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1.
Bioeng Transl Med ; 8(6): e10538, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38023712

RESUMEN

Chimeric antigen receptor (CAR)-modified T-cell therapy has shown enormous clinical promise against blood cancers, yet efficacy against solid tumors remains a challenge. Here, we investigated the potential of a new combination cell therapy, where tumor-homing induced neural stem cells (iNSCs) are used to enhance CAR-T-cell therapy and achieve efficacious suppression of brain tumors. Using in vitro and in vivo migration assays, we found iNSC-secreted RANTES/IL-15 increased CAR-T-cell migration sixfold and expansion threefold, resulting in greater antitumor activity in a glioblastoma (GBM) tumor model. Furthermore, multimodal imaging showed iNSC delivery of RANTES/IL-15 in combination with intravenous administration of CAR-T cells reduced established orthotopic GBM xenografts 2538-fold within the first week, followed by durable tumor remission through 60 days post-treatment. By contrast, CAR-T-cell therapy alone only partially controlled tumor growth, with a median survival of only 19 days. Together, these studies demonstrate the potential of combined cell therapy platforms to improve the efficacy of CAR-T-cell therapy for brain tumors.

2.
Cell Rep Med ; 4(6): 101042, 2023 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-37192626

RESUMEN

Functional precision medicine platforms are emerging as promising strategies to improve pre-clinical drug testing and guide clinical decisions. We have developed an organotypic brain slice culture (OBSC)-based platform and multi-parametric algorithm that enable rapid engraftment, treatment, and analysis of uncultured patient brain tumor tissue and patient-derived cell lines. The platform has supported engraftment of every patient tumor tested to this point: high- and low-grade adult and pediatric tumor tissue rapidly establishes on OBSCs among endogenous astrocytes and microglia while maintaining the tumor's original DNA profile. Our algorithm calculates dose-response relationships of both tumor kill and OBSC toxicity, generating summarized drug sensitivity scores on the basis of therapeutic window and allowing us to normalize response profiles across a panel of U.S. Food and Drug Administration (FDA)-approved and exploratory agents. Summarized patient tumor scores after OBSC treatment show positive associations to clinical outcomes, suggesting that the OBSC platform can provide rapid, accurate, functional testing to ultimately guide patient care.


Asunto(s)
Neoplasias Encefálicas , Humanos , Niño , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Encéfalo
4.
JAMA Oncol ; 9(2): 188-196, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36547970

RESUMEN

Importance: Accurate identification of patient groups with the lowest level of protection following COVID-19 vaccination is important to better target resources and interventions for the most vulnerable populations. It is not known whether SARS-CoV-2 antibody testing has clinical utility for high-risk groups, such as people with cancer. Objective: To evaluate whether spike protein antibody vaccine response (COV-S) following COVID-19 vaccination is associated with the risk of SARS-CoV-2 breakthrough infection or hospitalization among patients with cancer. Design, Setting, and Participants: This was a population-based cross-sectional study of patients with cancer from the UK as part of the National COVID Cancer Antibody Survey. Adults with a known or reported cancer diagnosis who had completed their primary SARS-CoV-2 vaccination schedule were included. This analysis ran from September 1, 2021, to March 4, 2022, a period covering the expansion of the UK's third-dose vaccination booster program. Interventions: Anti-SARS-CoV-2 COV-S antibody test (Elecsys; Roche). Main Outcomes and Measures: Odds of SARS-CoV-2 breakthrough infection and COVID-19 hospitalization. Results: The evaluation comprised 4249 antibody test results from 3555 patients with cancer and 294 230 test results from 225 272 individuals in the noncancer population. The overall cohort of 228 827 individuals (patients with cancer and the noncancer population) comprised 298 479 antibody tests. The median age of the cohort was in the age band of 40 and 49 years and included 182 741 test results (61.22%) from women and 115 737 (38.78%) from men. There were 279 721 tests (93.72%) taken by individuals identifying as White or White British. Patients with cancer were more likely to have undetectable anti-S antibody responses than the general population (199 of 4249 test results [4.68%] vs 376 of 294 230 [0.13%]; P < .001). Patients with leukemia or lymphoma had the lowest antibody titers. In the cancer cohort, following multivariable correction, patients who had an undetectable antibody response were at much greater risk for SARS-CoV-2 breakthrough infection (odds ratio [OR], 3.05; 95% CI, 1.96-4.72; P < .001) and SARS-CoV-2-related hospitalization (OR, 6.48; 95% CI, 3.31-12.67; P < .001) than individuals who had a positive antibody response. Conclusions and Relevance: The findings of this cross-sectional study suggest that COV-S antibody testing allows the identification of patients with cancer who have the lowest level of antibody-derived protection from COVID-19. This study supports larger evaluations of SARS-CoV-2 antibody testing. Prevention of SARS-CoV-2 transmission to patients with cancer should be prioritized to minimize impact on cancer treatments and maximize quality of life for individuals with cancer during the ongoing pandemic.


Asunto(s)
COVID-19 , Neoplasias , Vacunas , Femenino , Adulto , Masculino , Humanos , Persona de Mediana Edad , Vacunas contra la COVID-19 , Glicoproteína de la Espiga del Coronavirus , Estudios Transversales , Formación de Anticuerpos , Calidad de Vida , COVID-19/epidemiología , COVID-19/prevención & control , SARS-CoV-2 , Neoplasias/epidemiología , Anticuerpos Antivirales , Atención a la Salud
5.
Gastroenterology Res ; 15(4): 155-161, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36128188

RESUMEN

Background: Transnasal endoscopy (TNE) has been introduced in the care of pediatric patients with eosinophilic esophagitis (EoE) who require repeated esophagoscopies. TNE, as compared to conventional endoscopy, is less invasive and avoids sedation or anesthesia allowing for frequent assessments of the esophageal mucosa when making management decisions. The aim of this study is to review our early experience with TNE. Methods: We extracted data from all patients with EoE who underwent TNE at UH Rainbow Babies & Children's Hospital, Cleveland, Ohio from December 2018 to April 2021. We assessed total visit time, procedure time, success rate, and complications. Data are presented as percentages or medians with interquartile ranges (IQRs). Comparisons were made using Chi-square (and Fisher's exact) test for categorical data, Mann-Whitney test and the unpaired t-test for non-normally distributed and normally distributed data, respectively. Results: Thirty-three patients underwent 65 TNE procedures during our study period. The male-to-female ratio was 4.5:1 and median age was 13 years (IQR: 10 - 15 years; range: 4 - 20 years). Sixty-three (96.9%) of 65 procedures were completed. Distraction methods were used in all procedures (virtual reality goggles in 19.3% and television in 80.7%). Isolated elevated blood pressure (BP) measurements prior to the procedure were more frequent in those undergoing TNE as compared to sedated esophagogastroduodenoscopy (P = 0.04). We also calculated the heart rate (HR) for patients undergoing TNE and sedated upper endoscopy; no difference was noted (P = 0.71). Only minor adverse events occurred with TNE: nosebleed (n = 1), pre-syncope (n = 1), and pain (n = 4). None of the patients who underwent a sedated upper endoscopy developed an event. Two TNE procedures were not completed due to an inability to traverse the upper esophageal sphincter. Conclusions: We demonstrate TNE is an efficient and well-tolerated means of monitoring patients with EoE. Various straight forward distraction methods may contribute to the successful completion of the procedure. The safety as compared to conventional esophagoscopy requires large multicenter studies.

6.
Mol Ther Oncolytics ; 26: 49-62, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35784402

RESUMEN

Genetically engineered neural stem cells (NSCs) are a promising therapy for the highly aggressive brain cancer glioblastoma (GBM); however, treatment durability remains a major challenge. We sought to define the events that contribute to dynamic adaptation of GBM during treatment with human skin-derived induced NSCs releasing the pro-apoptotic agent TRAIL (iNSC-TRAIL) and develop strategies that convert initial tumor kill into sustained GBM suppression. In vivo and ex vivo analysis before, during, and after treatment revealed significant shifts in tumor transcriptome and spatial distribution as the tumors adapted to treatment. To address this, we designed iNSC delivery strategies that increased spatiotemporal TRAIL coverage and significantly decreased GBM volume throughout the brain, reducing tumor burden 100-fold as quantified in live ex vivo brain slices. The varying impact of different strategies on treatment durability and median survival of both solid and invasive tumors provides important guidance for optimizing iNSC therapy.

7.
Stem Cell Rev Rep ; 18(7): 2474-2493, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35441348

RESUMEN

The spread of non-small cell lung cancer (NSCLC) to the leptomeninges is devastating with a median survival of only a few months. Radiation offers symptomatic relief, but new adjuvant therapies are desperately needed. Spheroidal, human induced neural stem cells (hiNeuroS) secreting the cytotoxic protein, TRAIL, have innate tumoritropic properties. Herein, we provide evidence that hiNeuroS-TRAIL cells can migrate to and suppress growth of NSCLC metastases in combination with radiation. In vitro cell tracking and post-mortem tissue analysis showed that hiNeuroS-TRAIL cells migrate to NSCLC tumors. Importantly, isobolographic analysis suggests that TRAIL with radiation has a synergistic cytotoxic effect on NSCLC tumors. In vivo, mice treated with radiation and hiNeuroS-TRAIL showed significant (36.6%) improvements in median survival compared to controls. Finally, bulk mRNA sequencing analysis showed both NSCLC and hiNeuroS-TRAIL cells showed changes in genes involved in migration following radiation. Overall, hiNeuroS-TRAIL cells +/- radiation have the capacity to treat NSCLC metastases.


Asunto(s)
Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Células-Madre Neurales , Animales , Antineoplásicos/farmacología , Apoptosis , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Línea Celular Tumoral , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Ratones , Células-Madre Neurales/metabolismo , ARN Mensajero , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología
8.
mSystems ; 7(2): e0127221, 2022 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-35289653

RESUMEN

Streptococcus mutans promotes a tooth-damaging dysbiosis in the oral microbiota because it can form biofilms and survive acid stress better than most of its ecological competitors, which are typically health associated. Many of these commensals produce hydrogen peroxide; therefore, S. mutans must manage both oxidative stress and acid stress with coordinated and complex physiological responses. In this study, the proteome of S. mutans was examined during regulated growth in acid and oxidative stresses as well as in deletion mutants with impaired oxidative stress phenotypes, Δnox and ΔtreR. A total of 607 proteins exhibited significantly different abundances across the conditions tested, and correlation network analysis identified modules of coexpressed proteins that were responsive to the deletion of nox and/or treR as well as acid and oxidative stress. The data explained the reactive oxygen species (ROS)-sensitive and mutacin-deficient phenotypes exhibited by the ΔtreR strain. SMU.1069-1070, a poorly understood LytTR system, had an elevated abundance in the ΔtreR strain. S. mutans LytTR systems regulate mutacin production and competence, which may explain how TreR affects mutacin production. Furthermore, the protein cluster that produces mutanobactin, a lipopeptide important in ROS tolerance, displayed a reduced abundance in the ΔtreR strain. The role of Nox as a keystone in the oxidative stress response was also emphasized. Crucially, this data set provides oral health researchers with a proteome atlas that will enable a more complete understanding of the S. mutans stress responses that are required for pathogenesis, and will facilitate the development of new and improved therapeutic approaches for dental caries. IMPORTANCE Dental caries is the most common chronic infectious disease worldwide and disproportionately affects marginalized socioeconomic groups. Streptococcus mutans is considered a primary etiological agent of caries, with its pathogenicity being dependent on coordinated physiological stress responses that mitigate the damage caused by the oxidative and acid stress common within dental plaque. In this study, the proteome of S. mutans was examined during growth in acidic and oxidative stresses as well in nox and treR deletion mutants. A total of 607 proteins were differentially expressed across the strains/growth conditions, and modules of coexpressed proteins were identified, which enabled mapping the acid and oxidative stress responses across S. mutans metabolism. The presence of TreR was linked to mutacin production via LytTR system signaling and to oxidative stress via mutanobactin production. The data provided by this study will guide future research elucidating S. mutans pathogenesis and developing improved preventative and treatment modalities for dental caries.


Asunto(s)
Proteínas Bacterianas , Caries Dental , Humanos , Proteínas Bacterianas/genética , Proteoma/metabolismo , Streptococcus mutans/genética , Especies Reactivas de Oxígeno/metabolismo , Estrés Oxidativo
9.
Can J Surg ; 64(4): E414-E418, 2021 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-34296812

RESUMEN

Background: In older adults facing knee arthroplasty, the ability to resume downhill skiing postoperatively is unclear. This study aimed to determine the perspectives of Alberta orthopedic surgeons and senior residents regarding downhill skiing after total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). Methods: In May 2019, a Web-based survey was sent through the Alberta Orthopaedic Society to poll orthopedic surgeons performing arthroplasty and senior orthopedic residents (postgraduate year 4 or 5) in Alberta regarding the permissibility of downhill skiing after TKA or UKA. The survey also elicited information regarding under which conditions or restrictions, if any, surgeons would allow patients to return to downhill skiing, whether these recommendations were evidence based, and whether surgeons had seen complications from downhill skiing in their patients who had undergone knee arthroplasty. Results: Of the 41 respondents, 21 (51%) were full-time fellowship-trained orthopedic surgeons, 15 (37%) were specialists with some arthroplasty in their practice, and 5 (12%) were orthopedic residents. Ten of 40 respondents (25%) would allow unrestricted downhill skiing after TKA, and 1 (2%) would not allow any skiing at all. The remaining 29 (72%) indicated that they might allow downhill skiing under specific conditions, with the top 3 being limitations on speed and intensity (29 [71%]), return of full range of motion and strength in the operative knee (26 [63%]), and years of downhill ski experience (23 [56%]). Fourteen respondents (34%) would allow unrestricted downhill skiing after UKA, and 27 (66%) would allow skiing with the same top 3 conditions as for TKA. Thirty-two respondents (78%) reported that their decisions were not evidence based, and 35 (85%) had never seen complications from downhill skiing after TKA or UKA. Conclusion: Alberta orthopedic surgeons and senior residents are cautious regarding skiing after knee arthroplasty. The majority reported that their restrictions were not evidence based, which indicates the need for further investigation to develop an approach for surgeons to consistently and safely address return to downhill skiing after TKA or UKA.


Contexte: Chez les adultes âgés qui doivent subir une arthroplastie du genou, la capacité de reprendre la pratique du ski alpin n'a pas été clairement évaluée. Cette étude visait à clarifier le point de vue des chirurgiens et résidents séniors en orthopédie de l'Alberta au sujet de la pratique du ski alpin après une intervention pour prothèse totale du genou (PTG) ou prothèse partielle du genou (PPG). Méthodes: En mai 2019, un sondage en ligne a été envoyé par l'entremise de l'Alberta Orthopaedic Society afin d'interroger les chirurgiens et résidents séniors (résidents 4 ou 5) en orthopédie pratiquant des arthroplasties en Alberta au sujet de l'autorisation à recommencer le ski alpin après une PTG ou une PPG. Le sondage portait aussi sur les conditions ou les restrictions, le cas échéant, imposées aux patients par leurs chirurgiens pour leur permettre de recommencer à skier, si ces recommandations étaient fondées sur des données probantes, et si les chirurgiens avaient observé des complications chez leurs patients ayant repris le ski après une PTG ou une PPG. Résultats: Sur les 41 répondants, 21 (51 %) étaient des médecins spécialistes en chirurgie orthopédique à temps complet, 15 (37 %) étaient des spécialistes ayant déjà effectué des arthroplasties dans le cadre de leur pratique et 5 (12 %) étaient des résidents en orthopédie. Dix répondants sur 40 (25 %) disaient qu'ils permettraient la pratique du ski alpin sans restrictions après la PTG et 1 (2 %) ne la permettrait pas du tout. Les 29 autres (72 %) ont indiqué qu'ils autoriseraient la pratique du ski alpin à certaines conditions, les 3 principales étant le contrôle de la vitesse et de l'intensité (29 [71 %]), le retour de la pleine amplitude de mouvement et de la force au genou opéré (26 [63 %]) et le nombre d'années d'expérience en ski alpin (23 [56 %]). Quatorze répondants (34 %) permettraient la reprise du ski alpin sans restrictions après la PPG et 27 (66 %) l'autoriseraient en appliquant les 3 mêmes conditions que pour la PTG. Trente-deux répondants (78 %) ont indiqué que leur décision ne reposait pas sur des données probantes et 35 (85 %) n'avaient observé aucune complication après la reprise de la pratique du skin suite à une PTG ou une PPG. Conclusion: Les chirurgiens et les résidents séniors en orthopédie de l'Alberta émettent des réserves relativement à la reprise de la pratique du skin après une arthroplastie du genou. Chez la majorité, les restrictions préconisées ne reposent pas sur des données probantes, ce qui indique que la recherche à ce sujet mérite d'être approfondie afin qu'on puisse élaborer une approche cohérente et sécuritaire en orthopédie pour la reprise de la pratique du ski alpin après une PTG ou une PPG.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Contraindicaciones , Cirujanos Ortopédicos , Esquí , Alberta , Toma de Decisiones Clínicas , Práctica Clínica Basada en la Evidencia , Humanos , Encuestas y Cuestionarios
10.
Sci Adv ; 7(24)2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34108203

RESUMEN

Engineered tumor-homing neural stem cells (NSCs) have shown promise in treating cancer. Recently, we transdifferentiated skin fibroblasts into human-induced NSCs (hiNSC) as personalized NSC drug carriers. Here, using a SOX2 and spheroidal culture-based reprogramming strategy, we generated a new hiNSC variant, hiNeuroS, that was genetically distinct from fibroblasts and first-generation hiNSCs and had significantly enhanced tumor-homing and antitumor properties. In vitro, hiNeuroSs demonstrated superior migration to human triple-negative breast cancer (TNBC) cells and in vivo rapidly homed to TNBC tumor foci following intracerebroventricular (ICV) infusion. In TNBC parenchymal metastasis models, ICV infusion of hiNeuroSs secreting the proapoptotic agent TRAIL (hiNeuroS-TRAIL) significantly reduced tumor burden and extended median survival. In models of TNBC leptomeningeal carcinomatosis, ICV dosing of hiNeuroS-TRAIL therapy significantly delayed the onset of tumor formation and extended survival when administered as a prophylactic treatment, as well as reduced tumor volume while prolonging survival when delivered as established tumor therapy.


Asunto(s)
Células-Madre Neurales , Neoplasias de la Mama Triple Negativas , Línea Celular Tumoral , Fibroblastos , Humanos , Células Madre Neoplásicas/patología , Células-Madre Neurales/patología , Neoplasias de la Mama Triple Negativas/patología
11.
Arthrosc Tech ; 10(1): e145-e150, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33532221

RESUMEN

Traditional Bankart repairs for anterior labral tears of the shoulder use suture anchors to repair the anterior shoulder labrum and capsule to the glenoid. The technique described here involves releasing the anterior capsule of the glenoid and shifting it superiorly along with the labrum before anchoring. The intention of this extra step is to replicate the open technique, where the entire capsule is shifted superiorly on the glenoid.

12.
iScience ; 23(9): 101459, 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-32861995

RESUMEN

We explore archaeal distributions in sedimentary subseafloor habitats of Guaymas Basin and the adjacent Sonora Margin, located in the Gulf of California, México. Sampling locations include (1) control sediments without hydrothermal or seep influence, (2) Sonora Margin sediments underlying oxygen minimum zone water, (3) compacted, highly reduced sediments from a pressure ridge with numerous seeps at the base of the Sonora Margin, and (4) sediments impacted by hydrothermal circulation at the off-axis Ringvent site. Generally, archaeal communities largely comprise Bathyarchaeal lineages, members of the Hadesarchaea, MBG-D, TMEG, and ANME-1 groups. Variations in archaeal community composition reflect locally specific environmental challenges. Background sediments are divided into surface and subsurface niches. Overall, the environmental setting and history of a particular site, not isolated biogeochemical properties out of context, control the subseafloor archaeal communities in Guaymas Basin and Sonora Margin sediments.

13.
Mol Ther ; 28(7): 1614-1627, 2020 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-32402245

RESUMEN

The conversion of human fibroblasts into personalized induced neural stem cells (iNSCs) that actively seek out tumors and deliver cytotoxic agents is a highly promising approach for treating various types of cancer. However, the ability to generate iNSCs from the skin of cancer patients has not been explored. Here, we take an important step toward clinical application by generating iNSCs from skin biopsies of human patients undergoing treatment for the aggressive brain cancer, glioblastoma (GBM). We then utilized a panel of functional and genomic studies to investigate the efficacy and tumor-homing capacity of these patient-derived cells, as well as genomic analysis, to characterize the impact of interpatient variability on this personalized cell therapy. From the skin-tissue biopsies, we established fibroblasts and transdifferentiated the cells into iNSCs. Genomic and functional testing revealed marked variability in growth rates, therapeutic agent production, and gene expression during fibroblast-to-iNSC conversion among patient lines. In vivo testing showed patient-derived iNSCs home to tumors, yet rates and expression of homing-related pathways varied among patients. With the use of surgical-resection mouse models of invasive human cluster of differentiation 133+ (CD133+) GBM cells and serial kinetic imaging, we found that "high-performing" patient-derived iNSC lines reduced the volume of GBM cells 60-fold and extended survival from 28 to 45 days. Treatment with "low-performing" patient lines had minimal effect on tumor growth, but the anti-tumor effect could be rescued by increasing the intracavity dose. Together, these data show, for the first time, that tumor-homing iNSCs can be generated from the skin of cancer patients and efficaciously suppress tumor growth. We also begin to define genetic markers that could be used to identify cells that will contain the most effective attributes for tumor homing and kill in human patients, including high gene expression of the semaphorin-3B (SEMA3B), which is known to be involved in neuronal cell migration. These studies should serve as an important guide toward clinical GBM therapy, where the personalized nature of optimized iNSC therapy has the potential to avoid transplant rejection and maximize treatment durability.


Asunto(s)
Glioblastoma/terapia , Células Madre Pluripotentes Inducidas/trasplante , Glicoproteínas de Membrana/genética , Células-Madre Neurales/trasplante , Semaforinas/genética , Piel/citología , Animales , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Supervivencia Celular , Transdiferenciación Celular , Células Cultivadas , Femenino , Fibroblastos/citología , Glioblastoma/genética , Humanos , Células Madre Pluripotentes Inducidas/citología , Masculino , Ratones , Células-Madre Neurales/citología , Cultivo Primario de Células , Ratas , Análisis de Supervivencia , Ensayos Antitumor por Modelo de Xenoinjerto
14.
Sci Rep ; 9(1): 13847, 2019 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-31554864

RESUMEN

The Guaymas Basin spreading center, at 2000 m depth in the Gulf of California, is overlain by a thick sedimentary cover. Across the basin, localized temperature anomalies, with active methane venting and seep fauna exist in response to magma emplacement into sediments. These sites evolve over thousands of years as magma freezes into doleritic sills and the system cools. Although several cool sites resembling cold seeps have been characterized, the hydrothermally active stage of an off-axis site was lacking good examples. Here, we present a multidisciplinary characterization of Ringvent, an ~1 km wide circular mound where hydrothermal activity persists ~28 km northwest of the spreading center. Ringvent provides a new type of intermediate-stage hydrothermal system where off-axis hydrothermal activity has attenuated since its formation, but remains evident in thermal anomalies, hydrothermal biota coexisting with seep fauna, and porewater biogeochemical signatures indicative of hydrothermal circulation. Due to their broad potential distribution, small size and limited life span, such sites are hard to find and characterize, but they provide critical missing links to understand the complex evolution of hydrothermal systems.

15.
Front Microbiol ; 10: 644, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30984153

RESUMEN

Orange filamentous Beggiatoaceae form massive microbial mats on hydrothermal sediments in Guaymas Basin; these bacteria are considered to oxidize sulfide with nitrate and nitrite as electron acceptors. From a previously analyzed genome of an orange Beggiatoaceae filament, three candidate genes for enzymes with nitrite-reducing function - an orange octaheme cytochrome, a nirS nitrite reductase, and a nitrite/tetrathionate-reducing octaheme cytochrome - were cloned and expressed in Escherichia coli. The expressed and purified orange cytochrome showed reduced nitrite-reducing activity compared to the multifunctional native protein obtained from microbial mats. The nirS gene product showed in vitro but no in-gel nitrite-reducing activity; and the nitrite/tetrathionate-reducing octaheme cytochrome was capable of reducing both nitrite and tetrathionate in vitro. Phylogenetic analysis shows that the orange Beggiatoaceae nirS, in contrast to the other candidate nitrite reductases, does not form monophyletic lineages with its counterparts in other large sulfur-oxidizing bacteria, and most likely represents a recent acquisition by lateral gene transfer. The nitrite/tetrathionate-reducing enzyme of the orange Beggiatoaceae is related to nitrite- and tetrathionate reductases harbored predominantly by Gammaproteobacteria, including obligate endosymbionts of hydrothermal vent tubeworms. Thus, the orange Guaymas Basin Beggiatoaceae have a repertoire of at least three different functional enzymes for nitrite reduction. By demonstrating the unusual diversity of enzymes with a potential role in nitrite reduction, we show that bacteria in highly dynamic, sulfide-rich hydrothermal vent habitats adapt to these conditions that usually prohibit nitrate and nitrite reduction. In the case of the orange Guaymas Beggiatoaceae, classical denitrification appears to be replaced by different multifunctional enzymes for nitrite and tetrathionate reduction; the resulting ecophysiological flexibility provides a new key to the dominance of these Beggiatoaceae in hydrothermal hot spots.

16.
Environ Microbiol ; 21(2): 557-571, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30452115

RESUMEN

The extent to which differences in microbial community structure result in variations in organic matter (OM) degradation is not well understood. Here, we tested the hypothesis that distinct marine microbial communities from North Atlantic surface and bottom waters would exhibit varying compositional succession and functional shifts in response to the same pool of complex high molecular weight (HMW-OM). We also hypothesized that microbial communities would produce a broader spectrum of enzymes upon exposure to HMW-OM, indicating a greater potential to degrade these compounds than reflected by initial enzymatic activities. Our results show that community succession in amended mesocosms was congruent with cell growth, increased bacterial production and most notably, with substantial shifts in enzymatic activities. In all amended mesocosms, closely related taxa that were initially rare became dominant at time frames during which a broader spectrum of active enzymes were detected compared to initial timepoints, indicating a similar response among different communities. However, succession on the whole-community level, and the rates, spectra and progression of enzymatic activities, reveal robust differences among distinct communities from discrete water masses. These results underscore the crucial role of rare bacterial taxa in ocean carbon cycling and the importance of bacterial community structure for HMW-OM degradation.


Asunto(s)
Bacterias/enzimología , Bacterias/metabolismo , Compuestos Orgánicos/metabolismo , Bacterias/clasificación , Ciclo del Carbono/fisiología , Microbiota
17.
J Orthop Trauma ; 32(11): 548-553, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30211788

RESUMEN

OBJECTIVES: To determine whether single or double screw (DS) fixation of medial malleolar fractures results in better long-term health outcomes. DESIGN: Randomized clinical trial; sealed envelope technique. SETTING: Level 1 Trauma Hospital at University of Calgary, Canada. PATIENTS: One hundred forty patients were randomized to receive either 1 or 2 screws to reduce a medial malleolar fracture. Thirteen patients were excluded because of loss to follow-up (n = 127). INTERVENTION: Surgical fixation of the medial malleolar fracture was performed using 1 or 2 stainless steel screws. MAIN OUTCOME MEASUREMENTS: Primary outcome was comparison of physical functioning summary score on Short Form 36 questionnaires between patients in the 2 groups. Secondary objectives were to compare the Ankle Hindfoot Scale and operating room time. Clinical and radiographic assessment occurred at the time of injury and 2, 6 weeks, 3, 6, 12, and 24 months postoperatively. RESULTS: Fourteen patients crossed over from the DS group to the single screw (SS) group based on intraoperative decisions by the surgeon (fragment too small for 2 screws), leaving the SS (n = 75) and DS groups (n = 52). There was no difference in the operating room time, SF36, or Ankle Hindfoot Scale at all follow-up time points. CONCLUSIONS: SS medial malleolar fixation provides an equally safe and effective method of fracture care as compared to DS fixation. Twenty percent of patients receiving 2 screws can be expected to crossover to receive SS fixation as a safer alternative. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Fracturas de Tobillo/cirugía , Tornillos Óseos , Fijación Interna de Fracturas/instrumentación , Rango del Movimiento Articular/fisiología , Adulto , Anciano , Fracturas de Tobillo/diagnóstico por imagen , Femenino , Fijación Interna de Fracturas/métodos , Curación de Fractura/fisiología , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Recuperación de la Función/fisiología , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
19.
J Pediatr Gastroenterol Nutr ; 66(2): 263-267, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28753175

RESUMEN

BACKGROUND: Computed tomography scans (CTs), more recently magnetic resonance imaging, are often used to assess the gastrointestinal tract in patients complaining of abdominal pain. We aim to determine the strength of agreement among abdominal imaging, endoscopic, and histologic findings. METHODS: Retrospective chart review of pediatric patients who underwent colonoscopy between January 1, 2012, and December 31, 2014, at Women and Children's Hospital of Buffalo. Patients who had abdominal and pelvic CTs or magnetic resonance imaging within 30 days before or after a colonoscopy were included. RESULTS: One hundred two patients were included: mean age 12.7 ±â€Š3.8 years, 66% girls. A total of 109 imaging studies were performed. Overall 61% of imaging studies were abnormal. The most frequent intestinal radiological findings were colonic wall thickening (CWT) (55%) and colonic wall enhancement (CWH) (24%). Free fluid (20%) and fat stranding (18%) were the most common extra-intestinal findings. Imaging studies agreed with histology in 81% and with colonoscopy in 75% with a moderate strength of agreement (k: 0.59 and 0.466, respectively). CWT agreed with histology in 74% with a moderate strength of agreement (k: 0.47). History of weight loss (OR 5.35, P = 0.041), chronic diarrhea (OR 4.22, P = 0.014), a positive lactoferrin (OR 7.00, P = 0.011), and presence of CWT on imaging study (OR 5.20, P = 0.001) were predictive of having abnormal histology. CONCLUSIONS: The strength of agreement among imaging, endoscopic, and histologic findings was suboptimal. Colonoscopy and imaging are both likely to be necessary in patients with suspected inflammatory bowel disease. Although colonoscopy may be superior in diagnosis of colitis, imaging may provide more information regarding small bowel disease.


Asunto(s)
Colon/patología , Enfermedades del Colon/diagnóstico , Colonoscopía/métodos , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Dolor Abdominal/diagnóstico , Adolescente , Niño , Colon/diagnóstico por imagen , Femenino , Humanos , Masculino , Estudios Retrospectivos , Sensibilidad y Especificidad
20.
J R Army Med Corps ; 164(4): 297-301, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28986388

RESUMEN

Automated external defibrillator (AED) devices have been in routine clinical use since the early 1990s to deliver life-saving shocks to appropriate patients in non-clinical environments. As expectations of survival from out-of-hospital cardiac arrest increase, and evidence incontrovertibly points to reduced timelines as the most crucial factor in achieving return of spontaneous circulation, questions regarding the availability and location of AEDs in the UK military need to be readdressed. This article explores the background of AEDs and reviews their history, life-saving potential and defines current and best practice. It goes on to review the evidence surrounding training and looks to identify knowledge gaps that might be addressed effectively by future research. Finally, it makes recommendations regarding training, availability of AEDs on military bases and locations most likely to deliver good outcomes for military personnel in the future.


Asunto(s)
Reanimación Cardiopulmonar/instrumentación , Desfibriladores , Servicios Médicos de Urgencia , Medicina Militar , Paro Cardíaco Extrahospitalario/terapia , Humanos , Personal Militar/estadística & datos numéricos , Paro Cardíaco Extrahospitalario/mortalidad
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