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1.
Sensors (Basel) ; 24(12)2024 Jun 16.
Article in English | MEDLINE | ID: mdl-38931676

ABSTRACT

In the realm of offline handwritten text recognition, numerous normalization algorithms have been developed over the years to serve as preprocessing steps prior to applying automatic recognition models to handwritten text scanned images. These algorithms have demonstrated effectiveness in enhancing the overall performance of recognition architectures. However, many of these methods rely heavily on heuristic strategies that are not seamlessly integrated with the recognition architecture itself. This paper introduces the use of a Pix2Pix trainable model, a specific type of conditional generative adversarial network, as the method to normalize handwritten text images. Also, this algorithm can be seamlessly integrated as the initial stage of any deep learning architecture designed for handwritten recognition tasks. All of this facilitates training the normalization and recognition components as a unified whole, while still maintaining some interpretability of each module. Our proposed normalization approach learns from a blend of heuristic transformations applied to text images, aiming to mitigate the impact of intra-personal handwriting variability among different writers. As a result, it achieves slope and slant normalizations, alongside other conventional preprocessing objectives, such as normalizing the size of text ascenders and descenders. We will demonstrate that the proposed architecture replicates, and in certain cases surpasses, the results of a widely used heuristic algorithm across two metrics and when integrated as the first step of a deep recognition architecture.

2.
Brain ; 147(2): 486-504, 2024 02 01.
Article in English | MEDLINE | ID: mdl-37776516

ABSTRACT

The spinocerebellar ataxias (SCAs) are a group of dominantly inherited neurodegenerative diseases, several of which are caused by CAG expansion mutations (SCAs 1, 2, 3, 6, 7 and 12) and more broadly belong to the large family of over 40 microsatellite expansion diseases. While dysregulation of alternative splicing is a well defined driver of disease pathogenesis across several microsatellite diseases, the contribution of alternative splicing in CAG expansion SCAs is poorly understood. Furthermore, despite extensive studies on differential gene expression, there remains a gap in our understanding of presymptomatic transcriptomic drivers of disease. We sought to address these knowledge gaps through a comprehensive study of 29 publicly available RNA-sequencing datasets. We identified that dysregulation of alternative splicing is widespread across CAG expansion mouse models of SCAs 1, 3 and 7. These changes were detected presymptomatically, persisted throughout disease progression, were repeat length-dependent, and were present in brain regions implicated in SCA pathogenesis including the cerebellum, pons and medulla. Across disease progression, changes in alternative splicing occurred in genes that function in pathways and processes known to be impaired in SCAs, such as ion channels, synaptic signalling, transcriptional regulation and the cytoskeleton. We validated several key alternative splicing events with known functional consequences, including Trpc3 exon 9 and Kcnma1 exon 23b, in the Atxn1154Q/2Q mouse model. Finally, we demonstrated that alternative splicing dysregulation is responsive to therapeutic intervention in CAG expansion SCAs with Atxn1 targeting antisense oligonucleotide rescuing key splicing events. Taken together, these data demonstrate that widespread presymptomatic dysregulation of alternative splicing in CAG expansion SCAs may contribute to disease onset, early neuronal dysfunction and may represent novel biomarkers across this devastating group of neurodegenerative disorders.


Subject(s)
Alternative Splicing , Olivopontocerebellar Atrophies , Spinocerebellar Ataxias , Animals , Mice , Alternative Splicing/genetics , Cerebellum , Mutation , Disease Progression , Trinucleotide Repeat Expansion
3.
Obes Pillars ; 7: 100081, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37990677

ABSTRACT

Background: Obesity has a negative impact on the physical and psychosocial quality of life of children. As rates of obesity continue to increase, it is important to recognize the widespread effects obesity has on children and their families. Methods: This clinical investigation evaluated the self-reported quality of life of children with obesity in a weight management program and compared this to a parent/guardian's perspective of the child's quality of life using the Pediatric Quality of Life survey 4.0. The quality of life of children with obesity was compared to children with other chronic diseases and healthy children. Results: An association was discovered between the guardians' responses to the Pediatric Quality of Life survey and the child's age. Guardians with children younger than 11 years reported higher quality of life scores than guardians of children 11 years and older. Race, comorbidities of obesity, insurance type, household structure, and parental education attainment were not significantly associated with a child's quality of life. Children with obesity had a lower quality of life compared to children who were organ transplant recipients and children with organic gastrointestinal disease. Conclusions: These results emphasize the need to evaluate and treat the physical and psychosocial components of wellbeing in children with obesity at an early age.

4.
Int J Mol Sci ; 24(6)2023 Mar 22.
Article in English | MEDLINE | ID: mdl-36983048

ABSTRACT

The DNA topoisomerases gyrase and topoisomerase I as well as the nucleoid-associated protein HU maintain supercoiling levels in Streptococcus pneumoniae, a main human pathogen. Here, we characterized, for the first time, a topoisomerase I regulator protein (StaR). In the presence of sub-inhibitory novobiocin concentrations, which inhibit gyrase activity, higher doubling times were observed in a strain lacking staR, and in two strains in which StaR was over-expressed either under the control of the ZnSO4-inducible PZn promoter (strain ΔstaRPZnstaR) or of the maltose-inducible PMal promoter (strain ΔstaRpLS1ROMstaR). These results suggest that StaR has a direct role in novobiocin susceptibility and that the StaR level needs to be maintained within a narrow range. Treatment of ΔstaRPZnstaR with inhibitory novobiocin concentrations resulted in a change of the negative DNA supercoiling density (σ) in vivo, which was higher in the absence of StaR (σ = -0.049) than when StaR was overproduced (σ = -0.045). We have located this protein in the nucleoid by using super-resolution confocal microscopy. Through in vitro activity assays, we demonstrated that StaR stimulates TopoI relaxation activity, while it has no effect on gyrase activity. Interaction between TopoI and StaR was detected both in vitro and in vivo by co-immunoprecipitation. No alteration of the transcriptome was associated with StaR amount variation. The results suggest that StaR is a new streptococcal nucleoid-associated protein that activates topoisomerase I activity by direct protein-protein interaction.


Subject(s)
DNA Topoisomerases, Type I , Streptococcus pneumoniae , Humans , DNA Topoisomerases, Type I/genetics , DNA Topoisomerases, Type I/metabolism , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/metabolism , Novobiocin/pharmacology , DNA, Bacterial/genetics , DNA Gyrase/genetics , DNA Gyrase/metabolism
5.
Hip Int ; 33(5): 925-933, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36348520

ABSTRACT

BACKGROUND: To describe the experience in the diagnostic process and treatment of patients with groin pain (GP) of neurological origin due to entrapment of the iliohypogastric (IH), ilioinguinal (IL) and genitofemoral (GF) nerves in a hip preservation clinic. METHODS: Retrospective study of patients with GP of neurological origin confirmed with ultrasound-guided nerve block. Clinical outcomes were reported in 21 cases (age, 53.3 ± 15.9 years) treated with conservative treatment from January to December 2019, and in 9 patients (age 43.7 ± 14.6 years) who underwent neurectomy from January 2015 to December 2019. Pain intensity was assessed with a numerical rating scale (NRS) before starting the diagnostic process (Day 0) and at the end of follow-up. RESULTS: All cases reported pain on groin palpation. Half of these cases also reported a positive FADIR test (flexion, adduction, internal rotation) (15/30). On day 0, the intensity of pain in cases treated with conservative treatment was severe in 19 patients (NRS 7-10) and moderate in 2 (NRS 4-6), with a median improvement of 7 points (interquartile range [IQR] 5.5-8.0) at the end of follow-up (p < 0.001). In neurectomy group, a similar improvement in pain severity was (Day 0: 9 points [IQR 8.0-9.0]; end of follow-up: 0 points [IQR: 0-2.0]; p = 0.002). At the end of the study, 17/21 patients with conservative treatment and 7/9 with neurectomy were pain free or with mild pain (NRS < 3). CONCLUSIONS: In cases with PG of neurological origin, there is a high frequency of false positives in the FADIR test. Our findings suggest that neurectomy is a treatment option for patients in whom conservative treatment fails, providing significant pain relief.


Subject(s)
Arthroplasty, Replacement, Hip , Femoracetabular Impingement , Humans , Adult , Middle Aged , Aged , Groin/innervation , Groin/surgery , Diagnosis, Differential , Retrospective Studies , Femoracetabular Impingement/complications , Femoracetabular Impingement/diagnosis , Femoracetabular Impingement/surgery , Pain
6.
Front Neural Circuits ; 16: 921568, 2022.
Article in English | MEDLINE | ID: mdl-36082109

ABSTRACT

In male Poeciliid fishes, the modified anal fin (i.e., gonopodium) and its axial and appendicular support are repositioned within the axial skeleton, creating a novel sexually dimorphic ano-urogenital region. During copulation, the relative location of the gonopodium is crucial for successful insemination. Therefore, the repositioning of these structures and organ relied on the reorganization of the efferent circuitry that controls spinal motor neurons innervating appendicular muscles critical for the movement of the gonopodium, including the fast and synchronous torque-trust motion during insemination attempts. Copulation occurs when a male positions himself largely outside a female's field of view, circumducts his gonopodium, and performs a rapid, complex maneuver to properly contact the female urogenital sinus with the distal tip of the gonopodium and transfers sperm. Although understanding of the efferent circuitry has significantly increased in the last 24 years, nothing is known about the cutaneous receptors involved in gonopodium movement, or how the afferent signals are processed to determine the location of this organ during copulation. Using Western mosquitofish, Gambusia affinis, as our model, we attempt to fill this gap in knowledge. Preliminary data showed cutaneous nerves and sensory neurons innervating superficial neuromasts surrounding the base of adult male gonopodium; those cutaneous nerves projected ventrally from the spinal cord through the 14th dorsal root ganglion and its corresponding ventral root towards the base and fin rays of the gonopodium. We asked what role the cutaneous superficial neuromasts play in controlling the positioning and timing of the gonopodium's fast and synchronous movements for effective sperm transfer. First, we found a greater number of superficial neuromasts surrounding the base of the male's gonopodium compared to the base of the female's anal fin. Second, we systemically removed superficial neuromasts surrounding the gonopodium base and observed significant impairment of the positioning and timing of gonopodial movements. Our findings provide a first step to supporting the following hypothesis: during radical reorganization of the Poeciliid body plan, superficial neuromasts have been partially co-opted as proprioceptors that allow the gonopodium to control precise positioning and timing during copulatory attempts.


Subject(s)
Copulation , Cyprinodontiformes , Animals , Cyprinodontiformes/physiology , Female , Male , Motor Neurons , Semen , Sensory Receptor Cells
9.
Odontol. sanmarquina (Impr.) ; 25(1): e22064, ene.-mar. 2022.
Article in Spanish, English | LILACS-Express | LILACS | ID: biblio-1358539

ABSTRACT

Objetivo. Reportar las manifestaciones orales más comunes asociadas a COVID-19 así como si estas persisten en un período de 3 meses. Métodos. Se realizó un estudio longitudinal, descriptivo, evaluando a 149 individuos positivos por reacción en cadena de la polimerasa (PCR) para SARS-CoV-2 a los cuales se les realizó un estudio inicial y un control 3 meses después. Resultados. El 65% de los participantes reportó alguna manifestación en cavidad bucal y el 24% alguna secuela. Dentro de estos síntomas y secuelas bucales observados, la de mayor frecuencia fue la disgeusia la cual se encontró en 51% de los pacientes seguida por xerostomía 27%, ganglios o glándulas inflamadas (17%). Dichas manifestaciones disminuyeron de forma importante en el seguimiento, sin embargo, prevalecieron en algunos pacientes. Conclusiones. La disgeusia es la manifestación oral de mayor frecuencia en este estudio y se presentó entre las cinco manifestaciones generales más comunes.


Objective. To report the oral manifestations associated with COVID-19 as well as whether these persist over a period of 3 months. Methods. A longitudinal, descriptive study was carried out evaluating 149 individuals positive for SARS-CoV-2 by polymerase chain reaction (PCR), who underwent an initial examination and a control 3 months later. Results. A total of 65% of the participants reported some manifestation in the oral cavity and 24% some sequelae. Within these observed symptoms and oral sequelae, the one with the highest incidence was dysgeusia, which was found in 51% of patients followed by xerostomia (27%), lymph nodes or swollen glands (17%). These manifestations decreased significantly during the follow-up, however they prevailed in some patients. Conclusions. Dysgeusia is the oral manifestation with the highest incidence in this study and was among the 5 most common general manifestations.

10.
Antibiotics (Basel) ; 10(5)2021 May 13.
Article in English | MEDLINE | ID: mdl-34068007

ABSTRACT

Antibiotic resistance in Streptococcus pneumoniae has increased worldwide, making fluoroquinolones an alternative therapeutic option. Fluoroquinolones inhibit the type II DNA topoisomerases (topoisomerase IV and gyrase). In this study we have evaluated the in vivo activity of seconeolitsine, an inhibitor of topoisomerase I. Levofloxacin (12.5 to 50 mg/kg) or seconeolitsine (5 to 40 mg/kg) were administered every 12 h during two days in mice infected with a serotype 8-resistant strain. At 48 h, a 70% protection was obtained with seconeolitsine (40 mg/kg; p < 0.001). However, survival with levofloxacin was 20%, regardless of the dose. In addition, seconeolitsine decreased bacteremia efficiently. Levofloxacin had higher levels in serum than seconeolitsine (Cmax of 14.7 vs. 1.6; p < 0.01) and higher values of area under the serum concentration-time curve (AUC0-12h of 17.3 vs. 5; p < 0.01). However, seconeolitsine showed higher levels of time to peak concentration and elimination half-life. This is consistent with the higher binding of seconeolitsine to plasma proteins (40% and 80% when used at 1 µg/mL and 50 µg/mL, respectively) in comparison to levofloxacin (12% at 5 µg/mL and 33% at 50 µg/mL). Our results suggest that seconeolitsine would be a promising therapeutic alternative against pneumococcal isolates with high fluoroquinolone resistance levels.

11.
Soft Matter ; 17(14): 3848-3854, 2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33885449

ABSTRACT

Spontaneous emergence of chirality is a pervasive theme in soft matter. We report a transient twist forming in achiral nematic liquid crystals confined to a capillary tube with square cross section. At the smectic-nematic phase transition, intertwined disclination line pairs are observed with both helical and kinked lozenge-like contours, configurations that we promote through capillary cross-section geometry and stabilize using fluorescent amphiphilic molecules. The observed texture is similar to that found in "exotic" materials such as chromonics, but it is here observed in common thermotropic nematics upon heating from the smectic into the nematic phase. Numerical modeling further reveals that the disclinations may possess winding characters that are intermediate between wedge and twist, and that vary along the defect contours. In our experiments, we utilize a phase transition to generate otherwise elusive defect structures in common liquid crystal materials.

12.
Sensors (Basel) ; 20(16)2020 Aug 15.
Article in English | MEDLINE | ID: mdl-32824232

ABSTRACT

This work compares Single Shot MultiBox Detector (SSD) and You Only Look Once (YOLO) deep neural networks for the outdoor advertisement panel detection problem by handling multiple and combined variabilities in the scenes. Publicity panel detection in images offers important advantages both in the real world as well as in the virtual one. For example, applications like Google Street View can be used for Internet publicity and when detecting these ads panels in images, it could be possible to replace the publicity appearing inside the panels by another from a funding company. In our experiments, both SSD and YOLO detectors have produced acceptable results under variable sizes of panels, illumination conditions, viewing perspectives, partial occlusion of panels, complex background and multiple panels in scenes. Due to the difficulty of finding annotated images for the considered problem, we created our own dataset for conducting the experiments. The major strength of the SSD model was the almost elimination of False Positive (FP) cases, situation that is preferable when the publicity contained inside the panel is analyzed after detecting them. On the other side, YOLO produced better panel localization results detecting a higher number of True Positive (TP) panels with a higher accuracy. Finally, a comparison of the two analyzed object detection models with different types of semantic segmentation networks and using the same evaluation metrics is also included.

14.
J Am Pharm Assoc (2003) ; 59(5): 651-659, 2019.
Article in English | MEDLINE | ID: mdl-31153824

ABSTRACT

OBJECTIVES: The objectives of this study were (1) to assess pharmacist readiness to provide pharmaceutical care for transgender patients through measuring both pharmacists' knowledge and attitudes towards transgender patients, (2) to assess transgender patients' perception of pharmacist readiness to provide them pharmaceutical care through measuring both pharmacists' knowledge and attitudes toward them, and (3) to compare pharmacist readiness to provide pharmaceutical care for transgender patients and patient perception of this readiness. DESIGN: The study used a descriptive, cross-sectional design. The pharmacist's readiness and the transgender patient's perception of their readiness, defined as a combination of knowledge and attitude, were evaluated. Two separate, validated questionnaires with dichotomous, multiple choice, and open-ended questions were used to measure both constructs among both populations. SETTING: Community-based research. PARTICIPANTS: Pharmacists practicing in Puerto Rico were provided the questionnaire by e-mail or in person. Transgender participants in Puerto Rico were recruited through health clinics and community partners and were surveyed in person. The analysis included responses from 96 pharmacists and 31 transgender participants. RESULTS: The majority of the pharmacists' knowledge scores (90%) were found in the low (0-5) and moderate (6-10) ranges, with a mean score of 7.23 out of a total possible score of 16 (SD ±2.36). For the attitude construct, most of the scores (81%) were found in the high (18-26) range, with a mean score of 19.63 out of a total possible score of 26 (SD ±3.65). For both constructs, transgender patient perceptions echoed the results of the pharmacists, indicating several perceived knowledge deficits in combination with mostly positive attitudes. CONCLUSION: The majority of pharmacists demonstrated positive attitudes toward caring for transgender patients, and transgender patients also perceived these positive attitudes from pharmacists. However, the measured and perceived knowledge deficits observed in this study suggest the need for educational interventions to improve pharmacist readiness to provide care for transgender patients.


Subject(s)
Community Pharmacy Services/trends , Education, Pharmacy/trends , Patient Care/trends , Transgender Persons , Adult , Aged , Attitude of Health Personnel , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Perception , Pharmacists , Professional Competence , Puerto Rico , Surveys and Questionnaires
15.
Psicol. Caribe ; 36(1): 45-60, ene.-abr. 2019.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1098487

ABSTRACT

Resumen Este artículo se desprende de la tesis "Relaciones sociales en la universidad: poder, conflicto y pluralidad entre jóvenes", presentada por la autora, Ana María Arias Cardona, como requisito para optar al título de Doctora en Ciencias Sociales: Niñez y Juventud, en el Centro de Estudios Avanzados en Niñez y Juventud de la Universidad De Manizales-CINDE, la cual se centra en universitarios y analiza formas simbólicas de exclusión. Se enfoca en la categoría "pluralidad", cuyo objetivo es comprender cómo configuran los jóvenes su encuentro con la diferencia, cómo afrontan la diversidad en sus relaciones. El diseño es cualitativo, el método hermenéutico y las técnicas empleadas talleres y entrevistas. Participaron 119 jóvenes de dos universidades públicas y dos privadas de Antioquia (Colombia). Los resultados se agrupan en tres subcategorías: "Todos somos 'el otro' del otro: la diferencia como déficit"; "Preferir no es excluir: ¿optar por unos sin vulnerar a otros?"; y "Procesos de inclusión que evidencian movilizaciones solidarias". Esto permite concluir que la diversidad se lee como algo negativo, y que es difuso el límite respecto a la discriminación, pues dichos actos se han "naturalizado".


Abstract This article summarizes the highlights of a thesis that analyses the symbolic ways of exclusion among university students. It focuses on the "plurality" category which objective was to understand how young frame their encounter with difference, how they confront diversity in their relationships. The design was qualitative, the hermeneutical method was used along with workshops and interviews techniques. 119 young people participated, from two public university and two private university in Antioquia (Colombia). The results are grouped into three subcategories: "We are all 'the other of the other: difference as deficit"; "To prefer is not to exclude: How to opt for certain ones without harming others?" and inclusion processes that show solidary mobilizations: which allows to conclude that diversity is read as something negative, that the limit regarding discrimination is diffuse and such, since those acts have been "naturalized".

16.
Genome ; 62(4): 287-293, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30817213

ABSTRACT

One of the major challenges in molecular analysis of arthropods, especially for natural enemies of insect pests, is the intact preservation of the specimens to be integrated into entomological collections. However, most of the DNA extraction protocols involve maceration of the tissue, avoiding the preservation of the original specimen. Two general methods were adapted into non-destructive DNA extraction protocols, DNeasy® Blood & Tissue Kit (A) and the CaCl2 lysis buffer method (B), while the potential of the method with the alkaline lysis buffer (HotSHOT; C) was evaluated for the first time on insect specimens. These protocols were assessed for the recovery of DNA from Ceraeochrysa valida, Tamarixia radiata, and Hippodamia convergens. Photographical records showed that morphological features of the specimens were preserved after the DNA extraction process. COI fragments were successfully amplified with method A (100%), B (77%), and C (88%), respectively. We conclude that these non-destructive DNA extraction methods avoid the destruction of tissue and preserve the original insects and their morphological characteristics for future reference.


Subject(s)
DNA/isolation & purification , Insecta/genetics , Animals , Biological Control Agents , Genetic Techniques , Polymerase Chain Reaction
17.
Transgend Health ; 4(1): 9-17, 2019.
Article in English | MEDLINE | ID: mdl-30719502

ABSTRACT

Purpose: Transgender and gender nonconforming (GNC) people continue to experience suboptimal health care, social exclusion, and lower quality of life. Globally, lack of access to services, institutional violence, and public harassment have been reported. However, there is limited data on transgender health in Puerto Rico and the Caribbean. The purpose of this study is to assess the social determinants of health and wellbeing of transgender and GNC people living in Puerto Rico. Methods: Utilizing a community-based participatory research approach, 52 self-identified transgender and GNC individuals living in Puerto Rico completed a survey, which included questions on access to health care services, social support, and violence, among others. Data were collected from March to Ma y of 2015 and descriptive statistical analysis was conducted. Results: Most of the participants reported experiences of discrimination across multiple social settings, most commonly at school (70.6%) and work (67.4%). Regarding experiences of violence, more than half (65.4%) had been verbally attacked in a public space. Many reported that access to gender-affirming health care services is difficult in Puerto Rico (88.5%) due to lack of knowledgeable providers (59.6%) and discomfort during the encounter (55.8%). The main perceived priority for their wellbeing was a transgender health care center. Conclusion: Although the LGBT equality movement has reached great milestones, access to gender-affirming health services and safe educational and work spaces are still needed. Findings from the study provide guidance for actions to reduce health disparities by addressing the needs for health and wellbeing among transgender and GNC individuals.

18.
Am J Case Rep ; 20: 83-90, 2019 Jan 21.
Article in English | MEDLINE | ID: mdl-30662059

ABSTRACT

BACKGROUND Pulmonary edema is the accumulation of fluid in the lung secondary to increased hydrostatic pressure. Hypertensive cardiogenic pulmonary edema presents with a sudden onset of severe dyspnea, tachycardia, and tachypnea, and can occur when the systolic blood pressure exceeds 160 mmHg in association with acute decompensated congestive cardiac failure (CCF). A case is presented of hypertensive cardiogenic pulmonary edema treated with high-dose nitroglycerin and includes a review of the literature. CASE REPORT A 63-year-old Hispanic male with a medical history of hypertension, coronary artery disease, heart failure with a reduced ejection fraction of 35%, chronic kidney disease (CKD) and diabetes mellitus, presented as an emergency with acute, severe dyspnea. The patient was initially managed with 100% oxygen supplementation and intravenous (IV) high-dose nitroglycerin (30 mcg/min), which was titrated every 3 minutes, increasing by 15 mcg/min until a dose of 120 mcg/min was reached. After 18 minutes of aggressive therapy, the patient's condition improved and he no longer required mechanical ventilation. CONCLUSIONS Hypertensive cardiogenic pulmonary edema is a challenging clinical condition that should be diagnosed and managed as early as possible, and distinguished from respiratory failure due to other causes. Although hypertensive cardiogenic pulmonary edema is usually managed acutely with high-dose diuretics, this case has highlighted the benefit of high-dose IV nitroglycerin, and review of the literature supports this treatment approach.


Subject(s)
Heart Failure/complications , Hypertension/complications , Nitroglycerin/administration & dosage , Pulmonary Edema/drug therapy , Respiratory Insufficiency/drug therapy , Vasodilator Agents/administration & dosage , Humans , Infusions, Intravenous , Male , Middle Aged , Pulmonary Edema/etiology , Respiratory Insufficiency/etiology
19.
Microb Ecol ; 77(2): 471-487, 2019 Feb.
Article in English | MEDLINE | ID: mdl-29978356

ABSTRACT

Proteins belonging to the Gls24 superfamily are involved in survival of pathogenic Gram-positive cocci under oligotrophic conditions and other types of stress, by a still unknown molecular mechanism. In Firmicutes, this superfamily includes three different valine-rich orthologal families (Gls24A, B, C) with different potential interactive partners. Whereas the Streptococcus pneumoniae Δgls24A deletion mutant experienced a general long growth delay, the Δgls24B mutant grew as the parental strain in the semisynthetic AGCH medium but failed to grow in the complex Todd-Hewitt medium. Bovine seroalbumin (BSA) was the component responsible for this phenotype. The effect of BSA on growth was concentration-dependent and was maintained when the protein was proteolyzed but not when heat-denatured, suggesting that BSA dependence was related to oligopeptide supplementation. Global transcriptional analyses of the knockout mutant revealed catabolic derepression and induction of chaperone and oligopeptide transport genes. This mutant also showed increased sensibility to cadmium and high temperature. The Δgls24B mutant behaved as a poor colonizer in the nasopharynx of mice and showed 20-fold competence impairment. Experimental data suggest that Gls24B plays a central role as a sensor of amino acid availability and its connection to sugar catabolism. This metabolic rewiring can be compensated in vitro, at the expenses of external oligopeptide supplementation, but reduce important bacteria skills prior to efficiently address systemic virulence traits. This is an example of how metabolic factors conserved in enterococci, streptococci, and staphylococci can be essential for survival in poor oligopeptide environments prior to infection progression.


Subject(s)
Amino Acids, Essential/metabolism , Bacterial Proteins/metabolism , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/metabolism , Animals , Bacterial Proteins/genetics , Culture Media/metabolism , Gene Expression Regulation, Bacterial , Humans , Mice , Mice, Inbred BALB C , Multigene Family , Sequence Deletion , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/growth & development
20.
Front Microbiol ; 9: 1659, 2018.
Article in English | MEDLINE | ID: mdl-30087665

ABSTRACT

The spread of multidrug-resistant isolates of Mycobacterium tuberculosis requires the discovery of new drugs directed to new targets. In this study, we investigated the activity of two boldine-derived alkaloids, seconeolitsine (SCN) and N-methyl-seconeolitsine (N-SCN), against M. tuberculosis. These compounds have been shown to target DNA topoisomerase I enzyme and inhibit growth of Streptococcus pneumoniae. Both SCN and N-SCN inhibited M. tuberculosis growth at 1.95-15.6 µM, depending on the strain. In M. smegmatis this inhibitory effect correlated with the amount of topoisomerase I in the cell, hence demonstrating that this enzyme is the target for these alkaloids in mycobacteria. The gene coding for topoisomerase I of strain H37Rv (MtbTopoI) was cloned into pQE1 plasmid of Escherichia coli. MtbTopoI was overexpressed with an N-terminal 6-His-tag and purified by affinity chromatography. In vitro inhibition of MtbTopoI activity by SCN and N-SCN was tested using a plasmid relaxation assay. Both SCN and N-SCN inhibited 50% of the enzymatic activity at 5.6 and 8.4 µM, respectively. Cleavage of single-stranded DNA was also inhibited with SCN. The effects on DNA supercoiling were also evaluated in vivo in plasmid-containing cultures of M. tuberculosis. Plasmid supercoiling densities were -0.060 in cells untreated or treated with boldine, and -0.072 in 1 × MIC N-SCN treated cells, respectively, indicating that the plasmid became hypernegatively supercoiled in the presence of N-SCN. Altogether, these results demonstrate that the M. tuberculosis topoisomerase I enzyme is an attractive drug target, and that SCN and N-SCN are promising lead compounds for drug development.

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