The synthesis of solid supports carrying base labile linkers to generate 3'-phosphate oligonucleotides.

Oligonucleotides carrying 3'-terminal phosphates and conjugates are important tools in molecular biology and diagnostic purposes. We described the preparation of solid supports carrying the base labile linker 4-((2-hydroxyethyl)sulfonyl)benzamide for the solid-phase synthesis of 3'-phosphorylated oligonucleotides. These supports are fully compatible with the phosphoramidite chemistry yielding the desired 3'-phosphate oligonucleotides in excellent yields. The use of mild deprotection conditions allows the generation of partially protected DNA fragments.

Modeling Dynamics of Human Gut Microbiota Derived from Gluten Metabolism: Obtention, Maintenance and Characterization of Complex Microbial Communities.

Western diets are rich in gluten-containing products, which are frequently poorly digested. The human large intestine harbors microorganisms able to metabolize undigested gluten fragments that have escaped digestion by human enzymatic activities. The aim of this work was obtaining and culturing complex human gut microbial communities derived from gluten metabolism to model the dynamics of healthy human large intestine microbiota associated with different gluten forms. For this purpose, stool samples from six healthy volunteers were inoculated in media containing predigested gluten or predigested gluten plus non-digested gluten. Passages were carried out every 24 h for 15 days in the same medium and community composition along time was studied via V3-V4 16S rDNA sequencing. Diverse microbial communities were successfully obtained. Moreover, communities were shown to be maintained in culture with stable composition for 14 days. Under non-digested gluten presence, communities were enriched in members of Bacillota, such as Lachnospiraceae, Clostridiaceae, Streptococcaceae, Peptoniphilaceae, Selenomonadaceae or Erysipelotrichaceae, and members of Actinomycetota, such as Bifidobacteriaceae and Eggerthellaceae. Contrarily, communities exposed to digested gluten were enriched in Pseudomonadota. Hence, this study shows a method for culture and stable maintenance of gut communities derived from gluten metabolism. This method enables the analysis of microbial metabolism of gluten in the gut from a community perspective.

Synthesis of 2'-O-Methyl/2'-O-MOE-L-Nucleoside Derivatives and Their Applications: Preparation of G-Quadruplexes, Their Characterization, and Stability Studies.

Nucleosides and their analogues constitute an important family of molecules with potential antiviral and antiproliferative activity. The enantiomers of natural nucleosides, l-nucleoside derivatives, which have comparable biological activity but more favorable toxicological properties and greater metabolic stability than d-nucleosides, have emerged as a new class of therapeutic agents. Furthermore, l-nucleosides can be used as a building block to prepare l-oligonucleotides, which have identical physical properties in terms of solubility, hybridization kinetics, and duplex thermal stability as d-oligonucleotides but completely orthogonal in nature. Consequently, they are resistant to nuclease degradation, nontoxic, and immunologically passive, which are desirable properties for biomedical applications. Herein, we describe the synthesis of several 2'-O-methyl/2'-O-MOE-l-nucleoside pyrimidine derivatives and their incorporation into G-rich oligonucleotides. Finally, we evaluated the stability and resistance against nucleases of these new G-quadruplexes, demonstrating the potential of the l-nucleosides described in this work in providing enhanced nuclease resistance with a minimal impact in the nucleic acid structural properties.

Early Diagnosis of Kidney Damage Associated with Tobacco Use: Preventive Application.

Although long-term smoking has been associated with chronic kidney disease, its effect on kidney function in early stages has not been clarified. Therefore, the proposed objectives were: (1) to identify subclinical kidney damage in smokers, through a panel of biomarkers; (2) to evaluate the progression of subclinical kidney damage after two years of consumption in these patients; and (3) study whether quitting smoking reduces kidney damage. A prospective study was carried out (patients recruited from a primary care centre and a clinical smoking unit). Kidney function was assessed using a panel of biomarkers and compared between smokers and non-smokers, taking into account potential risk factors for kidney damage. These results show, for the first time in the literature, the relationship between smoking and early (subclinical) kidney damage and provide a panel of biomarkers capable of detecting this condition (Neutrophil gelatinase-associated lipocalin, Kidney injury molecule-1, N-acetyl-beta-D-glucosaminidase, transferrin, and ganglioside-activating protein GM2). This study also indicates that subclinical damage is maintained when use continues, but can be reversed if patients stop smoking. The use of these biomarkers as diagnostic tools can be a preventive measure in the development of chronic kidney disease associated with smoking and in the prevention of acute events associated with potentially nephrotoxic pharmacological treatment in smokers. Trial registration number: NCT03850756.

Sustainable Protocol for the Synthesis of 2',3'-Dideoxynucleoside and 2',3'-Didehydro-2',3'-dideoxynucleoside Derivatives.

An improved protocol for the transformation of ribonucleosides into 2',3'-dideoxynucleoside and 2',3'-didehydro-2',3'-dideoxynucleoside derivatives, including the anti-HIV drugs stavudine (d4T), zalcitabine (ddC) and didanosine (ddI), was established. The process involves radical deoxygenation of xanthate using environmentally friendly and low-cost reagents. Bromoethane or 3-bromopropanenitrile was the alkylating agent of choice to prepare the ribonucleoside 2',3'-bisxanthates. In the subsequent radical deoxygenation reaction, tris(trimethylsilyl)silane and 1,1'-azobis(cyclohexanecarbonitrile) were used to replace hazardous Bu3SnH and AIBN, respectively. In addition, TBAF was substituted for camphorsulfonic acid in the deprotection step of the 5'-O-silyl ether group, and an enzyme (adenosine deaminase) was used to transform 2',3'-dideoxyadenosine into 2',3'-dideoxyinosine (ddI) in excellent yield.

Patient Satisfaction Using a Home-Based Rehabilitation Protocol for the Non-Surgical Treatment of Proximal Humeral Fractures: A Prospective Longitudinal Cohort Study.

Supervised, center-based, daily physiotherapy presents limitations: transport, need for an accompanying person, or risk of infection. Home-based rehabilitation protocols (HBRP) can be effective alternatives. We use a HBRP for the non-surgically treated proximal humeral fractures (PHF) in older patients. OBJECTIVES: To assess patient satisfaction and preferences of using a booklet, videos, or an app to guide physiotherapy. PATIENTS AND METHODS: Prospective, single-center observational study of patients ≥55 years old who sustained a non-surgically treated PHF. The HBRP consisted of immediate mobilization, followed by 5 physiotherapist-guided, weekly sessions of rehabilitation and standard physiotherapy after 3 months, if needed. A booklet with images, videos, or a smartphone application were offered to guide the patients. RESULTS: Mean degree of satisfaction (1-5) was 4.66 ± .9: 84 patients (82.4%) were very satisfied, 11 patients (10.8%) were satisfied, and 5 patients (4.9%) were not satisfied at all. Mean Oxford Shoulder Score achieved was 40.5 ± 6.6. 59.8% patients preferred the booklet and 29.4% the videos. Exercise compliance was considered very high in 87.3% of patients, while 4% hardly never followed the HBRP. Only 17.7% patients needed center-based physiotherapy after the HBRP. DISCUSSION: Reasons for satisfaction were good final functional outcome, no need for transportation, being away from hospital, immediate rehabilitation availability and being capable of maintaining independence. Adherence is a major concern. Videos are more didactic explaining the exercises. CONCLUSION: If standard physiotherapy is not available, the HBRP can be a valid treatment option for PHF management in older patients, with a high degree of patient satisfaction. Older patients preferred the booklet to guide physiotherapy.

Long-Term Results of Joint Arthroplasty with Total Prosthesis for Trapeziometacarpal Osteoarthritis in Patients over 65 Years of Age.

Trapeziometacarpal osteoarthritis (TMCOA) is a highly prevalent disease in the older population. Many different types of surgical treatments are possible, depending on the degree of joint involvement, the personal and professional circumstances of the patient and the preferences of the orthopedic surgeon. This paper evaluated the clinical and radiological results of consecutive cohorts of patients over 65 years old treated with total joint arthroplasties (TJA) of the ball and socket type (B&S) for TMCOA, with a minimum of 10 years follow-up. The survival rate (Kaplan-Meier) of the functional prostheses at 10 years was 92.2% (95% CI (89.1%, 96.1%). These functional arthroplasty patients, after 10 years of follow-up, showed little or no pain, good function and good key pinch, without radiological alterations. TJAs of the B&S type are a long lasting, effective and reliable alternative to surgical treatment of TMCOA in patients over 65 years of age, when they are performed with the patient selection criteria and surgical technique described throughout this study.

Total Knee Arthroplasty in Octogenarians: Should We Still Be so Restrictive?

Demand for total knee arthroplasty (TKA) in octogenarians will increase in subsequent years as society ages. We conducted a retrospective observational study in octogenarians operated on with TKA between 2015 and 2019, comparing preoperative and postoperative Knee Society Score (KSS), Knee Society Function Score (KSFS), extension and flexion balance, and radiologic alignment using a paired Student t-test. A chi-squared test was used to correlate mortality with Charlson comorbidities index score and with ASA scale. Kaplan-Meier analysis was performed to calculate patient survival. In this period 36 patients ≥80 years underwent TKA, with a mean age of 81.6 years. Of these, 24 patients (66.7%) were classified as ASA II and 12 (33.3%) as ASA III. Sixteen patients (44.4%) were Charlson 0, 14 (38.9%) Charlson 1, two (5.6%) Charlson 2, and four (11.1%) Charlson 3. KSS, KSFS, flexion and extension range, and radiologic alignment were statistically significant (p < 0.001) when comparing preoperatory and post-operatory data. No correlation (p > 0.05) was found between mortality and ASA or Charlson score. Seven patients (19.4%) suffered a medical complication and two patients experienced surgical complications. Four patient died (11.1%) during follow-up. The mean patient survival was 67.4 months. Patients ≥80 years achieve clinical improvement after TKA. Comorbidities, not age, are the burden for surgery in older patients.

Oligonucleotides Containing 1-Aminomethyl or 1-Mercaptomethyl-2-deoxy-d-ribofuranoses: Synthesis, Purification, Characterization, and Conjugation with Fluorophores and Lipids.

Oligonucleotide conjugates are widely used as therapeutic drugs, gene analysis, and diagnostic tools. A critical step in the biologically relevant oligonucleotide conjugates is the design and synthesis of functional molecules that connect oligonucleotide with ligands. Here, we report the synthesis and application for oligonucleotide functionalization of novel tethers based on aminomethyl and mercaptomethyl sugar derivatives. Starting from a common cyano sugar precursor, three novel phosphoramidites have been prepared in the two α- and ß-anomeric forms. The mercaptomethyl sugar was protected with the S-acetyl group, while two different protecting groups have been developed for the aminomethyl sugar. These two protecting groups are orthogonal, as they can be removed independently using photolysis or ammonolysis. This combination allowed the introduction of two different ligands in a single oligonucleotide.

Valoración por los estudiantes de la formación práctica de grado de Medicina. El caso de la Neumología / Valuation by the students of the practical training of degree of Medicine. The case of pneumology

INTRODUCCIÓN: La formación práctica en el grado de Medicina se imparte en los últimos cursos y está determinada por numerosos factores condicionantes, entre ellos, la formación MIR. En general, la evaluación de la formación práctica recibe mucha menos atención que la teórica, su calidad no es evaluada y el profesorado no recibe retroalimentación. El objetivo de nuestro estudio ha sido conocer la valoración que dan los alumnos a la formación práctica de Neumología después de una rotación de 3semanas, con el objetivo de obtener información para el proceso de mejora continua. MÉTODOS: El estudio incluye 2encuestas anónimas realizadas a los alumnos de grado en el mismo curso académico. Una interna, aplicada por el propio Servicio de Neumología y otra externa, por la Unidad de Evaluación de la Calidad Docente de la USAL. RESULTADOS: En la evaluación interna la opinión de los alumnos acerca de la calidad de la formación práctica es alta (8,26) y la utilidad percibida también es elevada (8,23), en una escala de 0 a 10, y no se observan diferencias por el hecho de que tenga lugar en cuarto, quinto o sexto curso. Estos resultados concuerdan con los obtenidos en la evaluación externa, con un valor medio de 4,56 en una escala de 0 a 5. Las preferencias de los alumnos durante su rotación por el servicio son las unidades de hospitalización y consultas, con menor valoración en las áreas técnicas. CONCLUSIONES: La calidad de la docencia práctica es un reto que es necesario evaluar para que los profesores dispongan de la retroalimentación (interna y externa) oportuna. La rotación por los servicios de Neumología constituye una oportunidad para la mejora de la percepción de la especialidad por los alumnos de grado. Es preciso reflexionar acerca de los contenidos de dicha rotación, buscando un equilibrio entre las áreas clínicas y las de técnicas

INTRODUCTION: Practical training for medical students is provided during the final years of study and is determined by several conditioning factors, including the MIR training that students receive simultaneously. In general, practical training evaluation receives much less attention than the theoretical one; its quality is not evaluated, and the professors do not receive feedback. The objective of our study was to determine how students value practical training in pulmonology rated the experience after completing a three-week rotation, in order to apply the information gained toward a process of continual improvement. METHODS: The study included 2anonymous surveys taken by medical students during the same academic year-one internal, prepared by the Department of Pneumology, itself, and another external one, prepared by the Evaluation Unit for Teaching Excellence at the University of Salamanca. RESULTS: On the internal evaluation, student opinions of their practical training ran high (8.26) and the perceived usefulness was also high (8.23), on a scale of 0 to 10 and no differences were noted according to whether the survey was taken during their fourth, fifth, or sixth year of study. These results agree with those obtained in the external evaluation with a mean value of 4.56 on a scale of 0 to 5. Student preferences during their rotation in the department were for hospitalization and consultation units, with the technical areas being lesser valued. CONCLUSIONS: Achieving and maintaining a high quality of practical training is a goal that should be consistently evaluated so that professors may receive feedback (internal and external). Rotations in the Department of Pneumology provide an opportunity to improve the perception that medical students have regarding this specialty. It is imperative to reflect upon the contents of these rotations, seeking a balance between clinical areas and technical areas

The Human Digestive Tract Is Capable of Degrading Gluten from Birth.

The human gastrointestinal system has the capacity to metabolize dietary gluten. The capacity to degrade gliadin-derived peptide is present in humans from birth and increases during the first stages of life (up to 6-12 months of age). Fecal samples from 151 new-born and adult non-celiac disease (NCD) volunteers were collected, and glutenase and glianidase activities were evaluated. The capacity of total fecal proteins to metabolize 33-mer, 19-mer, and 13-mer gliadin peptides was also evaluated by high-performance liquid chromatography (HPLC). Feces from new-borns (meconium) showed glutenase and gliadinase activities, and peptidase activity against all three gliadin peptides. Maximal gluten degradative activity was observed in fecal samples from the youngest volunteers (0-12 months old). After the age of nine months, the gluten digestive capacity of gastrointestinal tract decreases and, from ±8 years old, individuals lose the ability to completely degrade toxic peptides. The gastrointestinal proteases involved in gluten digestion: elastase 2A, elastase 3B, and carboxipeptidase A1 are present from earlier stages of life. The human digestive tract contains the proteins capable of metabolizing gluten from birth, even before starting gluten intake. Humans are born with the ability to digest gluten and to completely degrade the potentially toxic gliadin-derived peptides (33-, 19-, and 13-mer).

Strategies for the Synthesis of 19-nor-Vitamin D Analogs.

1α,25-Dihydroxyvitamin D3 [1α,25-(OH)2-D3], the hormonally active form of vitamin D3, classically regulates bone formation, calcium, and phosphate homeostasis. In addition, this hormone also exerts non-classical effects in a wide variety of target tissues and cell types, such as inhibition of the proliferation and stimulation of the differentiation of normal and malignant cells. However, to produce these actions, supraphysiological doses are required resulting in calcemic effects that limit the use of this natural hormone. During the past 30 years, many structurally modified analogs of the 1α,25-(OH)2-D3 have been synthesized in order to find derivatives that can dissociate the beneficial antiproliferative effects from undesired calcemic effects. Among these candidates, 1α,25-(OH)2-19-nor-D3 analogs have shown promise as good derivatives since they show equal or better activity relative to the parent hormone but with reduced calcemic effects. In this review, we describe the synthetic strategies to obtain the 19-nor-D3 derivatives and briefly describe their physiological activities.

El currículum oculto ligeramente al descubierto / A Glimpse Behind the Hidden Curriculum

No disponible

Effect of Two Meal Replacement strategies on Cardiovascular Risk Parameters in Advanced Age Patients with Obesity and Osteoarthritis.

BACKGROUND AND AIMS: Meal replacement diets consist of replacing one or more meals with an artificial nutritional supplement. The objective of this study was to compare the effect of one against two meal replacement strategies on body composition and cardiovascular risk parameters in patients with obesity. METHODS: A randomized clinical trial was designed with a modified hypocaloric diet with an artificial nutritional preparation replacing one or two meals for three months in patients with obesity and osteoarthritis pending orthopedic surgery. An anthropometric evaluation and a measurement of the body composition were done with bioelectrical impedance measurement at the beginning and at three months. RESULTS: A total of 112 patients were recruited. Fifty-two patients (46.4%) were randomized to one replacement and 60 patients (53.6%) to two meal replacements. Eighty-one patients (72.3%) were women, and the average age was 61 (11.03) years. The percentage of weight loss at three months was 8.27 (4.79)% (one meal replacement: 7.98 (5.97)%; two meal replacements: 8.50 (3.48)%; p = 0.56). A decrease in fat mass measured by the fat mass index (FMI) was detected (one meal replacement: -2.15 (1.45) kg/m2 vs. two meal replacements: -2.78 (2.55) kg/m2; p > 0.05), and a relative increase in fat-free mass was observed (one meal replacement: +3.57 (4.61)% vs. two meal replacements: +2.14 (4.45)%; p > 0.05). A decrease in HOMA-IR, systolic blood pressure (SBP), and total cholesterol was observed in both groups without differences between them. CONCLUSIONS: The substitution strategies of one or two meal replacements were effective in weight loss and fat mass decrease without differences between the two groups. An improvement in lipid parameters, glycemic control, and systolic blood pressure was observed without differences between strategies.

Utilidad del aula para la enseñanza de neumología en el grado de medicina. Una oportunidad poco aprovechada / The Usefulness of the Classroom in the Teaching of Pulmonology To Medical Students. An Underexploited Opportunity

No disponible

Three-sectioning method: A procedure for studying hard tissues and large pieces under light and electron microscopy.

The histological study of hard pieces such as tendons and calcified lesions and tissues is a field that has been gaining increased attention owing to the rapid development of implantable prostheses, among other factors. In these studies, serial sectioning is utilized to detect areas of interest throughout the entire piece, as it enables the application of the appropriate light and electron microscopy techniques in these areas. We propose the "three-sectioning method" that subjects the pieces to three consecutive cycles of embedding and sectioning to localize and study the areas of interest, as an efficient technique for these histological studies. The pieces were first embedded in epoxy resin and then cut into thick sections (approximately 300 µm) for the first cycle. Next, areas of interest selected on these thick sections were re-embedded in epoxy resin to be sectioned again (second sectioning) to obtain a series of semithin sections (1-3 µm). These semithin sections are usually studied using the most relevant techniques for light microscopy. Smaller areas of interest are selected to be cut into ultrathin sections (60-90 nm) for transmission electron microscopy. If necessary, the selected areas of the semithin sections can be embedded again, and then cut into new ultrathin sections. The different kinds of sections we have described here may also be studied using scanning electron microscopy. This systematic method facilitates correlative microscopy from lower to higher magnifications along with the usage of a broad variety of histological techniques including electron microscopy.

Novel 1'-homo-N-2'-deoxy-α-nucleosides: synthesis, characterization and biological activity.

For the first time, a series of novel 1'-homo-N-2'-deoxy-α-nucleosides containing natural nucleobases as well as 5-fluoro and 5-iodopyrimidine analogs have been synthesized in an efficient manner. Additionally, a high yield protocol for the assembly of a dimeric scaffold containing two sugar moieties linked to the N-1 and N-3 positions of a single pyrimidine base has been accomplished. The structures of the novel homonucleosides were established by a single crystal X-ray structure of 1'-homo-N-2'-deoxy-α-adenosine and NMR studies. The biological activity of these 1'-homo-N-2'-deoxy-α-nucleosides as antiviral (HIV-1 and HBV) and cytotoxic studies was measured in multiple cell systems. The unique structure and easy accessibility of these compounds may allow their use in the design of new nucleoside analogs with potential biological activity and as a scaffold for combinatorial chemistry.