitin and proteasome-dependent degradation of the XRCC1 protein, resulting in a significant decrease in the half-life of the protein after {gamma}-ray irradiation. The effect of forskolin on XRCC1 expression was not inhibited by PKA inhibitor, but 8-pCPT-2 Prime -O-Me-cAMP, an Epac-selective cAMP analog, increased ubiquitination of XRCC1 protein and decreased XRCC1 expression. Knockdown of Epac1 abolished the effect of 8-pCPT-2 Prime -O-Me-cAMP and restored XRCC1 protein level following {gamma}-ray irradiation. From these results, we conclude that the cAMP signaling system inhibits the repair of {gamma}-ray-induced DNA damage by promoting the ubiquitin-proteasome dependent degradation of XRCC1 in an Epac-dependent pathway in lung cancer cells.« less

Conservation and divergence of the cyclic adenosine monophosphate-protein kinase A (cAMP–PKA) pathway in two plant-pathogenic fungi: Fusarium graminearum and F. verticillioides

USDA-ARS?s Scientific Manuscript database

The cyclic AMP (cAMP)-PKA pathway is a central signaling cascade that transmits extracellular stimuli and governs cell responses through the second messenger cAMP. The importance of cAMP signaling in fungal biology has been well documented. Two key conserved components, adenylate cyclase (AC) and ca...

An adenylyl cyclase gene (NlAC9) influences growth and fecundity in the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

USDA-ARS?s Scientific Manuscript database

The cAMP/PKA intracellular signaling pathway is launched by adenylyl cyclase (AC) conversion of adenosine triphosphate (ATP) to 3', 5'-cyclic AMP (cAMP) and cAMP-dependent activation of PKA. Although this pathway is very well known in insect physiology, there is little to no information on it in som...

Is This Op-Amp Any Good?: Lab-Built Checker Removes All Doubt!

ERIC Educational Resources Information Center

Harman, Charles

2007-01-01

Electronics instructors and students find it very helpful to be able to check an operational amplifier at the proto-board stage. Most students lack the experience or knowledge that it takes to recognize whether an op-amp is operating normally or not. This article discusses a handy op-amp checker that allows one to check and/or test op-amps at the…

Prevalence and characterization of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producing Enterobacteriaceae in fresh pork meat at processing level in Germany.

PubMed

Schill, Franziska; Abdulmawjood, Amir; Klein, Günter; Reich, Felix

2017-09-18

ESBL or AmpC β-lactamase producing Enterobacteriaceae is an increasing concern in human medicine. A distribution via the food chain is discussed, but less is known about these bacteria on fresh pork meat. The aim of this study was to investigate the prevalence of ESBL/AmpC Enterobacteriaceae bacteria in fresh pork meat at processing level in Germany. The analysis comprised microbiological hygiene parameters and further pheno- and genotypical characterization of ESBL/AmpC isolates. The examination included three pools of meat and one corresponding meat juice sample from each of the tested pork meat batches (n=63). ESBL/AmpC producers were found in 42.9% (36.5% confirmed by genotype, gt) of the investigated batches, either in meat or meat juice. Meat juice was more often (28.6%) contaminated with ESBL/AmpC bacteria than meat (20.6%). Hygiene parameters were satisfactory in all samples and were thus not a suitable tool for predicting the presence of ESBL/AmpC producers. Most of the 37 confirmed ESBL/AmpC bacteria were identified as Escherichia coli (n=18) or Serratia fonticola (n=13). Susceptibility testing identified 32 of the 37 isolates to be multidrug-resistant. The most common resistance genes TEM, SHV, and CTX-M were found in 19 of the ESBL/AmpC isolates, mostly E. coli. A single detected AmpC β-lactamase producing E. coli carried a CMY-2 gene. Multilocus sequence typing (MLST) investigations of the ESBL/AmpC E. coli revealed 11 different sequence types. In conclusion, fresh pork meat can harbor highly diverse multidrug-resistant ESBL Enterobacteriaceae, even though at low rates. The study suggests that fresh pork meat might be a source for multidrug-resistant ESBL/AmpC Enterobacteriaceae of various origins. Therefore these data contribute to the epidemiological understanding of the distribution of resistant bacteria and the impact of the food chain on public health. Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolic control mechanisms in mammalian systems. Involvement of adenosine 3′:5′-cyclic monophosphate in androgen action

PubMed Central

Singhal, Radhey L.; Parulekar, M. R.; Vijayvargiya, R.; Robison, G. Alan

1971-01-01

1. The ability of exogenously administered cyclic AMP (adenosine 3′:5′-monophosphate) to exert andromimetic action on certain carbohydrate-metabolizing enzymes was investigated in the rat prostate gland and seminal vesicles. 2. Cyclic AMP, when injected concurrently with theophylline, produced marked increases in hexokinase, phosphofructokinase, glyceraldehyde phosphate dehydrogenase, pyruvate kinase, and two hexose monophosphate-shunt enzymes, as well as α-glycerophosphate dehydrogenase activity in accessory sexual tissues of castrated rats. The 6-N,2′-O-dibutyryl analogue of cyclic AMP caused increases of enzyme activity that were greater than those induced by the parent compound. 3. Time-course studies demonstrated that, whereas significant increases in the activities of most enzymes occurred within 4h after the injection of cyclic AMP, maximal increases were attained at 16–24h. 4. Increase in the activity of the various prostatic and vesicular enzymes was dependent on the dose of cyclic AMP; in most instances, 2.5mg of the cyclic nucleotide/rat was sufficient to elicit a statistically significant response. 5. Administration of cyclic AMP and theophylline also produced stimulation of enzyme activities in secondary sexual tissues of immature rats. 6. Cyclic AMP and theophylline did not affect significantly any of the enzymes studied in hepatic tissue. 7. Stimulation of various carbohydrate-metabolizing enzymes in the prostate gland and seminal vesicles by cyclic AMP was independent of adrenal function. 8. Concurrent treatment with actinomycin or cycloheximide prevented the cyclic AMP- and theophylline-induced increases in enzyme activities in both castrated and adrenalectomized–castrated animals. 9. Administration of a single dose of testosterone propionate (5.0mg/100g) to castrated rats caused a significant increase in cyclic AMP concentration in both accessory sexual tissues. 10. In addition, treatment with theophylline potentiated the effects of a submaximal dose of testosterone (1.0mg/100g) on all those prostatic and seminal-vesicular enzymes that are increased by exogenous cyclic AMP. 11. The evidence indicates that cyclic AMP may be involved in triggering the known metabolic actions of androgens on secondary sexual tissues of the rat. PMID:4110460

ICT and mobile health to improve clinical process delivery. a research project for therapy management process innovation.

PubMed

Locatelli, Paolo; Montefusco, Vittorio; Sini, Elena; Restifo, Nicola; Facchini, Roberta; Torresani, Michele

2013-01-01

The volume and the complexity of clinical and administrative information make Information and Communication Technologies (ICTs) essential for running and innovating healthcare. This paper tells about a project aimed to design, develop and implement a set of organizational models, acknowledged procedures and ICT tools (Mobile & Wireless solutions and Automatic Identification and Data Capture technologies) to improve actual support, safety, reliability and traceability of a specific therapy management (stem cells). The value of the project is to design a solution based on mobile and identification technology in tight collaboration with physicians and actors involved in the process to ensure usability and effectivenes in process management.

Modulation of PC12 cell viability by forskolin-induced cyclic AMP levels through ERK and JNK pathways: an implication for L-DOPA-induced cytotoxicity in nigrostriatal dopamine neurons.

PubMed

Park, Keun Hong; Park, Hyun Jin; Shin, Keon Sung; Choi, Hyun Sook; Kai, Masaaki; Lee, Myung Koo

2012-07-01

The intracellular levels of cyclic AMP (cAMP) increase in response to cytotoxic concentrations of L-DOPA in PC12 cells, and forskolin that induces intracellular cAMP levels either protects PC12 cells from L-DOPA-induced cytotoxicity or enhances cytotoxicity in a concentration-dependent manner. This study investigated the effects of cAMP induced by forskolin on cell viability of PC12 cells, relevant to L-DOPA-induced cytotoxicity in Parkinson's disease therapy. The low levels of forskolin (0.01 and 0.1 μM)-induced cAMP increased dopamine biosynthesis and tyrosine hydroxylase (TH) phosphorylation, and induced transient phosphorylation of ERK1/2 within 1 h. However, at the high levels of forskolin (1.0 and 10 μM)-induced cAMP, dopamine biosynthesis and TH phosphorylation did not increase, but rapid differentiation in neurite-like formation was observed with a steady state. The high levels of forskolin-induced cAMP also induced sustained increase in ERK1/2 phosphorylation within 0.25-6 h and then led to apoptosis, which was apparently mediated by JNK1/2 and caspase-3 activation. Multiple treatment of PC12 cells with nontoxic L-DOPA (20 μM) for 4-6 days induced neurite-like formation and decreased intracellular dopamine levels by reducing TH phosphorylation. These results suggest that the low levels of forskolin-induced cAMP increased dopamine biosynthesis in cell survival via transient ERK1/2 phosphorylation. In contrast, the high levels of forskolin-induced cAMP induced differentiation via sustained ERK1/2 phosphorylation and then led to apoptosis. Taken together, the intracellular levels of cAMP play a dual role in cell survival and death through the ERK1/2 and JNK1/2 pathways in PC12 cells.

Role of exchange protein directly activated by cAMP (EPAC1) in breast cancer cell migration and apoptosis.

PubMed

Kumar, Naveen; Gupta, Sonal; Dabral, Surbhi; Singh, Shailja; Sehrawat, Seema

2017-06-01

Despite the current progress in cancer research and therapy, breast cancer remains the leading cause of mortality among half a million women worldwide. Migration and invasion of cancer cells are associated with prevalent tumor metastasis as well as high mortality. Extensive studies have powerfully established the role of prototypic second messenger cAMP and its two ubiquitously expressed intracellular cAMP receptors namely the classic protein kinaseA/cAMP-dependent protein kinase (PKA) and the more recently discovered exchange protein directly activated by cAMP/cAMP-regulated guanine nucleotide exchange factor (EPAC/cAMP-GEF) in cell migration, cell cycle regulation, and cell death. Herein, we performed the analysis of the Cancer Genome Atlas (TCGA) dataset to evaluate the essential role of cAMP molecular network in breast cancer. We report that EPAC1, PKA, and AKAP9 along with other molecular partners are amplified in breast cancer patients, indicating the importance of this signaling network. To evaluate the functional role of few of these proteins, we used pharmacological modulators and analyzed their effect on cell migration and cell death in breast cancer cells. Hence, we report that inhibition of EPAC1 activity using pharmacological modulators leads to inhibition of cell migration and induces cell death. Additionally, we also observed that the inhibition of EPAC1 resulted in disruption of its association with the microtubule cytoskeleton and delocalization of AKAP9 from the centrosome as analyzed by in vitro imaging. Finally, this study suggests for the first time the mechanistic insights of mode of action of a primary cAMP-dependent sensor, Exchange protein activated by cAMP 1 (EPAC1), via its interaction with A-kinase anchoring protein 9 (AKAP9). This study provides a new cell signaling cAMP-EPAC1-AKAP9 direction to the development of additional biotherapeutics for breast cancer.

Elevation of cAMP Levels Inhibits Doxorubicin-Induced Apoptosis in Pre- B ALL NALM- 6 Cells Through Induction of BAD Phosphorylation and Inhibition of P53 Accumulation.

PubMed

Fatemi, Ahmad; Kazemi, Ahmad; Kashiri, Meysam; Safa, Majid

2015-01-01

Recognition of the molecular mechanisms of cAMP action against DNA damage-induced apoptosis can be useful to improve the efficacy of DNA damaging therapeutic agents. Considering the critical role of bcl-2-associated death promoter (BAD) and p53 proteins in DNA damage -induced apoptosis, the aim of this study was to assess the effect of cAMP-elevating agents on these proteins in doxorubicin-treated pre-B acute lymphoblastic leukemia (pre-B ALL) NALM-6 cells.The pre-B ALL cell line NALM-6 was cultured and treated with doxorubicin in combination with or without cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX). Cell viability was measured by trypan blue staining and MTT assay. For evaluation of apoptosis, annexin-V staining by flow cytometry and caspase-3 activity assay were used. Protein expression of p53, BAD and phoshorylated BAD was detected by western blotting analysis.cAMP-increasing agents diminished the doxorubicin-mediated cytotoxicity in NALM-6 cells as indicated by the viability assays. Annexin-V apoptosis assay showed that the cAMP-elevating agents decreased doxorubicin-induced apoptosis. Moreover, doxorubicin-induced caspase-3 activity was attenuated in the presence of cAMP-increasing agents. Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone. Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents. However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents. Our study suggests that elevated cAMP levels inhibit doxorubicin-induced apoptosis in pre-B ALL cells through induction of BAD phosphorylation and abrogation of p53 accumulation.

Mediation by prostaglandins of the stimulatory effect of substance P on cyclic AMP production in dog iris sphincter smooth muscle.

PubMed

Marathe, G K; Yousufzai, S Y; Abdel-Latif, A A

1996-10-25

The purpose of the present study was to examine the mechanism of the stimulatory effect of substance P (SP) on cyclic AMP (cAMP) accumulation in dog iris sphincter. We found that: (1) SP increased cAMP accumulation in a time- and concentration-dependent manner, the T1/2 and EC50 values being 1.2 min and 44 nM, respectively. SP has no effect on inositol trisphosphate and muscle contraction in this tissue. (2) SP-stimulated cAMP formation was inhibited by quinacrine, a non-specific phospholipase A2 inhibitor (IC50 = 9.5 microM), and by indomethacin (Indo), a cyclooxygenase inhibitor (IC50 = 3.5 nM), in a concentration-dependent manner, suggesting that SP induces cAMP accumulation via an Indo-sensitive pathway. (3) SP-induced arachidonic acid release and SP-induced prostaglandin E2 (PGE2) release were inhibited concentration dependently by quinacrine and Indo, with IC50 values of 11 microM and 0.8 nM, respectively. (4) PGE2 (1 microM) increased cAMP formation in the sphincter muscle by 94%, and, furthermore, the PG, but not SP, stimulated the activity of adenylyl cyclase in membrane fractions isolated from this tissue. (5) Indo (1 microM) blocked the relaxing effect of SP (1 microM) in iris sphincter precontracted with carbachol (1 microM). (6) The inhibitory effect of Indo on SP-induced cAMP accumulation was species specific. Increases in cAMP represent a mechanism by which extracellular SP can regulate smooth muscle function. Thus, we conclude from these studies that in dog iris sphincter SP-induced cAMP accumulation is mediated through PGs, and that in this cholinergically innervated muscle SP via cAMP could function, in part, to modulate the physiological responses to muscarinic receptor stimulation.

Toll-like receptor 4-mediated cAMP production up-regulates B-cell activating factor expression in Raw264.7 macrophages.

PubMed

Moon, Eun-Yi; Lee, Yu-Sun; Choi, Wahn Soo; Lee, Mi-Hee

2011-10-15

B-cell activating factor (BAFF) plays a role in the generation and the maintenance of mature B cells. Lipopolysaccharide (LPS) increased BAFF expression through the activation of toll-like receptor 4 (TLR4)-dependent signal transduction. Here, we investigated the mechanism of action on mouse BAFF (mBAFF) expression by cAMP production in Raw264.7 mouse macrophages. mBAFF expression was increased by the treatment with a cAMP analogue, dibutyryl-cAMP which is the activator of protein kinase A (PKA), cAMP effector protein. PKA activation was measured by the phosphorylation of cAMP-response element binding protein (CREB) on serine 133 (S133). cAMP production and CREB (S133) phosphorylation were augmented by LPS-stimulation. While mBAFF promoter activity was enhanced by the co-transfection with pS6-RSV-CREB, it was reduced by siRNA-CREB. PKA inhibitor, H-89, reduced CREB (S133) phosphorylation and mBAFF expression in control and LPS-stimulated macrophages. Another principal cAMP effector protein is cAMP-responsive guanine nucleotide exchange factor (Epac), a Rap GDP exchange factor. Epac was activated by the treatment with 8-(4-chloro-phenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (CPT), Epac activator, as judged by the measurement of Rap1 activation. Basal level of mBAFF expression was increased by CPT treatment. LPS-stimulated mBAFF expression was also slightly enhanced by co-treatment with CPT. In addition, dibutyryl-cAMP and CPT enhanced mBAFF expression in bone marrow-derived macrophages (BMDM). With these data, it suggests that the activation of PKA and cAMP/Epac1/Rap1 pathways could be required for basal mBAFF expression, as well as being up-regulated in the TLR4-induced mBAFF expression. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Structural basis of DNA folding and recognition in an AMP-DNA aptamer complex: distinct architectures but common recognition motifs for DNA and RNA aptamers complexed to AMP.

PubMed

Lin, C H; Patel, D J

1997-11-01

Structural studies by nuclear magnetic resonance (NMR) of RNA and DNA aptamer complexes identified through in vitro selection and amplification have provided a wealth of information on RNA and DNA tertiary structure and molecular recognition in solution. The RNA and DNA aptamers that target ATP (and AMP) with micromolar affinity exhibit distinct binding site sequences and secondary structures. We report below on the tertiary structure of the AMP-DNA aptamer complex in solution and compare it with the previously reported tertiary structure of the AMP-RNA aptamer complex in solution. The solution structure of the AMP-DNA aptamer complex shows, surprisingly, that two AMP molecules are intercalated at adjacent sites within a rectangular widened minor groove. Complex formation involves adaptive binding where the asymmetric internal bubble of the free DNA aptamer zippers up through formation of a continuous six-base mismatch segment which includes a pair of adjacent three-base platforms. The AMP molecules pair through their Watson-Crick edges with the minor groove edges of guanine residues. These recognition G.A mismatches are flanked by sheared G.A and reversed Hoogsteen G.G mismatch pairs. The AMP-DNA aptamer and AMP-RNA aptamer complexes have distinct tertiary structures and binding stoichiometries. Nevertheless, both complexes have similar structural features and recognition alignments in their binding pockets. Specifically, AMP targets both DNA and RNA aptamers by intercalating between purine bases and through identical G.A mismatch formation. The recognition G.A mismatch stacks with a reversed Hoogsteen G.G mismatch in one direction and with an adenine base in the other direction in both complexes. It is striking that DNA and RNA aptamers selected independently from libraries of 10(14) molecules in each case utilize identical mismatch alignments for molecular recognition with micromolar affinity within binding-site pockets containing common structural elements.

A novel EGFR-TKI inhibitor (cAMP-H3BO3complex) combined with thermal therapy is a promising strategy to improve lung cancer treatment outcomes

PubMed Central

Tong, Yongpeng; Huang, Chunliu; Zhang, Junfang

2017-01-01

Purpose Although EGFR-TKIs (epidermal growth factor receptor tyrosine kinase inhibitors) induce favorable responses as first-line non-small cell lung cancer treatments, drug resistance remains a serious problem. Meanwhile, thermal therapy also shows promise as a cancer therapy strategy. Here we combine a novel EGFR-TKI treatment with thermal therapy to improve lung cancer treatment outcomes. Results The results suggest that the cAMP-H3BO3 complex effectively inhibits EGFR auto-phosphorylation, while inducing apoptosis and cell cycle arrest in vitro. Compared to the negative control, tumor growth was significantly suppressed in mice treated with oxidative phosphorylation uncoupler thyroxine sodium and either cAMP-H3BO3 complex or cAMP-H3BO3 complex (P < 0.05). Moreover, the body temperature increase induced by treatment with thyroxine sodium inhibited tumor growth. Immunohistochemical analyses showed that A549 cell apoptosis was significantly higher in the cAMP-H3BO3 complex plus thyroxine sodium treatment group than in the other groups. Moreover,Ca2+ content analysis showed that the Ca2+ content of tumor tissue was significantly higher in the cAMP-H3BO3 complex plus thyroxine sodium treatment group than in other groups. Materials and Methods Inhibition of EGFR auto-phosphorylation by cAMP and cAMP-H3BO3 complex was studied using autoradiography and western blot. The antitumor activity of the novel EGFR inhibitor (cAMP-H3BO3 complex) with or without an oxidative phosphorylation uncoupler (thyroxine sodium) was investigated in vitro and in a nude mouse xenograft lung cancer model incorporating human A549 cells. Conclusions cAMP-H3BO3 complex is a novel EGFR-TKI. Combination therapy using cAMP-H3BO3 with thyroxine sodium-induced thermal therapy may improve lung cancer treatment outcomes. PMID:28915593

Human computer confluence applied in healthcare and rehabilitation.

PubMed

Viaud-Delmon, Isabelle; Gaggioli, Andrea; Ferscha, Alois; Dunne, Stephen

2012-01-01

Human computer confluence (HCC) is an ambitious research program studying how the emerging symbiotic relation between humans and computing devices can enable radically new forms of sensing, perception, interaction, and understanding. It is an interdisciplinary field, bringing together researches from horizons as various as pervasive computing, bio-signals processing, neuroscience, electronics, robotics, virtual & augmented reality, and provides an amazing potential for applications in medicine and rehabilitation.

Oceanographic Measurements Program Review.

DTIC Science & Technology

1982-03-01

prototype Advanced Microstructure Profiler (AMP) was completed and the unit was operationally tested in local waters (Lake Washington and Puget Sound ...Expendables ....... ............. ..21 A.W. Green The Developent of an Air-Launched ................ 25 Expendable Sound Velocimeter (AXSV); R. Bixby...8217., ,? , .’,*, ;; .,’...; "’ . :" .* " . .. ". ;’ - ~ ~ ~ ~ ’ V’ 7T W, V a .. -- THE DEVELOPMENT OF AN AIR-LAUNCHED EXPENDABLE SOUND VELOCIMETER (AXSV) Richard Bixby

Armed Forces Radiobiology Research Institute Annual Research Report, Fiscal Year 1984.

DTIC Science & Technology

1984-01-01

thromboxane B2, cyclic AMP and GMP, ACTH, beta -endorphin, cortisol/corticosterone, and complement in bio- logical fluids and tissues. Mediators will...immunomodulators are being tested for their ability to enhance the *recovery of hemopoiesis following irradiation. These include glucan , detoxified...endotoxin, and selected agents from the Biological Response Modifiers Program (NCI, Frederick, MD). Glucan has proved to be very effective in stimulating

AMP Short Course: Neurological, Psychiatric and Psychological Aspects of Aerospace Medicine (Aspects Neurologiques, Psychiatriques et Psychologiques de la Medecine Aerospatiale)

DTIC Science & Technology

1991-09-01

States did riot comtplete its Etich medical speciality within acroispace medicine (iffers research program and curre: nly does not use unqecnrbtosI crp...Iii res ew iig the sleep) listor%. you cain deterriiine ’Il he obese liatierits knowni toi have sleep a1prica would be if there is art iinadeqcuate

Signaling pathways coordinating the alkaline pH response confer resistance to the hevein-type plant antimicrobial peptide Pn-AMP1 in Saccharomyces cerevisiae.

PubMed

Kwon, Youngho; Chiang, Jennifer; Tran, Grant; Giaever, Guri; Nislow, Corey; Hahn, Bum-Soo; Kwak, Youn-Sig; Koo, Ja-Choon

2016-12-01

Genome-wide screening of Saccharomyces cerevisiae revealed that signaling pathways related to the alkaline pH stress contribute to resistance to plant antimicrobial peptide, Pn-AMP1. Plant antimicrobial peptides (AMPs) are considered to be promising candidates for controlling phytopathogens. Pn-AMP1 is a hevein-type plant AMP that shows potent and broad-spectrum antifungal activity. Genome-wide chemogenomic screening was performed using heterozygous and homozygous diploid deletion pools of Saccharomyces cerevisiae as a chemogenetic model system to identify genes whose deletion conferred enhanced sensitivity to Pn-AMP1. This assay identified 44 deletion strains with fitness defects in the presence of Pn-AMP1. Strong fitness defects were observed in strains with deletions of genes encoding components of several pathways and complex known to participate in the adaptive response to alkaline pH stress, including the cell wall integrity (CWI), calcineurin/Crz1, Rim101, SNF1 pathways and endosomal sorting complex required for transport (ESCRT complex). Gene ontology (GO) enrichment analysis of these genes revealed that the most highly overrepresented GO term was "cellular response to alkaline pH". We found that 32 of the 44 deletion strains tested (72 %) showed significant growth defects compared with their wild type at alkaline pH. Furthermore, 9 deletion strains (20 %) exhibited enhanced sensitivity to Pn-AMP1 at ambient pH compared to acidic pH. Although several hundred plant AMPs have been reported, their modes of action remain largely uncharacterized. This study demonstrates that the signaling pathways that coordinate the adaptive response to alkaline pH also confer resistance to a hevein-type plant AMP in S. cerevisiae. Our findings have broad implications for the design of novel and potent antifungal agents.

m6A RNA Degradation Products are Catabolized by an Evolutionarily Conserved N6-methyl-AMP Deaminase in Plant and Mammalian Cells.

PubMed

Chen, Mingjia; Urs, Mounashree J; Sánchez-González, Ismael; Olayioye, Monilola A; Herde, Marco; Witte, Claus-Peter

2018-06-08

N6-methylated adenine (m6A) is the most frequent posttranscriptional modification in eukaryotic mRNA. Turnover of RNA generates N6-methylated AMP (N6-mAMP), which has an unclear metabolic fate. We show that Arabidopsis thaliana and human cells require an N6-mAMP deaminase (ADAL, renamed MAPDA) to catabolize N6-mAMP to inosine monophosphate (IMP) in vivo by hydrolytically removing the aminomethyl group. A phylogenetic, structural, and biochemical analysis revealed that many fungi partially or fully lack MAPDA, which coincides with a minor role of N6A-RNA methylation in these organisms. MAPDA likely protects RNA from m6A mis-incorporation. This is required because eukaryotic RNA polymerase can use N6-mATP as a substrate. Upon abrogation of MAPDA, root growth is slightly reduced, and the N6-methyladenosine, N6-mAMP, and N6-mATP concentrations are increased in Arabidopsis. Although this will potentially lead to m6A mis-incorporation into RNA, we show that the frequency is too low to be reliably detected in vivo. Since N6-mAMP was several fold more abundant than N6-mATP in MAPDA mutants, we speculate that additional molecular filters suppress the generation of N6-mATP. Enzyme kinetic data indicate that adenylate kinases represent such filters being highly selective for AMP versus N6-mAMP phosphorylation. We conclude that a multilayer molecular protection system is in place preventing N6-mAMP accumulation and salvage. © 2018 American Society of Plant Biologists. All rights reserved.

Effects of adolescent exposure to methylmercury and d-amphetamine on reversal learning and an extradimensional shift in male mice

PubMed Central

Boomhower, Steven R.; Newland, M. Christopher

2016-01-01

Adolescence is associated with the continued maturation of dopamine neurotransmission and is implicated in the etiology of many psychiatric illnesses. Adolescent exposure to neurotoxicants that distort dopamine neurotransmission, such as methylmercury (MeHg), may modify the effects of chronic d-amphetamine (d-AMP) administration on reversal learning and attentional-set shifting. Male C57Bl/6n mice were randomly assigned to two MeHg-exposure groups (0 ppm and 3 ppm) and two d-AMP-exposure groups (saline and 1 mg/kg/day), producing four treatment groups (n = 10–12/group): Control, MeHg, d-AMP, and MeHg + d-AMP. MeHg exposure (via drinking water) spanned postnatal day 21–59 (the murine adolescent period), and once daily i.p. injections of d-AMP or saline spanned postnatal day 28–42. As adults, mice were trained on a spatial-discrimination-reversal (SDR) task in which the spatial location of a lever press predicted reinforcement. Following two SDRs, a visual-discrimination task (extradimensional shift) was instated in which the presence of a stimulus light above a lever predicted reinforcement. Responding was modeled using a logistic function, which estimated the rate (slope) of a behavioral transition and trials required to complete half a transition (half-max). MeHg, d-AMP, and MeHg + d-AMP exposure increased estimates of half-max on the second reversal. MeHg exposure increased half-max and decreased the slope term following the extradimensional shift, but these effects did not occur following MeHg + d-AMP exposure. MeHg + d-AMP exposure produced more perseverative errors and omissions following a reversal. Adolescent exposure to MeHg can modify the behavioral effects of chronic d-AMP administration. PMID:28287789

Prevalence of AmpC and other beta-lactamases in enterobacteria at a large urban university hospital in Brazil

PubMed Central

Dias, Rubens Clayton da Silva; Borges-Neto, Armando Alves; Ferraiuoli, Giovanna Ianini D’Almeida; de-Oliveira, Márcia P.; Riley, Lee W.; Moreira, Beatriz Meurer

2010-01-01

Production of extended-spectrum β-lactamases (ESBL) has been reported in virtually all species of Enterobacteriaceae, which greatly complicates the therapy of infections caused by these organisms. However, the frequency of isolates producing AmpC β-lactamases, especially plasmid mediated AmpC (pAmpC), is largely unknown. These β-lactamases confer resistance to extended spectrum cephalosporins and aztreonam, a multidrug-resistant (MDR) profile. The aim of the present study was to determine the occurrence of ESBL and pAmpC β-lactamases in a hospital where MDR enterobacterial isolates recently emerged. A total of 123 consecutive enterobacterial isolates obtained from 112 patients at a university hospital in Rio de Janeiro, Brazil during March-June 2001 were included in the study. ESBL was detected by the addition of clavulanate to cephalosporin containing disks and by double diffusion. AmpC production was evaluated by a modified tridimensional test and a modified Hodge test. The presence of plasmid-mediated ampC β-lactamase genes was evaluated by multiplex-PCR. Sixty-five (53%) of 123 enterobacterial isolates were MDR, obtained from 56 patients. ESBL production was detected in 35 isolates; 5 clonal E. coli isolates exhibited high levels of chromosomal AmpC and ESBL production. However, no isolates contained pAmpC genes. Infection or colonization by MDR enterobacteria was not associated with any predominant resistant clones. A large proportion of hospital infections caused by ESBL-producing enterobacteria identified during the study period were due to sporadic infections rather than undetected outbreaks. This observation emphasizes the need to improve our detection methods for ESBL- and AmpC-producing organisms in hospitals where extended-spectrum cephalosporins are in wide use. PMID:17900845

Utility of Adenosine Monophosphate Detection System for Monitoring the Activities of Diverse Enzyme Reactions.

PubMed

Mondal, Subhanjan; Hsiao, Kevin; Goueli, Said A

Adenosine monophosphate (AMP) is a key cellular metabolite regulating energy homeostasis and signal transduction. AMP is also a product of various enzymatic reactions, many of which are dysregulated during disease conditions. Thus, monitoring the activities of these enzymes is a primary goal for developing modulators for these enzymes. In this study, we demonstrate the versatility of an enzyme-coupled assay that quantifies the amount of AMP produced by any enzymatic reaction regardless of its substrates. We successfully implemented it to enzyme reactions that use adenosine triphosphate (ATP) as a substrate (aminoacyl tRNA synthetase and DNA ligase) by an elaborate strategy of removing residual ATP and converting AMP produced into ATP; so it can be detected using luciferase/luciferin and generating light. We also tested this assay to measure the activities of AMP-generating enzymes that do not require ATP as substrate, including phosphodiesterases (cyclic adenosine monophosphate) and Escherichia coli DNA ligases (nicotinamide adenine dinucleotide [NAD + ]). In a further elaboration of the AMP-Glo platform, we coupled it to E. coli DNA ligase, enabling measurement of NAD + and enzymes that use NAD + like monoadenosine and polyadenosine diphosphate-ribosyltransferases. Sulfotransferases use 3'-phosphoadenosine-5'-phosphosulfate as the universal sulfo-group donor and phosphoadenosine-5'-phosphate (PAP) is the universal product. PAP can be quantified by converting PAP to AMP by a Golgi-resident PAP-specific phosphatase, IMPAD1. By coupling IMPAD1 to the AMP-Glo system, we can measure the activities of sulfotransferases. Thus, by utilizing the combinations of biochemical enzymatic conversion of various cellular metabolites to AMP, we were able to demonstrate the versatility of the AMP-Glo assay.

Potentiation of adenosine triphosphate-induced contractile responses of the guinea-pig isolated vas deferens by adenosine monophosphate and adenosine 5'-monophosphorothioate.

PubMed Central

Fedan, J. S.

1987-01-01

The effects of incubating the guinea-pig isolated vas deferens in the presence of adenine nucleotides (adenosine triphosphate, ATP; adenosine diphosphate, ADP; and adenosine monophosphate, AMP), or in the presence of their phosphorothioate analogues (adenosine 5'-O-(3-thiotriphosphate), ATP gamma S; adenosine 5'-O-(2-thiodiphosphate), ADP beta S; and adenosine 5'-monophosphorothioate, AMP alpha S), on contractile responses to ATP were compared. After challenge with a low (1 microM) or high (300 microM) concentration of ATP to obtain control responses, one vas deferens of a pair was incubated for 5 min with one of the adenine nucleotides, while the contralateral preparation was incubated with the corresponding phosphorothioate analogue. At the conclusion of the incubation the preparations were challenged again with ATP. Incubation with AMP or AMP alpha S resulted in a transient potentiation of responses to 1 microM and 300 microM ATP. The potentiation following incubation with AMP alpha S was larger than that produced by AMP. After incubation with ADP, ADP beta S, ATP and ATP gamma S, responses to 1 microM ATP were decreased, while those to 300 microM ATP were unaffected. Thus, incubation with AMP and AMP alpha S results in potentiation, rather than inhibition, of ATP-induced responses. On the other hand, 5'-diphosphate, 5'-triphosphate, 5'-O-(2-thiodiphosphate) and 5'-O-(3-thiotriphosphate) moieties on adenosine have no effect or cause autoinhibition. These results indicate that AMP exerts a potentiating effect on reactivity to exogenous ATP. AMP arising from the enzymatic degradation of ATP might modulate the level of response to ATP released endogenously as a cotransmitter. PMID:3038248

Development of Antimicrobial Peptide Prediction Tool for Aquaculture Industries.

PubMed

Gautam, Aditi; Sharma, Asuda; Jaiswal, Sarika; Fatma, Samar; Arora, Vasu; Iquebal, M A; Nandi, S; Sundaray, J K; Jayasankar, P; Rai, Anil; Kumar, Dinesh

2016-09-01

Microbial diseases in fish, plant, animal and human are rising constantly; thus, discovery of their antidote is imperative. The use of antibiotic in aquaculture further compounds the problem by development of resistance and consequent consumer health risk by bio-magnification. Antimicrobial peptides (AMPs) have been highly promising as natural alternative to chemical antibiotics. Though AMPs are molecules of innate immune defense of all advance eukaryotic organisms, fish being heavily dependent on their innate immune defense has been a good source of AMPs with much wider applicability. Machine learning-based prediction method using wet laboratory-validated fish AMP can accelerate the AMP discovery using available fish genomic and proteomic data. Earlier AMP prediction servers are based on multi-phyla/species data, and we report here the world's first AMP prediction server in fishes. It is freely accessible at http://webapp.cabgrid.res.in/fishamp/ . A total of 151 AMPs related to fish collected from various databases and published literature were taken for this study. For model development and prediction, N-terminus residues, C-terminus residues and full sequences were considered. Best models were with kernels polynomial-2, linear and radial basis function with accuracy of 97, 99 and 97 %, respectively. We found that performance of support vector machine-based models is superior to artificial neural network. This in silico approach can drastically reduce the time and cost of AMP discovery. This accelerated discovery of lead AMP molecules having potential wider applications in diverse area like fish and human health as substitute of antibiotics, immunomodulator, antitumor, vaccine adjuvant and inactivator, and also for packaged food can be of much importance for industries.

Protein kinase A-mediated cell proliferation in brown preadipocytes is independent of Erk1/2, PI{sub 3}K and mTOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yanling; Sato, Masaaki; Guo, Yuan

2014-10-15

The physiological agonist norepinephrine promotes cell proliferation of brown preadipocytes during the process of tissue recruitment. In a primary culture system, cAMP mediates these adrenergic effects. In the present study, we demonstrated that, in contrast to other systems where the mitogenic effect of cAMP requires the synergistic action of (serum) growth factors, especially insulin/IGF, the cAMP effect in brown preadipocytes was independent of serum and insulin. Protein kinase A, rather than Epac, mediated the cAMP mitogenic effect. The Erk 1/2 family of MAPK, the PI{sub 3}K system and the mTOR complexes were all activated by cAMP, but these activations weremore » not necessary for cAMP-induced cell proliferation; a protein kinase C isoform may be involved in mediating cAMP-activated cell proliferation. We conclude that the generally acknowledged cellular mediators for induction of cell proliferation are not involved in this process in the brown preadipocyte system; this conclusion may be of relevance both for examination of mechanisms for induction of brown adipose tissue recruitment but also for understanding the mechanism behind e.g. certain endocrine neoplasias. - Highlights: • cAMP can mimick norepinephrine-induced proliferation of brown preadipocytes. • The cAMP-induced proliferation can occur in the absence of serum, of any other growth factors, and of insulin. • Erk1/2, PI{sub 3}K and mTOR are cAMP activated but not involved in induction of proliferation. • A Protein Kinase C member may be in the signalling cascade. • This pathway analysis may also be of importance for certain endocrine hyper- and neoplasias.« less

Activation of exchange protein activated by cAMP in the rat basolateral amygdala impairs reconsolidation of a memory associated with self-administered cocaine.

PubMed

Wan, Xun; Torregrossa, Mary M; Sanchez, Hayde; Nairn, Angus C; Taylor, Jane R

2014-01-01

The intracellular mechanisms underlying memory reconsolidation critically involve cAMP signaling. These events were originally attributed to PKA activation by cAMP, but the identification of Exchange Protein Activated by cAMP (Epac), as a distinct mediator of cAMP signaling, suggests that cAMP-regulated processes that subserve memory reconsolidation are more complex. Here we investigated how activation of Epac with 8-pCPT-cAMP (8-CPT) impacts reconsolidation of a memory that had been associated with cocaine self-administration. Rats were trained to lever press for cocaine on an FR-1 schedule, in which each cocaine delivery was paired with a tone+light cue. Lever pressing was then extinguished in the absence of cue presentations and cocaine delivery. Following the last day of extinction, rats were put in a novel context, in which the conditioned cue was presented to reactivate the cocaine-associated memory. Immediate bilateral infusions of 8-CPT into the basolateral amygdala (BLA) following reactivation disrupted subsequent cue-induced reinstatement in a dose-dependent manner, and modestly reduced responding for conditioned reinforcement. When 8-CPT infusions were delayed for 3 hours after the cue reactivation session or were given after a cue extinction session, no effect on cue-induced reinstatement was observed. Co-administration of 8-CPT and the PKA activator 6-Bnz-cAMP (10 nmol/side) rescued memory reconsolidation while 6-Bnz alone had no effect, suggesting an antagonizing interaction between the two cAMP signaling substrates. Taken together, these studies suggest that activation of Epac represents a parallel cAMP-dependent pathway that can inhibit reconsolidation of cocaine-cue memories and reduce the ability of the cue to produce reinstatement of cocaine-seeking behavior.

Hydrostatic pressure-dependent changes in cyclic AMP signaling in optic nerve head astrocytes from Caucasian and African American donors

PubMed Central

Chen, Lin; Hernandez, M. Rosario

2009-01-01

Purpose Investigate the effect of hydrostatic pressure (HP) on 3′, 5′-cyclic adenosine monophosphate (cAMP) levels and downstream signaling in cultures of normal optic nerve head (ONH) astrocytes from Caucasian American (CA) and African American (AA) donors. Methods Intracellular cAMP levels were assayed after exposing ONH astrocytes to HP for varying times. Quantitative RT–PCR was used to determine the expression levels of selected cAMP pathway genes in human ONH astrocytes after HP treatment. Western blots were used to measure changes in the phosphorylation state of cAMP response element binding protein (CREB) in astrocytes subjected to HP, ATP, and phosphodiesterase or kinase inhibitors. Results The basal intracellular cAMP level is similar among AA and CA astrocytes. After exposure to HP for 15 min and 30 min in the presence of a phosphodiesterase inhibitor a further increase of intracellular cAMP was observed in AA astrocytes, but not in CA astrocytes. Consistent with activation of the cAMP-dependent protein kinase pathway, CREB phosphorylation (Ser-133) was increased to a greater extent in AA than in CA astrocytes after 3 h of HP. Exposure to elevated HP for 3–6 h differentially altered the expression levels of selected cAMP pathway genes (ADCY3, ADCY9, PTHLH, PDE7B) in AA compared to CA astrocytes. Treatment with ATP increased more CREB phosphorylation in CA than in AA astrocytes, suggesting differential Ca2+ signaling in these populations. Conclusions Activation of the cAMP-dependent signaling pathway by pressure may be an important contributor to increased susceptibility to elevated intraocular pressure and glaucoma in AA, a population at higher risk for the disease. PMID:19710943

Effects of adolescent exposure to methylmercury and d-amphetamine on reversal learning and an extradimensional shift in male mice.

PubMed

Boomhower, Steven R; Newland, M Christopher

2017-04-01

Adolescence is associated with the continued maturation of dopamine neurotransmission and is implicated in the etiology of many psychiatric illnesses. Adolescent exposure to neurotoxicants that distort dopamine neurotransmission, such as methylmercury (MeHg), may modify the effects of chronic d -amphetamine ( d -AMP) administration on reversal learning and attentional-set shifting. Male C57Bl/6n mice were randomly assigned to two MeHg-exposure groups (0 ppm and 3 ppm) and two d -AMP-exposure groups (saline and 1 mg/kg/day), producing four treatment groups (n = 10-12/group): control, MeHg , d -AMP, and MeHg + d -AMP. MeHg exposure (via drinking water) spanned postnatal days 21-59 (the murine adolescent period), and once daily intraperitoneal injections of d -AMP or saline spanned postnatal days 28-42. As adults, mice were trained on a spatial-discrimination-reversal (SDR) task in which the spatial location of a lever press predicted reinforcement. Following 2 SDRs, a visual-discrimination task (extradimensional shift) was instated in which the presence of a stimulus light above a lever predicted reinforcement. Responding was modeled using a logistic function, which estimated the rate (slope) of a behavioral transition and trials required to complete half a transition (half-max). MeHg, d -AMP, and MeHg + d -AMP exposure increased estimates of half-max on the second reversal. MeHg exposure increased half-max and decreased the slope term following the extradimensional shift, but these effects did not occur following MeHg + d -AMP exposure. MeHg + d -AMP exposure produced more perseverative errors and omissions following a reversal. Adolescent exposure to MeHg can modify the behavioral effects of chronic d -AMP administration. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Activation of Exchange Protein Activated by cAMP in the Rat Basolateral Amygdala Impairs Reconsolidation of a Memory Associated with Self-Administered Cocaine

PubMed Central

Sanchez, Hayde; Nairn, Angus C.; Taylor, Jane R.

2014-01-01

The intracellular mechanisms underlying memory reconsolidation critically involve cAMP signaling. These events were originally attributed to PKA activation by cAMP, but the identification of Exchange Protein Activated by cAMP (Epac), as a distinct mediator of cAMP signaling, suggests that cAMP-regulated processes that subserve memory reconsolidation are more complex. Here we investigated how activation of Epac with 8-pCPT-cAMP (8-CPT) impacts reconsolidation of a memory that had been associated with cocaine self-administration. Rats were trained to lever press for cocaine on an FR-1 schedule, in which each cocaine delivery was paired with a tone+light cue. Lever pressing was then extinguished in the absence of cue presentations and cocaine delivery. Following the last day of extinction, rats were put in a novel context, in which the conditioned cue was presented to reactivate the cocaine-associated memory. Immediate bilateral infusions of 8-CPT into the basolateral amygdala (BLA) following reactivation disrupted subsequent cue-induced reinstatement in a dose-dependent manner, and modestly reduced responding for conditioned reinforcement. When 8-CPT infusions were delayed for 3 hours after the cue reactivation session or were given after a cue extinction session, no effect on cue-induced reinstatement was observed. Co-administration of 8-CPT and the PKA activator 6-Bnz-cAMP (10 nmol/side) rescued memory reconsolidation while 6-Bnz alone had no effect, suggesting an antagonizing interaction between the two cAMP signaling substrates. Taken together, these studies suggest that activation of Epac represents a parallel cAMP-dependent pathway that can inhibit reconsolidation of cocaine-cue memories and reduce the ability of the cue to produce reinstatement of cocaine-seeking behavior. PMID:25259911

AMP-18 Targets p21 to Maintain Epithelial Homeostasis.

PubMed

Chen, Peili; Li, Yan Chun; Toback, F Gary

2015-01-01

Dysregulated homeostasis of epithelial cells resulting in disruption of mucosal barrier function is an important pathogenic mechanism in inflammatory bowel diseases (IBD). We have characterized a novel gastric protein, Antrum Mucosal Protein (AMP)-18, that has pleiotropic properties; it is mitogenic, anti-apoptotic and can stimulate formation of tight junctions. A 21-mer synthetic peptide derived from AMP-18 exhibits the same biological functions as the full-length protein and is an effective therapeutic agent in mouse models of IBD. In this study we set out to characterize therapeutic mechanisms and identify molecular targets by which AMP-18 maintains and restores disrupted epithelial homeostasis in cultured intestinal epithelial cells and a mouse model of IBD. Tumor necrosis factor (TNF)-α, a pro-inflammatory cytokine known to mediate gastrointestinal (GI) mucosal injury in IBD, was used to induce intestinal epithelial cell injury, and study the effects of AMP-18 on apoptosis and the cell cycle. An apoptosis array used to search for targets of AMP-18 in cells exposed to TNF-α identified the cyclin-dependent kinase inhibitor p21 WAF1/CIP1. Treatment with AMP-18 blunted increases in p21 expression and apoptosis, while reversing disturbed cell cycle kinetics induced by TNF-α. AMP-18 appears to act through PI3K/AKT pathways to increase p21 phosphorylation, thereby reducing its nuclear accumulation to overcome the antiproliferative effects of TNF-α. In vitamin D receptor-deficient mice with TNBS-induced IBD, the observed increase in p21 expression in colonic epithelial cells was suppressed by treatment with AMP peptide. The results indicate that AMP-18 can maintain and/or restore the homeostatic balance between proliferation and apoptosis in intestinal epithelial cells to protect and repair mucosal barrier homeostasis and function, suggesting a therapeutic role in IBD.

Protection from AMP 579 can be added to that from either cariporide or ischemic preconditioning in ischemic rabbit heart.

PubMed

Xu, Zhelong; Jiao, Zhe; Cohen, Michael V; Downey, James M

2002-10-01

AMP 579, an adenosine A /A receptor agonist, is cardioprotective when administered at reperfusion. Pretreatment with the Na /H exchanger inhibitor cariporide or ischemic preconditioning (PC) also limits infarct size. To gain insight into the mechanism of AMP 579 we investigated whether its protection could be added to that from either cariporide or PC. rabbit hearts were subjected to 45 min of regional ischemia followed by 3 h of reperfusion. Infarct size in the control group was 55.8 +/- 3.9% of the risk zone. PC significantly reduced infarct size to 26.0 +/- 6.7% (p<0.05). AMP 579 (30 micro g/kg) given just before reperfusion followed by 3 micro g/kg/min infusion for 70 min also limited infarct size (32.1 +/- 1.8%,) but the combination of AMP 579 and PC showed a significantly greater limitation of infarct size (5.5 +/- 2.7%, p < 0.05). Because cariporide pretreatment was so protective (8.5 +/- 3.7% infarction), we had to increase the ischemic insult to 60 min to test for any additive effect of the combination of AMP 579 + cariporide. Infarct size in the untreated group was 66.0 +/- 4.9% of the risk zone. Cariporide (0.5 mg/kg) 5 min prior to ischemia significantly reduced infarct size to 41.5 +/- 7.7%. When cariporide pre-treatment was combined with AMP 579 at reperfusion, infarction was further limited (14.2 +/- 4.5%). Because AMP 579's protection can be added to that of either cariporide or PC, AMP 579's mechanism of protection probably differs from either of them. The combination of AMP 579 + cariporide was particularly efficacious and could be useful in the surgical setting.

The ceramide-1-phosphate analogue PCERA-1 modulates tumour necrosis factor-alpha and interleukin-10 production in macrophages via the cAMP-PKA-CREB pathway in a GTP-dependent manner.

PubMed

Avni, Dorit; Philosoph, Amir; Meijler, Michael M; Zor, Tsaffrir

2010-03-01

The synthetic phospho-ceramide analogue-1 (PCERA-1) down-regulates production of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha) and up-regulates production of the anti-inflammatory cytokine interleukin-10 (IL-10) in lipopolysaccharide (LPS) -stimulated macrophages. We have previously reported that PCERA-1 increases cyclic adenosine monophosphate (cAMP) levels. The objective of this study was to delineate the signalling pathway leading from PCERA-1 via cAMP to modulation of TNF-alpha and IL-10 production. We show here that PCERA-1 elevates intra-cellular cAMP level in a guanosine triphosphate-dependent manner in RAW264.7 macrophages. The cell-permeable dibutyryl cAMP was able to mimic the effects of PCERA-1 on cytokine production, whereas 8-chloro-phenylthio-methyladenosine-cAMP, which specifically activates the exchange protein directly activated by cAMP (EPAC) but not protein kinase A (PKA), failed to mimic PCERA-1 activities. Consistently, the PKA inhibitor H89 efficiently blocked PCERA-1-driven cytokine modulation as well as PCERA-1-stimulated phosphorylation of cAMP response element binding protein (CREB) on Ser-133. Finally, PCERA-1 activated cAMP-responsive transcription of a luciferase reporter, in synergism with the phosphodiesterase (PDE)-4 inhibitor rolipram. Our results suggest that PCERA-1 activates a G(s) protein-coupled receptor, leading to elevation of cAMP, which acts via the PKA-CREB pathway to promote TNF-alpha suppression and IL-10 induction in LPS-stimulated macrophages. Identification of the PCERA-1 receptor is expected to set up a new target for development of novel anti-inflammatory drugs.

AMP-Conjugated Quantum Dots: Low Immunotoxicity Both In Vitro and In Vivo

NASA Astrophysics Data System (ADS)

Dai, Tongcheng; Li, Na; Liu, Lu; Liu, Qin; Zhang, Yuanxing

2015-11-01

Quantum dots (QDs) are engineered nanoparticles that possess special optical and electronic properties and have shown great promise for future biomedical applications. In this work, adenosine 5'-monophosphate (AMP), a small biocompatible molecular, was conjugated to organic QDs to produce hydrophilic AMP-QDs. Using macrophage J774A.1 as the cell model, AMP-QDs exhibited both prior imaging property and low toxicity, and more importantly, triggered limited innate immune responses in macrophage, indicating low immunotoxicity in vitro. Using BALB/c mice as the animal model, AMP-QDs were found to be detained in immune organs but did not evoke robust inflammation responses or obvious histopathological abnormalities, which reveals low immunotoxicity in vivo. This work suggests that AMP is an excellent surface ligand with low immunotoxicity, and potentially used in surface modification for more extensive nanoparticles.

An amino acid composition criterion for membrane active antimicrobials

NASA Astrophysics Data System (ADS)

Schmidt, Nathan; Lai, Ghee Hwee; Mishra, Abhijit; Bong, Dennis; McCray, Paul, Jr.; Selsted, Michael; Ouellette, Andre; Wong, Gerard

2011-03-01

Membrane active antimicrobials (AMPs) are short amphipathic peptides with broad spectrum anti microbial activity. While it is believed that their hydrophobic and cationic moieties are responsible for membrane-based mechanisms of action, membrane disruption by AMPs is manifested in a diversity of outcomes, such as pore formation, blebbing, and budding. This complication, along with others, have made a detailed, molecular understanding of AMPs difficult. We use synchrotron small angle xray scattering to investigate the interaction of model bacterial and eukaryotic cell membranes with archetypes from beta-sheet AMPs (e.g. defensins) and alpha-helical AMPs (e.g. magainins). The relationship between membrane composition and peptide induced changes in membrane curvature and topology is examined. By comparing the membrane rearrangement and phase behavior induced by these different peptides we will discuss the importance of amino acid composition on AMP design.

Blockade of beta-adrenoceptors enhances cAMP signal transduction in vivo

NASA Technical Reports Server (NTRS)

Whalen, E. J.; Johnson, A. K.; Lewis, S. J.

1998-01-01

The aim of this study was to determine whether the blockade of beta-adrenoceptors would enhance cAMP-mediated signal transduction processes in vivo. The administration of the membrane permeable cAMP analogue, 8-(4-chlorophenylthiol)-cAMP (8-CPT-cAMP, 10 micromol/kg, i.v.) produced an increase in heart rate (+27 +/- 2%, P < 0.05), a fall in mean arterial blood pressure (-21 +/- 3%, P < 0.05) and falls in hindquarter (-12 +/- 3%, P < 0.05) and mesenteric (-32 +/- 3%, P < 0.05) vascular resistances in pentobarbital-anesthetized rats. The beta-adrenoceptor antagonist, propranolol (1 mg/kg, i.v.) lowered heart rate (-12 +/- 3%, P < 0.05) but did not affect mean arterial blood pressure or vascular resistances. The tachycardia, hypotension and vasodilation produced by 8-CPT-cAMP were exaggerated after administration of propranolol (P < 0.05 for all comparisons). The nitric oxide-donor, sodium nitroprusside (2 microg/kg, i.v.), produced falls in mean arterial blood pressure and vascular resistances of similar magnitude to those produced by 8-CPT-cAMP. These sodium nitroprusside-induced responses were unaffected by propranolol (P < 0.05 for all comparisons). Sodium nitroprusside also produced a minor increase in heart rate (+5 +/- 1%, P < 0.05) which was abolished by propranolol. These findings suggest that 8-CPT-cAMP directly increases heart rate and that blockade of beta-adrenoceptors enhances the potency of cAMP within the heart and vasculature.

3-aminopropyl functionalized magnesium phyllosilicate as an organoclay based drug carrier for improving the bioavailability of flurbiprofen.

PubMed

Yang, Liang; Choi, Soo-Kyung; Shin, Hyun-Jae; Han, Hyo-Kyung

2013-01-01

This study aimed to develop an oral delivery system using clay-based organic-inorganic hybrid materials to improve the bioavailability of the drug, flurbiprofen, which is poorly soluble in water. 3-aminopropyl functionalized magnesium phyllosilicate (AMP clay) was synthesized by a one-pot direct sol-gel method, and then flurbiprofen (FB) was incorporated into AMP clay (FB-AMP) at different drug/clay ratios. The structural characteristics of AMP and FB-AMP formulation were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. Among tested formulations, FB-AMP(3), dramatically increased the dissolution of FB and achieved rapid and complete drug release within 2 hours. More than 60% of FB was released from FB-AMP(3) after 30 minutes; the drug was completely dissolved in the water within 2 hours. Under the acidic condition (pH 1.2), FB-AMP(3) also increased the dissolution of FB by up to 47.1% within 1 hour, which was three-fold higher than that of untreated FB. Furthermore, following an oral administration of FB-AMP(3) to Sprague-Dawley rats, the peak plasma concentration and area under the plasma concentration-time curve of FB increased two-fold, and the time to reach the peak plasma concentration was shortened compared with that in the untreated FB. This result suggests that the oral drug delivery system using clay-based organic-inorganic hybrid material might be useful to improve the bioavailability of FB.

3-aminopropyl functionalized magnesium phyllosilicate as an organoclay based drug carrier for improving the bioavailability of flurbiprofen

PubMed Central

Yang, Liang; Choi, Soo-Kyung; Shin, Hyun-Jae; Han, Hyo-Kyung

2013-01-01

This study aimed to develop an oral delivery system using clay-based organic–inorganic hybrid materials to improve the bioavailability of the drug, flurbiprofen, which is poorly soluble in water. 3-aminopropyl functionalized magnesium phyllosilicate (AMP clay) was synthesized by a one-pot direct sol-gel method, and then flurbiprofen (FB) was incorporated into AMP clay (FB-AMP) at different drug/clay ratios. The structural characteristics of AMP and FB-AMP formulation were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. Among tested formulations, FB-AMP(3), dramatically increased the dissolution of FB and achieved rapid and complete drug release within 2 hours. More than 60% of FB was released from FB-AMP(3) after 30 minutes; the drug was completely dissolved in the water within 2 hours. Under the acidic condition (pH 1.2), FB-AMP(3) also increased the dissolution of FB by up to 47.1% within 1 hour, which was three-fold higher than that of untreated FB. Furthermore, following an oral administration of FB-AMP(3) to Sprague-Dawley rats, the peak plasma concentration and area under the plasma concentration-time curve of FB increased two-fold, and the time to reach the peak plasma concentration was shortened compared with that in the untreated FB. This result suggests that the oral drug delivery system using clay-based organic–inorganic hybrid material might be useful to improve the bioavailability of FB. PMID:24204143

Human antimicrobial peptides and cancer.

PubMed

Jin, Ge; Weinberg, Aaron

2018-05-30

Antimicrobial peptides (AMPs) have long been a topic of interest for entomologists, biologists, immunologists and clinicians because of these agents' intriguing origins in insects, their ubiquitous expression in many life forms, their capacity to kill a wide range of bacteria, fungi and viruses, their role in innate immunity as microbicidal and immunoregulatory agents that orchestrate cross-talk with the adaptive immune system, and, most recently, their association with cancer. We and others have theorized that surveillance through epithelial cell-derived AMPs functions to keep the natural flora of microorganisms in a steady state in different niches such as the skin, the intestines, and the mouth. More recently, findings related to specific activation pathways of some of these AMPs have led investigators to associate them with pro-tumoral activity; i.e., contributing to a tumorigenic microenvironment. This area is still in its infancy as there are intriguing yet contradictory findings demonstrating that while some AMPs have anti-tumoral activity and are under-expressed in solid tumors, others are overexpressed and pro-tumorigenic. This review will introduce a new paradigm in cancer biology as it relates to AMP activity in neoplasia to address the following questions: Is there evidence that AMPs contribute to tumor promoting microenvironments? Can an anti-AMP strategy be of use in cancer therapy? Do AMPs, expressed in and released from tumors, contribute to compositional shifting of bacteria in cancerous lesions? Can specific AMP expression characteristics be used one day as early warning signs for solid tumors? Copyright © 2018 Elsevier Ltd. All rights reserved.

cAMP regulates DEP domain-mediated binding of the guanine nucleotide exchange factor Epac1 to phosphatidic acid at the plasma membrane.

PubMed

Consonni, Sarah V; Gloerich, Martijn; Spanjaard, Emma; Bos, Johannes L

2012-03-06

Epac1 is a cAMP-regulated guanine nucleotide exchange factor for the small G protein Rap. Upon cAMP binding, Epac1 undergoes a conformational change that results in its release from autoinhibition. In addition, cAMP induces the translocation of Epac1 from the cytosol to the plasma membrane. This relocalization of Epac1 is required for efficient activation of plasma membrane-located Rap and for cAMP-induced cell adhesion. This translocation requires the Dishevelled, Egl-10, Pleckstrin (DEP) domain, but the molecular entity that serves as the plasma membrane anchor and the possible mechanism of regulated binding remains elusive. Here we show that Epac1 binds directly to phosphatidic acid. Similar to the cAMP-induced Epac1 translocation, this binding is regulated by cAMP and requires the DEP domain. Furthermore, depletion of phosphatidic acid by inhibition of phospholipase D1 prevents cAMP-induced translocation of Epac1 as well as the subsequent activation of Rap at the plasma membrane. Finally, mutation of a single basic residue within a polybasic stretch of the DEP domain, which abolishes translocation, also prevents binding to phosphatidic acid. From these results we conclude that cAMP induces a conformational change in Epac1 that enables DEP domain-mediated binding to phosphatidic acid, resulting in the tethering of Epac1 at the plasma membrane and subsequent activation of Rap.

Deconvoluting AMP-activated protein kinase (AMPK) adenine nucleotide binding and sensing

PubMed Central

Gu, Xin; Yan, Yan; Novick, Scott J.; Kovach, Amanda; Goswami, Devrishi; Ke, Jiyuan; Tan, M. H. Eileen; Wang, Lili; Li, Xiaodan; de Waal, Parker W.; Webb, Martin R.; Griffin, Patrick R.; Xu, H. Eric

2017-01-01

AMP-activated protein kinase (AMPK) is a central cellular energy sensor that adapts metabolism and growth to the energy state of the cell. AMPK senses the ratio of adenine nucleotides (adenylate energy charge) by competitive binding of AMP, ADP, and ATP to three sites (CBS1, CBS3, and CBS4) in its γ-subunit. Because these three binding sites are functionally interconnected, it remains unclear how nucleotides bind to individual sites, which nucleotides occupy each site under physiological conditions, and how binding to one site affects binding to the other sites. Here, we comprehensively analyze nucleotide binding to wild-type and mutant AMPK protein complexes by quantitative competition assays and by hydrogen-deuterium exchange MS. We also demonstrate that NADPH, in addition to the known AMPK ligand NADH, directly and competitively binds AMPK at the AMP-sensing CBS3 site. Our findings reveal how AMP binding to one site affects the conformation and adenine nucleotide binding at the other two sites and establish CBS3, and not CBS1, as the high affinity exchangeable AMP/ADP/ATP-binding site. We further show that AMP binding at CBS4 increases AMP binding at CBS3 by 2 orders of magnitude and reverses the AMP/ATP preference of CBS3. Together, these results illustrate how the three CBS sites collaborate to enable highly sensitive detection of cellular energy states to maintain the tight ATP homeostastis required for cellular metabolism. PMID:28615457

Extended-spectrum β-lactamase/AmpC- and carbapenemase-producing Enterobacteriaceae in animals: a threat for humans?

PubMed

Madec, J-Y; Haenni, M; Nordmann, P; Poirel, L

2017-11-01

There has been a great and long-term concern that extended-spectrum β-lactamase (ESBL)/AmpC- and carbapenemase-producing Enterobacteriaceae occurring in animals may constitute a public-health issue. A large number of factors with complex interrelations contribute to the spread of those bacteria among animals and humans. ESBL/AmpC- or carbapenemase-encoding genes are most often located on mobile genetic elements favouring their dissemination. Some shared reservoirs of ESBL/AmpC or carbapenemase genes, plasmids or clones have been identified and suggest cross-transmissions. Even though exposure to animals is regarded as a risk factor, evidence for a direct transfer of ESBL/AmpC-producing bacteria from animals to humans through close contacts is limited. Nonetheless, the size of the commensal ESBL/AmpC reservoir in non-human sources is dramatically rising. This may constitute an indirect risk to public health by increasing the gene pool from which pathogenic bacteria can pick up ESBL/AmpC/carbapenemase genes. The extent to which food contributes to potential transmission of ESBL/AmpC producers to humans is also not well established. Overall, events leading to the occurrence of ESBL/AmpC- and carbapenemase-encoding genes in animals seem very much multifactorial. The impact of animal reservoirs on human health still remains debatable and unclear; nonetheless, there are some examples of direct links that have been identified. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Role of Antimicrobial Peptides in Amphibian Defense Against Trematode Infection

PubMed Central

Calhoun, Dana M.; Woodhams, Doug; Howard, Cierra; LaFonte, Bryan E.; Gregory, Jacklyn R.; Johnson, Pieter T. J.

2016-01-01

Antimicrobial peptides (AMPs) contribute to the immune defenses of many vertebrates, including amphibians. As larvae, amphibians are often exposed to the infectious stages of trematode parasites, many of which must penetrate the host’s skin, potentially interacting with host AMPs. We tested the effects of the natural AMPs repertoires on both the survival of trematode infectious stages as well as their ability to infect larval amphibians. All five trematode species exhibited decreased survival of cercariae in response to higher concentrations of adult bullfrog AMPs, but no effect when exposed to AMPs from larval bullfrogs. Similarly, the use of norepinephrine to remove AMPs from larval bullfrogs, Pacific chorus frogs, and gray treefrogs had only weak (gray treefrogs) or non-significant (other tested species) effects on infection success by Ribeiroia ondatrae. We nonetheless observed strong differences in parasite infection as a function of both host stage (first- versus second-year bullfrogs) and host species (Pacific chorus frogs versus gray treefrogs) that were apparently unrelated to AMPs. Taken together, our results suggest that AMPs do not play a significant role in defending larval amphibians against trematode cercariae, but that they could be one mechanism helping to prevent infection of post-metamorphic amphibians, particularly for highly aquatic species. PMID:26911920

Atypical one-carbon metabolism of an acetogenic and hydrogenogenic Moorella thermoacetica strain.

PubMed

Jiang, Bo; Henstra, Anne-Meint; Paulo, Paula L; Balk, Melike; van Doesburg, Wim; Stams, Alfons J M

2009-02-01

A thermophilic spore-forming bacterium (strain AMP) was isolated from a thermophilic methanogenic bioreactor that was fed with cobalt-deprived synthetic medium containing methanol as substrate. 16S rRNA gene analysis revealed that strain AMP was closely related to the acetogenic bacterium Moorella thermoacetica DSM 521(T) (98.3% sequence similarity). DNA-DNA hybridization showed 75.2 +/- 4.7% similarity to M. thermoacetica DSM 521(T), suggesting that strain AMP is a M. thermoacetica strain. Strain AMP has a unique one-carbon metabolism compared to other Moorella species. In media without cobalt growth of strain AMP on methanol was only sustained in coculture with a hydrogen-consuming methanogen, while in media with cobalt it grew acetogenically in the absence of the methanogen. Addition of thiosulfate led to sulfide formation and less acetate formation. Growth of strain AMP with CO resulted in the formation of hydrogen as the main product, while other CO-utilizing Moorella strains produce acetate as product. Formate supported growth only in the presence of thiosulfate or in coculture with the methanogen. Strain AMP did not grow with H(2)/CO(2), unlike M. thermoacetica (DSM 521(T)). The lack of growth with H(2)/CO(2) likely is due to the absence of cytochrome b in strain AMP.

A winged helix forkhead (FOXD2) tunes sensitivity to cAMP in T lymphocytes through regulation of cAMP-dependent protein kinase RIalpha.

PubMed

Johansson, C Christian; Dahle, Maria K; Blomqvist, Sandra Rodrigo; Grønning, Line M; Aandahl, Einar M; Enerbäck, Sven; Taskén, Kjetil

2003-05-09

Forkhead/winged helix (FOX) transcription factors are essential for control of the cell cycle and metabolism. Here, we show that spleens from Mf2-/- (FOXD2-/-) mice have reduced mRNA (50%) and protein (35%) levels of the RIalpha subunit of the cAMP-dependent protein kinase. In T cells from Mf2-/- mice, reduced levels of RIalpha translates functionally into approximately 2-fold less sensitivity to cAMP-mediated inhibition of proliferation triggered through the T cell receptor-CD3 complex. In Jurkat T cells, FOXD2 overexpression increased the endogenous levels of RIalpha through induction of the RIalpha1b promoter. FOXD2 overexpression also increased the sensitivity of the promoter to cAMP. Finally, co-expression experiments demonstrated that protein kinase Balpha/Akt1 work together with FOXD2 to induce the RIalpha1b promoter (10-fold) and increase endogenous RIalpha protein levels further. Taken together, our data indicate that FOXD2 is a physiological regulator of the RIalpha1b promoter in vivo working synergistically with protein kinase B to induce cAMP-dependent protein kinase RIalpha expression, which increases cAMP sensitivity and sets the threshold for cAMP-mediated negative modulation of T cell activation.

Rapid, efficient charging of lead-acid and nickel-zinc traction cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1978-01-01

Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

Crystal structures of the adenylate sensor from fission yeast AMP-activated protein kinase.

PubMed

Townley, Robert; Shapiro, Lawrence

2007-03-23

The 5'-AMP (adenosine monophosphate)-activated protein kinase (AMPK) coordinates metabolic function with energy availability by responding to changes in intracellular ATP (adenosine triphosphate) and AMP concentrations. Here, we report crystal structures at 2.9 and 2.6 A resolution for ATP- and AMP-bound forms of a core alphabetagamma adenylate-binding domain from the fission yeast AMPK homolog. ATP and AMP bind competitively to a single site in the gamma subunit, with their respective phosphate groups positioned near function-impairing mutants. Unexpectedly, ATP binds without counterions, amplifying its electrostatic effects on a critical regulatory region where all three subunits converge.

The Affect Misattribution Procedure: hot or not?

PubMed

Blaison, Christophe; Imhoff, Roland; Hühnel, Isabell; Hess, Ursula; Banse, Rainer

2012-04-01

The Affect Misattribution Procedure (AMP; Payne, Cheng, Govorun, & Stewart, 2005) is an important tool in implicit social cognition research, but little is known about its underlying mechanisms. This paper investigates whether, as the name implies, affect-based processes really underlie the AMP. We used a modified AMP that enabled us to separate the influence of affective and nonaffective processes. In three studies, evidence for the implication of nonaffective processes was consistently found. In contrast, there was no evidence for affect-based processes. Thus, the AMP rather seems cold than hot. The generalizability of the results obtained with the modified AMP is discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Calcium-dependent mitochondrial cAMP production enhances aldosterone secretion.

PubMed

Katona, Dávid; Rajki, Anikó; Di Benedetto, Giulietta; Pozzan, Tullio; Spät, András

2015-09-05

Glomerulosa cells secrete aldosterone in response to agonists coupled to Ca(2+) increases such as angiotensin II and corticotrophin, coupled to a cAMP dependent pathway. A recently recognized interaction between Ca(2+) and cAMP is the Ca(2+)-induced cAMP formation in the mitochondrial matrix. Here we describe that soluble adenylyl cyclase (sAC) is expressed in H295R adrenocortical cells. Mitochondrial cAMP formation, monitored with a mitochondria-targeted fluorescent sensor (4mtH30), is enhanced by HCO3(-) and the Ca(2+) mobilizing agonist angiotensin II. The effect of angiotensin II is inhibited by 2-OHE, an inhibitor of sAC, and by RNA interference of sAC, but enhanced by an inhibitor of phosphodiesterase PDE2A. Heterologous expression of the Ca(2+) binding protein S100G within the mitochondrial matrix attenuates angiotensin II-induced mitochondrial cAMP formation. Inhibition and knockdown of sAC significantly reduce angiotensin II-induced aldosterone production. These data provide the first evidence for a cell-specific functional role of mitochondrial cAMP. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A substrate selectivity and inhibitor design lesson from the PDE10-cAMP crystal structure: a computational study.

PubMed

Lau, Justin Kai-Chi; Li, Xiao-Bo; Cheng, Yuen-Kit

2010-04-22

Phosphodiesterases (PDEs) catalyze the hydrolysis of second messengers cAMP and cGMP in regulating many important cellular signals and have been recognized as important drug targets. Experimentally, a range of specificity/selectivity toward cAMP and cGMP is well-known for the individual PDE families. The study reported here reveals that PDEs might also exhibit selectivity toward conformations of the endogenous substrates cAMP and cGMP. Molecular dynamics simulations and free energy study have been applied to study the binding of the cAMP torsional conformers about the glycosyl bond in PDE10A2. The computational results elucidated that PDE10A2 is energetically more favorable in complex with the syn cAMP conformer (as reported in the crystal structure) and the binding of anti cAMP to PDE10A2 would lead to either a nonreactive configuration or significant perturbation on the catalytic pocket of the enzyme. This experimentally inaccessible information provides important molecular insights for the development of effective PDE10 ligands.

Solution Properties of Amphoteric Random Copolymers Bearing Pendant Sulfonate and Quaternary Ammonium Groups with Controlled Structures.

PubMed

Nakahata, Rina; Yusa, Shin-Ichi

2018-01-05

Amphoteric random copolymers P(AMPS/APTAC50) x , where x = 41, 89, and 117, composed of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) and 3-acrylamidopropyltrimethylammonium chloride (APTAC) were prepared via reversible addition-fragmentation chain transfer radical polymerization. P(AMPS/APTAC50) x can dissolve in pure water to form small interpolymer aggregates. In aqueous solutions of NaCl, P(AMPS/APTAC50) x can dissolve in the unimer state. Amphoteric random copolymer P(AMPS/APTAC50) c with high molecular weight was prepared via conventional free-radical polymerization. Although P(AMPS/APTAC50) c cannot dissolve in pure water, it can dissolve in aqueous solutions of NaCl. In amphoteric random copolymers with high molecular weight, the possibility of continuous sequences of monomers with the same charge may increase, which may cause strong interactions between polymer chains. When fetal bovine serum (FBS) and polyelectrolytes were mixed in phosphate-buffered saline, the hydrodynamic radius and light-scattering intensity increased. There was no interaction between P(AMPS/APTAC50) x and FBS because corresponding increases could not be observed.

High-Throughput Identification of Antimicrobial Peptides from Amphibious Mudskippers

PubMed Central

You, Xinxin; Bian, Chao; Chen, Shixi; Lv, Zhao; Qiu, Limei; Shi, Qiong

2017-01-01

Widespread existence of antimicrobial peptides (AMPs) has been reported in various animals with comprehensive biological activities, which is consistent with the important roles of AMPs as the first line of host defense system. However, no big-data-based analysis on AMPs from any fish species is available. In this study, we identified 507 AMP transcripts on the basis of our previously reported genomes and transcriptomes of two representative amphibious mudskippers, Boleophthalmus pectinirostris (BP) and Periophthalmus magnuspinnatus (PM). The former is predominantly aquatic with less time out of water, while the latter is primarily terrestrial with extended periods of time on land. Within these identified AMPs, 449 sequences are novel; 15 were reported in BP previously; 48 are identically overlapped between BP and PM; 94 were validated by mass spectrometry. Moreover, most AMPs presented differential tissue transcription patterns in the two mudskippers. Interestingly, we discovered two AMPs, hemoglobin β1 and amylin, with high inhibitions on Micrococcus luteus. In conclusion, our high-throughput screening strategy based on genomic and transcriptomic data opens an efficient pathway to discover new antimicrobial peptides for ongoing development of marine drugs. PMID:29165344

Effect of the dB-c-AMP and forskolin on /sup 45/Ca influx, net Ca uptake and tension on rabbit aortic smooth muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-03-01

The effect of dibutiryl-adenosine-3',5'-cyclic-monophosphate (dB-c-AMP) and forskolin on aortic tension and /sup 45/Ca influx were measured. dB-c-AMP reduced both the rate of force development and the maximal tension achieved in solutions containing various K/sup +/ concentrations. Stimulated /sup 45/Ca influx was also reduced however to a lesser extent than was the tension. Forskolin showed more marked effects of a similar nature. Thus, both these agents which increase intracellular c-AMP caused a rightward shift in the curve expressing force(ordinate) as a function of Ca influx (abscissa). Consequently, they found that dB-c-AMP stimulated more net Ca to be taken up by themore » sarcoplasmic reticulum(SR) at the same influx rate. The conclusion that c-AMP produced these effects by stimulating Ca uptake into the superficial SR was supported by the finding that dB-c-AMP increased the amount of Ca taken up into a caffeine releasable fraction.« less

Spatiotemporal regulation of cAMP signaling controls the human trophoblast fusion

PubMed Central

Gerbaud, Pascale; Taskén, Kjetil; Pidoux, Guillaume

2015-01-01

During human placentation, mononuclear cytotrophoblasts fuse to form multinucleated syncytia ensuring hormonal production and nutrient exchanges between the maternal and fetal circulation. Syncytial formation is essential for the maintenance of pregnancy and for fetal growth. The cAMP signaling pathway is the major route to trigger trophoblast fusion and its activation results in phosphorylation of specific intracellular target proteins, in transcription of fusogenic genes and assembly of macromolecular protein complexes constituting the fusogenic machinery at the plasma membrane. Specificity in cAMP signaling is ensured by generation of localized pools of cAMP controlled by cAMP phosphodiesterases (PDEs) and by discrete spatial and temporal activation of protein kinase A (PKA) in supramolecular signaling clusters inside the cell organized by A-kinase-anchoring proteins (AKAPs) and by organization of signal termination by protein phosphatases (PPs). Here we present original observations on the available components of the cAMP signaling pathway in the human placenta including PKA, PDE, and PP isoforms as well as AKAPs. We continue to discuss the current knowledge of the spatiotemporal regulation of cAMP signaling triggering trophoblast fusion. PMID:26441659

Cationic antimicrobial peptides in penaeid shrimp.

PubMed

Tassanakajon, Anchalee; Amparyup, Piti; Somboonwiwat, Kunlaya; Supungul, Premruethai

2011-08-01

Penaeid shrimp aquaculture has been consistently affected worldwide by devastating diseases that cause a severe loss in production. To fight a variety of harmful microbes in the surrounding environment, particularly at high densities (of which intensive farming represents an extreme example), shrimps have evolved and use a diverse array of antimicrobial peptides (AMPs) as part of an important first-line response of the host defense system. Cationic AMPs in penaeid shrimps composed of penaeidins, crustins, and anti-lipopolysaccharide factors are comprised of multiple classes or isoforms and possess antibacterial and antifungal activities against different strains of bacteria and fungi. Shrimp AMPs are primarily expressed in circulating hemocytes, which is the main site of the immune response, and hemocytes expressing AMPs probably migrate to infection sites to fight against pathogen invasion. Indeed, most AMPs are produced as early as the nauplii developmental stage to protect shrimp larvae from infections. In this review, we discuss the sequence diversity, expression, gene structure, and antimicrobial activities of cationic AMPs in penaeid shrimps. The information available on antimicrobial activities indicates that these shrimp AMPs have potential therapeutic applications in the control of disease problems in aquaculture.

Limited Dissemination of Extended-Spectrum β-Lactamase- and Plasmid-Encoded AmpC-Producing Escherichia coli from Food and Farm Animals, Sweden.

PubMed

Börjesson, Stefan; Ny, Sofia; Egervärn, Maria; Bergström, Jakob; Rosengren, Åsa; Englund, Stina; Löfmark, Sonja; Byfors, Sara

2016-04-01

Extended-spectrum β-lactamase (ESBL)- and plasmid-encoded ampC (pAmpC)-producing Enterobacteriaceae might spread from farm animals to humans through food. However, most studies have been limited in number of isolates tested and areas studied. We examined genetic relatedness of 716 isolates from 4,854 samples collected from humans, farm animals, and foods in Sweden to determine whether foods and farm animals might act as reservoirs and dissemination routes for ESBL/pAmpC-producing Escherichia coli. Results showed that clonal spread to humans appears unlikely. However, we found limited dissemination of genes encoding ESBL/pAmpC and plasmids carrying these genes from foods and farm animals to healthy humans and patients. Poultry and chicken meat might be a reservoir and dissemination route to humans. Although we found no evidence of clonal spread of ESBL/pAmpC-producing E. coli from farm animals or foods to humans, ESBL/pAmpC-producing E. coli with identical genes and plasmids were present in farm animals, foods, and humans.

Bioactivity of Natural and Engineered Antimicrobial Peptides from Venom of the Scorpions Urodacus yaschenkoi and U. manicatus.

PubMed

Luna-Ramirez, Karen; Tonk, Miray; Rahnamaeian, Mohammad; Vilcinskas, Andreas

2017-01-06

The spread of multidrug-resistant human pathogens has drawn attention towards antimicrobial peptides (AMPs), which are major players in the innate immune systems of many organisms, including vertebrates, invertebrates, plants and microbes. Scorpion venom is an abundant source of novel and potent AMPs. Here, we investigated natural and engineered AMPs from the scorpions Urodacus yaschenkoi and U. manicatus to determine their antimicrobial spectra as well as their hemolytic/cytotoxic activity. None of the AMPs were active against fungi, but many of them were active at low concentrations (0.25-30 µM) against seven different bacteria. Hemolytic and cytotoxic activities were determined using pig erythrocytes and baby hamster kidney cells, respectively. The amino acid substitutions in the engineered AMPs did not inhibit cytotoxicity, but reduced hemolysis and therefore increased the therapeutic indices. The phylogenetic analysis of scorpion AMPs revealed they are closely related and the GXK motif is highly conserved. The engineered scorpion AMPs offer a promising alternative for the treatment of multidrug-resistant bacterial infections and could be modified further to reduce their hemolytic/cytotoxic activity.

High-Throughput Identification of Antimicrobial Peptides from Amphibious Mudskippers.

PubMed

Yi, Yunhai; You, Xinxin; Bian, Chao; Chen, Shixi; Lv, Zhao; Qiu, Limei; Shi, Qiong

2017-11-22

Widespread existence of antimicrobial peptides (AMPs) has been reported in various animals with comprehensive biological activities, which is consistent with the important roles of AMPs as the first line of host defense system. However, no big-data-based analysis on AMPs from any fish species is available. In this study, we identified 507 AMP transcripts on the basis of our previously reported genomes and transcriptomes of two representative amphibious mudskippers, Boleophthalmus pectinirostris (BP) and Periophthalmus magnuspinnatus (PM). The former is predominantly aquatic with less time out of water, while the latter is primarily terrestrial with extended periods of time on land. Within these identified AMPs, 449 sequences are novel; 15 were reported in BP previously; 48 are identically overlapped between BP and PM; 94 were validated by mass spectrometry. Moreover, most AMPs presented differential tissue transcription patterns in the two mudskippers. Interestingly, we discovered two AMPs, hemoglobin β1 and amylin, with high inhibitions on Micrococcus luteus . In conclusion, our high-throughput screening strategy based on genomic and transcriptomic data opens an efficient pathway to discover new antimicrobial peptides for ongoing development of marine drugs.

Constitutional abnormalities of chromosome 21 predispose to iAMP21-acute lymphoblastic leukaemia.

PubMed

Harrison, Christine J; Schwab, Claire

2016-03-01

In addition to Down syndrome, individuals with other constitutional abnormalities of chromosome 21 have an increased risk of developing childhood acute lymphoblastic leukaemia (ALL). Specifically, carriers of the Robertsonian translocation between chromosomes 15 and 21, rob(15;21) (q10; q10)c, have ∼2,700 increased risk of developing ALL with iAMP21 (intrachromosomal amplification of chromosome 21). In these patients, chromosome 15 as well as chromosome 21 is involved in the formation of iAMP21, referred to here as der(21)(15;21). Individuals with constitutional ring chromosomes involving chromosome 21, r(21)c, are also predisposed to iAMP21-ALL, involving the same series of mutational processes as seen in sporadic- and der(21)(15;21)-iAMP21 ALL. Evidence is accumulating that the dicentric nature of the Robertsonian and ring chromosome is the initiating factor in the formation of the complex iAMP21 structure. Unravelling these intriguing predispositions to iAMP21-ALL may provide insight into how other complex rearrangements arise in cancer. Copyright © 2016. Published by Elsevier Masson SAS.

Automated innovative diagnostic, data management and communication tool, for improving malaria vector control in endemic settings.

PubMed

Vontas, John; Mitsakakis, Konstantinos; Zengerle, Roland; Yewhalaw, Delenasaw; Sikaala, Chadwick Haadezu; Etang, Josiane; Fallani, Matteo; Carman, Bill; Müller, Pie; Chouaïbou, Mouhamadou; Coleman, Marlize; Coleman, Michael

2016-01-01

Malaria is a life-threatening disease that caused more than 400,000 deaths in sub-Saharan Africa in 2015. Mass prevention of the disease is best achieved by vector control which heavily relies on the use of insecticides. Monitoring mosquito vector populations is an integral component of control programs and a prerequisite for effective interventions. Several individual methods are used for this task; however, there are obstacles to their uptake, as well as challenges in organizing, interpreting and communicating vector population data. The Horizon 2020 project "DMC-MALVEC" consortium will develop a fully integrated and automated multiplex vector-diagnostic platform (LabDisk) for characterizing mosquito populations in terms of species composition, Plasmodium infections and biochemical insecticide resistance markers. The LabDisk will be interfaced with a Disease Data Management System (DDMS), a custom made data management software which will collate and manage data from routine entomological monitoring activities providing information in a timely fashion based on user needs and in a standardized way. The ResistanceSim, a serious game, a modern ICT platform that uses interactive ways of communicating guidelines and exemplifying good practices of optimal use of interventions in the health sector will also be a key element. The use of the tool will teach operational end users the value of quality data (relevant, timely and accurate) to make informed decisions. The integrated system (LabDisk, DDMS & ResistanceSim) will be evaluated in four malaria endemic countries, representative of the vector control challenges in sub-Saharan Africa, (Cameroon, Ivory Coast, Ethiopia and Zambia), highly representative of malaria settings with different levels of endemicity and vector control challenges, to support informed decision-making in vector control and disease management.

Atmosphere, Magnetosphere and Plasmas in Space (AMPS). Spacelab payload definition study. Volume 3, book 2: AMPS equipment to Spacelab ICD

NASA Technical Reports Server (NTRS)

1976-01-01

The interfaces between AMPS Payload No.(TBD) and Spacelab are described. The interfaces specified cover the AMPS physical, electrical, and thermal interfaces that are established to prescribe the standard Spacelab configuration required to perform the mission. If the configuration definition changes due to change of Spacelab equipment model, or serial numbers, then reidentification of the Labcraft payload may be required.

Critical Role of Nitric Oxide-cGMP Cascade in the Formation of cAMP-Dependent Long-Term Memory

ERIC Educational Resources Information Center

Aonuma, Hitoshi; Mizunami, Makoto; Matsumoto, Yukihisa; Unoki, Sae

2006-01-01

Cyclic AMP pathway plays an essential role in formation of long-term memory (LTM). In some species, the nitric oxide (NO)-cyclic GMP pathway has been found to act in parallel and complementary to the cAMP pathway for LTM formation. Here we describe a new role of the NO-cGMP pathway, namely, stimulation of the cAMP pathway to induce LTM. We have…

cAMP-responsive Element-binding Protein (CREB) and cAMP Co-regulate Activator Protein 1 (AP1)-dependent Regeneration-associated Gene Expression and Neurite Growth*

PubMed Central

Ma, Thong C.; Barco, Angel; Ratan, Rajiv R.; Willis, Dianna E.

2014-01-01

To regenerate damaged axons, neurons must express a cassette of regeneration-associated genes (RAGs) that increases intrinsic growth capacity and confers resistance to extrinsic inhibitory cues. Here we show that dibutyrl-cAMP or forskolin combined with constitutive-active CREB are superior to either agent alone in driving neurite growth on permissive and inhibitory substrates. Of the RAGs examined, only arginase 1 (Arg1) expression correlated with the increased neurite growth induced by the cAMP/CREB combination, both of which were AP1-dependent. This suggests that cAMP-induced AP1 activity is necessary and interacts with CREB to drive expression of RAGs relevant for regeneration and demonstrates that combining a small molecule (cAMP) with an activated transcription factor (CREB) stimulates the gene expression necessary to enhance axonal regeneration. PMID:25296755

Antimicrobial Peptides: An Emerging Category of Therapeutic Agents.

PubMed

Mahlapuu, Margit; Håkansson, Joakim; Ringstad, Lovisa; Björn, Camilla

2016-01-01

Antimicrobial peptides (AMPs), also known as host defense peptides, are short and generally positively charged peptides found in a wide variety of life forms from microorganisms to humans. Most AMPs have the ability to kill microbial pathogens directly, whereas others act indirectly by modulating the host defense systems. Against a background of rapidly increasing resistance development to conventional antibiotics all over the world, efforts to bring AMPs into clinical use are accelerating. Several AMPs are currently being evaluated in clinical trials as novel anti-infectives, but also as new pharmacological agents to modulate the immune response, promote wound healing, and prevent post-surgical adhesions. In this review, we provide an overview of the biological role, classification, and mode of action of AMPs, discuss the opportunities and challenges to develop these peptides for clinical applications, and review the innovative formulation strategies for application of AMPs.

Adenosine monophosphate affects competence development and plasmid DNA transformation in Escherichia coli.

PubMed

Zhang, Yan; Li, Wenhua; Wang, Liming; Shen, Ping; Xie, Zhixiong

2013-11-01

Artificial plasmid DNA transformation of Escherichia coli induced by calcium chloride is a routine technique in molecular biology and genetic engineering processes, but its mechanism has remained elusive. Because adenosine monophosphate (AMP) has been found to regulate natural transformation in Haemophilus influenza, we aimed to investigate the effects of AMP and its derivatives on E. coli transformation by treating competence with different concentrations of them. Analysis of the transformation efficiencies revealed that AMP inhibited the artificial plasmid DNA transformation of E. coli in a concentration- and time-dependent manner. Furthermore, we found that AMP had no effect on the expression of the transformed gene but that the intracellular AMP level of the competent cells rose after a 6 h treatment. These results suggested that the intracellular AMP level had an important role in E. coli transformation. And these have useful implications for the further investigation of the mechanism of E. coli transformation.

The heterologous expression strategies of antimicrobial peptides in microbial systems.

PubMed

Deng, Ting; Ge, Haoran; He, Huahua; Liu, Yao; Zhai, Chao; Feng, Liang; Yi, Li

2017-12-01

Antimicrobial peptides (AMPs) consist of molecules acting on the defense systems of numerous organisms toward tumor and multiple pathogens, such as bacteria, fungi, viruses, and parasites. Compared to traditional antibiotics, AMPs are more stable and have lower propensity for developing resistance through functioning in the innate immune system, thus having important applications in the fields of medicine, food and so on. However, despite of their high economic values, the low yield and the cumbersome extraction process in AMPs production are problems that limit their industrial application and scientific research. To conquer these obstacles, optimized heterologous expression technologies were developed that could provide effective ways to increase the yield of AMPs. In this review, the research progress on heterologous expression of AMPs using Escherichia coli, Bacillus subtilis, Pichia pastoris and Saccharomyces cerevisiae as host cells was mainly summarized, which might guide the expression strategies of AMPs in these cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Interaction of Mastoparan with Model Membranes

NASA Astrophysics Data System (ADS)

Haloot, Justin

2010-10-01

The use of antimicrobial agents began during the 20th century to reduce the effects of infectious diseases. Since the 1990s, antimicrobial resistance has become an ever-increasing global problem. Our laboratory recently found that small antimicrobial peptides (AMPs) have potent antimicrobial activity against a wide range of Gram-negative and Gram-positive organisms including antibiotic resistant organisms. These AMPs are potential therapeutic agents against the growing problem of antimicrobial resistance. AMPs are small peptides produced by plants, insects and animals. Several hypotheses concede that these peptides cause some type of structural perturbations and increased membrane permeability in bacteria however, how AMPs kill bacteria remains unclear. The goal of this study was to design an assay that would allow us to evaluate and monitor the pore forming ability of an AMP, Mastoparan, on model membrane structures called liposomes. Development of this model will facilitate the study of how mastoparan and related AMPs interact with the bacterial membrane.

Inhibitory effects of ginseng total saponin on up-regulation of cAMP pathway induced by repeated administration of morphine.

PubMed

Seo, Jeong-Ju; Lee, Jae-Woong; Lee, Wan-Kyu; Hong, Jin-Tae; Lee, Chong-Kil; Lee, Myung-Koo; Oh, Ki-Wan

2008-02-01

We have reported that ginseng total saponin (GTS) inhibited the development of physical and psychological dependence on morphine. However, the possible molecular mechanisms of GTS are unclear. Therefore, this study was undertaken to understand the possible molecular mechanism of GTS on the inhibitory effects of morphine-induced dependence. It has been reported that the up-regulated cAMP pathway in the LC of the mouse brain after repeated administration of morphine contributes to the feature of withdrawals. GTS inhibited up-regulation of cAMP pathway in the LC after repeated administration of morphine in this experiment. GTS inhibited cAMP levels and protein expression of protein kinase A (PKA). In addition, GTS inhibited the increase of cAMP response element binding protein (CREB) phosphorylation. Therefore, we conclude that the inhibitory effects of GTS on morphine-induced dependence might be mediated by the inhibition of cAMP pathway.

Identification of a new stem cell population that generates Drosophila flight muscles.

PubMed

Gunage, Rajesh D; Reichert, Heinrich; VijayRaghavan, K

2014-08-18

How myoblast populations are regulated for the formation of muscles of different sizes is an essentially unanswered question. The large flight muscles of Drosophila develop from adult muscle progenitor (AMP) cells set-aside embryonically. The thoracic segments are all allotted the same small AMP number, while those associated with the wing-disc proliferate extensively to give rise to over 2500 myoblasts. An initial amplification occurs through symmetric divisions and is followed by a switch to asymmetric divisions in which the AMPs self-renew and generate post-mitotic myoblasts. Notch signaling controls the initial amplification of AMPs, while the switch to asymmetric division additionally requires Wingless, which regulates Numb expression in the AMP lineage. In both cases, the epidermal tissue of the wing imaginal disc acts as a niche expressing the ligands Serrate and Wingless. The disc-associated AMPs are a novel muscle stem cell population that orchestrates the early phases of adult flight muscle development.

Reward-based hypertension control by a synthetic brain-dopamine interface.

PubMed

Rössger, Katrin; Charpin-El Hamri, Ghislaine; Fussenegger, Martin

2013-11-05

Synthetic biology has significantly advanced the design of synthetic trigger-controlled devices that can reprogram mammalian cells to interface with complex metabolic activities. In the brain, the neurotransmitter dopamine coordinates communication with target neurons via a set of dopamine receptors that control behavior associated with reward-driven learning. This dopamine transmission has recently been suggested to increase central sympathetic outflow, resulting in plasma dopamine levels that correlate with corresponding brain activities. By functionally rewiring the human dopamine receptor D1 (DRD1) via the second messenger cyclic adenosine monophosphate (cAMP) to synthetic promoters containing cAMP response element-binding protein 1(CREB1)-specific cAMP-responsive operator modules, we have designed a synthetic dopamine-sensitive transcription controller that reversibly fine-tunes specific target gene expression at physiologically relevant brain-derived plasma dopamine levels. Following implantation of circuit-transgenic human cell lines insulated by semipermeable immunoprotective microcontainers into mice, the designer device interfaced with dopamine-specific brain activities and produced a systemic expression response when the animal's reward system was stimulated by food, sexual arousal, or addictive drugs. Reward-triggered brain activities were able to remotely program peripheral therapeutic implants to produce sufficient amounts of the atrial natriuretic peptide, which reduced the blood pressure of hypertensive mice to the normal physiologic range. Seamless control of therapeutic transgenes by subconscious behavior may provide opportunities for treatment strategies of the future.

β2 adrenergic receptor activation governs cardiac repolarization and arrhythmogenesis in a guinea pig model of heart failure.

PubMed

Wang, Yao; Yuan, Jiamin; Qian, Zhiyong; Zhang, Xiwen; Chen, Yanhong; Hou, Xiaofeng; Zou, Jiangang

2015-01-08

β2-AR activation increases the risk of sudden cardiac death (SCD) in heart failure (HF) patients. Non-selective β-AR blockers have greater benefits on survival than selective β1-AR blockers in chronic HF patients, indicating that β2-AR activation contributes to SCD in HF. This study investigated the role of β2-AR activation on repolarization and ventricular arrhythmia (VA) in the experimental HF model. The guinea pig HF was induced by descending aortic banding. The effective refractoriness period (ERP), corrected QT (QTc) and the incidence of VA were examined using Langendorff and programmed electrical stimulation. Ikr and APD were recorded by the whole cell patch clamp. Selective β2-AR agonist salbutamol significantly increased the incidence of VA, prolonged QTc and shortened ERP. These effects could be prevented by the selective β2-AR antagonist, ICI118551. Salbutamol prolonged APD90 and reduced Ikr in guinea pig HF myocytes. The antagonists of cAMP (Rp-cAMP) and PKA (KT5720) attenuated Ikr inhibition and APD prolongation induced by salbutamol. However, the antagonists of Gi protein (PTX) and PDE III (amrinone) showed opposite effects. This study indicates that β2-AR activation increases the incidence of VA in the experimental HF model via activation of Gs/cAMP/PKA and/or inhibition of Gi/PDE pathways.

β2 adrenergic receptor activation governs cardiac repolarization and arrhythmogenesis in a guinea pig model of heart failure

PubMed Central

Wang, Yao; Yuan, Jiamin; Qian, Zhiyong; Zhang, Xiwen; Chen, Yanhong; Hou, Xiaofeng; Zou, Jiangang

2015-01-01

β2-AR activation increases the risk of sudden cardiac death (SCD) in heart failure (HF) patients. Non-selective β-AR blockers have greater benefits on survival than selective β1-AR blockers in chronic HF patients, indicating that β2-AR activation contributes to SCD in HF. This study investigated the role of β2-AR activation on repolarization and ventricular arrhythmia (VA) in the experimental HF model. The guinea pig HF was induced by descending aortic banding. The effective refractoriness period (ERP), corrected QT (QTc) and the incidence of VA were examined using Langendorff and programmed electrical stimulation. Ikr and APD were recorded by the whole cell patch clamp. Selective β2-AR agonist salbutamol significantly increased the incidence of VA, prolonged QTc and shortened ERP. These effects could be prevented by the selective β2-AR antagonist, ICI118551. Salbutamol prolonged APD90 and reduced Ikr in guinea pig HF myocytes. The antagonists of cAMP (Rp-cAMP) and PKA (KT5720) attenuated Ikr inhibition and APD prolongation induced by salbutamol. However, the antagonists of Gi protein (PTX) and PDE III (amrinone) showed opposite effects. This study indicates that β2-AR activation increases the incidence of VA in the experimental HF model via activation of Gs/cAMP/PKA and/or inhibition of Gi/PDE pathways. PMID:25567365

Adenosine monophosphate as a mediator of ATP effects at P1 purinoceptors

PubMed Central

Ross, Fiona M; Brodie, Martin J; Stone, Trevor W

1998-01-01

When perfused with a medium containing no added magnesium and 4-aminopyridine (4AP) (50 μM) hippocampal slices generated epileptiform bursts of an interictal nature. We have shown in a previous study that adenosine 5′-triphosphate (ATP) depressed epileptiform activity and that this effect was blocked by the adenosine A1 receptor antagonist cyclopentyltheophylline but was not affected by adenosine deaminase. This implied that ATP might act indirectly at P1 receptors or at a xanthine-sensitive P2 receptor. The aim of the present study was to investigate further the action of ATP on epileptiform activity.ATP can be metabolized by ecto-nucleotidases to adenosine 5′-diphosphate (ADP), adenosine 5′-monophosphate (AMP) and adenosine, respectively. Each of these metabolites can activate receptors in its own right: P2 receptors for ADP and P1 receptors for AMP and adenosine.We now show that both AMP and ATP (50 μM) significantly decrease epileptiform discharge rate in a rapid and reversible manner. 5′Adenylic acid deaminase (AMP deaminase, AMPase) (0.2 u ml−1), when perfused alone did not significantly alter the discharge rate over the 10 min superfusion period used for drug application. When perfused concurrently with AMP (50 μM), AMP deaminase prevented the depressant effect of AMP on discharge rate.AMP deaminase, at a concentration of 0.2 u ml−1 which annulled the effect of AMP (50 μM), prevented the inhibitory activity of ATP (50 μM). A higher concentration of ATP (200 μM) depressed the frequency of spontaneous bursts to approximately 30% control and this response was also prevented by AMP deaminase.Superfusion of the slices with 5′-nucleotidase also prevented the inhibitory activity of ATP on epileptiform discharges.The results suggest that AMP mediates the inhibitory effects of ATP on epileptiform activity, a conclusion which can explain the earlier finding that cyclopentyltheophylline but not adenosine deaminase inhibited the effect of ATP. A corollary to this is that, when examining the pharmacology of ATP, care must be taken to inactivate AMP with AMP deaminase, as well as adenosine with adenosine deaminase, before a direct action of ATP on P1 receptors can be postulated. Failure to do so may have led to erroneous conclusions in some previous studies of nucleotide activity on nucleotside receptors. PMID:9690876

Understanding cAMP-dependent allostery by NMR spectroscopy: comparative analysis of the EPAC1 cAMP-binding domain in its apo and cAMP-bound states.

PubMed

Mazhab-Jafari, Mohammad T; Das, Rahul; Fotheringham, Steven A; SilDas, Soumita; Chowdhury, Somenath; Melacini, Giuseppe

2007-11-21

cAMP (adenosine 3',5'-cyclic monophosphate) is a ubiquitous second messenger that activates a multitude of essential cellular responses. Two key receptors for cAMP in eukaryotes are protein kinase A (PKA) and the exchange protein directly activated by cAMP (EPAC), which is a recently discovered guanine nucleotide exchange factor (GEF) for the small GTPases Rap1 and Rap2. Previous attempts to investigate the mechanism of allosteric activation of eukaryotic cAMP-binding domains (CBDs) at atomic or residue resolution have been hampered by the instability of the apo form, which requires the use of mixed apo/holo systems, that have provided only a partial picture of the CBD apo state and of the allosteric networks controlled by cAMP. Here, we show that, unlike other eukaryotic CBDs, both apo and cAMP-bound states of the EPAC1 CBD are stable under our experimental conditions, providing a unique opportunity to define at an unprecedented level of detail the allosteric interactions linking two critical functional sites of this CBD. These are the phosphate binding cassette (PBC), where cAMP binds, and the N-terminal helical bundle (NTHB), which is the site of the inhibitory interactions between the regulatory and catalytic regions of EPAC. Specifically, the combined analysis of the cAMP-dependent changes in chemical shifts, 2 degrees structure probabilities, hydrogen/hydrogen exchange (H/H) and hydrogen/deuterium exchange (H/D) protection factors reveals that the long-range communication between the PBC and the NTHB is implemented by two distinct intramolecular cAMP-signaling pathways, respectively, mediated by the beta2-beta3 loop and the alpha6 helix. Docking of cAMP into the PBC perturbs the NTHB inner core packing and the helical probabilities of selected NTHB residues. The proposed model is consistent with the allosteric role previously hypothesized for L273 and F300 based on site-directed mutagenesis; however, our data show that such a contact is part of a significantly more extended allosteric network that, unlike PKA, involves a tight coupling between the alpha- and beta-subdomains of the EPAC CBD. The proposed mechanism of allosteric activation will serve as a basis to understand agonism and antagonism in the EPAC system and provides also a general paradigm for how small ligands control protein-protein interfaces.

Antimicrobial peptides as a possible interlink between periodontal diseases and its risk factors: A systematic review.

PubMed

Li, S; Schmalz, G; Schmidt, J; Krause, F; Haak, R; Ziebolz, D

2018-04-01

Antimicrobial peptides (AMPs) play a critical role in controlling innate and acquired immune responses. Local dysregulation of AMP is implicated in the pathogenesis of periodontal diseases as a response to periodontal pathogen challenge. Changes in AMP expression also characterize tobacco smoking, diabetes mellitus, obesity and rheumatoid arthritis, which are established risk factors of periodontal diseases, suggesting AMP may act as putative mechanistic links between these. The aim was to evaluate and summarize critically the current evidence pertaining to interrelationships between AMPs, periodontal diseases and selected periodontal disease risk factors. General and theme specific keywords were used to search the PUBMED database for studies relevant to AMP, periodontal diseases, smoking, diabetes mellitus, obesity and rheumatoid arthritis and critically reviewed. A total of 131 abstracts and 119 full text articles were screened for relevance; 13 studies were selected for inclusion after critical review. Local AMP dysregulation characteristic to periodontal diseases appears to occur within a broader landscape of complex systemic immune perturbations independently induced by smoking, metabolic and rheumatoid disease. The nature of these interactions and mechanistic pathways involved are inadequately understood. AMPs could be possible mechanistic interlinks between periodontal diseases and its risk factors. However, such evidence is very limited and more in vivo and in vitro studies are necessary to clarify the nature of such relationships. A greater understanding of AMPs as shared mediators is essential for unraveling their value as therapeutic or biomarker candidates. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

AmpC-BETA Lactamases among Enterobacteriaceae Isolated at a Tertiary Hospital, South Western Uganda

PubMed Central

Nakaye, Martha; Bwanga, Freddie; Itabangi, Herbert; Stanley, Iramiot J.; Bashir, Mwambi; Bazira, Joel

2015-01-01

Aim To characterize AmpC-beta lactamases among Enterobacteriaceae isolates from clinical samples at Mbarara Regional Referral Hospital. Study Design Laboratory-based descriptive cross-sectional study Place and Duration of Study Microbiology Department, Mbarara Regional Referral Hospital and MBN clinical Laboratories, between May to September 2013. Methodology This study included 293 Enterobacteriaceae isolates recovered from clinical specimens that included blood, urine, stool and aspirates. AmpC Beta lactamase production was determined using disc placement method for cefoxitin at a break point of <18mm. Common AmpC plasmid mediated genes were EBC, ACC, FOX, DHA, CIT and MOX were; was determined by Multiplex PCR as described by Hanson and Perez-Perez. Results Plasmid mediated AmpC phenotype was confirmed in 107 of the 293 (36.5%) cefoxitin resistant isolates with 30 isolates having more than one gene coding for resistance. The commonest source that harbored AmpC beta lactamases was urine and E. coli was the most common AmpC producer (59.5%). The genotypes detected in this study, included EBC (n=36), FOX (n=18), ACC (n=11), CIT (n=10), DHA (n=07) and MOX (n=1). Conclusion Our findings showed that prevalence of AmpC beta-lactamase at MRRH was high (39.6), with EBC as the commonest genotype among Enterobacteriaceae Urine and E. coli were the commonest source and organism respectively that harbored AmpC beta-lactamases. There‘s rational antimicrobial therapy and antibiotic susceptibility tests should be requested by health workers especially patients presenting with urinary tract infections and bacteraemias. PMID:26078920

A Role of Erythrocytes in Adenosine Monophosphate Initiation of Hypometabolism in Mammals*

PubMed Central

Daniels, Isadora Susan; Zhang, Jianfa; O'Brien, William G.; Tao, Zhenyin; Miki, Tomoko; Zhao, Zhaoyang; Blackburn, Michael R.; Lee, Cheng Chi

2010-01-01

Biochemical and mechanistic aspects into how various hypometabolic states are initiated in mammals are poorly understood. Here, we show how a state of hypometabolism is initiated by 5′-AMP uptake by erythrocytes. Wild type, ecto-5′-nucleotidase-deficient, and adenosine receptor-deficient mice undergo 5′-AMP-induced hypometabolism in a similar fashion. Injection of 5′-AMP leads to two distinct declining phases of oxygen consumption (VO2). The phase I response displays a rapid and steep decline in VO2 that is independent of body temperature (Tb) and ambient temperature (Ta). It is followed by a phase II decline that is linked to Tb and moderated by Ta. Altering the dosages of 5′-AMP from 0.25- to 2-fold does not change the phase I response. For mice, a Ta of 15 °C is effective for induction of DH with the appropriate dose of 5′-AMP. Erythrocyte uptake of 5′-AMP leads to utilization of ATP to synthesize ADP. This is accompanied by increased glucose but decreased lactate levels, suggesting that glycolysis has slowed. Reduction in glycolysis is known to stimulate erythrocytes to increase intracellular levels of 2,3-bisphosphoglycerate, a potent allosteric inhibitor of hemoglobin's affinity for oxygen. Our studies showed that both 2,3-bisphosphoglycerate and deoxyhemoglobin levels rose following 5′-AMP administration and is in parallel with the phase I decline in VO2. In summary, our investigations reveal that 5′-AMP mediated hypometabolism is probably triggered by reduced oxygen transport by erythrocytes initiated by uptake of 5′-AMP. PMID:20430891

A role of erythrocytes in adenosine monophosphate initiation of hypometabolism in mammals.

PubMed

Daniels, Isadora Susan; Zhang, Jianfa; O'Brien, William G; Tao, Zhenyin; Miki, Tomoko; Zhao, Zhaoyang; Blackburn, Michael R; Lee, Cheng Chi

2010-07-02

Biochemical and mechanistic aspects into how various hypometabolic states are initiated in mammals are poorly understood. Here, we show how a state of hypometabolism is initiated by 5'-AMP uptake by erythrocytes. Wild type, ecto-5'-nucleotidase-deficient, and adenosine receptor-deficient mice undergo 5'-AMP-induced hypometabolism in a similar fashion. Injection of 5'-AMP leads to two distinct declining phases of oxygen consumption (VO(2)). The phase I response displays a rapid and steep decline in VO(2) that is independent of body temperature (T(b)) and ambient temperature (T(a)). It is followed by a phase II decline that is linked to T(b) and moderated by T(a). Altering the dosages of 5'-AMP from 0.25- to 2-fold does not change the phase I response. For mice, a T(a) of 15 degrees C is effective for induction of DH with the appropriate dose of 5'-AMP. Erythrocyte uptake of 5'-AMP leads to utilization of ATP to synthesize ADP. This is accompanied by increased glucose but decreased lactate levels, suggesting that glycolysis has slowed. Reduction in glycolysis is known to stimulate erythrocytes to increase intracellular levels of 2,3-bisphosphoglycerate, a potent allosteric inhibitor of hemoglobin's affinity for oxygen. Our studies showed that both 2,3-bisphosphoglycerate and deoxyhemoglobin levels rose following 5'-AMP administration and is in parallel with the phase I decline in VO(2). In summary, our investigations reveal that 5'-AMP mediated hypometabolism is probably triggered by reduced oxygen transport by erythrocytes initiated by uptake of 5'-AMP.

Peptides: β-cyclodextrin inclusion compounds as highly effective antimicrobial and anti-epithelial proliferation agents.

PubMed

Consuegra, Jessika; de Lima, Maria Elena; Santos, Daniel; Sinisterra, Rubén Dario; Cortés, Maria Esperanza

2013-12-01

The use of antimicrobial peptides (AMPs) as therapeutic agents for periodontal infections has great advantages, such as broad spectrum of action, low toxicity, and limited bacterial resistance. However, their practical use is limited because of the large amount of peptide required to exercise the microbicidal function. LyeTxI, LL37f, and KR12 cationic peptides were prepared with β-cyclodextrin (βCD) at 1:1 molar ratios. The susceptibility of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum were assessed in anaerobic conditions. Cytotoxicity assays were performed using osteoblast and Caco-2 epithelial cells, and hemolytic activity was assessed on rabbit erythrocytes at an absorbance of 414 nm. Parameters of surface roughness and electrical charge were established by atomic force microscopy and zeta (ζ) potential, respectively. AMP/βCDs drastically decreased the peptide concentration required for activity against the bacteria tested. Moreover, AMPs associated with βCD were able to modify cell-surface parameters, such as roughness and ζ potential. On the other hand, AMP/βCD did not alter the degree of hemolysis induced by the pure AMPs. The effective concentration at half-maximum values of the peptides and compounds on osteoblasts were greater than the concentrations required to achieve inhibition of bacterial growth in all the species tested. AMP/βCDs inhibited the proliferation of Caco-2 epithelial cells in a more efficient manner than AMPs alone. AMP/βCD compounds more effectively inhibit periodontopathogenic bacteria than AMPs alone, with the additional ability of inhibiting the proliferation of epithelial cells at concentrations that are non-cytotoxic for osteoblasts and erythrocytes.

Mapping membrane activity in undiscovered peptide sequence space using machine learning

PubMed Central

Fulan, Benjamin M.; Wong, Gerard C. L.

2016-01-01

There are some ∼1,100 known antimicrobial peptides (AMPs), which permeabilize microbial membranes but have diverse sequences. Here, we develop a support vector machine (SVM)-based classifier to investigate ⍺-helical AMPs and the interrelated nature of their functional commonality and sequence homology. SVM is used to search the undiscovered peptide sequence space and identify Pareto-optimal candidates that simultaneously maximize the distance σ from the SVM hyperplane (thus maximize its “antimicrobialness”) and its ⍺-helicity, but minimize mutational distance to known AMPs. By calibrating SVM machine learning results with killing assays and small-angle X-ray scattering (SAXS), we find that the SVM metric σ correlates not with a peptide’s minimum inhibitory concentration (MIC), but rather its ability to generate negative Gaussian membrane curvature. This surprising result provides a topological basis for membrane activity common to AMPs. Moreover, we highlight an important distinction between the maximal recognizability of a sequence to a trained AMP classifier (its ability to generate membrane curvature) and its maximal antimicrobial efficacy. As mutational distances are increased from known AMPs, we find AMP-like sequences that are increasingly difficult for nature to discover via simple mutation. Using the sequence map as a discovery tool, we find a unexpectedly diverse taxonomy of sequences that are just as membrane-active as known AMPs, but with a broad range of primary functions distinct from AMP functions, including endogenous neuropeptides, viral fusion proteins, topogenic peptides, and amyloids. The SVM classifier is useful as a general detector of membrane activity in peptide sequences. PMID:27849600

Antimicrobial peptides (AMP) with antiviral activity against fish nodavirus.

PubMed

Chia, Ta-Jui; Wu, Yu-Chi; Chen, Jyh-Yih; Chi, Shau-Chi

2010-03-01

Nervous necrosis virus (NNV) is classified as betanodavirus of Nodaviridae, and has caused mass mortality of numerous marine fish species at larval stage. Antimicrobial peptides (AMPs) play an important role of innate immunity either against bacterial pathogens or viruses. Up to date, little is known if any AMP could effectively inhibit fish nodaviruses and its mechanism. In this study, the antiviral activities of three antimicrobial peptides (AMPs) against grouper NNV (GNNV) were screened in the fish cell line. Two of the three AMPs, tilapia hepcidin 1-5 (TH 1-5) and cyclic shrimp anti-lipopolysaccharide factor (cSALF), were able to agglutinate purified NNV particles into clump, and the clumps were further confirmed to be viral proteins by TEM and Western blot. The NNV solution, separately pre-mixed with AMP (TH 1-5 or cSALF) or deionized-distilled water for 1 h, was used to infect GF-1 cells, and the levels of capsid protein in the GNNV-AMP-infected cells at 1 h post infection were much lower than that in the GNNV-H(2)O-infected cells, indicating that only a small portion of viral particles in the GNNV-AMP mixture could successfully infected the cells. Treatment of cBB cells with TH 1-5 and cSALF did not induce Mx gene expression; however, grouper epinecidin-1 (CP643-1) could induce the expression of Mx in the pre-treated cBB cells. This study revealed three AMPs with anti-NNV activity through two different mechanisms, and shed light on the future application in aquaculture. Copyright 2009 Elsevier Ltd. All rights reserved.

Accumulation mode particles and LPS exposure induce TLR-4 dependent and independent inflammatory responses in the lung.

PubMed

Fonceca, Angela M; Zosky, Graeme R; Bozanich, Elizabeth M; Sutanto, Erika N; Kicic, Anthony; McNamara, Paul S; Knight, Darryl A; Sly, Peter D; Turner, Debra J; Stick, Stephen M

2018-01-22

Accumulation mode particles (AMP) are formed from engine combustion and make up the inhalable vapour cloud of ambient particulate matter pollution. Their small size facilitates dispersal and subsequent exposure far from their original source, as well as the ability to penetrate alveolar spaces and capillary walls of the lung when inhaled. A significant immuno-stimulatory component of AMP is lipopolysaccharide (LPS), a product of Gram negative bacteria breakdown. As LPS is implicated in the onset and exacerbation of asthma, the presence or absence of LPS in ambient particulate matter (PM) may explain the onset of asthmatic exacerbations to PM exposure. This study aimed to delineate the effects of LPS and AMP on airway inflammation, and potential contribution to airways disease by measuring airway inflammatory responses induced via activation of the LPS cellular receptor, Toll-like receptor 4 (TLR-4). The effects of nebulized AMP, LPS and AMP administered with LPS on lung function, cellular inflammatory infiltrate and cytokine responses were compared between wildtype mice and mice not expressing TLR-4. The presence of LPS administered with AMP appeared to drive elevated airway resistance and sensitivity via TLR-4. Augmented TLR4 driven eosinophilia and greater TNF-α responses observed in AMP-LPS treated mice independent of TLR-4 expression, suggests activation of allergic responses by TLR4 and non-TLR4 pathways larger than those induced by LPS administered alone. Treatment with AMP induced macrophage recruitment independent of TLR-4 expression. These findings suggest AMP-LPS as a stronger stimulus for allergic inflammation in the airways then LPS alone.

N-Acetyl-D- and L-esters of 5'-AMP hydrolyze at different rates

NASA Technical Reports Server (NTRS)

Wickramasinghe, N. S.; Lacey, J. C. Jr; Lacey JC, J. r. (Principal Investigator)

1993-01-01

Studies of the properties of aminoacyl derivatives of 5'-AMP are aimed at understanding the origin of the process of protein synthesis. Aminoacyl (2',3') esters of 5'-AMP can serve as models of the 3'-terminus of aminoacyl tRNA. We report here on the relative rates of hydrolysis of Ac-D- and L-Phe AMP esters as a function of pH. At all pHs above 3, the rate constant of hydrolysis of the Ac-L-Phe ester is 1.7 to 2.1 times that of Ac-D-Phe ester. The D-isomer seems partially protected from hydrolysis by a stronger association with the adenine ring of the 5'-AMP.

[Research progress in fusion expression of antimicrobial peptides].

PubMed

Ma, Qingshan; Yu, Zhanqiao; Han, Bing; Zhang, Rijun

2011-10-01

Antimicrobial peptides (AMPs) are of great significance in the field of food, feed and medicine due to their wide spectrum of antimicrobial activity and new mechanism of action different from conventional antibiotics. AMPs production from natural sources is usually limited, and chemical synthesis is not economically practical, especially for the production of long peptides. Therefore, heterologous expression of AMPs has been widely studied as an alternative, and fusion expression plays an important role in increasing production. The present review mainly focuses on the types and bioactivities of AMPs. In addition, the recent strategies to the most commonly used carrier proteins for fusion expression of AMPs and prospects for future research were also discussed.

Regulation of theta-antigen expression by agents altering cyclic AMP level and by thymic factor.

PubMed

Bach, M A; Fournier, C; Bach, J F

1975-02-28

Thymic factor, cyclic AMP, and products increasing its cellular level, such as Prostaglandin E1, induce the appearance of the theta-antigen on T-cell precursors whether assessed by a rossette-inhibition assay or a cytotoxic assay after cell fractionation on BSA discontinuous gradiet. Synergism has been demonstrated between cyclic AMPT and TF for that effect. Conversely, decrease of theta expression has been obtained by altering cyclic AMP level in theta-positive cells either increasing it by dibutyryl cAMP treatment or decreasing it by indomethacin treatment. Finally, these data suggest the involvement of cyclic AMP in the regulation of theta expression under thymic hormone control.

Microwave assisted synthesis of amorphous magnesium phosphate nanospheres.

PubMed

Zhou, Huan; Luchini, Timothy J F; Bhaduri, Sarit B

2012-12-01

Magnesium phosphate (MgP) materials have been investigated in recent years for tissue engineering applications, attributed to their biocompatibility and biodegradability. This paper describes a novel microwave assisted approach to produce amorphous magnesium phosphate (AMP) in a nanospherical form from an aqueous solution containing Mg(2+) and HPO(4) (2-)/PO(4) (3-). Some synthesis parameters such as pH, Mg/P ratio, solution composition were studied and the mechanism of AMP precursors was also demonstrated. The as-produced AMP nanospheres were characterized and tested in vitro. The results proved these AMP nanospheres can self-assemble into mature MgP materials and support cell proliferation. It is expected such AMP has potential in biomedical applications.

Chemistry of aminoacylation of 5'-AMO and the origin of protein synthesis

NASA Technical Reports Server (NTRS)

Lacey, J. C., Jr.

1991-01-01

Much of our recent work has been a study of aminoacyl AMP derivatives. Elucidation of the character of aminoacyl AMP derivatives has made it obvious that AMP has characteristics which should allow it to preferentially catalyze the synthesis of L-amino acid peptides. The essential features which lead to this conclusion are that all l-amino acids (but not all D amino acids) when esterified to 5'-AMP preferentially (65 percent) distribute to the 3' position of the 5'-AMP; that esterification is predominantly at the 2' position; that 2', 3' diaminoacyl esters are readily formed; and that a peptide bond can be formed between adjacent 2',3' aminoacyl esters.

The implementation and development of complex alcohol control policies in indigenous communities in Queensland (Australia).

PubMed

Clough, Alan R; Bird, Katrina

2015-04-01

Very high rates of injury and death during the 1990s were linked with increased alcohol availability and misuse in discrete Indigenous communities in rural and remote Queensland (Australia). To address widespread concerns about a public health crisis, from 2002, the Queensland Government implemented alcohol control strategies known as 'Alcohol Management Plans' (AMPs) in 19 of these communities. Although resources for prevention and treatment were promised, AMPs became increasingly focused on local prohibition, restricted access to alcohol and punitive measures for breaching restrictions. An examination of legislation, regulations, explanatory notes, and published documents indicates this focus evolved across four phases since 2002. The first phase, from 2002 to 2004, saw 'restricted areas' with alcohol 'carriage limits' introduced, restricting the amounts and types of liquor permitted within some communities. The second phase (2002-2007) featured evaluations and reviews by the Queensland Government bringing recommendations for more stringent controls. Additionally, beyond the 'restricted areas', licenced premises situated within the 'catchments' of the targeted communities, mainly located in the nearby regional towns, became subject to 'minimising harm' provisions. These more stringent controls were implemented widely in the third phase (2008-2011) when: the operations of seven community-managed liquor outlets were terminated; the trading arrangements of two others were modified; Police powers to search and seize were increased; and 'attempting' to take liquor into a 'restricted area' also became an offence. Some communities have seen a reduction in alcohol-related harms that have been attributed to these alcohol control strategies. This commentary maps the recent regulatory history of Queensland's alcohol controls targeting discrete Indigenous communities highlighting their increasing focus on punitive measures to reduce access to alcohol. With AMPs in Queensland currently under Government review, and with community resolve for change rising, the limits to Government controls and punitive measures may have been reached. Copyright © 2015 Elsevier B.V. All rights reserved.

Absorption performance for CO2 capture process using MDEA-AMP aqueous solution

NASA Astrophysics Data System (ADS)

Liu, Gang; Kou, Liqing; Li, Chao

2017-03-01

The absorption capacity and the absorption rate of CO2 in 2-amino-2-methyl-1-propanol (AMP)-N-methyldiethanolamine (MDEA) aqueous solution were measured. The temperatures ranged from 303.2K to 323.2K. The mass fractions of AMP and MDEA respectively ranged from 0 to 0.03 and 0.2 to 0.3. The influence of temperature and w AMP on the absorption capacity and absorption rate of CO2 was illustrated.

Characterization of AmpC, CTX-M and MBLs types of β-lactamases in clinical isolates of Klebsiella pneumoniae and Escherichia coli producing Extended Spectrum β-lactamases in Kerman, Iran

PubMed Central

Mansouri, Shahla; Kalantar Neyestanaki, Davood; Shokoohi, Mostafa; Halimi, Shahnaz; Beigverdi, Reza; Rezagholezadeh, Fereshteh; Hashemi, Ali

2014-01-01

Background: Extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae. Increasing frequency of the co-existence of ESBLs with AmpC-β-lactamases in bacteria is a serious threat for treating bacterial infections. Objectives: The aim of this study was to determine the presence of AmpC and CTX-M types of β-lactamases in clinical isolates of E. coli and K. pneumoniae producing ESBLs. Materials and Methods: Resistance to different antibiotics was determined using the standard disk diffusion method. ESBLs, MBLs and AmpC-β-lactamases were detected by the combination double disk test (CDDT) method and polymerase chain reaction (PCR) was used to determine blaCTX-M genes in the ESBLs and AmpC positive isolates. Results: The prevalence of ESBLs and AmpC-β-lactamase producer isolates was 181 (43.8%) and 133 (37.2%), respectively. The prevalence of blaCTX-M among isolates was 61 (14.7%). Conclusions: Outbreak of isolates co-expressing AmpC-β-lactamases and ESBLs can cause serious problems in the future, regarding the treatment of infections caused by these common enteric pathogens. PMID:25147671

Inhibition of Rho Is Required for cAMP-induced Melanoma Cell Differentiation

PubMed Central

Buscà, Roser; Bertolotto, Corine; Abbe, Patricia; Englaro, Walter; Ishizaki, Toshimasa; Narumiya, Shuh; Boquet, Patrice; Ortonne, Jean-Paul; Ballotti, Robert

1998-01-01

Up-regulation of the cAMP pathway by forskolin or α-melanocyte stimulating hormone induces melanocyte and melanoma cell differentiation characterized by stimulation of melanin synthesis and dendrite development. Here we show that forskolin-induced dendricity is associated to a disassembly of actin stress fibers. Since Rho controls actin organization, we studied the role of this guanosine triphosphate (GTP)-binding protein in cAMP-induced dendrite formation. Clostridium botulinum C3 exotransferase, which inhibits Rho, mimicked the effect of forskolin in promoting dendricity and stress fiber disruption, while the Escherichia coli toxin cytotoxic necrotizing factor-1 (CNF-1), which activates Rho and the expression of a constitutively active Rho mutant, blocked forskolin-induced dendrite outgrowth. In addition, overexpression of a constitutively active form of the Rho target p160 Rho-kinase (P160ROCK) prevented the dendritogenic effects of cAMP. Our results suggest that inhibition of Rho and of its target p160ROCK are required events for cAMP-induced dendrite outgrowth in B16 cells. Furthermore, we present evidence that Rho is involved in the regulation of melanogenesis. Indeed, Rho inactivation enhanced the cAMP stimulation of tyrosinase gene transcription and protein expression, while Rho constitutive activation impaired these cAMP-induced effects. This reveals that, in addition to controlling dendricity, Rho also participates in the regulation of melanin synthesis by cAMP. PMID:9614180

Distinct Action of Flavonoids, Myricetin and Quercetin, on Epithelial Cl− Secretion: Useful Tools as Regulators of Cl− Secretion

PubMed Central

Sun, Hongxin; Niisato, Naomi; Nishio, Kyosuke; Hamilton, Kirk L.; Marunaka, Yoshinori

2014-01-01

Epithelial Cl− secretion plays important roles in water secretion preventing bacterial/viral infection and regulation of body fluid. We previously suggested that quercetin would be a useful compound for maintaining epithelial Cl− secretion at a moderate level irrespective of cAMP-induced stimulation. However, we need a compound that stimulates epithelial Cl− secretion even under cAMP-stimulated conditions, since in some cases epithelial Cl− secretion is not large enough even under cAMP-stimulated conditions. We demonstrated that quercetin and myricetin, flavonoids, stimulated epithelial Cl− secretion under basal conditions in epithelial A6 cells. We used forskolin, which activates adenylyl cyclase increasing cytosolic cAMP concentrations, to study the effects of quercetin and myricetin on cAMP-stimulated epithelial Cl− secretion. In the presence of forskolin, quercetin diminished epithelial Cl− secretion to a level similar to that with quercetin alone without forskolin. Conversely, myricetin further stimulated epithelial Cl− secretion even under forskolin-stimulated conditions. This suggests that the action of myricetin is via a cAMP-independent pathway. Therefore, myricetin may be a potentially useful compound to increase epithelial Cl− secretion under cAMP-stimulated conditions. In conclusion, myricetin would be a useful compound for prevention from bacterial/viral infection even under conditions that the amount of water secretion driven by cAMP-stimulated epithelial Cl− secretion is insufficient. PMID:24818160

[Expression of plant antimicrobial peptide pro-SmAMP2 gene increases resistance of transgenic potato plants to Alternaria and Fusarium pathogens].

PubMed

Vetchinkina, E M; Komakhina, V V; Vysotskii, D A; Zaitsev, D V; Smirnov, A N; Babakov, A V; Komakhin, R A

2016-09-01

The chickweed (Stellaria media L.) pro-SmAMP2 gene encodes the hevein-like peptides that have in vitro antimicrobial activity against certain harmful microorganisms. These peptides play an important role in protecting the chickweed plants from infection, and the pro-SmAMP2 gene was previously used to protect transgenic tobacco and Arabidopsis plants from phytopathogens. In this study, the pro-SmAMP2 gene under control of viral CaMV35S promoter or under control of its own pro-SmAMP2 promoter was transformed into cultivated potato plants of two cultivars, differing in the resistance to Alternaria: Yubiley Zhukova (resistant) and Skoroplodny (susceptible). With the help of quantitative real-time PCR, it was demonstrated that transgenic potato plants expressed the pro-SmAMP2 gene under control of both promoters at the level comparable to or exceeding the level of the potato actin gene. Assessment of the immune status of the transformants demonstrated that expression of antimicrobial peptide pro-SmAMP2 gene was able to increase the resistance to a complex of Alternaria sp. and Fusarium sp. phytopathogens only in potato plants of the Yubiley Zhukova cultivar. The possible role of the pro-SmAMP2 products in protecting potatoes from Alternaria sp. and Fusarium sp. is discussed.

The role of the RAS pathway in iAMP21-ALL

PubMed Central

Ryan, S L; Matheson, E; Grossmann, V; Sinclair, P; Bashton, M; Schwab, C; Towers, W; Partington, M; Elliott, A; Minto, L; Richardson, S; Rahman, T; Keavney, B; Skinner, R; Bown, N; Haferlach, T; Vandenberghe, P; Haferlach, C; Santibanez-Koref, M; Moorman, A V; Kohlmann, A; Irving, J A E; Harrison, C J

2016-01-01

Intrachromosomal amplification of chromosome 21 (iAMP21) identifies a high-risk subtype of acute lymphoblastic leukaemia (ALL), requiring intensive treatment to reduce their relapse risk. Improved understanding of the genomic landscape of iAMP21-ALL will ascertain whether these patients may benefit from targeted therapy. We performed whole-exome sequencing of eight iAMP21-ALL samples. The mutation rate was dramatically disparate between cases (average 24.9, range 5–51) and a large number of novel variants were identified, including frequent mutation of the RAS/MEK/ERK pathway. Targeted sequencing of a larger cohort revealed that 60% (25/42) of diagnostic iAMP21-ALL samples harboured 42 distinct RAS pathway mutations. High sequencing coverage demonstrated heterogeneity in the form of multiple RAS pathway mutations within the same sample and diverse variant allele frequencies (VAFs) (2–52%), similar to other subtypes of ALL. Constitutive RAS pathway activation was observed in iAMP21 samples that harboured mutations in the predominant clone (⩾35% VAF). Viable iAMP21 cells from primary xenografts showed reduced viability in response to the MEK1/2 inhibitor, selumetinib, in vitro. As clonal (⩾35% VAF) mutations were detected in 26% (11/42) of iAMP21-ALL, this evidence of response to RAS pathway inhibitors may offer the possibility to introduce targeted therapy to improve therapeutic efficacy in these high-risk patients. PMID:27168466

Accidents of Electrical and Mechanical Works for Public Sector Projects in Hong Kong.

PubMed

Wong, Francis K W; Chan, Albert P C; Wong, Andy K D; Hon, Carol K H; Choi, Tracy N Y

2018-03-10

A study on electrical and mechanical (E&M) works-related accidents for public sector projects provided the opportunity to gain a better understanding of the causes of accidents by analyzing the circumstances of all E&M works accidents. The research aims to examine accidents of E&M works which happened in public sector projects. A total of 421 E&M works-related accidents in the "Public Works Programme Construction Site Safety and Environmental Statistics" (PCSES) system were extracted for analysis. Two-step cluster analysis was conducted to classify the E&M accidents into different groups. The results identified three E&M accidents groups: (1) electricians with over 15 years of experience were prone to 'fall of person from height'; (2) electricians with zero to five years of experience were prone to 'slip, trip or fall on same level'; (3) air-conditioning workers with zero to five years of experience were prone to multiple types of accidents. Practical measures were recommended for each specific cluster group to avoid recurrence of similar accidents. The accident analysis would be vital for industry practitioners to enhance the safety performance of public sector projects. This study contributes to filling the knowledge gap of how and why E&M accidents occur and promulgating preventive measures for E&M accidents which have been under researched.

Antimicrobial peptides and induced membrane curvature: geometry, coordination chemistry, and molecular engineering

PubMed Central

Schmidt, Nathan W.; Wong, Gerard C. L.

2013-01-01

Short cationic, amphipathic antimicrobial peptides are multi-functional molecules that have roles in host defense as direct microbicides and modulators of the immune response. While a general mechanism of microbicidal activity involves the selective disruption and permeabilization of cell membranes, the relationships between peptide sequence and membrane activity are still under investigation. Here, we review the diverse functions that AMPs collectively have in host defense, and show that these functions can be multiplexed with a membrane mechanism of activity derived from the generation of negative Gaussian membrane curvature. As AMPs preferentially generate this curvature in model bacterial cell membranes, the selective generation of negative Gaussian curvature provides AMPs with a broad mechanism to target microbial membranes. The amino acid constraints placed on AMPs by the geometric requirement to induce negative Gaussian curvature are consistent with known AMP sequences. This ‘saddle-splay curvature selection rule’ is not strongly restrictive so AMPs have significant compositional freedom to multiplex membrane activity with other useful functions. The observation that certain proteins involved in cellular processes which require negative Gaussian curvature contain domains with similar motifs as AMPs, suggests this rule may be applicable to other curvature-generating proteins. Since our saddle-splay curvature design rule is based upon both a mechanism of activity and the existing motifs of natural AMPs, we believe it will assist the development of synthetic antimicrobials. PMID:24778573