Naphthoquinone-Quinolone Hybrids with Antitumor Effects on Breast Cancer Cell Lines-From the Synthesis to 3D-Cell Culture Effects.

Breast cancer stands as one of the foremost cause of cancer-related deaths globally, characterized by its varied molecular subtypes. Each subtype requires a distinct therapeutic strategy. Although advancements in treatment have enhanced patient outcomes, significant hurdles remain, including treatment toxicity and restricted effectiveness. Here, we explore the anticancer potential of novel 1,4-naphthoquinone/4-quinolone hybrids on breast cancer cell lines. The synthesized compounds demonstrated selective cytotoxicity against Luminal and triple-negative breast cancer (TNBC) cells, which represent the two main molecular types of breast cancer that depend most on cytotoxic chemotherapy, with potency comparable to doxorubicin, a standard chemotherapeutic widely used in breast cancer treatment. Notably, these derivatives exhibited superior selectivity indices (SI) when compared to doxorubicin, indicating lower toxicity towards non-tumor MCF10A cells. Compounds 11a and 11b displayed an improvement in IC50 values when compared to their precursor, 1,4-naphthoquinone, for both MCF-7 and MDA-MB-231 and a comparable value to doxorubicin for MCF-7 cells. Also, their SI values were superior to those seen for the two reference compounds for both cell lines tested. Mechanistic studies revealed the ability of the compounds to induce apoptosis and inhibit clonogenic potential. Additionally, the irreversibility of their effects on cell viability underscores their promising therapeutic utility. In 3D-cell culture models, the compounds induced morphological changes indicative of reduced viability, supporting their efficacy in a more physiologically relevant model of study. The pharmacokinetics of the synthesized compounds were predicted using the SwissADME webserver, indicating that these compounds exhibit favorable drug-likeness properties and potential as antitumor agents. Overall, our findings underscore the promise of these hybrid compounds as potential candidates for breast cancer chemotherapy, emphasizing their selectivity and efficacy.

Tipifarnib Reduces Extracellular Vesicles and Protects From Heart Failure.

BACKGROUND: Heart failure (HF) is one of the leading causes of mortality worldwide. Extracellular vesicles, including small extracellular vesicles or exosomes, and their molecular cargo are known to modulate cell-to-cell communication during multiple cardiac diseases. However, the role of systemic extracellular vesicle biogenesis inhibition in HF models is not well documented and remains unclear. METHODS: We investigated the role of circulating exosomes during cardiac dysfunction and remodeling in a mouse transverse aortic constriction (TAC) model of HF. Importantly, we investigate the efficacy of tipifarnib, a recently identified exosome biogenesis inhibitor that targets the critical proteins (Rab27a [Ras associated binding protein 27a], nSMase2 [neutral sphingomyelinase 2], and Alix [ALG-2-interacting protein X]) involved in exosome biogenesis for this mouse model of HF. In this study, 10-week-old male mice underwent TAC surgery were randomly assigned to groups with and without tipifarnib treatment (10 mg/kg 3 times/wk) and monitored for 8 weeks, and a comprehensive assessment was conducted through performed echocardiographic, histological, and biochemical studies. RESULTS: TAC significantly elevated circulating plasma exosomes and markedly increased cardiac left ventricular dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, injection of plasma exosomes from TAC mice induced left ventricular dysfunction and cardiomyocyte hypertrophy in uninjured mice without TAC. On the contrary, treatment of tipifarnib in TAC mice reduced circulating exosomes to baseline and remarkably improved left ventricular functions, hypertrophy, and fibrosis. Tipifarnib treatment also drastically altered the miRNA profile of circulating post-TAC exosomes, including miR 331-5p, which was highly downregulated both in TAC circulating exosomes and in TAC cardiac tissue. Mechanistically, miR 331-5p is crucial for inhibiting the fibroblast-to-myofibroblast transition by targeting HOXC8, a critical regulator of fibrosis. Tipifarnib treatment in TAC mice upregulated the expression of miR 331-5p that acts as a potent repressor for one of the fibrotic mechanisms mediated by HOXC8. CONCLUSIONS: Our study underscores the pathological role of exosomes in HF and fibrosis in response to pressure overload. Tipifarnib-mediated inhibition of exosome biogenesis and cargo sorting may serve as a viable strategy to prevent progressive cardiac remodeling in HF.

Efficacy and safety of brexpiprazole for the treatment of agitation in Alzheimer's disease: a meta-analysis of randomized controlled trials.

Recent randomized controlled trials (RCTs) have shown a benefit of brexpiprazole in managing agitation in patients with Alzheimer's disease (AD). However, its efficacy and safety remain unclear. We systematically searched PubMed, Embase, and Cochrane Library for RCTs comparing brexpiprazole with placebo in patients with agitation and AD. Three studies comprising 1,048 patients were included. In patients with agitation and AD, brexpiprazole significantly improved the Cohen-Mansfield Agitation Inventory total score (CMAI) at any dose (MD -3.05; 95% CI -5.12, -0.98; p < 0.01; I2 = 19%) and at 2 mg (MD -4.36; 95% CI -7.02, -1.70; p < 0.01; I2 = 0%) over 12 weeks. Brexpiprazole at any dose and 2 mg also showed benefit in the Clinical Global Impression - Severity of illness (CGI-S) score as related to agitation over 12 weeks (MD -0.20; 95% CI -0.36, -0.05; p < 0.01; I2 = 35%). There is no significant difference between the groups in the incidence of at least one treatment-emergent adverse events (TEAEs; RR 1.14; 95% CI 0.95, 1.37; p = 0.16; I2 = 45%) and all-cause mortality (RR 1.99; 95% CI 0.37, 10.84; p = 0.42; I2 = 0%). Brexpiprazole at any dose significantly increased the Simpson-Angus Scale (SAS; MD 0.47; 95% CI 0.28, 0.66; p < 0.01). Our results suggest that brexpiprazole is more efficacious than placebo in the treatment of agitation in AD patients. Further studies are still necessary to confirm long-term effects of brexpiprazole.Prospero registry: CRD42023486694.

Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources.

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to ß-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

FOXO1 regulates wound-healing responses in human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Forkhead box-O 1 (FOXO1) is a transcription factor actively involved in oral wound healing at the epithelial barrier. However, less is known regarding the role of FOXO1 during the tissue repair response in the connective tissue compartment. This study explored the involvement of FOXO1 in the modulation of fibroblast activity related to wound healing. METHODS: Primary cultures of human gingival fibroblasts were obtained from four healthy young donors. Myofibroblastic differentiation, collagen gel contraction, cell migration, cell spreading, and integrin activation were evaluated in the presence or absence of a FOXO1 inhibitor (AS1842856). Variations in mRNA and proteins of interest were evaluated through qRT-PCR and western blot, respectively. Distribution of actin, α-smooth muscle actin, and ß1 integrin was evaluated using immunofluorescence. FOXO1 and TGF-ß1 expression in gingival wound healing was assessed by immunohistochemistry in gingival wounds performed in C57BL/6 mice. Images were analyzed using ImageJ/Fiji. ANOVA or Kruskal-Wallis test followed by Tukey's or Dunn's post-hoc test was performed. All data are expressed as mean ± SD. p < .05 was considered statistically significant. RESULTS: FOXO1 inhibition caused a decrease in the expression of the myofibroblastic marker α-SMA along with a reduction in fibronectin, type I collagen, TGF-ß1, and ß1 integrin mRNA level. The FOXO1 inhibitor also caused decreases in cell migration, cell spreading, collagen gel contraction, and ß1 integrin activation. FOXO1 and TGF-ß1 were prominently expressed in gingival wounds in fibroblastic cells located at the wound bed. CONCLUSION: The present study indicates that FOXO1 plays an important role in the modulation of several wound-healing functions in gingival fibroblast. Moreover, our findings reveal an important regulatory role for FOXO1 on the differentiation of gingival myofibroblasts, the regulation of cell migration, and collagen contraction, all these functions being critical during tissue repair and fibrosis.

Failure in syndromic management due to drug-resistant Mycoplasma genitalium in Florianópolis, South Brazil / Falha no manejo sindrômico devido a Mycoplasma genitalium resistente em Florianópolis, Sul do Brasil

Introduction: Mycoplasma genitalium is a bacterium associated with sexually transmitted infections that can cause urethritis in men and complications in women, including preterm birth. Increasing macrolide resistance in M. genitalium poses challenges to treatment efficacy. Objective: To present a case of treatment failure of urethritis caused by macrolide-resistant M. genitalium. Case report: This case report describes a 20-year-old man with persistent urethral symptoms despite azithromycin treatment, wherein M. genitalium harbored the A2058G mutation in the 23S rRNA. Subsequent treatment with moxifloxacin resolved symptoms and cleared M. genitalium. Conclusion: The study highlights the importance of resistance testing to guide antimicrobial therapy and emphasizes the need for updated treatment guidelines in Brazil. (AU)

Introdução:Mycoplasma genitalium é uma bactéria associada a infecções sexualmente transmissíveis, que pode causar uretrite em homens e complicações em mulheres, incluindo nascimento prematuro. O aumento da resistência aos macrolídeos em M. genitalium coloca desafios à eficácia do tratamento. Objetivo: Apresentar um caso de falha terapêutica de uretrite causada por M. genitalium resistente aos macrolídeos. Relato de caso: Este relato de caso descreve um homem de 20 anos com sintomas uretrais persistentes, apesar do tratamento com azitromicina, em que M. genitalium possuía a mutação A2058G no rRNA 23S. O tratamento subsequente com moxifloxacino resolveu os sintomas e eliminou M. genitalium. Conclusão: O estudo destacou a importância dos testes de resistência para orientar a terapia antimicrobiana e enfatizou a necessidade de atualizar as diretrizes de tratamento no Brasil. (AU)

Second generation of pyrimidin-quinolone hybrids obtained from virtual screening acting as sphingosine kinase 1 inhibitors and potential anticancer agents.

We report here the virtual screening design, synthesis and activity of eight new inhibitors of SphK1. For this study we used a pre-trained Graph Convolutional Network (GCN) combined with docking calculations. This exploratory analysis proposed nine compounds from which eight displayed significant inhibitory effect against sphingosine kinase 1 (SphK1) demonstrating a high level of efficacy for this approach. Four of these compounds also displayed anticancer activity against different tumor cell lines, and three of them (5), (6) and (7) have shown a wide inhibitory action against many of the cancer cell line tested, with GI50 below 5 µM, being (5) the most promising with TGI below 10 µM for the half of cell lines. Our results suggest that the three most promising compounds reported here are the pyrimidine-quinolone hybrids (1) and (6) linked by p-aminophenylsulfanyl and o-aminophenol fragments respectively, and (8) without such aryl linker. We also performed an exhaustive study about the molecular interactions that stabilize the different ligands at the binding site of SphK1. This molecular modeling analysis was carried out by using combined techniques: docking calculations, MD simulations and QTAIM analysis. In this study we also included PF543, as reference compound, in order to better understand the molecular behavior of these ligands at the binding site of SphK1.These results provide useful information for the design of new inhibitors of SphK1 possessing these structural scaffolds.

Use of elexacaftor+tezacaftor+ivacaftor in individuals with cystic fibrosis and at least one F508del allele: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the effect of treatment with the combination of three cystic fibrosis transmembrane conductance regulator (CFTR) modulators-elexacaftor+tezacaftor+ivacaftor (ETI)-on important clinical endpoints in individuals with cystic fibrosis. METHODS: This was a systematic review and meta-analysis of randomized clinical trials that compared the use of ETI in individuals with CF and at least one F508del allele with that of placebo or with an active comparator such as other combinations of CFTR modulators, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations and the Patients of interest, Intervention to be studied, Comparison of interventions, and Outcome of interest (PICO) methodology. We searched the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from their inception to December 26th, 2022. The risk of bias was assessed using the Cochrane risk-of-bias tool, and the quality of evidence was based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: We retrieved 54 studies in the primary search. Of these, 6 met the inclusion criteria and were analyzed (1,127 patients; 577 and 550 in the intervention and control groups, respectively). The meta-analysis revealed that the use of ETI increased FEV1% [risk difference (RD), +10.47%; 95% CI, 6.88-14.06], reduced the number of acute pulmonary exacerbations (RD, -0.16; 95% CI, -0.28 to -0.04), and improved quality of life (RD, +14.93; 95% CI, 9.98-19.89) and BMI (RD, +1.07 kg/m2; 95% CI, 0.90-1.25). Adverse events did not differ between groups (RD, -0.03; 95% CI, -0.08 to 0.01), and none of the studies reported deaths. CONCLUSIONS: Our findings demonstrate that ETI treatment substantially improves clinically significant, patient-centered outcomes.

Novel Fluoroquinolones with Possible Antibacterial Activity in Gram-Negative Resistant Pathogens: In Silico Drug Discovery.

Antibiotic resistance is a global threat to public health, and the search for new antibacterial therapies is a current research priority. The aim of this in silico study was to test nine new fluoroquinolones previously designed with potential leishmanicidal activity against Campylobacter jejuni, Escherichia coli, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Salmonella typhi, all of which are considered by the World Health Organization to resistant pathogens of global concern, through molecular docking and molecular dynamics (MD) simulations using wild-type (WT) and mutant-type (MT) DNA gyrases as biological targets. Our results showed that compound 9FQ had the best binding energy with the active site of E. coli in both molecular docking and molecular dynamics simulations. Compound 9FQ interacted with residues of quinolone resistance-determining region (QRDR) in GyrA and GyrB chains, which are important to enzyme activity and through which it could block DNA replication. In addition to compound 9FQ, compound 1FQ also showed a good affinity for DNA gyrase. Thus, these newly designed molecules could have antibacterial activity against Gram-negative microorganisms. These findings represent a promising starting point for further investigation through in vitro assays, which can validate the hypothesis and potentially facilitate the development of novel antibiotic drugs.

CFTR modulator therapy: transforming the landscape of clinical care in cystic fibrosis.

Following discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989 and subsequent elucidation of the varied CFTR protein abnormalities that result, a new era of cystic fibrosis management has emerged-one in which scientific principles translated from the bench to the bedside have enabled us to potentially treat the basic defect in the majority of children and adults with cystic fibrosis, with a resultant burgeoning adult cystic fibrosis population. However, the long-term effects of these therapies on the multiple manifestations of cystic fibrosis are still under investigation. Understanding the effects of modulators in populations excluded from clinical trials is also crucial. Furthermore, establishing appropriate disease measures to assess efficacy in the youngest potential trial participants and in those whose post-modulator lung function is in the typical range for people without chronic lung disease is essential for continued drug development. Finally, recognising that a health outcome gap has been created for some people and widened for others who are not eligible for, cannot tolerate, or do not have access to modulators is important.

Molecular characterization of PMQR carrying bacteriophages in effluent discharge samples of Azerbaijan hospitals.

Quinolones are one of the most widely used drugs in medicine. Resistance to this agent has been increased significantly among the nosocomial isolates. The objective of this research was to study generalized transduction, as a potential mechanism for plasmid-mediated quinolone resistance (PMQR) genes acquisition among hospital effluent isolates. Discharge samples from hospital effluent were taken from four medical centers in Azerbaijan. Resident phages were enriched against resident enterobacterial hosts using standard phage enrichment protocols. Polymerase chain reaction (PCR) was used to examine phage stocks and bacterial isolates for the presence of PMQR determinants. All positive bacterial isolates for target genes were subjected to transduction assays. Restriction fragment length polymorphism (RFLP) profiles were determined for cluster analysis. A total of 55 pure phage stocks were prepared from 42 effluents. A total of 95 non-duplicated Gram-negative bacteria were isolated. Thirty-two EcoRV-RFLP profiles were determined for the 40 Escherichia coli phage stocks. Twenty-six of 40 (65%) E. coli phages were positive for qnrB (n = 15), qnrD (n = 7), qnrA (n = 3), and qnrC (n = 2) genes. A total of 34 (35.7%) bacterial isolates were recognized to have any PMQR genes including qnrB (n = 23), qnrD (n = 8), qnrA (n = 5), and qnrC (n = 3) genes. Present research provided a strong evidence for potential role of generalized transduction in persistence and circulation of PMQR genes in health care settings of Azerbaijan.

Transferable mechanisms of quinolone resistance are more frequent among enterotoxigenic Escherichia coli isolates displaying low-level quinolone resistance.

This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6')Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children's diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6') Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC >= 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.

Bacterial profile, antimicrobial resistance, and molecular detection of ESBL and quinolone resistance gene of uropathogens causing urinary tract infection in the southeastern part of Bangladesh.

Humans frequently contract urinary tract infections (UTIs), which can be brought on by uropathogens (UPs) that are multi-drug resistant. Treatment for UTIs brought on by pathogenic UPs that produce extended-spectrum lactamases (ESBLs) is more costly and potentially fatal. As a result, the objective of this study was to use culture, biochemical, and 16S rRNA sequencing to identify and characterize UPs isolated from outpatients in Noakhali, Bangladesh, who had symptoms of UTIs. ESBL gene identification and quinolone resistance gene typing were then performed on the isolates using polymerase chain reaction (PCR). Throughout the trial's 8-month duration, 152 (76%) of 200 urine samples were positive for the presence of UPs. The overall number of UPs recovered was 210, with 39 individuals having multiple UPs present in their samples. Among all of the isolates, Escherichia coli (45.24%, 95/210; 95% confidence interval (CI): 35.15-57.60%), Enterobacter spp. (24.76%, 52/210; CI: 19.15-35.77%), Klebsiella spp. (20.95%; 44/210; CI: 15.15-30.20%), and Providencia spp. (9.05%; 19/210; CI: 4.95-19.25%) were the four most prevalent bacteria found in the isolates. The UPs displayed a very high level of resistance to piperacillin 96.92% (126/130), ampicillin 90% (117/130), nalidixic acid 77.69% (101/130), cefazolin 70% (91/130), amoxicillin 50% (55/130), cefazolin 42.31% (55/130), nitrofurantoin 43.08% (56/130), and ciprofloxacin 33.08% (43/130), whereas resistance to netilmicin (3.85%), amikacin (4.62%), and imipenem (9.23%) was low. Individually, every species of E. coli and Providencia spp. showed greater ampicillin, amikacin, cefazolin, cefazolin, and nalidixic acid resistance than the others. The bivariate results indicate several antibiotic pairings, and isolates had meaningful associations. All MDR isolates were subjected to PCR, which revealed that blaCTX-M-15 genes predominated among the isolates, followed by the blaTEM class (37%). Isolates also had the qnrS, aac-6´-Ib-cr, and gyrA genes. The findings provide worrying indications of a major expansion of MDR isolates in the study locations, particularly the epidemiological balCTX-M 15, with the potential for the transmission of multi-drug-resistant UP strains in the population.

High frequency of non-susceptibility to ciprofloxacin in nontyphoid Salmonella recovered from Brazilian broiler chicken.

1. This study evaluated the minimal inhibitory concentration (MIC) of ciprofloxacin and the presence of plasmid-mediated quinolone resistance (PMQR) mechanisms in 97 nontyphoidal Salmonella spp. isolated from broilers and carcases from three different regions in Brazil. The presence of mutations in quinolone resistance determination regions (QRDRS) was investigated in the ciprofloxacin-resistant strain by DNA sequencing.2. Most of the Salmonella spp. (85.6%) had intermediate resistance to ciprofloxacin and only one isolate was resistant. MIC breakpoints ranged from ≤0.03 to 1 µg/ml and 67.0% of the strains had a MIC of 0.25 µg/ml (n=65). Thirteen strains (13.4%) were susceptible to ciprofloxacin with MIC ≤0.06 µg/ml. The qnrB gene was detected in eight isolates with intermediate resistance and in two susceptible strains. The other PMQR genes, qnrA, qnrC, qnrD, qnrS, qnrVC, aac(6')-Ib, qepA, oqxAB and mutations in QRDR were not detected in any strain.3. There was a high frequency of ciprofloxacin intermediate resistant Salmonella from broiler and broiler carcases from Brazil. The presence of these strains in poultry and derived products poses a risk to public health.

High Frequency of Antibiotic Resistance Genes (ARGs) in the Lerma River Basin, Mexico.

The spread of beta-lactamase-producing bacteria is of great concern and the environment has been found to be a main source of contamination. Herein, it was proposed to determine the frequency of antimicrobial-resistant-Gram-negative bacteria throughout the Lerma River basin using phenotypic and molecular methods. Resistant bacteria were isolated with chromogenic media and antimicrobial susceptibility tests were used to characterize their resistance. ARGs for beta-lactams, aminoglycosides, and quinolones were detected by PCR. Species were identified by Sanger sequencing the 16S rRNA gene and the representative genomes of MDR strains were sequenced by NGS. A high variation in the number of isolates was observed in the 20 sampled sites, while observing a low diversity among the resistant bacteria. Of the 12 identified bacterial groups, C. freundii, E. coli, and S. marcescens were more predominant. A high frequency of resistance to beta-lactams, quinolones, and aminoglycosides was evidenced, where the blaCTX,qnrB, qnrS y, and aac(6')lb-cr genes were the most prevalent. C. freundii showed the highest frequency of MDR strains. Whole genome sequencing revealed that S. marcescens and K. pneumoniae showed a high number of shared virulence and antimicrobial resistance genes, while E. coli showed the highest number of unique genes. The contamination of the Lerma River with MDR strains carrying various ARGs should raise awareness among environmental authorities to assess the risks and regulations regarding the optimal hygienic and sanitary conditions for this important river that supports economic activities in the different communities in Mexico.

Aminoquinolones and Their Benzoquinone Dimer Hybrids as Modulators of Prion Protein Conversion.

Prion Diseases or Transmissible Spongiform Encephalopathies are neurodegenerative conditions associated with a long incubation period and progressive clinical evolution, leading to death. Their pathogenesis is characterized by conformational changes of the cellular prion protein-PrPC-in its infectious isoform-PrPSc-which can form polymeric aggregates that precipitate in brain tissues. Currently, there are no effective treatments for these diseases. The 2,5-diamino-1,4-benzoquinone structure is associated with an anti-prion profile and, considering the biodynamic properties associated with 4-quinolones, in this work, 6-amino-4-quinolones derivatives and their respective benzoquinone dimeric hybrids were synthesized and had their bioactive profile evaluated through their ability to prevent prion conversion. Two hybrids, namely, 2,5-dichloro-3,6-bis((3-carboxy-1-pentyl-4-quinolone-6-yl)amino)-1,4-benzoquinone (8e) and 2,5-dichloro-3,6-bis((1-benzyl-3-carboxy-4-quinolone-6-yl)amino)-1,4-benzoquinone (8f), stood out for their prion conversion inhibition ability, affecting the fibrillation process in both the kinetics-with a shortening of the lag phase-and thermodynamics and their ability to inhibit the formation of protein aggregates without significant cytotoxicity at ten micromolar.

Noncovalent interactions as a solution for the metal-free one-pot asymmetric synthesis of (S)-2-aryl-2,3-dihydro-4(1H)-quinolones.

4-Quinolones compose a remarkable class of compounds that show various pharmacological applications. In particular, the activities of both (S) and (R) enantiomers of 2-aryl-2,3-dihydro-4(1H)-quinolones have made them an object of befitting interest for asymmetric synthesis. Although readily yielded as a racemic mixture from an one-pot reaction between 2-aminoacetophenone and benzaldehyde, a pathway for the metal-free enantioselective one-pot synthesis of the (S) isomer is not completely clear. In the present work, guided by the burgeoning role of organocatalysis in asymmetric synthesis and recent experimental insight into the most likely reaction mechanism, we report the in silico screening for a roster of MacMillan chiral imidazolidinones through quantum mechanics calculations. Two stereopredictive models yielding similarly high expected ee (up to 97%) were proposed. The role of aromatic interactions for the control of enantioselectivity was systemically studied, as well as the Pro-S si-enantiofacial attack activation energies, which were found to correlate well (R2 = 0.75) with the reported Bürgi-Dunitz angle for the expected intramolecular Mannich reaction mechanism.

Identificación de enterobacterias multirresistentes a antibióticos en muestras de heces de lactantes residentes en Talara, Piura, Perú / Identification of multidrug-resistant enterobacteriaceae in fecal samples from infants residing in Talara, Piura, Peru Arturo

La colonización fecal en lactantes por bacterias resistentes a los antimicrobianos es un potencial riesgo para futuras terapias antibióticas. Nuestro objetivo fue determinar la frecuencia y características sociodemográficas de lactantes portadores fecales de enterobacterias resistentes a ciprofloxacina (PFRC) y sus genes de resistencia asociados. Analizamos muestras fecales de 41 niños lactantes residentes en el distrito de Talara-Piura, Perú, en 2019. Evaluamos la presencia de 3 genes de resistencia a quinolonas: aac(6')-Ib-cr, qnrB y oqxA y 2 de betalactamasas: bla CTX-M, bla PER-2.El 68% de lactantes fueron PFRC, Escherichia coli (83,3%) fue el más frecuente. El análisis genotípico detectó: oqxA (41,1%), qnrB (26,7%) y aac(6')-Ib-cr (20%) y al gen bla CTX-M en el 93,3% de los aislados con betalactamasas. La elevada frecuencia de PFRC nos alertan sobre el potencial riesgo en la pérdida de utilidad de esta familia antibiótica en el área de estudio.

Fecal colonization by antimicrobial-resistant bacteria in infants is a potential risk for future antibiotic therapy. We aimed to determine the sociodemographic characteristics and frequency of infants who were fecal carriers of ciprofloxacin-resistant enterobacteriaceae (FCCRE) and their associated resistance genes. We analyzed fecal samples from 41 infants from the district of Talara, Piura, Peru in 2019. The presence of 3 quinolone resistance genes was evaluated: aac(6')-Ib-cr, qnrB and oqxA as well as of 2 beta-lactamase genes: bla CTX-M,bla PER-2. We found that 68% of infants were FCCRE, Escherichia coli (83.3%) was the most frequent bacteria. The genotypic analysis detected: oqxA (41.1%), qnrB (26.7%), aac(6')-Ib-cr (20%) and the bla CTX-M gene (93.3%) of the isolates with beta-lactamases. The high frequency of FCCRE alerts us of the potential risk of this antibiotic family becoming less useful over time.