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1.
Proc Natl Acad Sci U S A ; 120(20): e2208673120, 2023 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-37155900

RESUMEN

The immune deficiency (IMD) pathway directs host defense in arthropods upon bacterial infection. In Pancrustacea, peptidoglycan recognition proteins sense microbial moieties and initiate nuclear factor-κB-driven immune responses. Proteins that elicit the IMD pathway in non-insect arthropods remain elusive. Here, we show that an Ixodes scapularis homolog of croquemort (Crq), a CD36-like protein, promotes activation of the tick IMD pathway. Crq exhibits plasma membrane localization and binds the lipid agonist 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol. Crq regulates the IMD and jun N-terminal kinase signaling cascades and limits the acquisition of the Lyme disease spirochete B. burgdorferi. Additionally, nymphs silenced for crq display impaired feeding and delayed molting to adulthood due to a deficiency in ecdysteroid synthesis. Collectively, we establish a distinct mechanism for arthropod immunity outside of insects and crustaceans.


Asunto(s)
Artrópodos , Infecciones Bacterianas , Borrelia burgdorferi , Ixodes , Enfermedad de Lyme , Animales , Ixodes/microbiología , Borrelia burgdorferi/genética , FN-kappa B , Enfermedad de Lyme/microbiología
2.
J Biomol NMR ; 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38856928

RESUMEN

Deuterium (2H) spin relaxation of 13CH2D methyl groups has been widely applied to investigate picosecond-to-nanosecond conformational dynamics in proteins by solution-state NMR spectroscopy. The B0 dependence of the 2H spin relaxation rates is represented by a linear relationship between the spectral density function at three discrete frequencies J(0), J(ωD) and J(2ωD). In this study, the linear relation between 2H relaxation rates at B0 fields separated by a factor of two and the interpolation of rates at intermediate frequencies are combined for a more robust approach for spectral density mapping. The general usefulness of the approach is demonstrated on a fractionally deuterated (55%) and alternate 13C-12C labeled sample of E. coli RNase H. Deuterium relaxation rate constants (R1, R1ρ, RQ, RAP) were measured for 57 well-resolved 13CH2D moieties in RNase H at 1H frequencies of 475 MHz, 500 MHz, 900 MHz, and 950 MHz. The spectral density mapping of the 475/950 MHz data combination was performed independently and jointly to validate the expected relationship between data recorded at B0 fields separated by a factor of two. The final analysis was performed by jointly analyzing 475/950 MHz rates with 700 MHz rates interpolated from 500/900 MHz data to yield six J(ωD) values for each methyl peak. The J(ω) profile for each peak was fit to the original (τM, Sf2, τf) or extended model-free function (τM, Sf2, Ss2, τf, τs) to obtain optimized dynamic parameters.

3.
J Chem Inf Model ; 64(8): 3477-3487, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38605537

RESUMEN

Allostery is an essential biological phenomenon in which perturbation at one site in a biomolecule elicits a functional response at a distal location(s). It is integral to biological processes, such as cellular signaling, metabolism, and transcription regulation. Understanding allostery is also crucial for rational drug discovery. In this work, we focus on an allosteric S100B protein that belongs to the S100 class of EF-hand Ca2+-binding proteins. The Ca2+-binding affinity of S100B is modulated allosterically by TRTK-12 peptide binding 25 Å away from the Ca2+-binding site. We investigated S100B allostery by carrying out nuclear magnetic resonance (NMR) measurements along with microsecond-long molecular dynamics (MD) simulations on S100B/Ca2+ with/without TRTK-12 at different NaCl salt concentrations. NMR HSQC results show that TRTK-12 reorganizes how S100B/Ca2+ responds to different salt concentrations at both orthosteric and allosteric sites. The MD data suggest that TRTK-12 breaks the dynamic aromatic and hydrogen-bond interactions (not observed in X-ray crystallographic structures) between the hinge/helix and Ca2+-binding EF-hand loop of the two subunits in the homodimeric protein. This triggers rearrangement in the protein network architectures and leads to allosteric communication. Finally, computational studies of S100B at distinct ionic strengths suggest that ligand-bound species are more robust to the changing environment relative to the S100B/Ca2+ complex.


Asunto(s)
Proteína CapZ , Simulación de Dinámica Molecular , Subunidad beta de la Proteína de Unión al Calcio S100 , Regulación Alostérica , Subunidad beta de la Proteína de Unión al Calcio S100/química , Subunidad beta de la Proteína de Unión al Calcio S100/metabolismo , Calcio/metabolismo , Humanos , Transducción de Señal , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Oligopéptidos/química , Oligopéptidos/metabolismo , Unión Proteica , Conformación Proteica
4.
Ann Hum Biol ; 51(1): 2298474, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38293777

RESUMEN

BACKGROUND: Lack of paediatric reference data limits the utility of handgrip strength as a measure of fitness and well-being. AIM: To develop paediatric handgrip reference curves and evaluate associations with body size and composition and race/ethnicity group. SUBJECTS AND METHODS: Handgrip, body size and composition data were obtained from National Health and Nutrition Examination Survey 2011-2014 participants aged 6-20 years. Densitometry-derived fat and appendicular lean soft tissue mass index Z-scores (FMIZ, ALSTMIZ) were generated in participants >8 years. Dominant and non-dominant handgrip reference curves were created using the LMS method. Analyses included sample weights to produce nationally representative estimates. RESULTS: Differences in handgrip strength according to hand dominance increased with age. Handgrip strength was associated with height and arm length Z-scores (R = 0.42 to 0.47) and ALSTMIZ (R = 0.54). Handgrip strength was higher in the non-Hispanic Black group and lower in the Mexican American compared to non-Hispanic White group. Group differences were attenuated when adjusted for height, arm length or ALSTMIZ. CONCLUSION: Paediatric handgrip reference curves were generated from which individual Z-scores can be calculated separately for dominant versus non-dominant hand and adjusted for body size. Association with ALSTMIZ suggests handgrip Z-score may be used as a measure of functional body composition.


Asunto(s)
Composición Corporal , Fuerza de la Mano , Humanos , Niño , Encuestas Nutricionales , Tamaño Corporal , Valores de Referencia
5.
Wilderness Environ Med ; 35(1_suppl): 20S-44S, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37945433

RESUMEN

To provide guidance to the general public, clinicians, and avalanche professionals about best practices, the Wilderness Medical Society convened an expert panel to revise the evidence-based guidelines for the prevention, rescue, and resuscitation of avalanche and nonavalanche snow burial victims. The original panel authored the Wilderness Medical Society Practice Guidelines for Prevention and Management of Avalanche and Nonavalanche Snow Burial Accidents in 2017. A second panel was convened to update these guidelines and make recommendations based on quality of supporting evidence.


Asunto(s)
Avalanchas , Nieve , Accidentes , Entierro , Sociedades Médicas , Humanos
6.
Wilderness Environ Med ; 35(2): 198-218, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38651342

RESUMEN

The Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an update of the 2014 version of the "WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments" published in Wilderness & Environmental Medicine 2014; 25:41-49.


Asunto(s)
Dolor Agudo , Manejo del Dolor , Sociedades Médicas , Medicina Silvestre , Medicina Silvestre/normas , Medicina Silvestre/métodos , Humanos , Dolor Agudo/terapia , Dolor Agudo/tratamiento farmacológico , Manejo del Dolor/métodos , Manejo del Dolor/normas , Configuración de Recursos Limitados
7.
Clin Infect Dis ; 76(3): e34-e41, 2023 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35997795

RESUMEN

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic had a considerable impact on US healthcare systems, straining hospital resources, staff, and operations. However, a comprehensive assessment of the impact on healthcare-associated infections (HAIs) across different hospitals with varying level of infectious disease (ID) physician expertise, resources, and infrastructure is lacking. METHODS: This retrospective longitudinal multicenter cohort study included central-line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), Clostridioides difficile infections (CDIs), and ventilator-associated events (VAEs) from 53 hospitals (academic and community) in Southeastern United States from 1 January 2018 to 31 March 2021. Segmented negative binomial regression generalized estimating equations models estimated changes in monthly incidence rates in the baseline (01/2018-02/2020) compared to the pandemic period (03/2020-03/2021, further divided into three pandemic phases). RESULTS: CLABSIs and VAEs increased by 24% and 34%, respectively, during the pandemic period. VAEs increased in all phases of the pandemic, while CLABSIs increased in later phases of the pandemic. CDI trend increased by 4.2% per month in the pandemic period. On stratifying the analysis by hospital characteristics, the impact of the pandemic on healthcare-associated infections was more significant in smaller sized and community hospitals. CAUTIs did not change significantly during the pandemic across all hospital types. CONCLUSIONS: CLABSIs, VAEs, and CDIs increased significantly during the pandemic, especially in smaller community hospitals, most of which lack ID physician expertise. Future efforts should focus on better understanding challenges faced by community hospitals, strengthening the infection prevention infrastructure, and expanding the ID workforce, particularly to community hospitals.


Asunto(s)
COVID-19 , Infecciones Relacionadas con Catéteres , Infecciones por Clostridium , Enfermedades Transmisibles , Infección Hospitalaria , Infecciones Urinarias , Humanos , Infecciones Relacionadas con Catéteres/prevención & control , Hospitales Comunitarios , Estudios Retrospectivos , Estudios de Cohortes , Pandemias , COVID-19/epidemiología , COVID-19/complicaciones , Infección Hospitalaria/prevención & control , Enfermedades Transmisibles/epidemiología , Infecciones Urinarias/epidemiología , Infecciones por Clostridium/epidemiología
8.
J Clin Microbiol ; 61(12): e0073123, 2023 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-38014985

RESUMEN

IMPORTANCE: Despite the relatively high mortality and the difficulty in diagnosis, nearly one-third of patients hospitalized with a documented diagnosis of encephalitis did not undergo a lumbar puncture (LP). When an LP was performed, pathogen-specific testing was greatly underutilized. Infectious etiologies were most common, but over 40% of cases were idiopathic at discharge. These findings suggest that there is a substantial opportunity to improve the quality of care through more accurate and timely diagnosis.


Asunto(s)
Líquidos Corporales , Encefalitis , Humanos , North Carolina/epidemiología , Encefalitis/diagnóstico , Encefalitis/epidemiología , Punción Espinal
9.
Crit Care Med ; 51(11): 1570-1586, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37902340

RESUMEN

RATIONALE: Fever is frequently an early indicator of infection and often requires rigorous diagnostic evaluation. OBJECTIVES: This is an update of the 2008 Infectious Diseases Society of America and Society (IDSA) and Society of Critical Care Medicine (SCCM) guideline for the evaluation of new-onset fever in adult ICU patients without severe immunocompromise, now using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. PANEL DESIGN: The SCCM and IDSA convened a taskforce to update the 2008 version of the guideline for the evaluation of new fever in critically ill adult patients, which included expert clinicians as well as methodologists from the Guidelines in Intensive Care, Development and Evaluation Group. The guidelines committee consisted of 12 experts in critical care, infectious diseases, clinical microbiology, organ transplantation, public health, clinical research, and health policy and administration. All task force members followed all conflict-of-interest procedures as documented in the American College of Critical Care Medicine/SCCM Standard Operating Procedures Manual and the IDSA. There was no industry input or funding to produce this guideline. METHODS: We conducted a systematic review for each population, intervention, comparison, and outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the GRADE approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak or as best-practice statements. RESULTS: The panel issued 12 recommendations and 9 best practice statements. The panel recommended using central temperature monitoring methods, including thermistors for pulmonary artery catheters, bladder catheters, or esophageal balloon thermistors when these devices are in place or accurate temperature measurements are critical for diagnosis and management. For patients without these devices in place, oral or rectal temperatures over other temperature measurement methods that are less reliable such as axillary or tympanic membrane temperatures, noninvasive temporal artery thermometers, or chemical dot thermometers were recommended. Imaging studies including ultrasonography were recommended in addition to microbiological evaluation using rapid diagnostic testing strategies. Biomarkers were recommended to assist in guiding the discontinuation of antimicrobial therapy. All recommendations issued were weak based on the quality of data. CONCLUSIONS: The guidelines panel was able to formulate several recommendations for the evaluation of new fever in a critically ill adult patient, acknowledging that most recommendations were based on weak evidence. This highlights the need for the rapid advancement of research in all aspects of this issue-including better noninvasive methods to measure core body temperature, the use of diagnostic imaging, advances in microbiology including molecular testing, and the use of biomarkers.


Asunto(s)
Enfermedades Transmisibles , Enfermedad Crítica , Humanos , Adulto , Enfermedad Crítica/terapia , Fiebre/diagnóstico , Cuidados Críticos/métodos , Unidades de Cuidados Intensivos , Biomarcadores
10.
Circ Res ; 129(12): e215-e233, 2021 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-34702049

RESUMEN

RATIONALE: Vascular smooth muscle cells (SMCs) exhibit remarkable plasticity and can undergo dedifferentiation upon pathological stimuli associated with disease and interventions. OBJECTIVE: Although epigenetic changes are critical in SMC phenotype switching, a fundamental regulator that governs the epigenetic machineries regulating the fate of SMC phenotype has not been elucidated. METHODS AND RESULTS: Using SMCs, mouse models, and human atherosclerosis specimens, we found that FAK (focal adhesion kinase) activation elicits SMC dedifferentiation by stabilizing DNMT3A (DNA methyltransferase 3A). FAK in SMCs is activated in the cytoplasm upon serum stimulation in vitro or vessel injury and active FAK prevents DNMT3A from nuclear FAK-mediated degradation. However, pharmacological or genetic FAK catalytic inhibition forced FAK nuclear localization, which reduced DNMT3A protein via enhanced ubiquitination and proteasomal degradation. Reduced DNMT3A protein led to DNA hypomethylation in contractile gene promoters, which increased SMC contractile protein expression. RNA-sequencing identified SMC contractile genes as a foremost upregulated group by FAK inhibition from injured femoral artery samples compared with vehicle group. DNMT3A knockdown in injured arteries reduced DNA methylation and enhanced contractile gene expression supports the notion that nuclear FAK-mediated DNMT3A degradation via E3 ligase TRAF6 (TNF [tumor necrosis factor] receptor-associated factor 6) drives differentiation of SMCs. Furthermore, we observed that SMCs of human atherosclerotic lesions exhibited decreased nuclear FAK, which was associated with increased DNMT3A levels and decreased contractile gene expression. CONCLUSIONS: This study reveals that nuclear FAK induced by FAK catalytic inhibition specifically suppresses DNMT3A expression in injured vessels resulting in maintaining SMC differentiation by promoting the contractile gene expression. Thus, FAK inhibitors may provide a new treatment option to block SMC phenotypic switching during vascular remodeling and atherosclerosis.


Asunto(s)
Desdiferenciación Celular , Proteínas Contráctiles/genética , Metilación de ADN , Quinasa 1 de Adhesión Focal/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Animales , Células Cultivadas , Proteínas Contráctiles/metabolismo , ADN Metiltransferasa 3A/genética , ADN Metiltransferasa 3A/metabolismo , Quinasa 1 de Adhesión Focal/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Ratones Endogámicos C57BL , Músculo Liso Vascular/citología , Miocitos del Músculo Liso/citología , Miocitos del Músculo Liso/fisiología , Proteolisis , Ubiquitinación , Regulación hacia Arriba
11.
Infection ; 51(6): 1759-1765, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37501013

RESUMEN

PURPOSE: Fever is a common cause for hospitalization among the pediatric population. The spectrum of causative agents is diverse. Human herpesvirus 6 (HHV-6) is a ubiquitous virus that often causes hospitalization of children in western countries. Previously, we investigated the cause of fever of 600 febrile hospitalized children in Gabon, and in 91 cases the causative pathogen was not determined. In this study, we assessed HHV-6 infection as potential cause of hospitalization in this group. METHODS: Blood samples were assessed for HHV-6 using real-time quantitative PCR. Three groups were investigated: (1) group of interest: 91 hospitalized children with febrile illness without a diagnosed causing pathogen; (2) hospitalized control: 91 age-matched children hospitalized with febrile illness with a potentially disease-causing pathogen identified; both groups were recruited at the Albert Schweitzer Hospital in Lambaréné, Gabon and (3) healthy control: 91 healthy children from the same area. RESULTS: Samples from 273 children were assessed. Age range was two months to 14 years, median (IQR) age was 36 (12-71) months; 52% were female. HHV-6 was detected in 64% (58/91), 41% (37/91), and 26% (24/91) of the samples from groups 1, 2, and 3, respectively; with statistically significant odds of being infected with HHV-6 in group 1 (OR = 4.62, 95% CI [2.46, 8.90]). Only HHV-6B was detected. CONCLUSIONS: Although tropical diseases account for a large proportion of children's hospitalizations, considering common childhood diseases such as HHV-6 when diagnosing febrile illnesses in pediatric populations in tropical countries is of importance.


Asunto(s)
Infecciones por Herpesviridae , Herpesvirus Humano 6 , Niño , Humanos , Femenino , Lactante , Preescolar , Masculino , Herpesvirus Humano 6/genética , Niño Hospitalizado , Gabón/epidemiología , Fiebre/epidemiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Infecciones por Herpesviridae/complicaciones , Infecciones por Herpesviridae/diagnóstico
12.
Pediatr Blood Cancer ; : e30419, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37194624

RESUMEN

Complex lymphatic anomalies are debilitating conditions characterized by aberrant development of the lymphatic vasculature (lymphangiogenesis). Diagnosis is typically made by history, examination, radiology, and histologic findings. However, there is significant overlap between conditions, making accurate diagnosis difficult. Recently, genetic analysis has been offered as an additional diagnostic modality. Here, we describe four cases of complex lymphatic anomalies, all with PIK3CA variants but with varying clinical phenotypes. Identification of PIK3CA resulted in transition to a targeted inhibitor, alpelisib. These cases highlight the genetic overlap between phenotypically diverse lymphatic anomalies.

13.
Bioorg Chem ; 139: 106700, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37392559

RESUMEN

Galeterone, 3ß-(hydroxy)-17-(1H-benzimidazole-1-yl)androsta-5,16-diene (Gal, 1) and VNPP433-3ß, 3ß-(1H-imidazole-1-yl-17-(1H-benzimidazole-1-yl)androsta-5,16-diene (2) are potent molecular glue degrader modulators of AR/AR-V7 and Mnk1/2-eIF4E signaling pathways, and are promising Phase 3 and Phase 1 drug candidates, respectively. Because appropriate salts can be utilized to create new chemical entities with enhanced aqueous solubility, in vivo pharmacokinetics, and enhanced in vitro and in vivo efficacies, the monohydrochloride salt of Gal (3) and the mono- and di-hydrochlorides salts of compound 2, compounds 4 and 5, respectively, were synthesized. The salts were characterized using 1H NMR, 13C NMR and HRMS analyses. Compound 3 displayed enhanced in vitro antiproliferative activity (7.4-fold) against three prostate cancer cell lines but surprisingly decreased plasma exposure in the pharmacokinetics study. The antiproliferative activities of the compound 2 salts (4 and 5) were equivalent to that of compound 2, but their oral pharmacokinetic profiles were significantly enhanced. Finally, and most importantly, oral administration of the parent compounds (1 and 2) and their corresponding salts (3, 4 and 5) caused dose-dependent potent inhibition/regression of aggressive and difficult-to-treat CWR22Rv1 tumor xenografts growth, with no apparent host toxicities and were highly more efficacious than the blockbuster FDA-approved prostate cancer drugs, Enzalutamide (Xtandi) and Docetaxel (Taxotere). Thus, the HCl salts of Gal (3) and VNPP433-3ß (4 and 5) are excellent orally bioavailable candidates for clinical development.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Masculino , Humanos , Animales , Ratones , Docetaxel/farmacología , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Xenoinjertos , Sales (Química) , Receptores Androgénicos/metabolismo , Nitrilos , Bencimidazoles/uso terapéutico , Línea Celular Tumoral
14.
Nucleic Acids Res ; 49(3): 1235-1246, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33398344

RESUMEN

We have identified chemical probes that simultaneously inhibit cancer cell progression and an immune checkpoint. Using the computational Site Identification by Ligand Competitive Saturation (SILCS) technology, structural biology and cell-based assays, we identify small molecules that directly and selectively bind to the RNA Recognition Motif (RRM) of hnRNP A18, a regulator of protein translation in cancer cells. hnRNP A18 recognizes a specific RNA signature motif in the 3'UTR of transcripts associated with cancer cell progression (Trx, VEGF, RPA) and, as shown here, a tumor immune checkpoint (CTLA-4). Post-transcriptional regulation of immune checkpoints is a potential therapeutic strategy that remains to be exploited. The probes target hnRNP A18 RRM in vitro and in cells as evaluated by cellular target engagement. As single agents, the probes specifically disrupt hnRNP A18-RNA interactions, downregulate Trx and CTLA-4 protein levels and inhibit proliferation of several cancer cell lines without affecting the viability of normal epithelial cells. These first-in-class chemical probes will greatly facilitate the elucidation of the underexplored biological function of RNA Binding Proteins (RBPs) in cancer cells, including their effects on proliferation and immune checkpoint activation.


Asunto(s)
Antineoplásicos/farmacología , Proteínas de Unión al ARN/antagonistas & inhibidores , Animales , Antineoplásicos/uso terapéutico , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Línea Celular Tumoral , Humanos , Ligandos , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Resonancia Magnética Nuclear Biomolecular , Biosíntesis de Proteínas , ARN/metabolismo , Motivo de Reconocimiento de ARN , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/metabolismo
15.
Proc Natl Acad Sci U S A ; 117(2): 1049-1058, 2020 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-31896582

RESUMEN

Targeting Clostridium difficile infection is challenging because treatment options are limited, and high recurrence rates are common. One reason for this is that hypervirulent C. difficile strains often have a binary toxin termed the C. difficile toxin, in addition to the enterotoxins TsdA and TsdB. The C. difficile toxin has an enzymatic component, termed CDTa, and a pore-forming or delivery subunit termed CDTb. CDTb was characterized here using a combination of single-particle cryoelectron microscopy, X-ray crystallography, NMR, and other biophysical methods. In the absence of CDTa, 2 di-heptamer structures for activated CDTb (1.0 MDa) were solved at atomic resolution, including a symmetric (SymCDTb; 3.14 Å) and an asymmetric form (AsymCDTb; 2.84 Å). Roles played by 2 receptor-binding domains of activated CDTb were of particular interest since the receptor-binding domain 1 lacks sequence homology to any other known toxin, and the receptor-binding domain 2 is completely absent in other well-studied heptameric toxins (i.e., anthrax). For AsymCDTb, a Ca2+ binding site was discovered in the first receptor-binding domain that is important for its stability, and the second receptor-binding domain was found to be critical for host cell toxicity and the di-heptamer fold for both forms of activated CDTb. Together, these studies represent a starting point for developing structure-based drug-design strategies to target the most severe strains of C. difficile.


Asunto(s)
ADP Ribosa Transferasas/química , ADP Ribosa Transferasas/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Clostridioides difficile/metabolismo , Enterotoxinas/química , Enterotoxinas/metabolismo , ADP Ribosa Transferasas/genética , Animales , Proteínas Bacterianas/genética , Sitios de Unión , Fenómenos Biofísicos , Chlorocebus aethiops , Microscopía por Crioelectrón , Cristalografía por Rayos X , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica , Dominios Proteicos , Células Vero
16.
J Infect Dis ; 226(Suppl 4): S456-S462, 2022 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-36265849

RESUMEN

The United States varicella vaccination program has successfully reduced varicella incidence and hospitalizations by ≥90%, consequently reducing the risk of nosocomial exposures. However, patients and healthcare personnel (HCP) continue to introduce varicella zoster virus (VZV) into healthcare settings. Herpes zoster (HZ) is less contagious than varicella, but it can also result in exposures. Unrecognized varicella and HZ may lead to extensive contact investigations, control efforts, and HCP furloughs that result in significant disruption of healthcare activities as well as substantial costs. Robust occupational health and infection prevention programs that ensure healthcare personnel immunity and prompt recognition and isolation of patients with varicella or HZ will lower the risk of VZV transmission and reduce or eliminate the need to furlough exposed HCP and associated costs.


Asunto(s)
Varicela , Infección Hospitalaria , Herpes Zóster , Humanos , Estados Unidos/epidemiología , Varicela/epidemiología , Varicela/prevención & control , Herpesvirus Humano 3 , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Herpes Zóster/epidemiología , Herpes Zóster/prevención & control , Vacunación , Vacuna contra la Varicela
17.
Clin Infect Dis ; 74(4): 648-656, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34017999

RESUMEN

BACKGROUND: Shedding of Clostridioides difficile spores from infected individuals contaminates the hospital environment and contributes to infection transmission. We assessed whether antibiotic selection affects C. difficile shedding and contamination of the hospital environment. METHODS: In this prospective, unblinded, randomized controlled trial of hospitalized adults with C. difficile infection, patients were randomized 1:1:1 to receive fidaxomicin, oral vancomycin, or metronidazole. The primary outcome was change in environmental contamination rate during treatment. Secondary outcomes included stool shedding, total burden of contamination, and molecular relatedness of stool versus environmental C. difficile isolates. RESULTS: Of 33 patients enrolled, 31 (94%) completed the study. Fidaxomicin (-0.36 log10 colony-forming units [CFUs]/d [95% confidence interval (CI), -.52 to -.19]; P < .01) and vancomycin (-0.17 log10 CFUs/d [-.34 to -.01]; P = .05) were associated with more rapid decline in C. difficile shedding than metronidazole (-0.01 log10 CFUs/d [95% CI, -.10 to .08). Both vancomycin (6.3% [95% CI, 4.7-8.3) and fidaxomicin (13.1% [10.7-15.9]) were associated with lower rates of environmental contamination than metronidazole (21.4% [18.0-25.2]). With specific modeling of within-subject change over time, fidaxomicin (adjusted odds ratio, 0.83 [95% CI, .70-.99]; P = .04) was associated with more rapid decline in environmental contamination than vancomycin or metronidazole. Overall, 207 of 233 environmental C. difficile isolates (88.8%) matched patient stool isolates by ribotyping, without significant difference by treatment. CONCLUSIONS: Fidaxomicin, and to a lesser extent vancomycin, reduces C. difficile shedding and contamination of the hospital environment relative to metronidazole. Treatment choice may play a role in reducing healthcare-associated C. difficile transmission. CLINICAL TRIALS REGISTRATION: NCT02057198.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Adulto , Aminoglicósidos/farmacología , Aminoglicósidos/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Clostridioides , Infecciones por Clostridium/tratamiento farmacológico , Fidaxomicina/uso terapéutico , Humanos , Metronidazol/farmacología , Metronidazol/uso terapéutico , Estudios Prospectivos , Vancomicina/farmacología , Vancomicina/uso terapéutico
18.
Clin Infect Dis ; 75(1): e307-e309, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-35023553

RESUMEN

We assessed environmental contamination of inpatient rooms housing coronavirus disease 2019 (COVID-19) patients in a dedicated COVID-19 unit. Contamination with severe acute respiratory syndrome coronavirus 2 was found on 5.5% (19/347) of surfaces via reverse transcriptase polymerase chain reaction and 0.3% (1/347) of surfaces via cell culture. Environmental contamination is uncommon in hospitals rooms; RNA presence is not a specific indicator of infectious virus.


Asunto(s)
COVID-19 , SARS-CoV-2 , Técnicas de Cultivo , Contaminación Ambiental/análisis , Hospitales , Humanos , ARN Viral
19.
Kidney Int ; 102(4): 894-903, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35752324

RESUMEN

Azithromycin is an antibiotic with QT-prolonging potential commonly prescribed to individuals receiving hemodialysis. Hemodialysis patients have a high prevalence of clinical conditions, such as structural heart disease, that can enhance the pro-arrhythmic effects azithromycin, but were excluded from prior investigations evaluating the cardiac safety of azithromycin. Using data from the United States Renal Data System (2007-2017), we conducted two cohort studies to examine the cardiac safety of azithromycin relative to amoxicillin-based antibiotics (amoxicillin, amoxicillin/clavulanic acid) and levofloxacin (a fluoroquinolone antibiotic known to prolong the QT-interval) in the hemodialysis population. The primary outcome was five-day sudden cardiac death. Using inverse probability of treatment weighted survival models, we estimated hazard ratios, risk differences, and 95% confidence intervals. The azithromycin vs. amoxicillin-based antibiotic cohort included 282,899 patients and 725,431 treatment episodes (381,306 azithromycin and 344,125 amoxicillin-based episodes). Azithromycin vs. amoxicillin-based antibiotic treatment was associated with higher relative and absolute risks of sudden cardiac death, weighted hazard ratio of 1.70 (95% Confidence Interval, 1.36 to 2.11) and weighted risk difference per 100,000 treatment episodes of 25.0 (15.5 to 36.5). The azithromycin vs. levofloxacin cohort included 245,143 patients and 554,557 treatment episodes (387,382 azithromycin and 167,175 levofloxacin episodes). Azithromycin vs. levofloxacin treatment was associated with lower relative and absolute risks of sudden cardiac death, weighted hazard ratio of 0.79 (0.64 to 0.96) and weighted risk difference per 100,000 treatment episodes of -18.9 (-35.5 to -3.8). Thus, when selecting among azithromycin, levofloxacin, and amoxicillin-based antibiotics, clinicians should weigh the relative antimicrobial benefits of these drugs against their potential cardiac risks.


Asunto(s)
Azitromicina , Insuficiencia Renal , Amoxicilina , Combinación Amoxicilina-Clavulanato de Potasio , Antibacterianos/efectos adversos , Azitromicina/efectos adversos , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/etiología , Fluoroquinolonas , Humanos , Levofloxacino/efectos adversos , Diálisis Renal/efectos adversos , Insuficiencia Renal/inducido químicamente , Estados Unidos/epidemiología
20.
Mol Carcinog ; 61(7): 643-654, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35512605

RESUMEN

Cancer stem cells (CSCs) virtually present in all tumors albeit in small numbers are primarily responsible for driving cancer progression, metastasis, drug resistance, and recurrence. Prostate cancer (PCa) is the second most frequent cancer in men worldwide, and castration resistant prostate cancer (CRPC) remains a major challenge despite the tremendous advancements in medicine. Currently, none of the available treatment options are effective in treating CRPC. We earlier reported that VNPP433-3ß, the lead next-generation galeterone analog is effective in treating preclinical in vivo models of CRPC. In this study using RNA-seq, cytological, and biochemical methods, we report that VNPP433-3ß inhibits prostate CSCs by targeting key pathways critical to stemness and epithelial-mesenchymal transition. VNPP433-3ß inhibits CSCs in PCa, presumably by degrading the androgen receptor (AR) thereby decreasing the AR-mediated transcription of several stem cell markers including BMI1 and KLF4. Transcriptome analyses by RNA-seq, Ingenuity Pathway Analysis, and Gene Set Enrichment Analysis demonstrate that VNPP433-3ß inhibits transcription of several genes and functional pathways critical to the prostate CSCs thereby inhibiting CSCs in PCa besides targeting the bulk of the tumor.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Androstadienos , Bencimidazoles , Línea Celular Tumoral , Transición Epitelial-Mesenquimal , Perfilación de la Expresión Génica , Humanos , Masculino , Células Madre Neoplásicas/patología , Próstata/patología , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo
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