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1.
Nature ; 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862027

RESUMEN

The recent acceleration of commercial, private, and multi-national spaceflight has created an unprecedented level of activity in low Earth orbit (LEO), concomitant with the highest-ever number of crewed missions entering space and preparations for exploration-class (>1 year) missions. Such rapid advancement into space from many new companies, countries, and space-related entities has enabled a"Second Space Age." This new era is also poised to leverage, for the first time, modern tools and methods of molecular biology and precision medicine, thus enabling precision aerospace medicine for the crews. The applications of these biomedical technologies and algorithms are diverse, encompassing multi-omic, single-cell, and spatial biology tools to investigate human and microbial responses to spaceflight. Additionally, they extend to the development of new imaging techniques, real-time cognitive assessments, physiological monitoring, and personalized risk profiles tailored for astronauts. Furthermore, these technologies enable advancements in pharmacogenomics (PGx), as well as the identification of novel spaceflight biomarkers and the development of corresponding countermeasures. In this review, we highlight some of the recent biomedical research from the National Aeronautics and Space Administration (NASA), Japan Aerospace Exploration Agency (JAXA), European Space Agency (ESA), and other space agencies, and also detail the commercial spaceflight sector's (e.g. SpaceX, Blue Origin, Axiom, Sierra Space) entrance into aerospace medicine and space biology, the first aerospace medicine biobank, and the myriad upcoming missions that will utilize these tools to ensure a permanent human presence beyond LEO, venturing out to other planets and moons.

2.
PLoS Pathog ; 19(8): e1010934, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37549163

RESUMEN

The genetic causes of phenotypic variation often differ depending on the population examined, particularly if the populations were founded by relatively small numbers of genotypes. Similarly, the genetic causes of phenotypic variation among similar traits (resistance to different xenobiotic compounds or pathogens) may also be completely different or only partially overlapping. Differences in genetic causes for variation in the same trait among populations suggests context dependence for how selection acts on those traits. Similarities in the genetic causes of variation for different traits, on the other hand, suggests pleiotropy which would also influence how natural selection shapes variation in a trait. We characterized immune defense against a natural Drosophila pathogen, the Gram-positive bacterium Lysinibacillus fusiformis, in three different populations and found almost no overlap in the genetic architecture of variation in survival post infection. However, when comparing our results to a similar experiment with the fungal pathogen, B. bassiana, we found a convincing shared QTL peak for both pathogens. This peak contains the Bomanin cluster of Drosophila immune effectors. Loss of function mutants and RNAi knockdown experiments confirms a role of some of these genes in immune defense against both pathogens. This suggests that natural selection may act on the entire cluster of Bomanin genes (and the linked region under the QTL) or specific peptides for specific pathogens.


Asunto(s)
Drosophila melanogaster , Drosophila , Animales , Drosophila melanogaster/genética , Drosophila/genética , Fenotipo , Variación Genética
3.
Indian J Clin Biochem ; 39(1): 124-129, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38223004

RESUMEN

The insertion/deletion, I/D polymorphism, in the gene encoding Angiotensin Converting Enzyme, ACE is a popular genetic marker for cardiovascular disease, CVD. With alarming rise in diabetes, the risk of CVD among Indian subjects is further enhanced. The present study explored the role of ACE I/D polymorphism, rs4340 as a genetic marker and its association with diabetes. Genomic DNA, isolated from a cohort of 410 urban subjects attending our hospital, was genotyped using polymerase chain reaction followed by electrophoresis. Among the subjects, 84 had type-2 diabetes and 68 had hypertension while 258 were free from these risk factors. Majority (57/84) of diabetic subjects were also suffering from hypertension. Genotype frequencies of ACE I/D polymorphism, of diabetic (84) patients were not different from that of non-diabetic subjects (258). In sharp contrast, we found significant differences, in genotype frequencies of women with diabetes (n = 38) compared to non-diabetic women (70). Diabetic women had significantly higher prevalence of the high risk 'D' allele. Analysis of odds ratio, OR revealed that women with 'D/D' genotype, exhibited threefold risk (OR 3.12, 95% CI 1.21-8.05; p = 0.018) of diabetes, in the recessive model (D/D vs I/I + I/D). Further when we analysed Odds ratio of diabetic women (8) who were free from hypertension, the results revealed even a greater, 6- fold (OR 6.0, 95% CI 1.29-27.96, p = 0.027) risk of diabetes for D/D homozygous women (D/D vs I/I + I/D). These results suggest 'sex-specific' association of ACE 'I/D' polymorphism, with type-2 diabetes, affecting women while there was no influence observed among men. In view of the increased cardiovascular mortality among Indians, data from our pilot study if confirmed in a larger cohort, could add value to our future intervention efforts.

4.
N Engl J Med ; 383(4): 334-346, 2020 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-32598831

RESUMEN

BACKGROUND: Understanding the epidemiology and clinical course of multisystem inflammatory syndrome in children (MIS-C) and its temporal association with coronavirus disease 2019 (Covid-19) is important, given the clinical and public health implications of the syndrome. METHODS: We conducted targeted surveillance for MIS-C from March 15 to May 20, 2020, in pediatric health centers across the United States. The case definition included six criteria: serious illness leading to hospitalization, an age of less than 21 years, fever that lasted for at least 24 hours, laboratory evidence of inflammation, multisystem organ involvement, and evidence of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on reverse-transcriptase polymerase chain reaction (RT-PCR), antibody testing, or exposure to persons with Covid-19 in the past month. Clinicians abstracted the data onto standardized forms. RESULTS: We report on 186 patients with MIS-C in 26 states. The median age was 8.3 years, 115 patients (62%) were male, 135 (73%) had previously been healthy, 131 (70%) were positive for SARS-CoV-2 by RT-PCR or antibody testing, and 164 (88%) were hospitalized after April 16, 2020. Organ-system involvement included the gastrointestinal system in 171 patients (92%), cardiovascular in 149 (80%), hematologic in 142 (76%), mucocutaneous in 137 (74%), and respiratory in 131 (70%). The median duration of hospitalization was 7 days (interquartile range, 4 to 10); 148 patients (80%) received intensive care, 37 (20%) received mechanical ventilation, 90 (48%) received vasoactive support, and 4 (2%) died. Coronary-artery aneurysms (z scores ≥2.5) were documented in 15 patients (8%), and Kawasaki's disease-like features were documented in 74 (40%). Most patients (171 [92%]) had elevations in at least four biomarkers indicating inflammation. The use of immunomodulating therapies was common: intravenous immune globulin was used in 144 (77%), glucocorticoids in 91 (49%), and interleukin-6 or 1RA inhibitors in 38 (20%). CONCLUSIONS: Multisystem inflammatory syndrome in children associated with SARS-CoV-2 led to serious and life-threatening illness in previously healthy children and adolescents. (Funded by the Centers for Disease Control and Prevention.).


Asunto(s)
Infecciones por Coronavirus/complicaciones , Neumonía Viral/complicaciones , Síndrome de Respuesta Inflamatoria Sistémica/epidemiología , Síndrome de Respuesta Inflamatoria Sistémica/virología , Adolescente , Betacoronavirus , COVID-19 , Centers for Disease Control and Prevention, U.S. , Niño , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/terapia , Cuidados Críticos , Femenino , Glucocorticoides/uso terapéutico , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Inmunomodulación , Inflamación , Tiempo de Internación , Masculino , Síndrome Mucocutáneo Linfonodular/epidemiología , Síndrome Mucocutáneo Linfonodular/terapia , Síndrome Mucocutáneo Linfonodular/virología , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/terapia , Estudios Prospectivos , Respiración Artificial , Estudios Retrospectivos , SARS-CoV-2 , Síndrome de Respuesta Inflamatoria Sistémica/terapia , Estados Unidos
5.
Chem Rec ; 23(11): e202300207, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37565381

RESUMEN

Our current unhealthy lifestyle and the exponential surge in the population getting affected by a variety of diseases have made pharmaceuticals or drugs an imperative part of life, making the development of innovative strategies for drug discovery or the introduction of refined, cost-effective and modern technologies for the synthesis of clinically used drugs, a need of the hour. Ever since their discovery, free radicals and radical cations or anions as reactive intermediates have captivated the chemists, resulting in an exceptional utilization of these moieties throughout the field of chemical synthesis, owing to their unprecedented and widespread reactivity. Sticking with the idea of not judging the book by its cover, despite the conventional thought process of radicals being unstable and difficult to control entities, scientists and academicians around the globe have done an appreciable amount of work utilizing both persistent as well as transient radicals for a variety of organic transformations, exemplifying them with the synthesis of significant biologically active pharmaceutical ingredients. This review truly accounts for the organic radical transformations including radical addition, radical cascade cyclization, radical/radical cross-coupling, coupling with metal-complexes and radical cations coupling with nucleophiles, that offers fascinating and unconventional approaches towards the construction of intricate structural frameworks of marketed APIs with high atom- and step-economy; complementing the otherwise employed traditional methods. This tutorial review presents a comprehensive package of diverse methods utilized for radical generation, featuring their reactivity to form critical bonds in pharmaceutical total synthesis or in building key starting materials or intermediates of their synthetic journey, acknowledging their excellence, downsides and underlying mechanisms, which are otherwise poorly highlighted in the literature. Despite great achievements over the past few decades in this area, many challenges and obstacles are yet to be unraveled to shorten the distance between the academics and the industry, which are all discussed in summary and outlook.


Asunto(s)
Complejos de Coordinación , Radicales Libres/química , Ciclización , Cationes , Preparaciones Farmacéuticas
6.
Environ Res ; 227: 115786, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37004858

RESUMEN

Various pesticides and organic compounds generated as a result of rapid industrialization and pharmaceutical companies pose a major threat to the environment. Novel photocatalysts based on zinc oxide and titanium oxide exhibit great potential towards absorption of these organic pollutants from wastewater. The photocatalysts possess various extraordinary properties like photocatalytic degradation potential, non-toxic and high stability. However, several limitations are also associated with the applications of these photocatalysts like poor affinity, particle agglomeration, high band gap and recovery issues. Hence, optimization is required to enhance their efficiency and at the same time make them cost effective and sustainable. The review covers the mechanism for water treatment, limitations and development of different modification strategies that improve the removal efficiency of titanium and zinc oxide based photocatalysts. Thus, further research in the field of photocatalysts can be encouraged for carrying out water remediation.


Asunto(s)
Nanoestructuras , Óxido de Zinc , Desinfección , Titanio , Catálisis
7.
Eur Arch Otorhinolaryngol ; 280(1): 455-459, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36029323

RESUMEN

PURPOSE: To illustrate the importance of tracheotomy in difficult cases of foreign body inhalation and to enumerate the indications of the same. METHODS: A retrospective analysis of 5 cases in which the standard rigid bronchoscopic approach had to be combined with the open surgical approach (tracheotomy) for the removal of the inhaled foreign body for different indications. RESULTS: Combining the two procedures lead to successful removal of foreign body and restoration of airway in all the cases. Tracheostomies whenever performed were temporary. CONCLUSIONS: Foreign body aspiration is an otorhinolaryngologic emergency that can rapidly prove fatal if not well-handled. Though most cases can be dealt with by traditional approaches, a proportion of the cases may prove challenging and need a quick tailoring of response according to the situation at hand. An approach combining tracheotomy with the traditional bronchoscopic approach is one such way and in well-selected cases, can have a significant impact on the outcome; sometimes even in terms of life and death.


Asunto(s)
Obstrucción de las Vías Aéreas , Cuerpos Extraños , Humanos , Broncoscopía/métodos , Traqueotomía , Traqueostomía , Estudios Retrospectivos , Tráquea , Bronquios , Obstrucción de las Vías Aéreas/diagnóstico , Obstrucción de las Vías Aéreas/etiología , Obstrucción de las Vías Aéreas/cirugía , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía
8.
Physiol Mol Biol Plants ; 29(12): 1915-1930, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38222287

RESUMEN

Cyanobacteria are ancestors of chloroplast and perform oxygen-evolving photosynthesis similar to higher plants and algae. However, an obligatory requirement of photons for their growth results in the exposure of cyanobacteria to varying light conditions. Therefore, the light environment could act as a signal to drive the developmental processes, in addition to photosynthesis, in cyanobacteria. These Gram-negative prokaryotes exhibit characteristic light-dependent developmental processes that maximize their fitness and resource utilization. The development occurring in response to radiance (photomorphogenesis) involves fine-tuning cellular physiology, morphology and metabolism. The best-studied example of cyanobacterial photomorphogenesis is chromatic acclimation (CA), which allows a selected number of cyanobacteria to tailor their light-harvesting antenna called phycobilisome (PBS). The tailoring of PBS under existing wavelengths and abundance of light gives an advantage to cyanobacteria over another photoautotroph. In this work, we will provide a comprehensive update on light-sensing, molecular signaling and signal cascades found in cyanobacteria. We also include recent developments made in other aspects of CA, such as mechanistic insights into changes in the size and shape of cells, filaments and carboxysomes.

9.
J Lipid Res ; 63(6): 100220, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35490741

RESUMEN

The localization of many membrane proteins within cholesterol- and sphingolipid-containing microdomains is essential for proper cell signaling and function. These membrane domains, however, are too small and dynamic to be recorded, even with modern super-resolution techniques. Therefore, the association of membrane proteins with these domains can only be detected with biochemical assays that destroy the integrity of cells require pooling of many cells and take a long time to perform. Here, we present a simple membrane fluidizer-induced clustering approach to identify the phase-preference of membrane-associated molecules in individual live cells within 10-15 min. Experiments in phase-separated bilayers and live cells on molecules with known phase preference show that heptanol hyperfluidizes the membrane and stabilizes phase separation. This results in a transition from nanosized to micronsized clusters of associated molecules allowing their identification using routine microscopy techniques. Membrane fluidizer-induced clustering is an inexpensive and easy to implement method that can be conducted at large-scale and allows easy identification of protein partitioning in live cell membranes.


Asunto(s)
Colesterol , Microdominios de Membrana , Membrana Celular/química , Colesterol/metabolismo , Heptanol/análisis , Heptanol/metabolismo , Membrana Dobles de Lípidos/metabolismo , Microdominios de Membrana/metabolismo , Proteínas de la Membrana/metabolismo
10.
Cancer ; 128(16): 3099-3108, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35719098

RESUMEN

BACKGROUND: This study examined whether the association of socioeconomic status (SES) and non-small cell lung cancer (NSCLC) stage varied by race/ethnicity and health care access measures. METHODS: This study used data from the 2004-2016 National Cancer Database for patients aged 18-89 years who had been diagnosed with Stage 0-IV NSCLC. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated for the associations of area-level SES with an advanced stage at diagnosis via multilevel, multivariable logistic regression. The stage at diagnosis was dichotomized into early (0-II) and advanced (III-IV) stages, and area-level SES was categorized on the basis of the patient's zip code level: (1) the proportion of adults aged ≥25 years without a high school degree and (2) the median household income. The models were stratified by race/ethnicity (non-Hispanic [NH] White, NH Black, Hispanic, Asian, American Indian/Alaskan Native, and Native Hawaiian/Pacific Islander), insurance status (none, government, and private), and health care facility type (community, comprehensive community, academic/research, and integrated network). RESULTS: The study population included 1,329,972 patients. Although only 17% of the NH White patients were in the lowest income quartile, 50% of the NH Black patients were in this group. Lower area-level education and income were associated with higher odds of an advanced-stage diagnosis (aOR for education, 1.12; 95% CI, 1.10-1.13; aOR for income, 1.13; 95% CI, 1.11-1.14). These associations persisted among NH White, NH Black, Hispanic, and Asian patients; among those with government and private insurance (but not the uninsured); and among those treated at each facility type. CONCLUSIONS: Area-level income and education are strongly associated with an advanced NSCLC diagnosis regardless of the facility type and among those with government and private insurance.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Adulto , Carcinoma de Pulmón de Células no Pequeñas/terapia , Etnicidad , Accesibilidad a los Servicios de Salud , Humanos , Clase Social , Factores Socioeconómicos , Estados Unidos/epidemiología
11.
J Natl Compr Canc Netw ; 20(11): 1255-1266.e11, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36351338

RESUMEN

BACKGROUND: Racial disparities exist in receipt of guideline-concordant treatment of ovarian cancer (OC). However, few studies have evaluated how various dimensions of healthcare access (HCA) contribute to these disparities. METHODS: We analyzed data from non-Hispanic (NH)-Black, Hispanic, and NH-White patients with OC diagnosed in 2008 to 2015 from the SEER-Medicare database and defined HCA dimensions as affordability, availability, and accessibility, measured as aggregate scores created with factor analysis. Receipt of guideline-concordant OC surgery and chemotherapy was defined based on the NCCN Guidelines for Ovarian Cancer. Multivariable-adjusted modified Poisson regression models were used to assess the relative risk (RR) for guideline-concordant treatment in relation to HCA. RESULTS: The study cohort included 5,632 patients: 6% NH-Black, 6% Hispanic, and 88% NH-White. Only 23.8% of NH-White patients received guideline-concordant surgery and the full cycles of chemotherapy versus 14.2% of NH-Black patients. Higher affordability (RR, 1.05; 95% CI, 1.01-1.08) and availability (RR, 1.06; 95% CI, 1.02-1.10) were associated with receipt of guideline-concordant surgery, whereas higher affordability was associated with initiation of systemic therapy (hazard ratio, 1.09; 95% CI, 1.05-1.13). After adjusting for all 3 HCA scores and demographic and clinical characteristics, NH-Black patients remained less likely than NH-White patients to initiate systemic therapy (hazard ratio, 0.86; 95% CI, 0.75-0.99). CONCLUSIONS: Multiple HCA dimensions predict receipt of guideline-concordant treatment but do not fully explain racial disparities among patients with OC. Acceptability and accommodation are 2 additional HCA dimensions which may be critical to addressing these disparities.


Asunto(s)
Neoplasias Ováricas , Población Blanca , Anciano , Humanos , Estados Unidos/epidemiología , Femenino , Negro o Afroamericano , Disparidades en Atención de Salud , Medicare , Carcinoma Epitelial de Ovario/terapia , Neoplasias Ováricas/terapia , Accesibilidad a los Servicios de Salud
12.
BMC Infect Dis ; 22(1): 254, 2022 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-35287602

RESUMEN

BACKGROUND: Racial/ethnic minorities are at higher risk for severe COVID-19. This may be related to social determinants that lead to chronic inflammatory states. The aims of the study were to determine if there are racial/ethnic disparities with inflammatory markers and association of methylprednisolone to in hospital survival. METHODS: This was a secondary analysis of a retrospective cohort study of patients ≥ 18 years of age and admitted for severe COVID-19 pneumonia between March and June 2020 in 13 Hospitals in New Jersey, United States. Patients who received other formulation of corticosteroids were not included. Area under the receiver operating characteristics curves were performed to test for discriminatory ability of each inflammatory makers. Univariate and multivariate Cox regression assessed the association of variables to in hospital survival. RESULTS: Propensity matched sample (n = 759) between no methylprednisolone (n = 380) and methylprednisolone (n = 379) had 338 Whites, 102 Blacks, 61 Asian/Indians, and 251 non-Black non-White Hispanics. Compared to CRP, area under receiving operating characteristic curve for d-dimer in Hispanics (0.742) was statistically different (DeLong Test P = 0.0041). Multivariate cox regression showed that different variables in Blacks [age ≥ 60 years (HR = 3.71, P = 0.0281), mechanical ventilation (HR = 5.07, P = 0.0281) and creatinine ≥ 1.5 mg/dL (HR = 3.61, P = 0.0007)], Whites [cancer (HR = 1.68, P = 0.0213), qSOFA score of 1 (HR = 1.81, P = 0.0213), qSOFA score of 2 (HR = 5.16, P < 0.0001), qSOFA score of 3 (HR = 11.81, P < 0.0001) and creatinine ≥ 1.5 mg/dL (HR = 2.16, P = 0.0006)], Hispanics [hypertension (HR = 2.52, P = 0.0007), cancer (HR = 2.99, P = 0.0244 and D-dimer ≥ 2 mcg/mL (HR = 2.22, P = 0.0077)], and Asian/Indians [ chronic kidney disease (HR = 6.36, P = 0.0031) and CRP > 20 mg/L (HR = 5.02, P = 0.0032)] were statistically significant for mortality. Low dose and high dose methylprednisolone were significantly associated with prolonged survival in Whites [low dose (HR = 0.37, P < 0.0001) and high dose (HR = 0.48, P < 0.0183)] and Asian/Indians [low dose (HR = 0.13, P = 0.0101) and high dose (HR = 0.15, P = 0.01)]. However, high dose was not associated with improved survival compared to low dose. Methylprednisolone was not associated with prolonged survival in Blacks and Hispanics. CONCLUSION: Racial/Ethnic disparities with inflammatory markers preclude the use of one marker as a predictor of survival. Methylprednisolone is associated with prolonged survival in Asian/Indians and Whites.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , Metilprednisolona , Etnicidad , Humanos , Inflamación/tratamiento farmacológico , Metilprednisolona/uso terapéutico , Persona de Mediana Edad , Estudios Retrospectivos , Estados Unidos/epidemiología
13.
BMC Cancer ; 21(1): 1051, 2021 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-34563146

RESUMEN

BACKGROUND: The association between obesity and breast cancer (BC) has been extensively studied among US, European and Asian study populations, with often conflicting evidence. However, despite the increasing prevalence of obesity and associated conditions in Africa, the continent with the highest age-standardized BC mortality rate globally, few studies have evaluated this association, and none has examined in relation to molecular subtypes among African women. The current analysis examines the association between body composition, defined by body mass index (BMI), height, and weight, and BC by molecular subtype among African women. METHODS: We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) for the association between measures of body composition and BC and molecular subtypes among 419 histologically confirmed cases of BC and 286 healthy controls from the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Women of Nigerian Descent (MEND) case-control study. RESULTS: Higher BMI (aOR: 0.79; 95% CI: 0.67, 0.95) and weight (aOR: 0.83; 95% CI: 0.69, 0.98) were associated with reduced odds of BC in adjusted models, while height was associated with non-statistically significant increased odds of BC (aOR: 1.07, 95% CI: 0.90, 1.28). In pre/peri-menopausal, but not post-menopausal women, both higher BMI and weight were significantly associated with reduced odds of BC. Further, higher BMI was associated with reduced odds of Luminal A, Luminal B, and HER2-enriched BC among pre/peri-menopausal women, and reduced odds of triple-negative BC among post-menopausal women. CONCLUSIONS: Higher BMI and weight were associated with reduced odds of BC overall and by molecular subtype among West African women. Larger studies of women of African descent are needed to definitively characterize these associations and inform cancer prevention strategies.


Asunto(s)
Composición Corporal , Neoplasias de la Mama/etiología , Adulto , Estatura , Índice de Masa Corporal , Peso Corporal , Neoplasias de la Mama/química , Estudios de Casos y Controles , Intervalos de Confianza , Femenino , Humanos , Menopausia , Persona de Mediana Edad , Nigeria , Oportunidad Relativa , Historia Reproductiva , Factores de Riesgo , Neoplasias de la Mama Triple Negativas/química , Neoplasias de la Mama Triple Negativas/etiología
14.
Chem Rec ; 21(4): 715-780, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33650751

RESUMEN

Among the known aromatic nitrogen heterocycles, pyrrole represents a privileged aromatic heterocycle ranging its occurrence in the key component of "pigments of life" to biologically active natural products to active pharmaceuticals. Pyrrole being an electron-rich heteroaromatic compound, its predominant functionalization is legendary to aromatic electrophilic substitution reactions. Although a few excellent reviews on the functionalization of pyrroles including the reports by Baltazzi in 1963, Casiraghi and Rassu in 1995, and Banwell in 2006 are available, they are fragmentary and over fifteen years old, and do not cover the modern aspects of catalysis. A review covering a comprehensive package of direct functionalization on pyrroles via catalytic and non-catalytic methods including their translational potential is described. Subsequent to statutory yet concise introduction, the classical functionalization on pyrroles using Lewis acids largely following an ionic mechanism is discussed. The subsequent discussion follows the various metal-catalyzed C-H functionalization on pyrroles, which are otherwise difficult to implement by Lewis acids. A major emphasize is given on the radical based pyrrole functionalization under metal-free oxidative conditions, which is otherwise poorly highlighted in the literature. Towards the end, the current development of pyrrole functionalization under photocatalyzed and electrochemical conditions is appended. Only a selected examples of substrates and important mechanisms are discussed for different methods highlighting their scopes and limitations. The aromatic nucleophillic substitution on pyrroles (being an electron-rich heterocycle) happened to be the subject of recent investigations, which has also been covered accentuating their underlying conceptual development. Despite great achievements over the past several years in these areas, many challenges and problems are yet to be solved, which are all discussed in summary and outlook.

15.
Biophys J ; 118(10): 2434-2447, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32333863

RESUMEN

Diffusion obstacles in membranes have not been directly visualized because of fast membrane dynamics and the occurrence of subresolution molecular complexes. To understand the obstacle characteristics, mobility-based methods are often used as an indirect way of assessing the membrane structure. Molecular movement in biological plasma membranes is often characterized by anomalous diffusion, but the exact underlying mechanisms are still elusive. Imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) is a well-established mobility-based method that provides spatially resolved diffusion coefficient maps and is combined with FCS diffusion law analysis to examine subresolution membrane organization. In recent years, although FCS diffusion law analysis has been instrumental in providing new insights into the membrane structure below the optical diffraction limit, there are certain exceptions and anomalies that require further clarification. To this end, we correlate the membrane structural features imaged by atomic force microscopy (AFM) with the dynamics measured using ITIR-FCS. We perform ITIR-FCS measurements on supported lipid bilayers (SLBs) of various lipid compositions to characterize the anomalous diffusion of lipid molecules in distinct obstacle configurations, along with the high-resolution imaging of the membrane structures with AFM. Furthermore, we validate our experimental results by performing simulations on image grids with experimentally determined obstacle configurations. This study demonstrates that FCS diffusion law analysis is a powerful tool to determine membrane heterogeneities implied from dynamics measurements. Our results corroborate the commonly accepted interpretations of imaging FCS diffusion law analysis, and we show that exceptions happen when domains reach the percolation threshold in a biphasic membrane and a network of domains behaves rather like a meshwork, resulting in hop diffusion.


Asunto(s)
Membrana Dobles de Lípidos , Membrana Celular , Difusión , Microscopía de Fuerza Atómica , Espectrometría de Fluorescencia
16.
J Lipid Res ; 61(2): 252-266, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31857388

RESUMEN

A fundamental feature of the eukaryotic cell membrane is the asymmetric arrangement of lipids in its two leaflets. A cell invests significant energy to maintain this asymmetry and uses it to regulate important biological processes, such as apoptosis and vesiculation. The dynamic coupling of the inner or cytoplasmic and outer or exofacial leaflets is a challenging open question in membrane biology. Here, we combined fluorescence lifetime imaging microscopy (FLIM) with imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) to differentiate the dynamics and organization of the two leaflets of live mammalian cells. We characterized the biophysical properties of fluorescent analogs of phosphatidylcholine, sphingomyelin, and phosphatidylserine in the plasma membrane of two mammalian cell lines (CHO-K1 and RBL-2H3). Because of their specific transverse membrane distribution, these probes allowed leaflet-specific investigation of the plasma membrane. We compared the results of the two methods having different temporal and spatial resolution. Fluorescence lifetimes of fluorescent lipid analogs were in ranges characteristic for the liquid ordered phase in the outer leaflet and for the liquid disordered phase in the inner leaflet. The observation of a more fluid inner leaflet was supported by free diffusion in the inner leaflet, with high average diffusion coefficients. The liquid ordered phase in the outer leaflet was accompanied by slower diffusion and diffusion with intermittent transient trapping. Our results show that the combination of FLIM and ITIR-FCS with specific fluorescent lipid analogs is a powerful tool for investigating lateral and transbilayer characteristics of plasma membrane in live cell lines.


Asunto(s)
Membrana Celular/metabolismo , Lípidos/química , Microscopía Fluorescente , Animales , Línea Celular , Membrana Celular/química , Estructura Molecular , Espectrometría de Fluorescencia , Liposomas Unilamelares/química , Liposomas Unilamelares/metabolismo
17.
J Biol Chem ; 294(16): 6468-6482, 2019 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-30819802

RESUMEN

Dehydrins are intrinsically disordered proteins, generally expressed in plants as a response to embryogenesis and water-related stress. Their suggested functions are in membrane stabilization and cell protection. All dehydrins contain at least one copy of the highly conserved K-segment, proposed to be a membrane-binding motif. The dehydrin Lti30 (Arabidopsis thaliana) is up-regulated during cold and drought stress conditions and comprises six K-segments, each with two adjacent histidines. Lti30 interacts with the membrane electrostatically via pH-dependent protonation of the histidines. In this work, we seek a molecular understanding of the membrane interaction mechanism of Lti30 by determining the diffusion and molecular organization of Lti30 on model membrane systems by imaging total internal reflection- fluorescence correlation spectroscopy (ITIR-FCS) and molecular dynamics (MD) simulations. The dependence of the diffusion coefficient explored by ITIR-FCS together with MD simulations yields insights into Lti30 binding, domain partitioning, and aggregation. The effect of Lti30 on membrane lipid diffusion was studied on fluorescently labeled supported lipid bilayers of different lipid compositions at mechanistically important pH conditions. In parallel, we compared the mode of diffusion for short individual K-segment peptides. The results indicate that Lti30 binds the lipid bilayer via electrostatics, which restricts the mobility of lipids and bound protein molecules. At low pH, Lti30 binding induced lipid microdomain formation as well as protein aggregation, which could be correlated with one another. Moreover, at physiological pH, Lti30 forms nanoscale aggregates when proximal to the membrane suggesting that Lti30 may protect the cell by "cross-linking" the membrane lipids.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Membrana Celular , Lípidos de la Membrana , Simulación de Dinámica Molecular , Presión Osmótica , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/química , Membrana Celular/genética , Membrana Celular/metabolismo , Lípidos de la Membrana/química , Lípidos de la Membrana/genética , Lípidos de la Membrana/metabolismo , Dominios Proteicos
18.
Infect Immun ; 88(8)2020 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-32482643

RESUMEN

Immune response to pathogens is energetically expensive to the host; however, the cellular source of energy to fuel immune response remains unknown. In this study, we show that Caenorhabditis elegans exposed to pathogenic Gram-positive and Gram-negative bacteria or yeast rapidly utilizes lipid droplets, the major energy reserve. The nematode's response to the pathogenic bacterium Enterococcus faecalis entails metabolic rewiring for the upregulation of several genes involved in lipid utilization and downregulation of lipid synthesis genes. Genes encoding acyl-CoA synthetase ACS-2, involved in lipid metabolism, and flavin monooxygenase FMO-2, involved in detoxification, are two highly upregulated genes during E. faecalis infection. We find that both ACS-2 and FMO-2 are necessary for survival and rely on NHR-49, a peroxisome proliferator-activated receptor alpha (PPARα) ortholog, for upregulation during E. faecalis infection. Thus, NHR-49 regulates an immunometabolic axis of survival in C. elegans by modulating breakdown of lipids as well as immune effector production upon E. faecalis exposure.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/inmunología , Coenzima A Ligasas/genética , Enterococcus faecalis/inmunología , Metabolismo de los Lípidos/inmunología , Oxigenasas/genética , Receptores Citoplasmáticos y Nucleares/genética , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/microbiología , Proteínas de Caenorhabditis elegans/inmunología , Coenzima A Ligasas/inmunología , Cryptococcus neoformans/crecimiento & desarrollo , Cryptococcus neoformans/inmunología , Enterococcus faecalis/crecimiento & desarrollo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata , Gotas Lipídicas/inmunología , Gotas Lipídicas/metabolismo , Longevidad/genética , Longevidad/inmunología , Oxigenasas/inmunología , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/inmunología , Receptores Citoplasmáticos y Nucleares/inmunología , Transducción de Señal
19.
Cytokine ; 125: 154811, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31446178

RESUMEN

Newcastle disease virus (NDV) infects domestic and wild avian species with high mortality and morbidity worldwide. Although this disease is mainly controlled through NDV vaccines, alternative use of antiviral compounds is increasingly under study. Resiquimod (R-848), an imidazoquinoline compound is a potent synthetic agonist of Toll-like receptor 7 (TLR7). Until now reports regarding the adjuvant potential of resiquimod is well established against human viruses but has been less explored against avian viruses. In the present study, we have analysed the anti-NDV effect of resiquimod in chicken embryo fibroblast cells (DF-1) and embryonated chicken eggs. About 70% reduction in NDV replication was observed 48 h and 72 h post-resiquimod treatment in DF-1 cells. Furthermore, differential host genes expression was observed in resiquimod treated DF-1 cells, PBMCs, and tissue sample of chicken embryos at a different time point. Among all the analyzed genes, significant up-regulation of viperin, IFNα, IFNγ, IL-1ß, TNFα, IL18 were observed in its transcriptional level. Furthermore, resiquimod treatment showed NDV reduction in two weeks old chickens. About 61% and 38% reduction in NDV replication was observed 72 h post-infection in lungs and spleen, respectively. The study suggests the modulation of host innate immunity regulatory genes by resiquimod, which eventually modulates the NDV replication. The result of the study could be explored further to establish resiquimod as an alternative antiviral compound against NDV.


Asunto(s)
Citocinas/metabolismo , Imidazoles/farmacología , Inmunidad Innata/efectos de los fármacos , Virus de la Enfermedad de Newcastle/efectos de los fármacos , Enfermedades de las Aves de Corral/tratamiento farmacológico , Receptor Toll-Like 7/metabolismo , Replicación Viral/efectos de los fármacos , Adyuvantes Inmunológicos/farmacología , Animales , Línea Celular , Embrión de Pollo , Fibroblastos/metabolismo , Interferón-alfa/metabolismo , Interferón gamma/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Pulmón/efectos de los fármacos , Pulmón/virología , Virus de la Enfermedad de Newcastle/genética , Virus de la Enfermedad de Newcastle/metabolismo , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/metabolismo , Bazo/efectos de los fármacos , Bazo/virología , Receptor Toll-Like 7/agonistas , Factor de Necrosis Tumoral alfa/metabolismo
20.
Mycopathologia ; 185(3): 591-594, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32270395

RESUMEN

Penicillium oxalicum strain SGAir0226 was isolated from a tropical air sample collected in Singapore. The complete genome was assembled from long reads obtained from single-molecule real-time sequencing and was further polished and error corrected using short read sequencing data. The assembly comprises 20 contigs with a total length of 30.7 Mb. The genome was predicted to contain 8310 protein-coding genes, 237 tRNAs and 83 rRNAs.


Asunto(s)
Microbiología del Aire , Genoma Fúngico , Penicillium/genética , ARN de Hongos/química , Anotación de Secuencia Molecular , Penicillium/química , Penicillium/clasificación , Penicillium/aislamiento & purificación , Filogenia , ARN de Hongos/aislamiento & purificación , ARN Ribosómico/química , ARN Ribosómico/aislamiento & purificación , ARN de Transferencia/química , ARN de Transferencia/aislamiento & purificación , Singapur , Clima Tropical
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