A Pooled Analysis of the Safety and Efficacy of Iclaprim Versus Vancomycin for the Treatment of Acute Bacterial Skin and Skin Structure Infections in Patients With Intravenous Drug Use: Phase 3 REVIVE Studies

Exploration and Biological Evaluation of 1,3-Diamino-7H-pyrrol[3,2-f]quinazoline Derivatives as Dihydrofolate Reductase Inhibitors

Dihydrofolate reductase (DHFR), a core enzyme of folate metabolism, plays a crucial role in the biosynthesis of purines and thymidylate for cell proliferation and growth in both prokaryotic and eukaryotic cells. However, the development of new DHFR inhibitors is challenging due to the limited number of scaffolds available for drug development. Hence, we designed and synthesized a new class of DHFR inhibitors with a 1,3-diamino-7H-pyrrol[3,2-f]quinazoline derivative (PQD) structure bearing condensed rings. Compound 6r exhibited therapeutic effects on mouse models of systemic infection and thigh infection caused by methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. Moreover, methyl-modified PQD compound 8a showed a strong efficacy in a murine model of breast cancer, which was better than the effects of taxol. The findings showcased in this study highlight the promising capabilities of novel DHFR inhibitors in addressing bacterial infections as well as breast cancer.

Dihydrofolate reductase inhibitors: patent landscape and phases of clinical development (2001-2021)

INTRODUCTION

Dihydrofolate reductase (DHFR) plays an important role in the biosynthesis of amino acid and folic acid. It participates by reducing dihydrofolate to tetrahydrofolate, in the presence of nicotinamide dinucleotide phosphate cofactor, and has been verified by various clinical studies to use DHFR as a target for the treatment of cancer and various bacterial infections.

AREA COVERED

In this review, we have disclosed patents of synthetics and natural DHFR inhibitors with diaminopyrimidine and quinazoline nucleus from 2001. Additionally, this review highlights the clinical progression of numerous DHFR inhibitors received from the last five years.

EXPERT OPINION

From 2001 to 2021, numerous active chemical scaffolds have been introduced and are exposed as lead candidates that have entered clinical trials as potent DHFR inhibitors. Moreover, researchers have paid considerable attention to the development of a new class of DHFR inhibitors with higher selectivity and potency. This development includes synthesis of synthetic as well as natural compounds that are potent DHFR inhibitors. On the basis of literature review, we can anticipate that there are a huge number of novel active molecules available for the future that could possess superior abilities to target this enzyme with a profound pharmacological profile.

Proposing a "Brain Health Checkup (BHC)" as a Global Potential "Standard of Care" to Overcome Reward Dysregulation in Primary Care Medicine: Coupling Genetic Risk Testing and Induction of "Dopamine Homeostasis"

In 2021, over 100,000 people died prematurely from opioid overdoses. Neuropsychiatric and cognitive impairments are underreported comorbidities of reward dysregulation due to genetic antecedents and epigenetic insults. Recent genome-wide association studies involving millions of subjects revealed frequent comorbidity with substance use disorder (SUD) in a sizeable meta-analysis of depression. It found significant associations with the expression of NEGR1 in the hypothalamus and DRD2 in the nucleus accumbens, among others. However, despite the rise in SUD and neuropsychiatric illness, there are currently no standard objective brain assessments being performed on a routine basis. The rationale for encouraging a standard objective Brain Health Check (BHC) is to have extensive data available to treat clinical syndromes in psychiatric patients. The BHC would consist of a group of reliable, accurate, cost-effective, objective assessments involving the following domains: Memory, Attention, Neuropsychiatry, and Neurological Imaging. Utilizing primarily PUBMED, over 36 years of virtually all the computerized and written-based assessments of Memory, Attention, Psychiatric, and Neurological imaging were reviewed, and the following assessments are recommended for use in the BHC: Central Nervous System Vital Signs (Memory), Test of Variables of Attention (Attention), Millon Clinical Multiaxial Inventory III (Neuropsychiatric), and Quantitative Electroencephalogram/P300/Evoked Potential (Neurological Imaging). Finally, we suggest continuing research into incorporating a new standard BHC coupled with qEEG/P300/Evoked Potentials and genetically guided precision induction of "dopamine homeostasis" to diagnose and treat reward dysregulation to prevent the consequences of dopamine dysregulation from being epigenetically passed on to generations of our children.

Current international and national guidelines for managing skin and soft tissue infections

PURPOSE OF REVIEW

Skin and soft tissue infections account for a significant percentage of both community and nosocomial infections. Several nosological entities are included in this concept. However, there is a very scarce body of doctrine for their treatment based on randomised trials. Therefore, we considered it necessary to review current treatment guidelines to bring new recommendations and improvements to our colleagues. In this review of recent literature, we identified updated guidelines in this area by searching the databases PubMed, evidence-based medicine online, York University reviewers group, Cochrane, MBE-Trip and Sumsearch using the terms: soft tissue infection, therapy, guideline.

RECENT FINDINGS

Developments focus on using new antimicrobials and on the prescription of shorter antibiotic treatment courses.

SUMMARY

With the development of new drugs and the current evidence of their use, there is a need to refine the appropriate drug's decision-making. Drugs with a long half-life, which allows weekly administration, can reduce hospital admission and length of stay with fewer healthcare resources. Shorter courses of antibiotics are recommended. The role of stewardship programmes will continue to expand. The surgical indication and its value are evident in many patients. Therefore, management should rely on a collaborative group with experience in this disease.

Current Treatment Strategies Against Multidrug-Resistant Bacteria: A Review

There are several bacteria called superbugs that are resistant to multiple antibiotics which can be life threatening specially for critically ill and hospitalized patients. This article provides up-to-date treatment strategies employed against some major superbugs, like methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococcus, multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Escherichia coli. The pathogen-directed therapeutics decrease the toxicity of bacteria by altering their virulence factors by specific processes. On the other hand, the host-directed therapeutics limits these superbugs by modulating immune cells, enhancing host cell functions, and modifying disease pathology. Several new antibiotics against the global priority superbugs are coming to the market or are in the clinical development phase. Medicinal plants possessing potent secondary metabolites can play a key role in the treatment against these superbugs. Nanotechnology has also emerged as a promising option for combatting them. There is urgent need to continuously figure out the best possible treatment strategy against these superbugs as resistance can also be developed against the new and upcoming antibiotics in future. Rational use of antibiotics and maintenance of proper hygiene must be practiced among patients.

Toward Broad Spectrum Dihydrofolate Reductase Inhibitors Targeting Trimethoprim Resistant Enzymes Identified in Clinical Isolates of Methicillin Resistant Staphylococcus aureus

The spread of plasmid borne resistance enzymes in clinical Staphylococcus aureus isolates is rendering trimethoprim and iclaprim, both inhibitors of dihydrofolate reductase (DHFR), ineffective. Continued exploitation of these targets will require compounds that can broadly inhibit these resistance-conferring isoforms. Using a structure-based approach, we have developed a novel class of ionized nonclassical antifolates (INCAs) that capture the molecular interactions that have been exclusive to classical antifolates. These modifications allow for a greatly expanded spectrum of activity across these pathogenic DHFR isoforms, while maintaining the ability to penetrate the bacterial cell wall. Using biochemical, structural, and computational methods, we are able to optimize these inhibitors to the conserved active sites of the endogenous and trimethoprim resistant DHFR enzymes. Here, we report a series of INCA compounds that exhibit low nanomolar enzymatic activity and potent cellular activity with human selectivity against a panel of clinically relevant TMP resistant (TMP^R) and methicillin resistant Staphylococcus aureus (MRSA) isolates.