Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.465
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nat Methods ; 21(7): 1166-1170, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38877315

RESUMEN

The growth of omic data presents evolving challenges in data manipulation, analysis and integration. Addressing these challenges, Bioconductor provides an extensive community-driven biological data analysis platform. Meanwhile, tidy R programming offers a revolutionary data organization and manipulation standard. Here we present the tidyomics software ecosystem, bridging Bioconductor to the tidy R paradigm. This ecosystem aims to streamline omic analysis, ease learning and encourage cross-disciplinary collaborations. We demonstrate the effectiveness of tidyomics by analyzing 7.5 million peripheral blood mononuclear cells from the Human Cell Atlas, spanning six data frameworks and ten analysis tools.


Asunto(s)
Programas Informáticos , Humanos , Biología Computacional/métodos , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/citología , Genómica/métodos , Análisis de Datos
2.
Proc Natl Acad Sci U S A ; 121(8): e2315190121, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38363865

RESUMEN

Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion transporter required for epithelial homeostasis in the lung and other organs, with CFTR mutations leading to the autosomal recessive genetic disease CF. Apart from excessive mucus accumulation and dysregulated inflammation in the airways, people with CF (pwCF) exhibit defective innate immune responses and are susceptible to bacterial respiratory pathogens such as Pseudomonas aeruginosa. Here, we investigated the role of CFTR in macrophage antimicrobial responses, including the zinc toxicity response that is used by these innate immune cells against intracellular bacteria. Using both pharmacological approaches, as well as cells derived from pwCF, we show that CFTR is required for uptake and clearance of pathogenic Escherichia coli by CSF-1-derived primary human macrophages. CFTR was also required for E. coli-induced zinc accumulation and zinc vesicle formation in these cells, and E. coli residing in macrophages exhibited reduced zinc stress in the absence of CFTR function. Accordingly, CFTR was essential for reducing the intramacrophage survival of a zinc-sensitive E. coli mutant compared to wild-type E. coli. Ectopic expression of the zinc transporter SLC30A1 or treatment with exogenous zinc was sufficient to restore antimicrobial responses against E. coli in human macrophages. Zinc supplementation also restored bacterial killing in GM-CSF-derived primary human macrophages responding to P. aeruginosa, used as an in vitro macrophage model relevant to CF. Thus, restoration of the zinc toxicity response could be pursued as a therapeutic strategy to restore innate immune function and effective host defense in pwCF.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Macrófagos , Humanos , Antibacterianos/uso terapéutico , Fibrosis Quística/microbiología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiología , Zinc/metabolismo
3.
Trends Biochem Sci ; 47(6): 492-505, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35305898

RESUMEN

Post-translational modifications (PTMs) immensely expand the diversity of the proteome. Glycosylation, among the most ubiquitous PTMs, is a dynamic and multifarious modification of proteins and lipids that generates an omnipresent foliage on the cell surface. The resulting protein glycoconjugates can serve important functions in biology. However, their vast complexity complicates the study of their structures, interactions, and functions. There is now a growing appreciation of the need to study glycans and proteins together as complete entities, as the sum of these two components can exhibit unique functions. In this review, we discuss the growing forestry toolbox to characterize the structure, interactions, and biological functions of protein glycoconjugates, as well as the potential payouts of understanding and controlling these enigmatic biomolecules.


Asunto(s)
Proteoma , Proteómica , Glicoconjugados , Glicosilación , Procesamiento Proteico-Postraduccional , Proteómica/métodos
4.
Cell ; 145(5): 665-77, 2011 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-21620134

RESUMEN

Development of malaria parasites within vertebrate erythrocytes requires nutrient uptake at the host cell membrane. The plasmodial surface anion channel (PSAC) mediates this transport and is an antimalarial target, but its molecular basis is unknown. We report a parasite gene family responsible for PSAC activity. We used high-throughput screening for nutrient uptake inhibitors to identify a compound highly specific for channels from the Dd2 line of the human pathogen P. falciparum. Inheritance of this compound's affinity in a Dd2 × HB3 genetic cross maps to a single parasite locus on chromosome 3. DNA transfection and in vitro selections indicate that PSAC-inhibitor interactions are encoded by two clag3 genes previously assumed to function in cytoadherence. These genes are conserved in plasmodia, exhibit expression switching, and encode an integral protein on the host membrane, as predicted by functional studies. This protein increases host cell permeability to diverse solutes.


Asunto(s)
Eritrocitos/metabolismo , Eritrocitos/parasitología , Plasmodium falciparum/genética , Proteínas Protozoarias/metabolismo , Secuencia de Aminoácidos , Cruzamientos Genéticos , Ensayos Analíticos de Alto Rendimiento , Humanos , Canales Iónicos/metabolismo , Leupeptinas/metabolismo , Datos de Secuencia Molecular , Mutación , Permeabilidad , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Alineación de Secuencia
5.
Nature ; 578(7795): 449-454, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32051587

RESUMEN

The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system1,2. Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the origin of these nerves and the mechanism of their inception are unknown1,3. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.


Asunto(s)
Neuronas Adrenérgicas/patología , Transdiferenciación Celular , Reprogramación Celular , Neoplasias de la Boca/patología , Células Receptoras Sensoriales/patología , Proteína p53 Supresora de Tumor/deficiencia , Antagonistas Adrenérgicos/farmacología , Antagonistas Adrenérgicos/uso terapéutico , Animales , División Celular , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , MicroARNs/genética , Neoplasias de la Boca/tratamiento farmacológico , Neoplasias de la Boca/genética , Neoplasias de la Boca/metabolismo , Fibras Nerviosas/patología , Neuritas/patología , Receptores Adrenérgicos/metabolismo , Estudios Retrospectivos , Microambiente Tumoral , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Emerg Infect Dis ; 30(7): 1467-1471, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38916721

RESUMEN

We detected malaria vector Anopheles stephensi mosquitoes in the Al Hudaydah governorate in Yemen by using DNA sequencing. We report 2 cytochrome c oxidase subunit I haplotypes, 1 previously found in Ethiopia, Somalia, Djibouti, and Yemen. These findings provide insight into invasive An. stephensi mosquitoes in Yemen and their connection to East Africa.


Asunto(s)
Anopheles , Mosquitos Vectores , Animales , Anopheles/genética , Anopheles/parasitología , Anopheles/clasificación , Yemen , Mosquitos Vectores/genética , Humanos , Complejo IV de Transporte de Electrones/genética , Haplotipos , Malaria/transmisión , Malaria/epidemiología , Filogenia
7.
Anal Chem ; 96(2): 904-909, 2024 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-38158374

RESUMEN

Analyzing coeluting impurities with similar masses in synthetic oligonucleotides by liquid chromatography-mass spectrometry (LC-MS) poses challenges due to inadequate separation in either dimension. Herein, we present a direct method employing fully resolved isotopic envelopes, enabled by high resolution mass spectrometry (HRMS), to identify and quantify isobaric impurity ions resulting from the deletion or addition of a uracil (U) or cytosine (C) nucleotide from or to the full-length sequence. These impurities may each encompass multiple sequence variants arising from various deletion or addition sites. The method utilizes a full or targeted MS analysis to measure accurate isotopic distributions that are chemical formula dependent but nucleotide sequence independent. This characteristic enables the quantification of isobaric impurity ions involving sequence variants, a capability typically unavailable in sequence-dependent MS/MS methods. Notably, this approach does not rely on standard curves to determine isobaric impurity compositions in test samples; instead, it utilizes the individual isotopic distributions measured for each impurity standard. Moreover, in cases where specific impurity standards are unavailable, the measured isotopic distributions can be adequately replaced with the theoretical distributions (calculated based on chemical formulas of standards) adjusted using experiment-specific correction factors. In summary, this streamlined approach overcomes the limitations of LC-MS analysis for coeluting isobaric impurity ions, offering a promising solution for the in-depth profiling of complex impurity mixtures in synthetic oligonucleotide therapeutics.


Asunto(s)
Oligonucleótidos , Espectrometría de Masas en Tándem , Espectrometría de Masas en Tándem/métodos , Oligonucleótidos/química , Cromatografía Líquida con Espectrometría de Masas , Peso Molecular , Contaminación de Medicamentos , Cromatografía Líquida de Alta Presión/métodos
8.
BMC Biotechnol ; 24(1): 41, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862994

RESUMEN

BACKGROUND: Genetic diversity, population structure, agro-morphological traits, and molecular characteristics, are crucial for either preserving genetic resources or developing new cultivars. Due to climate change, water availability for agricultural use is progressively diminishing. This study used 100 molecular markers (25 TRAP, 22 SRAP, 23 ISTR, and 30 SSR). Additionally, 15 morphological characteristics were utilized to evaluate the optimal agronomic traits of 12 different barley genotypes under arid conditions. RESULTS: Substantial variations, ranging from significant to highly significant, were observed in the 15 agromorphological parameters evaluated among the 12 genotypes. The KSU-B101 barley genotype demonstrated superior performance in five specific traits: spike number per plant, 100-grain weight, spike number per square meter, harvest index, and grain yield. These results indicate its potential for achieving high yields in arid regions. The Sahrawy barley genotype exhibited the highest values across five parameters, namely leaf area, spike weight per plant, spike length, spike weight per square meter, and biological yield, making it a promising candidate for animal feed. The KSU-B105 genotype exhibited early maturity and a high grain count per spike, which reflects its early maturity and ability to produce a high number of grains per spike. This suggests its suitability for both animal feed and human food in arid areas. Based on marker data, the molecular study found that the similarity coefficients between the barley genotypes ranged from 0.48 to 0.80, with an average of 0.64. The dendrogram constructed from these data revealed three distinct clusters with a similarity coefficient of 0.80. Notably, the correlation between the dendrogram and its similarity matrix was high (0.903), indicating its accuracy in depicting the genetic relationships. The combined analysis revealed a moderate correlation between the morphological and molecular analysis, suggesting alignment between the two characterization methods. CONCLUSIONS: The morphological and molecular analyses of the 12 barley genotypes in this study effectively revealed the varied genetic characteristics of their agro-performance in arid conditions. KSU-B101, Sahrawy, and KSU-B105 have emerged as promising candidates for different agricultural applications in arid regions. Further research on these genotypes could reveal their full potential for breeding programs.


Asunto(s)
Genotipo , Hordeum , Hordeum/genética , Variación Genética , Marcadores Genéticos/genética
9.
BMC Plant Biol ; 24(1): 918, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39354351

RESUMEN

Drought stress (DS) adversely affects a plant's development and growth by negatively altering the plant's physio-biochemical functions. Previous investigations have illustrated that seed priming with growth regulators is an accessible, affordable, and effective practice to elevate a plant's tolerance to drought stress. Melatonin (MT) is derived from the precursor tryptophan and can improve germination, biomass, and photosynthesis under stress conditions. The current study examined the effect of melatonin seed priming on two wheat cultivars (Fakhar-e-Bhakkar and Akber-19) cultivated under severe drought conditions (35% FC). There were 6 levels of melatonin (i.e., M0 = control, M1 = 1 mg L- 1, M2 = 2 mg L- 1, M3 = 3 mg L- 1, M4 = 4 mg L- 1 and M5 = mg L- 1) which were used for seed priming. Our results confirmed that seed priming with M2 = 2 mgL- 1 concentration of MT alleviates the negative effects of DS by boosting the germination rate by 54.84% in Akber-19 and 33.33% in Fakhar-e-Bhakkar. Similarly, leaf-relative water contents were enhanced by 22.38% and 13.28% in Akber-19 and Fakhar-e-Bhakkar, respectively. Melatonin pre-treatment with 2 mgL- 1 significantly enhanced fresh and dry biomass of shoot and root, leaf area, photosynthetic pigments, osmoprotectants accumulation [total soluble proteins (TSP), total free amino acids (TFAA), proline, soluble sugars, glycine betaine (GB)] and lowered the amount of malondialdehyde (MDA) and hydrogen peroxide (H2O2) production by elevating antioxidants [Ascorbic acid, catalase (CAT), Phenolics, peroxidase (POD) and superoxide dismutase (SOD)] activity under drought stress (DS). Meanwhile, under control conditions (NoDS), the melatonin treatment M1 = 1 mgL- 1 effectively enhanced all the growth-related physio-biochemical attributes in both wheat cultivars. In the future, more investigations are suggested on different crops under variable agroclimatic conditions to declare 2 mgL- 1 melatonin as an efficacious amendment to alleviate drought stress.


Asunto(s)
Sequías , Germinación , Melatonina , Semillas , Triticum , Melatonina/farmacología , Melatonina/metabolismo , Triticum/crecimiento & desarrollo , Triticum/efectos de los fármacos , Triticum/fisiología , Triticum/metabolismo , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Semillas/fisiología , Germinación/efectos de los fármacos , Antioxidantes/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Fotosíntesis/efectos de los fármacos , Resistencia a la Sequía
10.
BMC Plant Biol ; 24(1): 919, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39354385

RESUMEN

In the rice-based system of mid-latitudes, mineral nitrogen (N) fertilizer serves as the largest source of the N cycle due to an insufficient supply of N from organic sources causing higher N losses due to varying soil and environmental factors. However, aiming to improve soil organic matter (OM) and nutrients availability using the best environmentally, socially, and economically sustainable cultural and agronomic management practices are necessary. This study aimed to enhance nitrogen use efficiency (NUE) and grain yield in rice-based systems of mid-latitudes by partially replacing inorganic N fertilizer with organic inputs. A randomized complete block design (RCBD) was employed to evaluate the effects of sole mineral N fertilizer (urea) and its combinations with organic sources-farmyard manure (FYM) and poultry compost-on different elite green super rice (GSR) genotypes and were named as NUYT-1, NUYT-2, NUYT-3, NUYT-4, NUYT-5, and NUYT-6. The study was conducted during the 2022 and 2023 rice growing seasons at the Rice Research Program, Crop Sciences Institute (CSI), National Agricultural Research Centre (NARC), Islamabad, one of the mid-latitudes of Pakistan. The key objective was to determine the most effective N management strategy for optimizing plant growth, N content in soil and plants, and overall crop productivity. The results revealed that the combined application of poultry compost and mineral urea significantly enhanced soil and leaf N content (1.36 g kg- 1 and 3.06 mg cm- 2, respectively) and plant morphophysiological traits compared to sole urea application. Maximum shoot dry weight (SDW) and root dry weight (RDW) were observed in compost-applied treatment with the values of 77.62 g hill- 1 and 8.36 g hill- 1, respectively. The two-year mean data indicated that applying 150 kg N ha⁻1, with half provided by organic sources (10 tons ha⁻1 FYM or poultry compost) and the remainder by mineral urea, resulted in the highest N uptake, utilization, and plant productivity. Thus, integrated management of organic carbon sources and inorganic fertilizers may sustain the productivity of rice-based systems more eco-efficiently. Further research is recommended to explore root and shoot morphophysiological, molecular, and biochemical responses under varying N regimes, aiming to develop N-efficient rice varieties through advanced breeding programs.


Asunto(s)
Fertilizantes , Nitrógeno , Oryza , Oryza/metabolismo , Oryza/crecimiento & desarrollo , Fertilizantes/análisis , Nitrógeno/metabolismo , Grano Comestible/crecimiento & desarrollo , Grano Comestible/metabolismo , Suelo/química , Pakistán , Estiércol , Urea/metabolismo , Agricultura/métodos , Compostaje/métodos , Producción de Cultivos/métodos
11.
Biol Proced Online ; 26(1): 16, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38831428

RESUMEN

BACKGROUND: It is necessary to develop advanced therapies utilizing natural ingredients with anti-inflammatory qualities in order to lessen the negative effects of chemotherapeutics. RESULTS: The bioactive N1-(5-methyl-5H-indolo[2,3-b]quinolin-11-yl)benzene-1,4-diamine hydrochloride (NIQBD) was synthesized. After that, soluble starch nanoparticles (StNPs) was used as a carrier for the synthesized NIQBD with different concentrations (50 mg, 100 mg, and 200 mg). The obtained StNPs loaded with different concentrations of NIQBD were coded as StNPs-1, StNPs-2, and StNPs-3. It was observed that, StNPs-1, StNPs-2, and StNPs-3 exhibited an average size of 246, 300, and 328 nm, respectively. Additionally, they also formed with homogeneity particles as depicted from polydispersity index values (PDI). The PDI values of StNPs-1, StNPs-2, and StNPs-3 are 0.298, 0.177, and 0.262, respectively. In vivo investigation of the potential properties of the different concentrations of StNPs loaded with NIQBD against MTX-induced inflammation in the lung and liver showed a statistically substantial increase in levels of reduced glutathione (GSH) accompanied by a significant decrease in levels of oxidants such as malondialdehyde (MDA), nitric oxide (NO), advanced oxidation protein product (AOPP), matrix metalloproteinase 9/Gelatinase B (MMP-9), and levels of inflammatory mediators including interleukin 1-beta (IL-1ß), nuclear factor kappa-B (NF-κB) in both lung and liver tissues, and a significant decrease in levels of plasma homocysteine (Hcy) compared to the MTX-induced inflammation group. The highly significant results were obtained by treatment with a concentration of 200 mg/mL. Histopathological examination supported these results, where treatment showed minimal inflammatory infiltration and congestion in lung tissue, a mildly congested central vein, and mild activation of Kupffer cells in liver tissues. CONCLUSION: Combining the treatment of MTX with natural antioxidant supplements may help reducing the associated oxidation and inflammation.

12.
J Transl Med ; 22(1): 664, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39014470

RESUMEN

BACKGROUND: Duchenne muscular dystrophy (DMD) is a progressive and devastating muscle disease, resulting from the absence of dystrophin. This leads to cell membrane instability, susceptibility to contraction-induced muscle damage, subsequent muscle degeneration, and eventually disability and early death of patients. Currently, there is no cure for DMD. Our recent studies identified that lipin1 plays a critical role in maintaining myofiber stability and integrity. However, lipin1 gene expression levels are dramatically reduced in the skeletal muscles of DMD patients and mdx mice. METHODS: To identify whether increased lipin1 expression could prevent dystrophic pathology, we employed unique muscle-specific mdx:lipin1 transgenic (mdx:lipin1Tg/0) mice in which lipin1 was restored in the dystrophic muscle of mdx mice, intramuscular gene delivery, as well as cell culture system. RESULTS: We found that increased lipin1 expression suppressed muscle degeneration and inflammation, reduced fibrosis, strengthened membrane integrity, and resulted in improved muscle contractile and lengthening force, and muscle performance in mdx:lipin1Tg/0 compared to mdx mice. To confirm the role of lipin1 in dystrophic muscle, we then administered AAV1-lipin1 via intramuscular injection in mdx mice. Consistently, lipin1 restoration inhibited myofiber necroptosis and lessened muscle degeneration. Using a cell culture system, we further found that differentiated primary mdx myoblasts had elevated expression levels of necroptotic markers and medium creatine kinase (CK), which could be a result of sarcolemmal damage. Most importantly, increased lipin1 expression levels in differentiated myoblasts from mdx:lipin1Tg/0 mice substantially inhibited the elevation of necroptotic markers and medium CK levels. CONCLUSIONS: Overall, our data suggest that lipin1 is a promising therapeutic target for the treatment of dystrophic muscles.


Asunto(s)
Ratones Endogámicos mdx , Músculo Esquelético , Distrofia Muscular de Duchenne , Fosfatidato Fosfatasa , Animales , Distrofia Muscular de Duchenne/patología , Distrofia Muscular de Duchenne/metabolismo , Fosfatidato Fosfatasa/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Ratones Transgénicos , Ratones , Contracción Muscular , Terapia Molecular Dirigida , Ratones Endogámicos C57BL , Terapia Genética , Masculino
13.
Hepatology ; 78(1): 179-194, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-36632994

RESUMEN

BACKGROUND AND AIM: Telehealth interventions may improve access to care, disease-specific, and quality outcomes in chronic liver diseases (CLDs). We aimed to systematically evaluate outcomes of telehealth interventions in CLDs. MATERIALS AND METHODS: We used key terms and searched PubMed/EMBASE from inception to January 10, 2022. Two authors independently screened abstracts. Disagreements were resolved by a third reviewer. We included any type of CLD, including posttransplant patients, and extracted outcomes as defined by authors for each etiology of CLD (sustained virological response in HCV or weight loss in NAFLD). Meta-analysis was not performed because of the heterogeneity of data. Quality assessment was performed using the Newcastle-Ottawa Scale for observational studies and the Cochrane Risk of Bias tool for clinical trials. RESULTS: Of 4250 studies screened, 43 met the inclusion criteria. Of these, 28 reported HCV treatment outcomes. All studies showed no statistically significant differences between sustained virological response rates in TH groups compared with control groups or historic cohorts. Eight studies evaluating liver transplant-related processes and outcomes demonstrated improved rates of transplant evaluation and referrals and decreased short-term readmission rates. Three randomized controlled trials and 1 observational study on NAFLD showed improved weight loss outcomes. One retrospective study showed reduced mortality risk in CLD patients with at least 1 TH encounter. CONCLUSIONS: TH interventions in patients with CLDs consistently show equivalent or improved clinical outcomes compared with traditional encounters. TH in CLDs can bridge the gap in access while maintaining the quality of care for underserved populations.


Asunto(s)
Hepatitis C , Enfermedad del Hígado Graso no Alcohólico , Telemedicina , Humanos , Enfermedad del Hígado Graso no Alcohólico/terapia , Estudios Retrospectivos , Pérdida de Peso , Estudios Observacionales como Asunto
14.
Chemistry ; 30(60): e202400785, 2024 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-38958609

RESUMEN

Organic halogen compounds are cornerstones of applied chemical sciences. Halogen substitution is a smart molecular design strategy adopted to influence reactivity, membrane permeability and receptor interaction. Chiral bioreceptors may restrict the stereochemical requirements in the halo-ligand design. Straightforward (but expensive) catalyzed stereospecific halogenation has been reported. Historically, PCl5 served access to uncatalyzed stereoselective chlorination although the stereochemical outcomes were influenced by steric parameters. Nonetheless, stereochemical investigation of PCl5 reaction mechanism with carbamoyl (RCONHX) compounds has never been addressed. Herein, we provide the first comprehensive stereochemical mechanistic explanation outlining halogenation of carbamoyl compounds with PCl5; the key regioselectivity-limiting nitrilimine intermediate (8-Z.HCl); how substitution pattern influences regioselectivity; why oxadiazole byproduct (P1) is encountered; stereo-electronic factors influencing the hydrazonoyl chloride (P2) production; and discovery of two stereoselectivity-limiting parallel mechanisms (stepwise and concerted) of elimination of HCl and POCl3. DFT calculations, synthetic methodology optimization, X-ray evidence and experimental reaction kinetics study evidence all supported the suggested mechanism proposal (Scheme 2). Finally, we provide mechanism-inspired future recommendations for directing the reaction stereoselectivity toward elusive and stereochemically inaccessible (E)-bis-hydrazonoyl chlorides along with potentially pivotal applications of both (E/Z)-stereoisomers especially in medicinal chemistry and protein modification.

15.
Nat Chem Biol ; 18(6): 634-642, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35551261

RESUMEN

Proteoglycans are heterogeneous macromolecular glycoconjugates that orchestrate many important cellular processes. While much attention has focused on the poly-sulfated glycosaminoglycan chains that decorate proteoglycans, other important elements of their architecture, such as core proteins and membrane localization, have garnered less emphasis. Hence, comprehensive structure-function relationships that consider the replete proteoglycan architecture as glycoconjugates are limited. Here we present an extensive approach to study proteoglycan structure and biology by fabricating defined semisynthetic modular proteoglycans that can be tailored for cell surface display. The expression of proteoglycan core proteins with unnatural amino acids permits bioorthogonal click chemistry with functionalized glycosaminoglycans for methodical dissection of the parameters required for optimal binding and function of various proteoglycan-binding proteins. We demonstrate that these sophisticated materials can recapitulate the functions of native proteoglycan ectodomains in mouse embryonic stem cell differentiation and cancer cell spreading while permitting the analysis of the contributing architectural elements toward function.


Asunto(s)
Proteoglicanos , Animales , Membrana Celular/metabolismo , Ratones , Proteoglicanos/análisis , Proteoglicanos/metabolismo
16.
Cell Mol Neurobiol ; 44(1): 55, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38977507

RESUMEN

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory impairment and cognitive dysfunctions. It has been shown that hypoglycemia can adversely affect AD neuropathology. It is well-known that chronic hyperglycemia in type 2 diabetes (T2D) is regarded as a potential risk factor for the development and progression of AD. However, the effect of recurrent hypoglycemia on the pathogenesis of AD was not deeply discussed, and how recurrent hypoglycemia affects AD at cellular and molecular levels was not intensely interpreted by the previous studies. The underlying mechanisms for hypoglycaemia-induced AD are diverse such as endothelial dysfunction, thrombosis, and neuronal injury that causing tau protein hyperphosphorylation and the accumulation of amyloid beta (Aß) in the brain neurons. Of note, the glucagon hormone, which controls blood glucose, can also regulate the cognitive functions. Glucagon increases blood glucose by antagonizing the metabolic effect of insulin. Therefore, glucagon, through attenuation of hypoglycemia, may prevent AD neuropathology. Glucagon/GLP-1 has been shown to promote synaptogenesis, hippocampal synaptic plasticity, and learning and memory, while attenuating amyloid and tau pathologies. Therefore, activation of glucagon receptors in the brain may reduce AD neuropathology. A recent glucagon receptor agonist dasiglucagon which used in the management of hypoglycemia may be effective in preventing hypoglycemia and AD neuropathology. This review aims to discuss the potential role of dasiglucagon in treating hypoglycemia in AD, and how this drug reduce AD neuropathology.


Asunto(s)
Enfermedad de Alzheimer , Hipoglucemia , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Hipoglucemia/metabolismo , Hipoglucemia/complicaciones , Animales , Factores de Riesgo
17.
World J Urol ; 42(1): 221, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38587648

RESUMEN

PURPOSE: Fosfomycin has been used more frequently in managing uncomplicated urinary tract infections (UTIs) due to decreased compliance and increased multidrug-resistant bacteria. The aim of this network meta-analysis was to assess the efficacy of Fosfomycin compared to Nitrofurantoin, Trimethoprim-Sulfamethoxazole (TMP-SMX), and Ciprofloxacin in terms of clinical and microbiological cure alongside with other measurements. MATERIALS AND METHODS: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). We included randomized control trials (RCTs) with uncomplicated UTI patients who received Fosfomycin, Nitrofurantoin, TMP-SMX, or Ciprofloxacin and reported the clinical or microbiological cure. We used Cochrane Risk of Bias Assessment Tool to assess the included studies' quality. R-software was used for all statistical analysis. We ranked all antibiotics using the netrank function which yielded P scores. Frequentist network meta-analysis was used to assess the efficacy of all outcomes. RESULTS: We included 13 RCTs with a total number of 3856 patients that showed Fosfomycin ranked the highest among the other antibiotics with respect to clinical cure (P-score = 0.99) and microbiological cure (P-score = 0.99) while Ciprofloxacin ranked the lowest (P-score = 0.11 and 0.02, respectively). Moreover, Ciprofloxacin yielded the highest relapse rate (P-score = 1), whereas TMP-SMX had the lowest relapse rate (P-score = 0.07). As for the adverse events, Ciprofloxacin demonstrated the highest adverse events as opposed to Fosfomycin (P-score = 0.98 and 0.05, respectively). CONCLUSION: The network meta-analysis demonstrated that Fosfomycin is the most effective antibiotic in treating uncomplicated UTIs with respect to clinical cure, microbiological cure, and adverse events profile.


Asunto(s)
Fosfomicina , Infecciones Urinarias , Humanos , Antibacterianos/uso terapéutico , Fosfomicina/uso terapéutico , Nitrofurantoína , Combinación Trimetoprim y Sulfametoxazol , Metaanálisis en Red , Infecciones Urinarias/tratamiento farmacológico , Ciprofloxacina/uso terapéutico , Recurrencia
18.
Diabetes Obes Metab ; 26(8): 3031-3044, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38802993

RESUMEN

Depression is a mood disorder that may increase risk for the development of insulin resistance (IR) and type 2 diabetes (T2D), and vice versa. However, the mechanistic pathway linking depression and T2D is not fully elucidated. The aim of this narrative review, therefore, was to discuss the possible link between depression and T2D. The coexistence of T2D and depression is twice as great compared to the occurrence of either condition independently. Hyperglycaemia and dyslipidaemia promote the incidence of depression by enhancing inflammation and reducing brain serotonin (5-hydroxytryptamine [5HT]). Dysregulation of insulin signalling in T2D impairs brain 5HT signalling, leading to the development of depression. Furthermore, depression is associated with the development of hyperglycaemia and poor glycaemic control. Psychological stress and depression promote the development of T2D. In conclusion, T2D could be a potential risk factor for the development of depression through the induction of inflammatory reactions and oxidative stress that affect brain neurotransmission. In addition, chronic stress in depression may induce the development of T2D through dysregulation of the hypothalamic-pituitary-adrenal axis and increase circulating cortisol levels, which triggers IR and T2D.


Asunto(s)
Depresión , Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Depresión/etiología , Estrés Psicológico/complicaciones , Estrés Psicológico/fisiopatología , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Encéfalo/metabolismo , Estrés Oxidativo/fisiología , Factores de Riesgo , Hiperglucemia/metabolismo , Sistema Hipófiso-Suprarrenal/fisiopatología , Sistema Hipófiso-Suprarrenal/metabolismo , Trastorno Depresivo/etiología , Serotonina/metabolismo
19.
Inorg Chem ; 63(8): 3769-3780, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38346334

RESUMEN

Lanthanide-based single-ion magnets have attracted much interest due to their great potential for information storage at the level of one molecule. Among various strategies to enhance magnetization blocking in such complexes, the synthesis of axially symmetric compounds is regarded as the most promising. Here, we investigate theoretically the magnetization blocking of several lanthanide ions (Tb3+, Dy3+, Ho3+, Er3+, and Tm3+) encapsulated in highly symmetric zigzag boron nitride nanotubes (BNNTs) of different diameters with ab initio methodology. We found that Tb3+@(7,0)BNNT, Dy3+@(7,0)BNNT, and Tm3+@(5,0)BNNT are suitable SIM candidates, while the other investigated complexes from this series show no signs of magnetization blocking owing to a hard competition between contributions to the crystal field of the lanthanide ion from neighboring and more distant atoms of the nanotube.

20.
BMC Infect Dis ; 24(1): 1005, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300351

RESUMEN

BACKGROUND: Tuberculosis (TB) is one of the most widespread infectious diseases worldwide, typically persisting in the body as a latent TB infection (LTBI). Patients with type 2 diabetes have an increased risk of LTBI progressing to active TB. Therefore, this study determined the prevalence and predictors of LTBI and assessed the agreement between tuberculin skin test (TST) and interferon-gamma release assay (IGRA) in diagnosing LTBI among type 2 diabetics in Sana'a city, Yemen. METHODS: A cross-sectional study was conducted among 150 type 2 diabetics in private health facilities in Sana'a in 2023. Data about demographics, diabetes-related characteristics, and potential risk factors for LTBI were collected using a structured questionnaire. Patients were then screened for LTBI using TST and IGRA. Univariate analysis was used to identify LTBI-associated risk factors, and multivariable binary logistic regression was used to identify independent predictors of LTBI. The agreement between TST and IGRA for diagnosing LTBI was assessed using Cohen's kappa coefficient (κ). RESULTS: LTBI was prevalent among 29.3% of type 2 diabetics using both types of tests (25.3% with IGRA and 21.3% with TST). Male gender was an independent predictor of LTBI (AOR = 4.4, 95% confidence interval: 1.30-15.08; P = 0.018). However, being employed (AOR = 0.3, 95% CI: 0.09-0.75; P = 0.013) and longer duration since diabetes diagnosis (AOR = 0.3, 95% CI: 0.12-0.98; P = 0.046) were identified as predictors of lower LTBI risk. The agreement between TST and IGRA for the diagnosis of LTBI was 88%, with a good and statistically significant agreement between the two test types (κ = 0.670; P < 0.001). CONCLUSIONS: LTBI is common among type 2 diabetics seeking medical care in Sana'a city, with about one-third of them possibly being latently infected. A higher LTBI risk can be predicted among males, while a lower risk can be predicted among those employed or being diagnosed with diabetes for at least five years. The TST shows good agreement with IGRA in diagnosing LTBI among type 2 diabetics, supporting its continued use as a cost-effective and easily accessible test for diagnosing LTBI in the country.


Asunto(s)
Diabetes Mellitus Tipo 2 , Ensayos de Liberación de Interferón gamma , Tuberculosis Latente , Prueba de Tuberculina , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Masculino , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/epidemiología , Tuberculosis Latente/complicaciones , Femenino , Yemen/epidemiología , Estudios Transversales , Persona de Mediana Edad , Ensayos de Liberación de Interferón gamma/métodos , Adulto , Prevalencia , Factores de Riesgo , Anciano
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA