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1.
Cell ; 150(3): 470-80, 2012 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-22863002

RESUMEN

Many of the immune and metabolic changes occurring during normal pregnancy also describe metabolic syndrome. Gut microbiota can cause symptoms of metabolic syndrome in nonpregnant hosts. Here, to explore their role in pregnancy, we characterized fecal bacteria of 91 pregnant women of varying prepregnancy BMIs and gestational diabetes status and their infants. Similarities between infant-mother microbiotas increased with children's age, and the infant microbiota was unaffected by mother's health status. Gut microbiota changed dramatically from first (T1) to third (T3) trimesters, with vast expansion of diversity between mothers, an overall increase in Proteobacteria and Actinobacteria, and reduced richness. T3 stool showed strongest signs of inflammation and energy loss; however, microbiome gene repertoires were constant between trimesters. When transferred to germ-free mice, T3 microbiota induced greater adiposity and insulin insensitivity compared to T1. Our findings indicate that host-microbial interactions that impact host metabolism can occur and may be beneficial in pregnancy.


Asunto(s)
Heces/microbiología , Tracto Gastrointestinal/microbiología , Metagenoma , Embarazo , Actinobacteria/aislamiento & purificación , Animales , Femenino , Vida Libre de Gérmenes , Humanos , Lactante , Síndrome Metabólico/microbiología , Ratones , Proteobacteria/aislamiento & purificación
2.
Proc Natl Acad Sci U S A ; 120(24): e2302580120, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37276423

RESUMEN

AmiA and AmiB are peptidoglycan-hydrolyzing enzymes from Escherichia coli that are required to break the peptidoglycan layer during bacterial cell division and maintain integrity of the cell envelope. In vivo, the activity of AmiA and AmiB is tightly controlled through their interactions with the membrane-bound FtsEX-EnvC complex. Activation of AmiA and AmiB requires access to a groove in the amidase-activating LytM domain of EnvC which is gated by ATP-driven conformational changes in FtsEX-EnvC complex. Here, we present a high-resolution structure of the isolated AmiA protein, confirming that it is autoinhibited in the same manner as AmiB and AmiC, and a complex of the AmiB enzymatic domain bound to the activating EnvC LytM domain. In isolation, the active site of AmiA is blocked by an autoinhibitory helix that binds directly to the catalytic zinc and fills the volume expected to accommodate peptidoglycan binding. In the complex, binding of the EnvC LytM domain induces a conformational change that displaces the amidase autoinhibitory helix and reorganizes the active site for activity. Our structures, together with complementary mutagenesis work, defines the conformational changes required to activate AmiA and/or AmiB through their interaction with their cognate activator EnvC.


Asunto(s)
Proteínas de Escherichia coli , Proteínas de Escherichia coli/metabolismo , Peptidoglicano/metabolismo , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Escherichia coli/metabolismo , Amidohidrolasas/metabolismo , Proteínas Bacterianas/metabolismo
3.
Proc Natl Acad Sci U S A ; 120(8): e2215426120, 2023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36791100

RESUMEN

Blast disease in cereal plants is caused by the fungus Magnaporthe oryzae and accounts for a significant loss in food crops. At the outset of infection, expression of a putative polysaccharide monooxygenase (MoPMO9A) is increased. MoPMO9A contains a catalytic domain predicted to act on cellulose and a carbohydrate-binding domain that binds chitin. A sequence similarity network of the MoPMO9A family AA9 showed that 220 of the 223 sequences in the MoPMO9A-containing cluster of sequences have a conserved unannotated region with no assigned function. Expression and purification of the full length and two MoPMO9A truncations, one containing the catalytic domain and the domain of unknown function (DUF) and one with only the catalytic domain, were carried out. In contrast to other AA9 polysaccharide monooxygenases (PMOs), MoPMO9A is not active on cellulose but showed activity on cereal-derived mixed (1→3, 1→4)-ß-D-glucans (MBG). Moreover, the DUF is required for activity. MoPMO9A exhibits activity consistent with C4 oxidation of the polysaccharide and can utilize either oxygen or hydrogen peroxide as a cosubstrate. It contains a predicted 3-dimensional fold characteristic of other PMOs. The DUF is predicted to form a coiled-coil with six absolutely conserved cysteines acting as a zipper between the two α-helices. MoPMO9A substrate specificity and domain architecture are different from previously characterized AA9 PMOs. The results, including a gene ontology analysis, support a role for MoPMO9A in MBG degradation during plant infection. Consistent with this analysis, deletion of MoPMO9A results in reduced pathogenicity.


Asunto(s)
Ascomicetos , Magnaporthe , Oryza , Oxigenasas de Función Mixta/metabolismo , Polisacáridos/metabolismo , Celulosa/metabolismo , Ascomicetos/metabolismo , Magnaporthe/genética , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/metabolismo , Oryza/metabolismo
4.
Mol Psychiatry ; 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38383768

RESUMEN

White matter (WM) fiber tract differences are present in autism spectrum disorder (ASD) and could be important markers of behavior. One of the earliest phenotypic differences in ASD are language atypicalities. Although language has been linked to WM in typical development, no work has evaluated this association in early ASD. Participants came from the Infant Brain Imaging Study and included 321 infant siblings of children with ASD at high likelihood (HL) for developing ASD; 70 HL infants were later diagnosed with ASD (HL-ASD), and 251 HL infants were not diagnosed with ASD (HL-Neg). A control sample of 140 low likelihood infants not diagnosed with ASD (LL-Neg) were also included. Infants contributed expressive language, receptive language, and diffusion tensor imaging data at 6-, 12-, and 24 months. Mixed effects regression models were conducted to evaluate associations between WM and language trajectories. Trajectories of microstructural changes in the right arcuate fasciculus were associated with expressive language development. HL-ASD infants demonstrated a different developmental pattern compared to the HL-Neg and LL-Neg groups, wherein the HL-ASD group exhibited a positive association between WM fractional anisotropy and language whereas HL-Neg and LL-Neg groups showed weak or no association. No other fiber tracts demonstrated significant associations with language. In conclusion, results indicated arcuate fasciculus WM is linked to language in early toddlerhood for autistic toddlers, with the strongest associations emerging around 24 months. To our knowledge, this is the first study to evaluate associations between language and WM development during the pre-symptomatic period in ASD.

5.
Nature ; 570(7759): 58-64, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31168105

RESUMEN

Biological invasions are both a pressing environmental challenge and an opportunity to investigate fundamental ecological processes, such as the role of top predators in regulating biodiversity and food-web structure. In whole-ecosystem manipulations of small Caribbean islands on which brown anole lizards (Anolis sagrei) were the native top predator, we experimentally staged invasions by competitors (green anoles, Anolis smaragdinus) and/or new top predators (curly-tailed lizards, Leiocephalus carinatus). We show that curly-tailed lizards destabilized the coexistence of competing prey species, contrary to the classic idea of keystone predation. Fear-driven avoidance of predators collapsed the spatial and dietary niche structure that otherwise stabilized coexistence, which intensified interspecific competition within predator-free refuges and contributed to the extinction of green-anole populations on two islands. Moreover, whereas adding either green anoles or curly-tailed lizards lengthened food chains on the islands, adding both species reversed this effect-in part because the apex predators were trophic omnivores. Our results underscore the importance of top-down control in ecological communities, but show that its outcomes depend on prey behaviour, spatial structure, and omnivory. Diversity-enhancing effects of top predators cannot be assumed, and non-consumptive effects of predation risk may be a widespread constraint on species coexistence.


Asunto(s)
Biodiversidad , Cadena Alimentaria , Lagartos/fisiología , Conducta Predatoria , Animales , Evolución Biológica , Biota , Conducta Competitiva , Conducta Alimentaria , Femenino , Lagartos/clasificación , Masculino , Especificidad de la Especie , Indias Occidentales
6.
Am J Respir Crit Care Med ; 209(12): 1463-1476, 2024 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-38358857

RESUMEN

Rationale: Acute cellular rejection (ACR) after lung transplant is a leading risk factor for chronic lung allograft dysfunction. Prior studies have demonstrated dynamic microbial changes occurring within the allograft and gut that influence local adaptive and innate immune responses. However, the lung microbiome's overall impact on ACR risk remains poorly understood. Objectives: To evaluate whether temporal changes in microbial signatures were associated with the development of ACR. Methods: We performed cross-sectional and longitudinal analyses (joint modeling of longitudinal and time-to-event data and trajectory comparisons) of 16S rRNA gene sequencing results derived from lung transplant recipient lower airway samples collected at multiple time points. Measurements and Main Results: Among 103 lung transplant recipients, 25 (24.3%) developed ACR. In comparing samples acquired 1 month after transplant, subjects who never developed ACR demonstrated lower airway enrichment with several oral commensals (e.g., Prevotella and Veillonella spp.) than those with current or future (beyond 1 mo) ACR. However, a subgroup analysis of those who developed ACR beyond 1 month revealed delayed enrichment with oral commensals occurring at the time of ACR diagnosis compared with baseline, when enrichment with more traditionally pathogenic taxa was present. In longitudinal models, dynamic changes in α-diversity (characterized by an initial decrease and a subsequent increase) and in the taxonomic trajectories of numerous oral commensals were more commonly observed in subjects with ACR. Conclusions: Dynamic changes in the lower airway microbiota are associated with the development of ACR, supporting its potential role as a useful biomarker or in ACR pathogenesis.


Asunto(s)
Rechazo de Injerto , Trasplante de Pulmón , Humanos , Trasplante de Pulmón/efectos adversos , Masculino , Rechazo de Injerto/microbiología , Femenino , Persona de Mediana Edad , Estudios Longitudinales , Estudios Transversales , Adulto , Microbiota , ARN Ribosómico 16S/genética , Pulmón/microbiología , Anciano , Enfermedad Aguda
7.
J Biol Chem ; 299(12): 105386, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37898401

RESUMEN

Aggregation behavior provides bacteria protection from harsh environments and threats to survival. Two uncharacterized proteases, LapX and Lap, are important for Vibrio cholerae liquid-based aggregation. Here, we determined that LapX is a serine protease with a preference for cleavage after glutamate and glutamine residues in the P1 position, which processes a physiologically based peptide substrate with a catalytic efficiency of 180 ± 80 M-1s-1. The activity with a LapX substrate identified by a multiplex substrate profiling by mass spectrometry screen was 590 ± 20 M-1s-1. Lap shares high sequence identity with an aminopeptidase (termed VpAP) from Vibrio proteolyticus and contains an inhibitory bacterial prepeptidase C-terminal domain that, when eliminated, increases catalytic efficiency on leucine p-nitroanilide nearly four-fold from 5.4 ± 4.1 × 104 M-1s-1 to 20.3 ± 4.3 × 104 M-1s-1. We demonstrate that LapX processes Lap to its mature form and thus amplifies Lap activity. The increase is approximately eighteen-fold for full-length Lap (95.7 ± 5.6 × 104 M-1s-1) and six-fold for Lap lacking the prepeptidase C-terminal domain (11.3 ± 1.9 × 105 M-1s-1). In addition, substrate profiling reveals preferences for these two proteases that could inform in vivo function. Furthermore, purified LapX and Lap restore the timing of the V. cholerae aggregation program to a mutant lacking the lapX and lap genes. Both proteases must be present to restore WT timing, and thus they appear to act sequentially: LapX acts on Lap, and Lap acts on the substrate involved in aggregation.


Asunto(s)
Proteínas Bacterianas , Leucil Aminopeptidasa , Serina Proteasas , Vibrio cholerae , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Leucil Aminopeptidasa/química , Leucil Aminopeptidasa/genética , Leucil Aminopeptidasa/fisiología , Péptidos , Serina Proteasas/química , Serina Proteasas/genética , Serina Proteasas/fisiología , Especificidad por Sustrato , Vibrio cholerae/enzimología , Vibrio cholerae/genética , Vibrio cholerae/fisiología , Catálisis
8.
Clin Infect Dis ; 79(1): 96-107, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-38466720

RESUMEN

BACKGROUND: There are limited data on whether hybrid immunity differs by count and order of immunity-conferring events (infection with severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] or vaccination against coronavirus disease 2019 [COVID-19]). From a multi-site cohort of frontline workers, we examined the heterogeneity of the effect of hybrid immunity on SARS-CoV-2 antibody levels. METHODS: Exposures included event count and event order, categorized into 7 permutations. Outcome was level of serum antibodies against receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein (total RBD-binding immunoglobulin). Means were examined up to 365 days after each of the first to seventh events. RESULTS: Analysis included 5793 participants measured from 7 August 2020 to 15 April 2023. Hybrid immunity from infection before 1 or 2 vaccine doses elicited modestly superior antibody responses after the second and third events (compared with infections or vaccine doses alone). This superiority was not repeated after additional events. Among adults infected before vaccination, adjusted geometric mean ratios (95% confidence interval [CI]) of anti-RBD early response (versus vaccinated only) were 1.23 (1.14-1.33), 1.09 (1.03-1.14), 0.87 (.81-.94), and 0.99 (.85-1.15) after the second to fifth events, respectively. Post-vaccination infections elicited superior responses; adjusted geometric mean ratios (95% CI) of anti-RBD early response (versus vaccinated only) were 0.93 (.75-1.17), 1.11 (1.06-1.16), 1.17 (1.11-1.24), and 1.20 (1.07-1.34) after the second to fifth events, respectively. CONCLUSIONS: Evidence of heterogeneity in antibody levels by permutations of infection and vaccination history could inform COVID-19 vaccination policy.


Asunto(s)
Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/epidemiología , SARS-CoV-2/inmunología , Estudios Prospectivos , Masculino , Adulto , Femenino , Glicoproteína de la Espiga del Coronavirus/inmunología , Persona de Mediana Edad , Vacunas contra la COVID-19/inmunología , Vacunación
9.
J Am Chem Soc ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598661

RESUMEN

Native ion mobility/mass spectrometry is well-poised to structurally screen proteomes but characterizes protein structures in the absence of a solvent. This raises long-standing unanswered questions about the biological significance of protein structures identified through ion mobility/mass spectrometry. Using newly developed computational and experimental ion mobility/ion mobility/mass spectrometry methods, we investigate the unfolding of the protein ubiquitin in a solvent-free environment. Our data suggest that the folded, solvent-free ubiquitin observed by ion mobility/mass spectrometry exists in a largely native fold with an intact ß-grasp motif and α-helix. The ensemble of folded, solvent-free ubiquitin ions can be partitioned into kinetically stable subpopulations that appear to correspond to the structural heterogeneity of ubiquitin in solution. Time-resolved ion mobility/ion mobility/mass spectrometry measurements show that folded, solvent-free ubiquitin exhibits a strongly stretched-exponential time dependence, which simulations trace to a rugged energy landscape with kinetic traps. Unfolding rate constants are estimated to be approximately 800 to 20,000 times smaller than in the presence of water, effectively quenching the unfolding process on the time scale of typical ion mobility/mass spectrometry measurements. Our proposed unfolding pathway of solvent-free ubiquitin shares substantial characteristics with that established for the presence of solvent, including a polarized transition state with significant native content in the N-terminal ß-hairpin and α-helix. Our experimental and computational data suggest that (1) the energy landscape governing the motions of folded, solvent-free proteins is rugged in analogy to that of glassy systems; (2) large-scale protein motions may at least partially be determined by the amino acid sequence of a polypeptide chain; and (3) solvent facilitates, rather than controls, protein motions.

10.
Am J Transplant ; 24(1): 115-122, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37717630

RESUMEN

In the United States, there is currently no system to track donated human tissue products to individual recipients. This posed a challenge during an investigation of a nationwide tuberculosis outbreak that occurred when bone allograft contaminated with Mycobacterium tuberculosis (Lot A) was implanted into 113 patients in 18 US states, including 2 patients at 1 health care facility in Colorado. A third patient at the same facility developed spinal tuberculosis with an isolate genetically identical to the Lot A outbreak strain. However, health care records indicated this patient had received bone allograft from a different donor (Lot B). We investigated the source of this newly identified infection, including the possibilities of Lot B donor infection, product switch or contamination during manufacturing, product switch at the health care facility, person-to-person transmission, and laboratory error. The findings included gaps in tissue traceability at the health care facility, creating the possibility for a product switch at the point of care despite detailed tissue-tracking policies. Nationally, 6 (3.9%) of 155 Lot B units could not be traced to final disposition. This investigation highlights the critical need to improve tissue-tracking systems to ensure unbroken traceability, facilitating investigations of recipient adverse events and enabling timely public health responses to prevent morbidity and mortality.


Asunto(s)
Tuberculosis , Humanos , Estados Unidos , Tuberculosis/epidemiología , Brotes de Enfermedades , Salud Pública , Donantes de Tejidos , Instituciones de Salud
11.
N Engl J Med ; 385(4): 320-329, 2021 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-34192428

RESUMEN

BACKGROUND: Information is limited regarding the effectiveness of the two-dose messenger RNA (mRNA) vaccines BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) in preventing infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and in attenuating coronavirus disease 2019 (Covid-19) when administered in real-world conditions. METHODS: We conducted a prospective cohort study involving 3975 health care personnel, first responders, and other essential and frontline workers. From December 14, 2020, to April 10, 2021, the participants completed weekly SARS-CoV-2 testing by providing mid-turbinate nasal swabs for qualitative and quantitative reverse-transcriptase-polymerase-chain-reaction (RT-PCR) analysis. The formula for calculating vaccine effectiveness was 100% × (1 - hazard ratio for SARS-CoV-2 infection in vaccinated vs. unvaccinated participants), with adjustments for the propensity to be vaccinated, study site, occupation, and local viral circulation. RESULTS: SARS-CoV-2 was detected in 204 participants (5%), of whom 5 were fully vaccinated (≥14 days after dose 2), 11 partially vaccinated (≥14 days after dose 1 and <14 days after dose 2), and 156 unvaccinated; the 32 participants with indeterminate vaccination status (<14 days after dose 1) were excluded. Adjusted vaccine effectiveness was 91% (95% confidence interval [CI], 76 to 97) with full vaccination and 81% (95% CI, 64 to 90) with partial vaccination. Among participants with SARS-CoV-2 infection, the mean viral RNA load was 40% lower (95% CI, 16 to 57) in partially or fully vaccinated participants than in unvaccinated participants. In addition, the risk of febrile symptoms was 58% lower (relative risk, 0.42; 95% CI, 0.18 to 0.98) and the duration of illness was shorter, with 2.3 fewer days spent sick in bed (95% CI, 0.8 to 3.7). CONCLUSIONS: Authorized mRNA vaccines were highly effective among working-age adults in preventing SARS-CoV-2 infection when administered in real-world conditions, and the vaccines attenuated the viral RNA load, risk of febrile symptoms, and duration of illness among those who had breakthrough infection despite vaccination. (Funded by the National Center for Immunization and Respiratory Diseases and the Centers for Disease Control and Prevention.).


Asunto(s)
Vacunas contra la COVID-19 , COVID-19/prevención & control , Carga Viral , Vacuna nCoV-2019 mRNA-1273 , Adolescente , Adulto , Vacuna BNT162 , COVID-19/diagnóstico , COVID-19/virología , Prueba de Ácido Nucleico para COVID-19 , Vacunas contra la COVID-19/inmunología , Portador Sano/diagnóstico , Portador Sano/prevención & control , Socorristas , Femenino , Personal de Salud , Humanos , Masculino , Persona de Mediana Edad , Gravedad del Paciente , Estudios Prospectivos , SARS-CoV-2/aislamiento & purificación , Resultado del Tratamiento , Adulto Joven
12.
Am J Physiol Heart Circ Physiol ; 326(2): H396-H407, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38099842

RESUMEN

Heart disease is a leading cause of death in patients with Duchenne muscular dystrophy (DMD), characterized by the progressive replacement of contractile tissue with scar tissue. Effective therapies for dystrophic cardiomyopathy will require addressing the disease before the onset of fibrosis, however, the mechanisms of the early disease are poorly understood. To understand the pathophysiology of DMD, we perform a detailed functional assessment of cardiac function of the mdx mouse, a model of DMD. These studies use a combination of functional, metabolomic, and spectroscopic approaches to fully characterize the contractile, energetic, and mitochondrial function of beating hearts. Through these innovative approaches, we demonstrate that the dystrophic heart has reduced cardiac reserve and is energetically limited. We show that this limitation does not result from poor delivery of oxygen. Using spectroscopic approaches, we provide evidence that mitochondria in the dystrophic heart have attenuated mitochondrial membrane potential and deficits in the flow of electrons in complex IV of the electron transport chain. These studies provide evidence that poor myocardial energetics precede the onset of significant cardiac fibrosis and likely results from mitochondrial dysfunction centered around complex IV and reduced membrane potential. The multimodal approach used here implicates specific molecular components in the etiology of reduced energetics. Future studies focused on these targets may provide therapies that improve the energetics of the dystrophic heart leading to improved resiliency against damage and preservation of myocardial contractile tissue.NEW & NOTEWORTHY Dystrophic hearts have poor contractile reserve that is associated with a reduction in myocardial energetics. We demonstrate that oxygen delivery does not contribute to the limited energy production of the dystrophic heart even with increased workloads. Cytochrome optical spectroscopy of the contracting heart reveals alterations in complex IV and evidence of depolarized mitochondrial membranes. We show specific alterations in the electron transport chain of the dystrophic heart that may contribute to poor myocardial energetics.


Asunto(s)
Cardiomiopatías , Distrofia Muscular de Duchenne , Animales , Ratones , Humanos , Ratones Endogámicos mdx , Miocardio , Corazón , Distrofia Muscular de Duchenne/complicaciones , Oxígeno , Modelos Animales de Enfermedad
13.
Small ; 20(25): e2310221, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38396158

RESUMEN

Porous substrate electroporation (PSEP) is a promising new method for intracellular delivery, yet fundamentals of PSEP are not well understood, especially the intermediate processes leading to delivery. PSEP is an electrical method, yet the relationship between PSEP and electrical impedance remains underexplored. In this study, a device capable of measuring impedance and performing PSEP is developed and the changes in transepithelial electrical impedance (TEEI) are monitored. These measurements show TEEI increases following PSEP, unlike other electroporation methods. The authors then demonstrate how cell culture conditions and electrical waveforms influence this response. More importantly, TEEI response features are correlated with viability and delivery efficiency, allowing prediction of outcomes without fluorescent cargo, imaging, or image processing. This label-free delivery also allows improved temporal resolution of transient processes following PSEP, which the authors expect will aid PSEP optimization for new cell types and cargos.


Asunto(s)
Impedancia Eléctrica , Electroporación , Electroporación/métodos , Porosidad , Animales , Humanos , Supervivencia Celular
14.
NMR Biomed ; : e5200, 2024 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-38881247

RESUMEN

In vivo estimation of cerebrospinal fluid (CSF) velocity is crucial for understanding the glymphatic system and its potential role in neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Current cardiac or respiratory-gated approaches, such as 4D flow magnetic resonance imaging (MRI), cannot capture CSF movement in real time because of limited temporal resolution and, in addition, deteriorate in accuracy at low fluid velocities. Other techniques like real-time phase-contrast-MRI or time-spatial labeling inversion pulse are not limited by temporal averaging but have limited availability, even in research settings. This study aims to quantify the inflow effect of dynamic CSF motion on functional MRI (fMRI) for in vivo, real-time measurement of CSF flow velocity. We considered linear and nonlinear models of velocity waveforms and empirically fit them to fMRI data from a controlled flow experiment. To assess the utility of this methodology in human data, CSF flow velocities were computed from fMRI data acquired in eight healthy volunteers. Breath-holding regimens were used to amplify CSF flow oscillations. Our experimental flow study revealed that CSF velocity is nonlinearly related to inflow effect-mediated signal increase and well estimated using an extension of a previous nonlinear framework. Using this relationship, we recovered velocity from in vivo fMRI signal, demonstrating the potential of our approach for estimating CSF flow velocity in the human brain. This novel method could serve as an alternative approach to quantifying slow flow velocities in real time, such as CSF flow in the ventricular system, thereby providing valuable insights into the glymphatic system's function and its implications for neurological disorders.

15.
MMWR Morb Mortal Wkly Rep ; 73(7): 145-148, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386802

RESUMEN

Nonhuman primates (NHP) can become infected with the same species of Mycobacteria that cause human tuberculosis. All NHP imported into the United States are quarantined and screened for tuberculosis; no confirmed cases of tuberculosis were diagnosed among NHP during CDC-mandated quarantine during 2013-2020. In February 2023, an outbreak of tuberculosis caused by Mycobacterium orygis was detected in a group of 540 cynomolgus macaques (Macaca fascicularis) imported to the United States from Southeast Asia for research purposes. Although the initial exposure to M. orygis is believed to have occurred before the macaques arrived in the United States, infected macaques were first detected during CDC-mandated quarantine. CDC collaborated with the importer and U.S. Department of Agriculture's National Veterinary Services Laboratories in the investigation and public health response. A total of 26 macaques received positive test results for M. orygis by culture, but rigorous occupational safety protocols implemented during transport and at the quarantine facility prevented cases among caretakers in the United States. Although the zoonotic disease risk to the general population remains low, this outbreak underscores the importance of CDC's regulatory oversight of NHP importation and adherence to established biosafety protocols to protect the health of the United States research animal population and the persons who interact with them.


Asunto(s)
Mycobacterium , Tuberculosis , Estados Unidos/epidemiología , Animales , Humanos , Macaca fascicularis , Brotes de Enfermedades , Asia Sudoriental
16.
MMWR Morb Mortal Wkly Rep ; 72(5253): 1385-1389, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38175804

RESUMEN

During July 7-11, 2023, CDC received reports of two patients in different states with a tuberculosis (TB) diagnosis following spinal surgical procedures that used bone allografts containing live cells from the same deceased donor. An outbreak associated with a similar product manufactured by the same tissue establishment (i.e., manufacturer) occurred in 2021. Because of concern that these cases represented a second outbreak, CDC and the Food and Drug Administration worked with the tissue establishment to determine that this product was obtained from a donor different from the one implicated in the 2021 outbreak and learned that the bone allograft product was distributed to 13 health care facilities in seven states. Notifications to all seven states occurred on July 12. As of December 20, 2023, five of 36 surgical bone allograft recipients received laboratory-confirmed TB disease diagnoses; two patients died of TB. Whole-genome sequencing demonstrated close genetic relatedness between positive Mycobacterium tuberculosis cultures from surgical recipients and unused product. Although the bone product had tested negative by nucleic acid amplification testing before distribution, M. tuberculosis culture of unused product was not performed until after the outbreak was recognized. The public health response prevented up to 53 additional surgical procedures using allografts from that donor; additional measures to protect patients from tissue-transmitted M. tuberculosis are urgently needed.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Estados Unidos/epidemiología , Tuberculosis/epidemiología , Tuberculosis/diagnóstico , Mycobacterium tuberculosis/genética , Donantes de Tejidos , Brotes de Enfermedades , Aloinjertos
17.
Ann Behav Med ; 58(1): 67-78, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37824850

RESUMEN

BACKGROUND: The shared provider responsibility between married couples does not translate to equally shared division of childcare (CC) and household labor. While some marriages contain highly positive aspects, marriages may also simultaneously contain both positive and negative aspects. The negativity in these relationships can negate the positivity and could potentially lead to the detriment of mothers' health. PURPOSE: We examined mothers' ambulatory blood pressure (ABP) associated with their marital relationship quality and perceived equity with her spouse on CC and household tasks. METHODS: We investigate these associations using a mixed multilevel model analysis on a sample of 224 mothers in heterosexual marriages, all of whom had children under the age of 18 years currently living in the home. RESULTS: Mothers' perception of equity in the division of CC responsibilities contributed to lower ABP. Additionally, mothers in supportive marital relationships (low negativity and high positivity) had lower ABP than those in ambivalent relationships (both high negativity and positivity). There was a crossover interaction such that the effect of relationship quality on ABP was moderated by the perception of equity in the division of CC. For mothers who report doing all the CC, they had lower ABP if they had a supportive marital relationship compared with mothers in ambivalent relationships. Whereas mothers who report more equity in CC and have a supportive relationship have higher ABP compared with mothers in ambivalent relationships. CONCLUSIONS: This study has implications related to dynamics within marital relationships. These results demonstrate important relational influences on mothers' ABP.


Married mothers disproportionately shoulder the responsibilities of childcare (CC) and household labor. This inequity of the division of family responsibilities can negatively affect the relationship between husbands and wives with marital satisfaction being higher when the load is more equally shared between partners. Additionally, marital satisfaction is associated with numerous health benefits including lower blood pressure. We examined mothers' ambulatory blood pressure (ABP) associated with their marital relationship quality and perceived equity with her spouse on CC and household tasks on a sample of 224 mothers in heterosexual marriages. Mothers' perception of equity in the division of CC responsibilities contributed to lower ABP. Additionally, mothers in supportive marital relationships had lower ABP than those reporting less supportive relationships. There was an interaction between the perception of equity in the division of CC and the effect that relationship quality had on mothers' ABP. Mothers who reported doing all the CC had lower ABP if they had a supportive marital relationship compared with mothers in less supportive relationships. Whereas mothers who reported more equity in CC and had a supportive relationship had higher ABP compared with mothers in less supportive relationships.


Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial , Matrimonio , Femenino , Niño , Humanos , Adolescente , Presión Sanguínea/fisiología , Conducta Social , Madres
18.
Acta Psychiatr Scand ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38600593

RESUMEN

BACKGROUND AND HYPOTHESIS: Speech markers are digitally acquired, computationally derived, quantifiable set of measures that reflect the state of neurocognitive processes relevant for social functioning. "Oddities" in language and communication have historically been seen as a core feature of schizophrenia. The application of natural language processing (NLP) to speech samples can elucidate even the most subtle deviations in language. We aim to determine if NLP based profiles that are distinctive of schizophrenia can be observed across the various clinical phases of psychosis. DESIGN: Our sample consisted of 147 participants and included 39 healthy controls (HC), 72 with first-episode psychosis (FEP), 18 in a clinical high-risk state (CHR), 18 with schizophrenia (SZ). A structured task elicited 3 minutes of speech, which was then transformed into quantitative measures on 12 linguistic variables (lexical, syntactic, and semantic). Cluster analysis that leveraged healthy variations was then applied to determine language-based subgroups. RESULTS: We observed a three-cluster solution. The largest cluster included most HC and the majority of patients, indicating a 'typical linguistic profile (TLP)'. One of the atypical clusters had notably high semantic similarity in word choices with less perceptual words, lower cohesion and analytical structure; this cluster was almost entirely composed of patients in early stages of psychosis (EPP - early phase profile). The second atypical cluster had more patients with established schizophrenia (SPP - stable phase profile), with more perceptual but less cognitive/emotional word classes, simpler syntactic structure, and a lack of sufficient reference to prior information (reduced givenness). CONCLUSION: The patterns of speech deviations in early and established stages of schizophrenia are distinguishable from each other and detectable when lexical, semantic and syntactic aspects are assessed in the pursuit of 'formal thought disorder'.

19.
J Immunol ; 208(1): 97-109, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34872978

RESUMEN

Dendritic cell (DC) activation is characterized by sustained commitment to glycolysis that is a requirement for survival in DC subsets that express inducible NO synthase (Nos2) due to NO-mediated inhibition of mitochondrial respiration. This phenomenon primarily has been studied in DCs from the classic laboratory inbred mouse strain C57BL/6J (B6) mice, where DCs experience a loss of mitochondrial function due to NO accumulation. To assess the conservation of NO-driven metabolic regulation in DCs, we compared B6 mice to the wild-derived genetically divergent PWD/PhJ (PWD) strain. We show preserved mitochondrial respiration and enhanced postactivation survival due to attenuated NO production in LPS-stimulated PWD DCs phenocopying human monocyte-derived DCs. To genetically map this phenotype, we used a congenic mouse strain (B6.PWD-Chr11.2) that carries a PWD-derived portion of chromosome 11, including Nos2, on a B6 background. B6.PWD-Chr11.2 DCs show preserved mitochondrial function and produce lower NO levels than B6 DCs. We demonstrate that activated B6.PWD-Chr11.2 DCs maintain mitochondrial respiration and TCA cycle carbon flux, compared with B6 DCs. However, reduced NO production by the PWD Nos2 allele results in impaired cellular control of Listeria monocytogenes replication. These studies establish a natural genetic model for restrained endogenous NO production to investigate the contribution of NO in regulating the interplay between DC metabolism and immune function. These findings suggest that reported differences between human and murine DCs may be an artifact of the limited genetic diversity of the mouse models used, underscoring the need for mouse genetic diversity in immunology research.


Asunto(s)
Células Dendríticas/inmunología , Listeria monocytogenes/fisiología , Listeriosis/inmunología , Mitocondrias/metabolismo , Óxido Nítrico/metabolismo , Alelos , Animales , Animales Salvajes , Supervivencia Celular , Células Cultivadas , Modelos Animales de Enfermedad , Resistencia a la Enfermedad , Antecedentes Genéticos , Humanos , Lipopolisacáridos/inmunología , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo
20.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-34580170

RESUMEN

African savannas are the last stronghold of diverse large-mammal communities, and a major focus of savanna ecology is to understand how these animals affect the relative abundance of trees and grasses. However, savannas support diverse plant life-forms, and human-induced changes in large-herbivore assemblages-declining wildlife populations and their displacement by livestock-may cause unexpected shifts in plant community composition. We investigated how herbivory affects the prevalence of lianas (woody vines) and their impact on trees in an East African savanna. Although scarce (<2% of tree canopy area) and defended by toxic latex, the dominant liana, Cynanchum viminale (Apocynaceae), was eaten by 15 wild large-herbivore species and was consumed in bulk by native browsers during experimental cafeteria trials. In contrast, domesticated ungulates rarely ate lianas. When we experimentally excluded all large herbivores for periods of 8 to 17 y (simulating extirpation), liana abundance increased dramatically, with up to 75% of trees infested. Piecewise exclusion of different-sized herbivores revealed functional complementarity among size classes in suppressing lianas. Liana infestation reduced tree growth and reproduction, but herbivores quickly cleared lianas from trees after the removal of 18-y-old exclosure fences (simulating rewilding). A simple model of liana contagion showed that, without herbivores, the long-term equilibrium could be either endemic (liana-tree coexistence) or an all-liana alternative stable state. We conclude that ongoing declines of wild large-herbivore populations will disrupt the structure and functioning of many African savannas in ways that have received little attention and that may not be mitigated by replacing wildlife with livestock.


Asunto(s)
Cynanchum/crecimiento & desarrollo , Ecosistema , Preferencias Alimentarias , Herbivoria/fisiología , Árboles/crecimiento & desarrollo , África , Animales , Animales Salvajes , Elefantes , Restauración y Remediación Ambiental , Jirafas , Humanos , Ganado
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