Chronic Hepatitis B Finite Treatment: Similar and Different Concerns With New Drug Classes.

Chronic hepatitis B, a major cause of liver disease and cancer, affects >250 million people worldwide. Currently there is no cure, only suppressive therapies. Efforts to develop finite curative hepatitis B virus (HBV) therapies are underway, consisting of combinations of multiple novel agents with or without nucleos(t)ide reverse-transcriptase inhibitors. The HBV Forum convened a webinar in July 2021, along with subsequent working group discussions to address how and when to stop finite therapy for demonstration of sustained off-treatment efficacy and safety responses. Participants included leading experts in academia, clinical practice, pharmaceutical companies, patient representatives, and regulatory agencies. This Viewpoints article outlines areas of consensus within our multistakeholder group for stopping finite therapies in chronic hepatitis B investigational studies, including trial design, patient selection, outcomes, biomarkers, predefined stopping criteria, predefined retreatment criteria, duration of investigational therapies, and follow-up after stopping therapy. Future research of unmet needs are discussed.

Percepción y satisfacción de estudiantes de Enfermería con la educación virtual en época de COVID-19

Objetivo: Analizar la percepción y la satisfacción con la educación en modalidad virtual de los estudiantes de la carrera de Licenciatura en Enfermería de una institución de educación superior de carácter público de la Ciudad Autónoma de Buenos Aires, Argentina, durante el segundo semestre de 2021. Metodología: Estudio analítico, transversal y cuantitativo. La muestra estuvo compuesta por 121 estudiantes, seleccionados mediante muestreo no probabilístico, quienes respondieron un instrumento conformado por 24 preguntas . Resultados: Los encuestados fueron mayormente de sexo femenino (84.30 %), con media de edad de 29.2 años (DE: 8), de tercer año (55.37 %) y con hijos (44.63 %). Respecto a la percepción sobre la modalidad virtual se halló que las clases fueron consideradas como motivantes para el aprendizaje (66.94 %), los alumnos pudieron mantener la atención entre un 75-99 % del tiempo durante la clase (38.84 %), una baja cantidad pudo realizar todas las consultas al docente (16.52 %) y la mayoría sintió nerviosismo ante la evaluación remota al mismo nivel que su contraparte presencial (52.89 %). La satisfacción global con la modalidad fue puntuada con una media de 6.9 sobre 10 y el 75.20 % los encuestados desea continuar con clases virtuales . Conclusiones: La satisfacción fue caracterizada como media. Las variables que se relacionaron con una mayor satisfacción con la educación remota son la tenencia de hijos, la mayor edad, la creencia de que se hubiese aprendido más con clases presenciales, el tiempo que perciben que pueden mantener la atención en clases virtuales, la baja sensación de nerviosismo ante la evaluación virtual y la ausencia de dificultades para la conexión a las clases sincrónicas.

Objetivo: Analisar a percepção e a satisfação com a educação na modalidade virtual dos alunos da Licenciatura em Enfermagem de uma instituição pública de ensino superior da Cidade Autônoma de Buenos Aires, Argentina durante o segundo semestre de 2021. Metodologia: Estudo analítico, transversal e quantitativo. A amostra foi composta por 121 alunos, selecionados por amostragem não probabilística, que responderam a um instrumento composto por 24 questões. Resultados: Os participantes eram maioritariamente do sexo feminino (84,30 %), com idade média de 29,2 anos (DP: 8), cursando o terceiro ano (55,37 %) e com filhos (44,63 %). Quanto à percepção sobre a modalidade virtual, constatou-se que as aulas foram consideradas em sua maioria com motivadoras para a aprendizagem (66,94 %), os alunos conseguiram manter a atenção entre 75- 99 % do tempo durante a aula (38,84 %), um baixo número conseguiu fazer todas as consultas ao professor (16,52 %) e a maioria se sentiu nervosa com a avaliação à distância no mesmo nível da presencial (52,89 %). A satisfação global com a modalidade foi pontuada com média de 6,9 sobre 10 e 75,20 % dos entrevistados desejam continuar com as aulas virtuais. Conclusões: A satisfação caracterizou-se como média. As variáveis que se relacionaram com a maior satisfação com o ensino a distância são ter filhos, a idade, a crença de que aprenderiam mais com as aulas presenciais, o tempo que percebem que conseguem manter a atenção nas aulas virtuais, a baixa sensação de nervosismo perante a avaliação virtual e a ausência de dificuldades para a conexão nas aulas síncronas.

Objective: To analyze the perception and satisfaction with education in virtual modality of Nursing Bachelor's degree students from a public higher education institution in the Autonomous City of Buenos Aires, Argentina during the second semester of 2021. Methods: Analytical, cross-sectional, and quantitative study. The sample consisted of 121 students, selected by non-probabilistic sampling, who answered an instrument made up of 24 questions. Results: The respondents were mostly female (84.30 %), with a mean age of 29.2 years (SD: 8), in their third year (55.37 %) and with children (44.63 %). Regarding the perception of the virtual modality, it was found that the classes were mostly considered as a motivating factor for learning (66.94 %), students were able to maintain their attention between 75-99 % of the time during the class (38.84 %), a low number were able to make all consultations with the teacher (16.52 %) and most of them felt nervousness before the remote evaluation at the same level as their face-to-face counterpart (52.89 %). Overall satisfaction with the modality was rated with an average of 6.9 out of 10 and 75.20 % of respondents would like to continue with virtual classes. Conclusions: Satisfaction was characterized as average. The variables that were associated with greater satisfaction with distance education are having children, older age, the belief that they would have learned more with face-to-face classes, the time they perceive they can maintain their attention in virtual classes, the low feeling of nervousness before the virtual evaluation, and the absence of difficulties in connecting to synchronous classes.

Efficacy of antiviral therapy and host-virus interactions visualised using serial liver sampling with fine-needle aspirates.

Background & Aims: Novel therapies for chronic hepatitis B (CHB), such as RNA interference, target all viral RNAs for degradation, whereas nucleoside analogues are thought to block reverse transcription with minimal impact on viral transcripts. However, limitations in technology and sampling frequency have been obstacles to measuring actual changes in HBV transcription in the liver of patients starting therapy. Methods: We used elective liver sampling with fine-needle aspirates (FNAs) to investigate the impact of treatment on viral replication in patients with CHB. Liver FNAs were collected from patients with CHB at baseline and 12 and 24 weeks after starting tenofovir alafenamide treatment. Liver FNAs were subjected to single-cell RNA sequencing and analysed using the Viral-Track method. Results: HBV was the only viral genome detected and was enriched within hepatocytes. The 5' sequencing technology identified protein-specific HBV transcripts and showed that tenofovir alafenamide therapy specifically reduced pre-genomic RNA transcripts with little impact on HBsAg or HBx transcripts. Infected hepatocytes displayed unique gene signatures associated with an immunological response to viral infection. Conclusions: Longitudinal liver sampling, combined with single-cell RNA sequencing, captured the dynamic impact of antiviral therapy on the replication status of HBV and revealed host-pathogen interactions at the transcriptional level in infected hepatocytes. This sequencing-based approach is applicable to early-stage clinical studies, enabling mechanistic studies of immunopathology and the effect of novel therapeutic interventions. Impact and Implications: Infection-dependent transcriptional changes and the impact of antiviral therapy on viral replication can be measured in longitudinal human liver biopsies using single-cell RNA sequencing data.

Structural Insights into Pseudomonas aeruginosa Exotoxin A-Elongation Factor 2 Interactions: A Molecular Dynamics Study.

Exotoxin A (ETA) is an extracellular secreted toxin and a single-chain polypeptide with A and B fragments that is produced by Pseudomonas aeruginosa. It catalyzes the ADP-ribosylation of a post-translationally modified histidine (diphthamide) on eukaryotic elongation factor 2 (eEF2), which results in the inactivation of the latter and the inhibition of protein biosynthesis. Studies show that the imidazole ring of diphthamide plays an important role in the ADP-ribosylation catalyzed by the toxin. In this work, we employ different in silico molecular dynamics (MD) simulation approaches to understand the role of diphthamide versus unmodified histidine in eEF2 on the interaction with ETA. Crystal structures of the eEF2-ETA complexes with three different ligands NAD+, ADP-ribose, and ßTAD were selected and compared in the diphthamide and histidine containing systems. The study shows that NAD+ bound to ETA remains very stable in comparison with other ligands, enabling the transfer of ADP-ribose to the N3 atom of the diphthamide imidazole ring in eEF2 during ribosylation. We also show that unmodified histidine in eEF2 has a negative impact on ETA binding and is not a suitable target for the attachment of ADP-ribose. Analyzing of radius of gyration and COM distances for NAD+, ßTAD, and ADP-ribose complexes revealed that unmodified His affects the structure and destabilizes the complex with all different ligands throughout the MD simulations.

Transcriptomic analyses reveal increased expression of dioxygenases, monooxygenases, and other metabolizing enzymes involved in anthracene degradation in the marine alga Ulva lactuca.

To analyze the mechanisms involved in anthracene (ANT) degradation in the marine alga Ulva lactuca, total RNA was obtained from the alga cultivated without ANT and with 5 µM of ANT for 24 h, and transcriptomic analyses were performed. A de novo transcriptome was assembled, transcripts differentially expressed were selected, and those overexpressed were identified. Overexpressed transcripts potentially involved in ANT degradation were: one aromatic ring dioxygenase, three 2-oxoglutarate Fe (II) dioxygenases (2-OGDOs), and three dienelactone hydrolases that may account for anthraquinone, phthalic anhydride, salicylic acid, and phthalic acid production (pathway 1). In addition, two flavin adenine dinucleotide (FAD)-dependent monooxygenases, four cytP450 monooxygenases, two epoxide hydrolase, one hydroxyphenylpyruvic acid dioxygenase (HPPDO), and two homogentisic acid dioxygenases (HGDOs) were identified that may also participate in ANT degradation (pathway 2). Moreover, an alkane monooxygenase (alkB), two alcohol dehydrogenases, and three aldehyde dehydrogenases were identified, which may participate in linear hydrocarbon degradation (pathway 3). Furthermore, the level of transcripts encoding some of mentioned enzymes were quantified by qRT-PCR are in the alga cultivated with 5 µM of ANT for 0-48 h, and those more increased were 2-OGDO, HGDO, and alkB monooxygenase. Thus, at least three pathways for ANT and linear hydrocarbons degradation may be existed in U. lactuca. In addition, ANT metabolites were analyzed by gas chromatography and mass spectrometry (GC-MS), allowing the identification of anthraquinone, phthalic anhydride, salicylic acid, and phthalic acid, thus validating the pathway 1.

Using newly optimized genetic tools to probe Strongyloides sensory behaviors.

The oft-neglected human-parasitic threadworm, Strongyloides stercoralis, infects roughly eight percent of the global population, placing disproportionate medical and economic burden upon marginalized communities. While current chemotherapies treat strongyloidiasis, disease recrudescence and the looming threat of anthelminthic resistance necessitate novel strategies for nematode control. Throughout its life cycle, S. stercoralis relies upon sensory cues to aid in environmental navigation and coordinate developmental progression. Odorants, tastants, gases, and temperature have been shown to shape parasite behaviors that drive host seeking and infectivity; however, many of these sensory behaviors remain poorly understood, and their underlying molecular and neural mechanisms are largely uncharacterized. Disruption of sensory circuits essential to parasitism presents a promising strategy for future interventions. In this review, we describe our current understanding of sensory behaviors - namely olfactory, gustatory, gas sensing, and thermosensory behaviors - in Strongyloides spp. We also highlight the ever-growing cache of genetic tools optimized for use in Strongyloides that have facilitated these findings, including transgenesis, CRISPR/Cas9-mediated mutagenesis, RNAi, chemogenetic neuronal silencing, and the use of fluorescent biosensors to measure neuronal activity. Bolstered by these tools, we are poised to enter an era of rapid discovery in Strongyloides sensory neurobiology, which has the potential to shape pioneering advances in the prevention and treatment of strongyloidiasis.

A Recurrent FAM83H Mutation in an Extended Colombian Family and Variable Craniofacial Phenotypes.

Amelogenesis imperfecta (AI) is a collection of rare genetic disorders affecting the quantity and/or quality of the tooth enamel. AI can be classified into three major types according to the clinical phenotype: hypoplastic, hypocalcified, and hypomatured. Among them, the hypocalcified type shows the weakest physical properties, leaving rough and discolored enamel surfaces after tooth eruption. To date, mutations in the FAM83H gene are responsible for the autosomal-dominant hypocalcified AI. In this study, we recruited a four-generation Colombian family with hypocalcified AI and identified a recurrent nonsense mutation in the FAM83H gene (NM_198488.5:c.1289C>A, p.(Ser430 *)) by candidate gene sequencing. Cephalometric analyses revealed the anterior open bite that occurred in the proband is not correlated with the AI in this family.

Immunological biomarker discovery in cure regimens for chronic hepatitis B virus infection.

There have been unprecedented advances in the identification of new treatment targets for chronic hepatitis B that are being developed with the goal of achieving functional cure in patients who would otherwise require lifelong nucleoside analogue treatment. Many of the new investigational therapies either directly target the immune system or are anticipated to impact immunity indirectly through modulation of the viral lifecycle and antigen production. While new viral biomarkers (HBV RNA, HBcAg, small, middle, large HBs isoforms) are proceeding through validation steps in clinical studies, immunological biomarkers are non-existent outside of clinical assays for antibodies to HBs, HBc and HBe. To develop clinically applicable immunological biomarkers to measure mechanisms of action, inform logical combination strategies, and guide clinical management for use and discontinuation of immune-targeting drugs, immune assays must be incorporated into phase I/II clinical trials. This paper will discuss the importance of sample collection, the assays available for immunological analyses, their advantages/disadvantages and suggestions for their implementation in clinical trials. Careful consideration must be given to ensure appropriate immunological studies are included as a primary component of the trial with deeper immunological analysis provided by ancillary studies. Standardising immunological assays and data obtained from clinical trials will identify biomarkers that can be deployed in the clinic, independently of specialised immunology laboratories.

Structural insights in galectin-1-glycan recognition: Relevance of the glycosidic linkage and the N-acetylation pattern of sugar moieties.

Galectins, soluble lectins widely expressed intra- and extracellularly in different cell types, play major roles in deciphering the cellular glycocode. Galectin-1 (Gal-1), a prototype member of this family, presents a carbohydrate recognition domain (CRD) with specific affinity for ß-galactosides such as N-acetyllactosamine (ß-d-Galp-(1 â†’ 4)-d-GlcpNAc), and mediate numerous physiological and pathological processes. In this work, Gal-1 binding affinity for ß-(1 â†’ 6) galactosides, including ß-d-Galp-(1 â†’ 6)-ß-d-GlcpNAc-(1 â†’ 4)-d-GlcpNAc was evaluated, and their performance was compared to that of ß-(1 â†’ 4) and ß-(1 â†’ 3) galactosides. To this end, the trisaccharide ß-d-Galp-(1 â†’ 6)-ß-d-GlcpNAc-(1 â†’ 4)-d-GlcpNAc was enzymatically synthesized, purified and structurally characterized. To evaluate the affinity of Gal-1 for the galactosides, competitive solid phase assays (SPA) and isothermal titration calorimetry (ITC) studies were carried out. The experimental dissociation constants and binding energies obtained were compared to those calculated by molecular docking. These analyses evidenced the critical role of the glycosidic linkage between the terminal galactopyranoside residue and the adjacent monosaccharide, as galactosides bearing ß-(1 â†’ 6) glycosidic linkages showed dissociation constants six- and seven-fold higher than those involving ß-(1 â†’ 4) and ß-(1 â†’ 3) linkages, respectively. Moreover, docking experiments revealed the presence of hydrogen bond interactions between the N-acetyl group of the glucosaminopyranose moiety of the evaluated galactosides and specific amino acid residues of Gal-1, relevant for galectin-glycan affinity. Noticeably, the binding free energies (ΔGbindcalc) derived from the molecular docking were in good agreement with experimental values determined by ITC measurements (ΔGbindexp), evidencing a good correlation between theoretical and experimental approaches, which validates the in silico simulations and constitutes an important tool for the rational design of future optimized ligands.

Herboxidiene Features That Mediate Conformation-Dependent SF3B1 Interactions to Inhibit Splicing.

Small molecules that target the spliceosome SF3B complex are potent inhibitors of cancer cell growth. The compounds affect an early stage of spliceosome assembly when U2 snRNP first engages the branch point sequence of an intron. Employing an inactive herboxidiene analog (iHB) as a competitor, we investigated factors that influence inhibitor interactions with SF3B to interfere with pre-mRNA splicing in vitro. Order-of-addition experiments show that inhibitor interactions are long lasting and affected by both temperature and the presence of ATP. Our data are also consistent with the model that not all SF3B conformations observed in structural studies are conducive to productive inhibitor interactions. Notably, SF3B inhibitors do not impact an ATP-dependent rearrangement in U2 snRNP that exposes the branch binding sequence for base pairing. We also report extended structure-activity relationship analysis of the splicing inhibitor herboxidiene. We identified features of the tetrahydropyran ring that mediate its interactions with SF3B and its ability to interfere with splicing. In the context of recent structures of SF3B bound to inhibitor, our results lead us to extend the model for early spliceosome assembly and inhibitor mechanism. We postulate that interactions between a carboxylic acid substituent of herboxidiene and positively charged SF3B1 side chains in the inhibitor binding channel are needed to maintain inhibitor occupancy while counteracting the SF3B transition to a closed state that is required for stable U2 snRNP interactions with the intron.

Engineering of Ancestors as a Tool to Elucidate Structure, Mechanism, and Specificity of Extant Terpene Cyclase.

Structural information is crucial for understanding catalytic mechanisms and to guide enzyme engineering efforts of biocatalysts, such as terpene cyclases. However, low sequence similarity can impede homology modeling, and inherent protein instability presents challenges for structural studies. We hypothesized that X-ray crystallography of engineered thermostable ancestral enzymes can enable access to reliable homology models of extant biocatalysts. We have applied this concept in concert with molecular modeling and enzymatic assays to understand the structure activity relationship of spiroviolene synthase, a class I terpene cyclase, aiming to engineer its specificity. Engineering a surface patch in the reconstructed ancestor afforded a template structure for generation of a high-confidence homology model of the extant enzyme. On the basis of structural considerations, we designed and crystallized ancestral variants with single residue exchanges that exhibited tailored substrate specificity and preserved thermostability. We show how the two single amino acid alterations identified in the ancestral scaffold can be transferred to the extant enzyme, conferring a specificity switch that impacts the extant enzyme's specificity for formation of the diterpene spiroviolene over formation of sesquiterpenes hedycaryol and farnesol by up to 25-fold. This study emphasizes the value of ancestral sequence reconstruction combined with enzyme engineering as a versatile tool in chemical biology.

Design and synthesis of herboxidiene derivatives that potently inhibit in vitro splicing.

Herboxidiene is a potent antitumor agent that targets the SF3B subunit of the spliceosome. Herboxidiene possesses a complex structural architecture with nine stereocenters and design of potent less complex structures would be of interest as a drug lead as well as a tool for studying SF3B1 function in splicing. We investigated a number of C-6 modified herboxidiene derivatives in an effort to eliminate this stereocenter and, also to understand the importance of this functionality. The syntheses of structural variants involved a Suzuki-Miyaura cross-coupling reaction as the key step. The functionalized tetrahydrofuran core has been constructed from commercially available optically active tri-O-acetyl-d-glucal. We investigated the effect of these derivatives on splicing chemistry. The C-6 alkene derivative showed very potent splicing inhibitory activity similar to herboxidiene. Furthermore, the C-6 gem-dimethyl derivative also exhibited very potent in vitro splicing inhibitory activity comparable to herboxidiene.

Un vistazo al liderazgo de las mujeres mexicanas en la medicina / A look at the leadership of Mexican women in medicine

A lo largo de la historia las mujeres han luchado por ser incluidas y reconocidas en el desarrollo de la ciencia médica. En la actualidad, las mujeres tienen mayor participación no solo en el estudio y ejercicio de la medicina sino en el liderazgo de diversas áreas médicas. Este artículo ofrece un panorama histórico de las primeras mujeres que formaron parte de la Academia Nacional de Medicina de México, así como una recopilación de la participación de las mujeres en puestos directivos; desde Jefaturas de Departamentos Académicos en la Universidad Nacional Autónoma de México hasta el sector salud

Throughout history women have been fighting to be included and recognized in the development of medical science. Actually, women have more participation not only in the study and practice of medicine, but in the leadership of various medical areas. This article provides a historical review of the first women it formed part of the National Academy of Medicine of Mexico as well as a compilation of the participation of women in management positions, from Headquarters of academic departments at the National Autonomous University of Mexico including health sector

Experience of the biggest School of Medicine in Mexico during the COVID-19 pandemic.

This article was migrated. The article was marked as recommended. The coronavirus 19 disease (COVID-19) pandemic affected virtually all activities worldwide. One of them was education, especially Health Sciences. In the world, many medical schools ceased their face-to-face activities and implemented institutional reorganization actions. According to their characteristics and possibilities, institutions adopted different strategies and tools to continue providing their services online during this health crisis. These situations implied enormous challenges, especially for specific regions, such as Latin America. This article exposes a quick overview of the pandemic experience at the biggest Mexican School of Medicine (UNAM School of Medicine): forecasting, reorganization, actions, challenges, and learnings. Among the most challenging situations experienced were: effective communication strategies; resistance to migrating from face-to-face activities to remote activities; technological development; students and teachers training to implement work and study in virtual spaces; students digital gap; internet and computers access; construction and application of online evaluations; online evaluation of practical skills, and the impossibility of maintaining students in clinical clerkships given the pandemic risks. UNAM School of Medicine reorganized to provide integral care to its community, but it also participated in tasks for Mexico's health and other countries' health benefits. We had a great amount of work, reorganization efforts, and creativity resulting in efficient innovations and new projects. This health crisis showed the best in our community. Actions will remain along the pandemic period and a progressive reincorporation to in-place activities at the end of the health crisis. Some strategies, such as remote activities within teaching, learning, work, evaluation, and research, will be maintained. When this situation ends, we will hopefully have learned and applied those new experiences to improve our School of Medicine, transitioning into a more robust, more united, and enriched community after the crisis caused by this pandemic.

Liver safety assessment in clinical trials of new agents for chronic hepatitis B.

Investigational agents that reduce or eliminate covalently closed circular DNA (cccDNA) or enhance host immunity against hepatitis B virus (HBV)-infected hepatocytes are intended to induce a durable off-treatment clearance of hepatitis B surface antigen (HBsAg) (referred to as functional cure). The aim of this paper was to highlight challenges in interpreting liver safety data in clinical trials of these agents when given alone or in combination regimens. The incidence, grading and management of spontaneous serum ALT flares in untreated chronic HBV patients are reviewed along with a summary of serum ALT flares observed during the registration trials for peginterferon and nucleos(t)ide reverse transcriptase inhibitors. Recommendations regarding the detection, management and interpretation of liver safety biomarker data in future clinical trials as well as suggested inclusion and exclusion criteria for phase 1/2 vs phase 3 studies are provided. Criteria to help classify liver safety signals as being due to the intended therapeutic response, emergence of drug-resistant HBV virions, or idiosyncratic drug-induced liver injury are provided along with a review of the role of an expert hepatic adjudication panel in assessing a compound's hepatotoxicity profile. Finally, an algorithmic approach to the differential diagnosis and recommended medical evaluation and management of individual clinical trial patients that develop a liver safety signal is provided along with the rationale to collect and test research blood samples for future mechanistic studies.

Enzymatic synthesis of non-natural trisaccharides and galactosides; Insights of their interaction with galectins as a function of their structure.

Galectins are a family of carbohydrate-recognizing proteins that by interacting with specific glycoepitopes can mediate important biological processes, including immune cell homeostasis and activation of tolerogenic circuits. Among the different members of this family, Galectin 1 and 3 have shown pro-tumorigenic effects, being overexpressed in numerous neoplasic diseases, proving to be relevant in tumor immune escape, tumor progression and resistance to drug-induced apoptosis. Thus, generation of specific glycosides that could inhibit their pro-tumorigenic ability by blocking their carbohydrate recognition domain is one of the current major challenges in the field. Considering that galectin-ligand binding strength is closely related to the ligand structure, analysis of this relationship provides valuable information for rational design of high-affinity ligands that could work as effective galectin inhibitors. Taking profit of the ability of glycosidases to catalyze transglycosylation reactions we achieved the enzymatic synthesis of ß-d-Galp-(1 → 6)-ß-d-Galp-(1 → 4)-d-Glcp(2), a mixture of ß-d-Galp-(1 → 6)-ß-d-Glcp-(1 → 4)-d-Glcp(5) and ß-d-Galp-(1 → 3)-ß-d-Glcp-(1 → 4)-d-Glcp(6), and finally benzyl ß-d-galactopyranoside (9), with reaction yields between 16 and 27%. All the galactosides were purified, and characterized using 1H and 13C nuclear magnetic resonance spectroscopy. Docking results performed between the synthesized compounds and human Galectin 1 (hGal-1) and human Galectin 3 (hGal-3) showed that the replacement of a glucose moiety linked to the terminal galactose with a galactose moiety, decreases the affinity for these galectins. Moreover, regarding the interglycosidic bond the most favorable ß-Gal linkage seems to be ß(1 → 4) followed by ß(1 → 3) and ß(1 → 6) for hGal-1, and ß(1 → 4) followed by ß(1 → 6) and ß(1 → 3) for hGal-3. These results were in accordance with the IC50 values obtained with in vitro solid phase inhibition assays. Therefore, docking results obtained in this work proved to be a very good approximation for predicting binding affinity of novel galactosides.

Exploring Polypharmacology in Drug Design.

Nowadays it is widely accepted that one compound can be able to hit several targets at once. This "magic shotgun" approach for drug development properly describes the mechanism of biomolecular recognition. The need to take into account the polypharmacology in structure-based drug design has led to the development of several computational tools. Here we present a computational protocol to identify promising compounds against several biological targets, a protocol known as inverse docking.

Unilateral Labial Edema in a Female Adolescent: A Gynecologic Presentation of Rhabdomyolysis.

BACKGROUND: Rhabdomyolysis can be the result of vigorous physical activity. Typical signs and symptoms at presentation are muscle pain, weakness, or dark colored urine. There is no scientific literature associating rhabdomyolysis with gynecologic signs and symptoms. CASE: We present a case of a 16-year-old girl who presented to our pediatric emergency department with complaints of progressive left vulvar swelling. The patient underwent magnetic resonance imaging, which showed polymyositis in the rectus abdominus, external and internal obliques, and bilateral vastus lateralis muscles. Laboratory evaluation showed elevated liver transaminases, creatine kinase, and myoglobin serum levels. SUMMARY AND CONCLUSION: Exertional rhabdomyolysis is associated with muscular damage after vigorous exercise. This case is an example of a patient with rhabdomyolysis presenting with an unusual external gynecological manifestation, as unilateral labial edema.

QM/MM Studies of Dph5 - A Promiscuous Methyltransferase in the Eukaryotic Biosynthetic Pathway of Diphthamide.

Eukaryotic diphthine synthase, Dph5, is a promiscuous methyltransferase that catalyzes an extraordinary N, O-tetramethylation of 2-(3-carboxy-3-aminopropyl)-l-histidine (ACP) to yield diphthine methyl ester (DTM). These are intermediates in the biosynthesis of the post-translationally modified histidine residue diphthamide (DTA), a unique and essential residue part of the eukaryotic elongation factor 2 (eEF2). Herein, the promiscuity of Saccharomyces cerevisiae Dph5 has been studied with in silico approaches, including homology modeling to provide the structure of Dph5, protein-protein docking and molecular dynamics to construct the Dph5-eEF2 complex, and quantum mechanics/molecular mechanics (QM/MM) calculations to outline a plausible mechanism. The calculations show that the methylation of ACP follows a typical SN2 mechanism, initiating with a complete methylation (trimethylation) at the N-position, followed by the single O-methylation. For each of the three N-methylation reactions, our calculations support a stepwise mechanism, which first involve proton transfer through a bridging water to a conserved aspartate residue D165, followed by a methyl transfer. Once fully methylated, the trimethyl amino group forms a weak electrostatic interaction with D165, which allows the carboxylate group of diphthine to attain the right orientation for the final methylation step to be accomplished.

Different routes into the glass state for soft thermo-sensitive colloids.

We report an experimental and theoretical investigation of glass formation in soft thermo-sensitive colloids following two different routes: a gradual increase of the particle number density at constant temperature and an increase of the radius in a fixed volume at constant particle number density. Confocal microscopy experiments and the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory consistently show that the two routes lead to a dynamically comparable state at sufficiently long aging times. However, experiments reveal the presence of moderate but persistent structural differences. Successive cycles of radius decrease and increase lead instead to a reproducible glass state, indicating a suitable route to obtain rejuvenation without using shear fields.