Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 266
Filter
1.
Ther Deliv ; : 1-9, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39023301

ABSTRACT

Aim: Rose Bengal photodynamic antimicrobial therapy (RB-PDAT) has poor corneal penetration, limiting its efficacy against acanthamoeba keratitis (AK). Iontophoresis enhances corneal permeation of charged molecules, piquing interest in its effects on RB in ex vivo human corneas. Methods: Five donor whole globes each underwent iontophoresis with RB, soaking in RB, or were soaked in normal saline (controls). RB penetration and corneal thickness was assessed using confocal microscopy. Results: Iontophoresis increased RB penetration compared with soaking (177 ± 9.5 µm vs. 100 ± 5.7 µm, p < 0.001), with no significant differences in corneal thickness between groups (460 ± 87 µm vs. 407 ± 69 µm, p = 0.432). Conclusion: Iontophoresis significantly improves RB penetration and its use in PDAT could offer a novel therapy for acanthamoeba keratitis. Further studies are needed to validate clinical efficacy.


The study aimed to improve a new treatment for eye infections known as photodynamic antimicrobial therapy. It investigated whether the use of electricity through a technique called iontophoresis could help a chemical called Rose Bengal go deeper into the eye in order to target more severe infections. The iontophoresis machine was custom built, with patient-contacting components 3D printed. The experiments were performed using donated human eye tissue and found that iontophoresis significantly improved the penetration depth of Rose Bengal as compared with the current technique of only soaking the eye in Rose Bengal.

2.
Cells ; 13(11)2024 May 23.
Article in English | MEDLINE | ID: mdl-38891028

ABSTRACT

Cervical cancer (CC) remains among the most frequent cancers worldwide despite advances in screening and the development of vaccines against human papillomavirus (HPV), involved in virtually all cases of CC. In mid-income countries, a substantial proportion of the cases are diagnosed in advanced stages, and around 40% of them are diagnosed in women under 49 years, just below the global median age. This suggests that members of this age group share common risk factors, such as chronic inflammation. In this work, we studied samples from 46 patients below 45 years old, searching for a miRNA profile regulating cancer pathways. We found 615 differentially expressed miRNAs between tumor samples and healthy tissues. Through bioinformatic analysis, we found that several of them targeted elements of the JAK/STAT pathway and other inflammation-related pathways. We validated the interactions of miR-30a and miR-34c with JAK1 and STAT3, respectively, through dual-luciferase and expression assays in cervical carcinoma-derived cell lines. Finally, through knockdown experiments, we observed that these miRNAs decreased viability and promoted proliferation in HeLa cells. This work contributes to understanding the mechanisms through which HPV regulates inflammation, in addition to its canonical oncogenic function, and brings attention to the JAK/STAT signaling pathway as a possible diagnostic marker for CC patients younger than 45 years. To our knowledge to date, there has been no previous description of a panel of miRNAs or even ncRNAs in young women with locally advanced cervical cancer.


Subject(s)
Gene Expression Regulation, Neoplastic , Inflammation , MicroRNAs , STAT3 Transcription Factor , Signal Transduction , Uterine Cervical Neoplasms , Humans , Female , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/virology , MicroRNAs/genetics , MicroRNAs/metabolism , Signal Transduction/genetics , Adult , Inflammation/genetics , Inflammation/pathology , STAT3 Transcription Factor/metabolism , STAT3 Transcription Factor/genetics , HeLa Cells , Janus Kinase 1/metabolism , Janus Kinase 1/genetics , Cell Proliferation/genetics , Cell Line, Tumor , Middle Aged
3.
Int J Mol Sci ; 25(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38892306

ABSTRACT

The development of specific antiviral therapies targeting SARS-CoV-2 remains fundamental because of the continued high incidence of COVID-19 and limited accessibility to antivirals in some countries. In this context, dark chemical matter (DCM), a set of drug-like compounds with outstanding selectivity profiles that have never shown bioactivity despite being extensively assayed, appears to be an excellent starting point for drug development. Accordingly, in this study, we performed a high-throughput screening to identify inhibitors of the SARS-CoV-2 main protease (Mpro) using DCM compounds as ligands. Multiple receptors and two different docking scoring functions were employed to identify the best molecular docking poses. The selected structures were subjected to extensive conventional and Gaussian accelerated molecular dynamics. From the results, four compounds with the best molecular behavior and binding energy were selected for experimental testing, one of which presented inhibitory activity with a Ki value of 48 ± 5 µM. Through virtual screening, we identified a significant starting point for drug development, shedding new light on DCM compounds.


Subject(s)
Antiviral Agents , Coronavirus 3C Proteases , Molecular Docking Simulation , Molecular Dynamics Simulation , Protease Inhibitors , SARS-CoV-2 , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Humans , Protease Inhibitors/pharmacology , Protease Inhibitors/chemistry , COVID-19/virology , Drug Discovery/methods , High-Throughput Screening Assays/methods , Drug Evaluation, Preclinical/methods , Protein Binding , Ligands
4.
Ocul Immunol Inflamm ; : 1-5, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829001

ABSTRACT

PURPOSE: To report two cases of bilateral blepharokeratoconjunctivitis associated with hidradenitis suppurativa (HS). METHODS: Case report and literature review. The clinical courses of two patients with HS, including ocular presentation and medical management, are described. RESULTS: Two female patients aged 18 and 23-years-old with severe HS presented with bilateral blepharokeratoconjunctivitis. Shared slit lamp findings included bilateral corneal neovascularization and inferior corneal thinning. Systemic immunosuppression was needed in the first case, which resulted in improvement in the patient's ophthalmic and dermatological findings. CONCLUSION: We report two cases of bilateral blepharokeratoconjunctivitis in two patients with severe HS. To our knowledge, this association has not previously been described in the literature. Clinicians should be aware of this association given its potentially visually devastating manifestations and the need for early therapeutic interventions.

5.
BMC Health Serv Res ; 24(1): 599, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38715039

ABSTRACT

BACKGROUND: In Mexico, this pioneering research was undertaken to assess the accessibility of timely diagnosis of Dyads [Children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) and their primary caregivers] at specialized mental health services. The study was conducted in two phases. The first phase involved designing an "Access Pathway" aimed to identify barriers and facilitators for ADHD diagnosis; several barriers, with only the teacher being identified as a facilitator. In the second phase, the study aimed to determine the time taken for dyads, to obtain a timely diagnosis at each stage of the Access Pathway. As well as identify any disparities based on gender and socioeconomic factors that might affect the age at which children can access a timely diagnosis. METHOD: In a retrospective cohort study, 177 dyads participated. To collect data, the Acceda Survey was used, based on the robust Conceptual Model Levesque, 2013. The survey consisted of 48 questions that were both dichotomous and polytomous allowing the creation of an Access Pathway that included five stages: the age of perception, the age of search, the age of first contact with a mental health professional, the age of arrival at the host hospital, and the age of diagnosis. The data was meticulously analyzed using a comprehensive descriptive approach and a nonparametric multivariate approach by sex, followed by post-hoc Mann-Whitney's U tests. Demographic factors were evaluated using univariable and multivariable Cox regression analyses. RESULTS: 71% of dyads experienced a late, significantly late, or highly late diagnosis of ADHD. Girls were detected one year later than boys. Both boys and girls took a year to seek specialized mental health care and an additional year to receive a formal specialized diagnosis. Children with more siblings had longer delays in diagnosis, while caregivers with formal employment were found to help obtain timely diagnoses. CONCLUSIONS: Our findings suggest starting the Access Pathway where signs and symptoms of ADHD are detected, particularly at school, to prevent children from suffering consequences. Mental health school-based service models have been successfully tested in other latitudes, making them a viable option to shorten the time to obtain a timely diagnosis.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Early Diagnosis , Health Services Accessibility , Mental Health Services , Humans , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/epidemiology , Child , Male , Female , Mexico/epidemiology , Adolescent , Retrospective Studies , Mental Health Services/statistics & numerical data , Socioeconomic Factors
6.
Article in English | MEDLINE | ID: mdl-38651633

ABSTRACT

Background: The aim of the present study was to describe the presence of co-infection by Toxoplasma gondii and Neospora caninum in goats reared in extensive systems from Mexico. Materials and Methods: A cross-sectional study was conducted to determine the frequency of T. gondii and N. caninum, by detecting antibodies to each parasite by mean commercial ELISA kits. A total of 176 blood samples were randomly collected from mature females reared in extensive system herds from 20 municipalities of state of Guanajuato, Mexico. Results: The general seroprevalence was 23.9 and 21.0% for T. gondii and N. caninum, respectively, while co-infection rate was 3.6%. For geographic and environmental variables, no differences were observed among T. gondii and coinfection; however, it was observed that altitude, annual precipitation, annual average temperature, and rainy period showed significant differences with N. caninum seropositive goats. Conclusion: The seroprevalence of both parasites was appreciated in most of the studied herds. The present study is the first report of T. gondii and N. caninum co-infection in goats from extensive herds in Mexico.

7.
JAMA Ophthalmol ; 142(5): 407-415, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38512246

ABSTRACT

Importance: Evaluation of the microbiological diagnostic profile of multidrug-resistant Pseudomonas aeruginosa keratitis and potential management with rose bengal-photodynamic antimicrobial therapy (RB-PDAT) is important. Objective: To document the disease progression of carbapenemase-resistant P aeruginosa keratitis after an artificial tear contamination outbreak. Design, Setting, and Participants: This retrospective observation case series included 9 patients 40 years or older who presented at Bascom Palmer Eye Institute and had positive test results for multidrug-resistant P aeruginosa keratitis between January 1, 2022, and October 31, 2023. Main Outcomes and Measures: Evaluation of type III secretion phenotype, carbapenemase-resistance genes blaGES and blaVIM susceptibility to antibiotics, and in vitro and in vivo outcomes of RB-PDAT against multidrug-resistant P aeruginosa keratitis. Results: Among the 9 patients included in the analysis (5 women and 4 men; mean [SD] age, 73.4 [14.0] years), all samples tested positive for exoU and carbapenemase-resistant blaVIM and blaGES genes. Additionally, isolates were resistant to carbapenems as indicated by minimum inhibitory concentration testing. In vitro efficacy of RB-PDAT indicated its potential application for treating recalcitrant cases. These cases highlight the rapid progression and challenging management of multidrug-resistant P aeruginosa. Two patients were treated with RB-PDAT as an adjuvant to antibiotic therapy and had improved visual outcomes. Conclusions and Relevance: This case series highlights the concerning progression in resistance and virulence of P aeruginosa and emphasizes the need to explore alternative therapies like RB-PDAT that have broad coverage and no known antibiotic resistance. The findings support further investigation into the potential effects of RB-PDAT for other multidrug-resistant microbes.


Subject(s)
Carbapenems , Eye Infections, Bacterial , Microbial Sensitivity Tests , Pseudomonas Infections , Pseudomonas aeruginosa , Humans , Female , Male , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/genetics , Retrospective Studies , Aged , Eye Infections, Bacterial/microbiology , Eye Infections, Bacterial/drug therapy , Eye Infections, Bacterial/diagnosis , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas Infections/diagnosis , Middle Aged , Carbapenems/therapeutic use , Carbapenems/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Aged, 80 and over , Treatment Outcome , Drug Resistance, Multiple, Bacterial , Bacterial Proteins/genetics
8.
Comput Biol Med ; 171: 108163, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38417382

ABSTRACT

SARS-CoV-2 must bind its principal receptor, ACE2, on the target cell to initiate infection. This interaction is largely driven by the receptor binding domain (RBD) of the viral Spike (S) protein. Accordingly, antiviral compounds that can block RBD/ACE2 interactions can constitute promising antiviral agents. To identify such molecules, we performed a virtual screening of the Selleck FDA approved drugs and the Selleck database of Natural Products using a multistep computational procedure. An initial set of candidates was identified from an ensemble docking process using representative structures determined from the analysis of four 3 µ s molecular dynamics trajectories of the RBD/ACE2 complex. Two procedures were used to construct an initial set of candidates including a standard and a pharmacophore guided docking procedure. The initial set was subsequently subjected to a multistep sieving process to reduce the number of candidates to be tested experimentally, using increasingly demanding computational procedures, including the calculation of the binding free energy computed using the MMPBSA and MMGBSA methods. After the sieving process, a final list of 10 candidates was proposed, compounds which were subsequently purchased and tested ex-vivo. The results identified estradiol cypionate and telmisartan as inhibitors of SARS-CoV-2 entry into cells. Our findings demonstrate that the methodology presented here enables the discovery of inhibitors targeting viruses for which high-resolution structures are available.


Subject(s)
COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Humans , Molecular Docking Simulation , Drug Repositioning/methods , Angiotensin-Converting Enzyme 2 , Molecular Dynamics Simulation , Protein Binding
9.
Res Sq ; 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38352587

ABSTRACT

Background: Negative dysphotopsias (ND) are visual aberrations associated with in-the-bag optic intraocular lens (IOL) placement, causing arc-shaped or linear shadows. Reverse optic capture (ROC) is employed to prevent ND, yet it poses the risk of posterior capsular opacification (PCO) which usually develops within 2-5 years post-surgery due to the lens epithelial cells (LECs) proliferation and migration onto the posterior capsule. This can lead to a cloudy or hazy appearance in the visual field. Early identification of posterior capsular opacities is crucial to ensure timely intervention and minimize visual impairment. Cases Presentations: Two cases of acute and rapidly progressive PCO following cataract extraction (CE) and IOL placement using the ROC technique to prevent ND are reported at the Bascom Palmer Eye Institute. At the two-week postoperative follow-up, both patients reported a significant progressive decrease in vision in the treated eye, and severe posterior capsular opacities were observed. A diagnosis of PCO was confirmed, and successful visual rehabilitation was achieved through the performance of ND:YAG laser capsulotomy without complications. This case series represents the first reported instances of patients developing PCO within two weeks of CE and IOL placement using the ROC technique. Conclusions: This case series sheds light on the occurrence of posterior capsular opacities shortly after CE and IOL placement using the ROC technique. It highlights the importance of preoperative patient education, postoperative monitoring, and prompt management of potential complications in cataract surgery.

10.
Cornea ; 43(2): 265-268, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37603688

ABSTRACT

PURPOSE: The aim of this study was to describe a combined surgical approach for ocular surface and visual rehabilitation in patients with limbal stem cell deficiency, corneal scarring, and cataract. We aimed to introduce this combined approach as an alternative to a staged approach and to describe the intraoperative use of a diamond ophthalmic burr (DOB) and optical coherence tomography (OCT) to achieve and confirm a smooth graft-host interface during the anterior lamellar keratoplasty (ALK) portion of the procedure. METHODS: The quintuple procedure described herein consists of a modified ALK, cataract extraction, intraocular lens implantation, simple limbal epithelial transplantation, and temporal tarsorrhaphy. Intraoperative OCT and DOB were used to guide the creation of the stromal bed during the ALK. The procedure was performed in a patient with limbal stem cell deficiency and corneal scarring after a chemical ocular burn. RESULTS: The tarsorrhaphy was removed at 3 months postoperatively once complete corneal epithelialization was observed. The best-corrected visual acuity improved from light perception preoperatively to 20/30 at 16 months postoperatively with the use of scleral contact lenses. At this postoperative time point, the cornea was clear and compact, and the ocular surface was stable. CONCLUSIONS: The quintuple procedure allowed for visual and ocular surface rehabilitation in cases in which follow-up for a staged approach was not possible. Intraoperative OCT allowed for real-time visualization and dissection of the stromal bed, whereas the use of the DOB helped achieve a smooth stromal surface for an optimal graft-host interface.


Subject(s)
Corneal Diseases , Corneal Injuries , Corneal Transplantation , Limbal Stem Cell Deficiency , Humans , Cicatrix/surgery , Visual Acuity , Cornea/surgery , Corneal Injuries/surgery , Receptor Protein-Tyrosine Kinases , Corneal Transplantation/methods , Corneal Diseases/surgery
11.
Int J Biol Macromol ; 255: 127843, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37956803

ABSTRACT

Bombesin is an endogenous peptide involved in a wide spectrum of physiological activities ranging from satiety, control of circadian rhythm and thermoregulation in the central nervous system, to stimulation of gastrointestinal hormone release, activation of macrophages and effects on development in peripheral tissues. Actions of the peptide are mediated through the two high affinity G-protein coupled receptors BB1R and BB2R. Under pathophysiological conditions, these receptors are overexpressed in many different types of tumors, such as prostate cancer, breast cancer, small and non-small cell lung cancer and pancreatic cancer. This observation has been used for designing cell markers, but it has not been yet exploited for therapeutical purposes. Despite the enormous biological interest of the peptide, little is known about the stereochemical features that contribute to their activity. On the one hand, mutagenesis studies identified a few receptor residues important for high bombesin affinity and on the other, a few studies focused on the relevance of diverse residues of the peptide for receptor activation. Models of the peptide bound to BB1R and BB2R can be helpful to improve our understanding of the stereochemical features granting bombesin activity. Accordingly, the present study describes the computational process followed to construct such models by means of Steered Molecular Dynamics, using models of the peptide and its receptors. Present results provide new insights into the structure-activity relationships of bombesin and its receptors, as well as render an explanation for the differential binding affinity observed towards BB1R and BB2R. Finally, these models can be further exploited to help for designing novel small molecule peptidomimetics with improved pharmacokinetics profile.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Male , Humans , Bombesin/chemistry , Bombesin/metabolism , Receptors, Bombesin/metabolism , Peptides
12.
Materials (Basel) ; 16(22)2023 Nov 15.
Article in English | MEDLINE | ID: mdl-38005097

ABSTRACT

This research analyses how different cement mortars behave in terms of their physical and mechanical properties. Several components were necessary to make seven mixes of mortars, such as Portland cement, standard sand, and solid waste from a factory of sodium silicate, in addition to graphene oxide. Furthermore, graphene oxide (GO) was selected to reduce the micropores and increase the nanopores in the cement mortar. Hence, some tests were carried out to determine their density, humidity content, water absorption capacity, open void porosity, the alkali-silica reaction, as well as flexural and mechanical strength and acid resistance. Thus, standard-sand-manufactured mortars' mechanical properties were proved to be slightly better than those manufactured with recycled waste; the mortars with this recycled aggregate presented problems of alkali-silica reaction. In addition, GO (in a ratio GO/cement = 0.0003) performed as a filler, improving the mechanical properties (30%), alkali-silica (80%), and acid resistance.

13.
J Chem Inf Model ; 63(20): 6412-6422, 2023 10 23.
Article in English | MEDLINE | ID: mdl-37824186

ABSTRACT

Mutants of Ras are oncogenic drivers of a large number of human tumors. Despite being recognized as an attractive target for the treatment of cancer, the high affinity for its substrate tagged the protein as undruggable for a few years. The identification of cryptic pockets on the protein surface gave the opportunity to identify molecules capable of acting as allosteric modulators. Several molecules were disclosed in recent years, with sotorasib and adagrasib already approved for clinical use. The present study makes use of computational methods to characterize eight prospective allosteric pockets (P1-P8) in K-Ras, four of which (P1-P4) were previously characterized in the literature. The present study also describes the results of a virtual screening study focused on the discovery of hit compounds, binders of the P4 site that can be considered as peptidomimetics of a fragment of the SOS αI helix, a guanine exchange factor of Ras. After a detailed description of the computational procedure followed, we disclose five hit compounds, prospective binders of the P4 allosteric site that exhibit an inhibitory capability higher than 30% in a cell proliferation assay at 50 µM.


Subject(s)
Neoplasms , Proteins , Humans , Allosteric Site , Prospective Studies , Neoplasms/drug therapy
14.
Microorganisms ; 11(7)2023 Jul 03.
Article in English | MEDLINE | ID: mdl-37512911

ABSTRACT

Despite the universal vaccination program, there are still regions and territories with a high prevalence of Hepatitis B Virus infection (HBV), such as the Amazon basin, where several indigenous communities live. Additionally, Hepatitis Delta Virus (HDV) is a defective that requires the hepatitis B surface antigen (HBsAg) for the assembly and release of de novo viral particles. Therefore, hepatitis D could be the result of HBV/HDV coinfection or HDV superinfection in individuals with chronic hepatitis B. Among the high prevalence HDV populations are indigenous communities of America. This study aims to describe and characterize the frequency of HBV and HDV infection, viral genotypes and HBV immune escape mutants in indigenous populations from different regions of Colombia. The diagnosis of hepatitis B and hepatitis D was confirmed by serological markers. Moreover, the HBV and HDV genome were amplified by PCR and RT-PCR, respectively, and, subsequently, the phylogenetic analysis was performed. We characterized 47 cases of chronic hepatitis B, 1 case of reactivation and 2 cases of occult hepatitis B infection (OBI). Furthermore, a high prevalence of HDV infection was identified in the study population (29.33%, 22/75) and the circulation of several HBV genotypes and subgenotypes (F1b, F3, F4, and D). Interestingly, this is the first report of the HDV genotype I circulation in this country. These findings demonstrated that HBV and HDV infections are still public health problems in indigenous communities in Colombia.

15.
PLoS One ; 18(7): e0288504, 2023.
Article in English | MEDLINE | ID: mdl-37440509

ABSTRACT

Antimicrobial resistance (AMR) represents a serious threat to global health. The development of new drugs to combat infections caused by bacteria resistant to multiple or even all available antibiotics is urgent. Most antibiotics used up to date have been identified from soil microorganisms. The marine environment represents an alternative source with great potential for the identification of microorganisms that produce bioactive molecules, including antibiotics. In this study, we analyzed the antibacterial activity of a collection of 82 bacterial strains isolated from marine water and sediment samples collected from the Southwestern Gulf of Mexico. Eight of the marine isolates inhibited the growth of different pathogenic bacteria, seven of which were identified as presumptive Pseudomonas aeruginosa. Interestingly, genome sequencing and phylogenetic analysis revealed that the remaining marine isolate showing antibacterial activity is a novel Pseudomonas species that we denominated Pseudomonas sp. GOM7, which was not pathogenic in the Galleria mellonella infection model in the conditions tested. Notably, Pseudomonas sp. GOM7 inhibited the growth of multidrug and methicillin-resistant strains of the priority pathogen Staphylococcus aureus. Our results show that the anti-S. aureus compound(s) produced by Pseudomonas sp. GOM7 can be extracted from the culture supernatant of this bacterium with the organic solvent ethyl acetate. Annotation of the Pseudomonas sp. GOM7 genome revealed the presence of several biosynthetic gene clusters predicted to code for possible antimicrobial compounds. Our results further highlight the potential of bacteria from the Gulf of Mexico as a source of novel antimicrobials.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Staphylococcus aureus , Staphylococcus aureus/genetics , Pseudomonas/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Phylogeny , Anti-Bacterial Agents/pharmacology , Pseudomonas aeruginosa/genetics , Bacteria , Genomics , Microbial Sensitivity Tests
16.
J Chem Inf Model ; 63(11): 3544-3556, 2023 06 12.
Article in English | MEDLINE | ID: mdl-37226335

ABSTRACT

Bak is a pro-apoptotic protein and a member of the Bcl-2 family that plays a key role in apoptosis, a programmed cell death mechanism of multicellular organisms. Its activation under death stimuli triggers the permeabilization of the mitochondrial outer membrane that represents a point of no return in the apoptotic pathway. This process is deregulated in many tumors where Bak is inactivated, whereas in other cases like in neurodegeneration, it exhibits an excessive response leading to disorders such as the Alzheimer disease. Members of the Bcl-2 family share a common 3D structure, exhibiting an extremely similar orthosteric binding site, a place where both pro and antiapoptotic proteins bind. This similarity raises a selectivity issue that hampers the identification of new drugs, capable of altering Bak activation in a selective manner. An alternative activation site triggered by antibodies has been recently identified, opening the opportunity to undertake new drug discovery studies. Despite this recent identification, an exhaustive study to identify cryptic pockets as prospective allosteric sites has not been yet performed. Thus, the present study aims to characterize novel hotspots in the Bak structure. For this purpose, we have carried out extensive molecular dynamics simulations using three different Bak systems including Bak in its apo form, Bak in complex with its endogen activator Bim and an intermediate form, set up by removing Bim from the previous complex. The results reported in the present work shed some light on future docking studies on Bak through the identification of new prospective allosteric sites, not previously described in this protein.


Subject(s)
Molecular Dynamics Simulation , bcl-2 Homologous Antagonist-Killer Protein , Bcl-2-Like Protein 11/metabolism , Allosteric Site , Prospective Studies , bcl-2 Homologous Antagonist-Killer Protein/chemistry , bcl-2 Homologous Antagonist-Killer Protein/metabolism , Apoptosis Regulatory Proteins/chemistry , Apoptosis Regulatory Proteins/metabolism , Apoptosis
17.
Oecologia ; 202(2): 239-250, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37253787

ABSTRACT

The general assumption that the survival patterns of tropical and southern temperate birds are similar lacks empirical data from higher latitudes. Regional comparisons of New World species are rare, and this assumption has been based on data from African studies. Here, we estimate the survival rates of 88 tropical and southern temperate bird populations (69 species) from eight localities in South America to evaluate the hypothesis that the survival of these populations is homogeneous at the regional scale. We estimated survival based on the Cormack-Jolly-Seber model and compared values from different environments. The survival estimates ranged from 0.30 to 0.80 (0.56 ± 0.12). Apparent survival did not differ significantly between low-latitude tropical environments (03°S) and the other sites from high-latitudes (between 22° and 34°S). Despite a predicted positive trend, body size was not significantly related to survival among passerines. On the other hand, phylogenetic relationships explained more than a third of the variation in bird survival. Based on the largest available database on South American bird species, our findings support the hypothesis that bird survival is homogeneous, at the regional scale, along the southern hemisphere. In particular, we reinforce the hypothesis that climatic variation has a limited influence on bird survival in the southern hemisphere.


Subject(s)
Tropical Climate , Phylogeny , South America , Body Size
18.
Acta Neurochir (Wien) ; 165(7): 1781-1790, 2023 07.
Article in English | MEDLINE | ID: mdl-37014451

ABSTRACT

BACKGROUND: Classically, the torcular Herophili is described as the symmetric junction between the superior sagittal sinus (SSS), transverse sinuses (TSs), and straight sinus (SS). However, finding this pattern in practice is not standard. Anatomical variations are common, and different drainage patterns should be expected. Existing literature proposes highly detailed descriptions and classifications of this region. Still, a simplified and practical categorization is not available. METHODS: We present an anatomical finding of the torcular Herophili discovered on a cadaveric dissection. Then, we conducted a retrospective study examining the 100 most recent cranial magnetic resonance venographies (MRVs) from the Mayo Clinic, labeling them with a new proposed dural sinus classification system. Images were initially classified by two authors and further validated by a board-certified neurosurgeon and a board-certified neuroradiologist from our institution. To measure consistency in image identification, two additional international neurosurgeons were asked to classify a subset of the same MRV images, and their answers were compared. RESULTS: Of the MRV cohort, 33 patients were male and 67 were female. Their ages ranged from 18 to 86 years, with a mean of 47.35 years and a median of 49 years. Upon examination, 53 patients presented as confluent (53%), 9 as SSS divergent (9%), 25 as SS divergent (25%), 11 as circular (11%), and 2 as trifurcated (2%). The inter-rater reliability ranked very good; agreement between the two neurosurgeons was 83% (κ = 0.830, p < 0.0005). CONCLUSION: The confluence of the venous sinuses is a highly variable anatomical area that is rarely evaluated with neuroimaging before surgery. The classic textbook configuration is not the rule. Using a simplified classification system may increase awareness and hopefully patient safety by preparing the physician for anatomical variations that they will encounter in a surgical or clinical scenario.


Subject(s)
Cranial Sinuses , Transverse Sinuses , Humans , Male , Female , Adolescent , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Retrospective Studies , Reproducibility of Results , Cranial Sinuses/diagnostic imaging , Transverse Sinuses/diagnostic imaging , Transverse Sinuses/anatomy & histology , Superior Sagittal Sinus/diagnostic imaging
19.
Foods ; 12(8)2023 Apr 07.
Article in English | MEDLINE | ID: mdl-37107361

ABSTRACT

The quality of wine grapes and wine depends on their content of phenolic compounds. Under commercial conditions, the phenolic maturity of grapes is mostly achieved by applying abscisic acid analogues. Some Ca forms represent a cost-effective alternative for these compounds. In this study, 'Shiraz' vines (veraison of 90%) were sprayed with CaCO3-rich residues from the cement industry (4.26 g of Ca per L). Fruit from treated and untreated vines was harvested 45 days after CaCO3 spraying and evaluated for quality. The fruit was vinified, and the obtained wines were bottled and stored in darkness for 15 months at 20 °C. Wines were evaluated for quality after storage. The evaluation of grape and wine quality included the content of phenolic compounds and antioxidant capacity. The treatment with CaCO3 did not affect the ripening rate of grapes. However, the treatment improved the fruit yield as well as the color development, the content of phenolic compounds, and antioxidant capacity of grapes and wine. The treatment favored especially the accumulation of malvidin-3-O-glucoside, pelargonidin-3-O-glucoside, caftaric acid, caffeic acid, trans-cinnamic acid, quercetin, catechin, epicatechin, resveratrol, and the procyanidins B1 and B2. Wine made with treated fruit was of higher quality than that of control fruit.

20.
Pharmaceuticals (Basel) ; 16(4)2023 Apr 13.
Article in English | MEDLINE | ID: mdl-37111342

ABSTRACT

Over 750 million cases of COVID-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), have been reported since the onset of the global outbreak. The need for effective treatments has spurred intensive research for therapeutic agents based on pharmaceutical repositioning or natural products. In light of prior studies asserting the bioactivity of natural compounds of the autochthonous Peruvian flora, the present study focuses on the identification SARS-CoV-2 Mpro main protease dimer inhibitors. To this end, a target-based virtual screening was performed over a representative set of Peruvian flora-derived natural compounds. The best poses obtained from the ensemble molecular docking process were selected. These structures were subjected to extensive molecular dynamics steps for the computation of binding free energies along the trajectory and evaluation of the stability of the complexes. The compounds exhibiting the best free energy behaviors were selected for in vitro testing, confirming the inhibitory activity of Hyperoside against Mpro, with a Ki value lower than 20 µM, presumably through allosteric modulation.

SELECTION OF CITATIONS
SEARCH DETAIL
...