Bacterial DnaK reduces the activity of anti-cancer drugs cisplatin and 5FU.

Background: Chemotherapy is a primary treatment for cancer, but its efficacy is often limited by cancer-associated bacteria (CAB) that impair tumor suppressor functions. Our previous research found that Mycoplasma fermentans DnaK, a chaperone protein, impairs p53 activities, which are essential for most anti-cancer chemotherapeutic responses.

Methods: To investigate the role of DnaK in chemotherapy, we treated cancer cell lines with M.

Influence of Substitutions in the Binding Motif of Proline-Rich Antimicrobial Peptide ARV-1502 on 70S Ribosome Binding and Antimicrobial Activity.

Proline-rich antimicrobial peptides (PrAMPs) are promising candidates to treat bacterial infections. The designer peptide ARV-1502 exhibits strong antimicrobial effects against both in vitro and in vivo. Since the inhibitory effects of ARV-1502 reported for the 70 kDa heat-shock protein DnaK do not fully explain the antimicrobial activity of its 176 substituted analogs, we further studied their effect on the bacterial 70S ribosome of , a known target of PrAMPs.

Functional Effects of ARV-1502 Analogs Against Bacterial Hsp70 and Implications for Antimicrobial Activity.

The antimicrobial peptide (AMP) ARV-1502 was designed based on naturally occurring short proline-rich AMPs, including pyrrhocoricin and drosocin. Identification of chaperone DnaK as a therapeutic target in triggered intense research on the ligand-DnaK-interactions using fluorescence polarization and X-ray crystallography to reveal the binding motif and characterize the influence of the chaperone on protein refolding activity, especially in stress situations. In continuation of this research, 182 analogs of ARV-1502 were designed by substituting residues involved in antimicrobial activity against Gram-negative pathogens.

Quantitation of a Novel Engineered Anti-infective Host Defense Peptide, ARV-1502: Pharmacokinetic Study of Different Doses in Rats and Dogs.

The designer proline-rich antimicrobial peptide (PrAMP) Chex1-Arg20 amide (ARV-1502) is active against Gram-negative and Gram-positive pathogens in different murine infection models when administered parenterally and possesses a wide therapeutic index. Here we studied the pharmacokinetics of ARV-1502 for the first time when administered intramuscularly or intravenously (IV) in Sprague Dawley rats and Beagle dogs. First, a specific and robust quantitation method relying on parallel reaction monitoring (PRM) using a high-resolution hybrid quadrupole-Orbitrap mass spectrometer coupled on-line to reversed-phase uHPLC was established and validated.

Safety and Pharmacokinetics of a Four Monoclonal Antibody Combination Against Botulinum C and D Neurotoxins.

Botulism is caused by botulinum neurotoxin (BoNT), the most poisonous substance known. BoNTs are also classified as Tier 1 biothreat agents due to their high potency and lethality. The existence of seven BoNT serotypes (A-G), which differ between 35% to 68% in amino acid sequence, necessitates the development of serotype specific countermeasures.

Efficacy of ARV-1502, a Proline-Rich Antimicrobial Peptide, in a Murine Model of Bacteremia Caused by Multi-Drug Resistant (MDR) .

bacteremia represents a serious and increasing clinical problem due to the high mortality and treatment failures because of high rates of antibiotic resistance. Any additional new therapies for bacteremia would address a growing unmet medical need. ARV-1502 (designated as Chex1-Arg20 or A3-APO monomer in prior publications) is a designer proline-rich antimicrobial peptide chaperone protein inhibitor derived from insects and has demonstrated potent activity against multi-drug resistant (MDR) Gram-negative bacteria.

Advantage of a Narrow Spectrum Host Defense (Antimicrobial) Peptide Over a Broad Spectrum Analog in Preclinical Drug Development.

The APO-type proline-arginine-rich host defense peptides exhibit potent killing parameters against but not to other bacteria. Because of the excellent properties against systemic and local infections, attempts are regularly made to further improve the activity spectrum. A C-terminal hydrazide analog of the Chex1-Arg20 amide (ARV-1502) shows somewhat improved minimal inhibitory concentration against .

Synergy Between Proline-Rich Antimicrobial Peptides and Small Molecule Antibiotics Against Selected Gram-Negative Pathogens and .

As monotherapy, modified proline-rich antimicrobial peptides (PrAMPs) protect animals from experimental bacteremia in a dose-dependent manner. We evaluated the synergy of a modified PrAMP, A3-APO, a dimer, previously shown to inhibit the 70 kDa bacterial heat shock protein DnaK, with imipenem or colistin against two antibiotic-resistant pathogens; a carbapenemase-expressing strain K97/09 and (ATCC BAA-1605). Combining antimicrobials resulted in synergy for PrAMP/colistin combination against both and (ΣFIC = 0.

Clinical implications of patient-provider agreements in opioid prescribing.

In June, 2012 the United States Food and Drug Administration (FDA) developed a "blueprint" for prescriber education as a means of directing Certified Medical Education (CME) activities that included content which would meet the regulatory requirements of the class-wide, longacting/ extended-release (LA-ER) opioid Risk Evaluation Mitigation Strategies (REMS). Within the blueprint is the suggested adoption of Patient-Provider Agreements (PPAs) to be used in association with opioid prescribing, but, to our knowledge, there have been no reported evaluations of the role played by opioid-agent PPAs in clinical practice, or of the perceptions of this regulatory mandate by clinicians. Therefore, we conducted a survey regarding PPA perceptions by opioid prescribers that was posted for five weeks on a well-trafficked online CME service provider (Medscape).

Ambush of Clostridium difficile spores by ramoplanin: activity in an in vitro model.

Clostridium difficile infection (CDI) is a gastrointestinal disease caused by C. difficile, a spore-forming bacterium that in its spore form is tolerant to standard antimicrobials. Ramoplanin is a glycolipodepsipeptide antibiotic that is active against C.

The practicing clinician and regulatory safety concerns.

Pharmaceutical agents are prescribed to produce a therapeutic effect, but safety concerns require constant attention to the benefit:risk relationship inherent in their use and the needs of the individual patient. Such calculations involve assumptions about the likely tolerability of harm, in that greater safety risks may be acceptable for use of a lifesaving drug, compared with those acceptable for an agent providing only improved "quality of life." Making such assumptions is an activity integral to the bedside clinician's role, is done during many (perhaps most) patient encounters, and is often undertaken with inadequate information.

Improving the effect of FDA-mandated drug safety alerts with Internet-based continuing medical education.

The US Food and Drug Administration (FDA) requires risk communication as an element of Risk Evaluation and Mitigation Strategies (REMS) to alert and educate healthcare providers about severe toxicities associated with approved drugs. The educational effectiveness of this approach has not been evaluated. To support the communication plan element of the ipilimumab REMS, a Medscape Safe Use Alert (SUA) letter was distributed by Medscape via email and mobile device distribution to clinicians specified in the REMS.

The safety record of fusidic acid in non-US markets: a focus on skin infections.

Fusidic acid has been in clinical use outside the United States (US) since 1962 for skin infections, including methicillin-resistant Staphylococcus aureus (MRSA). Non-US labeling reflects safety concerns related to gastrointestinal, allergic, hematologic, and neurologic adverse events. We sought to survey available safety data on fusidic acid through the review of published global literature between 1962 and 2007 that contained data on oral fusidic acid safety and a centralized database (VigiBase) of spontaneous safety reports.

Low hanging fruit in infectious disease drug development.

Cost estimates for developing new molecular entities (NME) are reaching non-sustainable levels and coupled with increasing regulatory requirements and oversight have led many pharmaceutical sponsors to divest their anti-microbial development portfolios [Projan SJ: Why is big Pharma getting out of anti-bacterial drug discovery?Curr Opin Microbiol 2003, 6:427-430] [Spellberg B, Powers JH, Brass EP, Miller LG, Edwards JE, Jr: Trends in antimicrobial drug development: implications for the future.Clin Infect Dis 2004, 38:1279-1286]. Operational issues such as study planning and execution are significant contributors to the overall cost of drug development that can benefit from the leveraging of pre-randomization data in an evidence-based approach to protocol development, site selection and patient recruitment.

CRAFT: Facilitating clinical trial execution quality.

The number of clinical investigators is declining in the United States, so it should come as no surprise that patient recruitment into clinical trials is the primary cause of study delay.2 CRAFT (Clinical Research Analysis and Feasibility Tool) is a java-based tool that mines the Ingenix claims database to find relevant patient populations ands associated health-care providers in order to accelerate clinical trial timelines.

Inhibition of Mycobacterium tuberculosis AhpD, an element of the peroxiredoxin defense against oxidative stress.

The resistance of Mycobacterium tuberculosis to isoniazid (INH) is largely linked to suppression of a catalase-peroxidase enzyme (KatG) that activates INH. In the absence of KatG, antioxidant protection is provided by enhanced expression of the peroxiredoxin AhpC, which is itself reduced by AhpD, a protein with low alkylhydroperoxidase activity of its own. Inhibition of AhpD might therefore impair the antioxidant protection afforded by AhpC and make KatG-negative strains more sensitive to oxidative stress.

The role of RelMtb-mediated adaptation to stationary phase in long-term persistence of Mycobacterium tuberculosis in mice.

Long-term survival of nonreplicating Mycobacterium tuberculosis (Mtb) is ensured by the coordinated shutdown of active metabolism through a broad transcriptional program called the stringent response. In Mtb, this response is initiated by the enzymatic action of RelMtb and deletion of relMtb produces a strain (H37RvDeltarelMtb) severely compromised in the maintenance of long-term viability. Although aerosol inoculation of mice with H37RvDeltarelMtb results in normal initial bacterial growth and containment, the ability of this strain to sustain chronic infection is severely impaired.