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1.
J Infect Dis ; 229(Supplement_2): S219-S228, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38243606

RESUMO

BACKGROUND: Pathology and Monkeypox virus (MPXV) tissue tropism in severe and fatal human mpox is not thoroughly described but can help elucidate the disease pathogenesis and the role of coinfections in immunocompromised patients. METHODS: We analyzed biopsy and autopsy tissues from 22 patients with severe or fatal outcomes to characterize pathology and viral antigen and DNA distribution in tissues by immunohistochemistry and in situ hybridization. Tissue-based testing for coinfections was also performed. RESULTS: Mucocutaneous lesions showed necrotizing and proliferative epithelial changes. Deceased patients with autopsy tissues evaluated had digestive tract lesions, and half had systemic tissue necrosis with thrombotic vasculopathy in lymphoid tissues, lung, or other solid organs. Half also had bronchopneumonia, and one-third had acute lung injury. All cases had MPXV antigen and DNA detected in tissues. Coinfections were identified in 5 of 16 (31%) biopsy and 4 of 6 (67%) autopsy cases. CONCLUSIONS: Severe mpox in immunocompromised patients is characterized by extensive viral infection of tissues and viremic dissemination that can progress despite available therapeutics. Digestive tract and lung involvement are common and associated with prominent histopathological and clinical manifestations. Coinfections may complicate mpox diagnosis and treatment. Significant viral DNA (likely correlating to infectious virus) in tissues necessitates enhanced biosafety measures in healthcare and autopsy settings.


Assuntos
Coinfecção , Mpox , Humanos , Monkeypox virus , Hospedeiro Imunocomprometido , Antígenos Virais , DNA Viral
2.
Int J Mol Sci ; 25(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38473724

RESUMO

Although the SARS-CoV-2 vaccination is the primary preventive intervention, there are still few antiviral therapies available, with current drugs decreasing viral replication once the virus is intracellular. Adding novel drugs to target additional points in the viral life cycle is paramount in preventing future pandemics. The purpose of this study was to create and test a novel protein to decrease SARS-CoV-2 replication. We created the recombinant rod domain of vimentin (rhRod) in E. coli and used biolayer interferometry to measure its affinity to the SARS-CoV-2 S1S2 spike protein and the ability to block the SARS-CoV-2-ACE2 interaction. We performed plaque assays to measure rhRod's effect on SARS-CoV-2 replication in Vero E6 cells. Finally, we measured lung inflammation in SARS-CoV-2-exposed K18-hACE transgenic mice given intranasal and intraperitoneal rhRod. We found that rhRod has a high affinity for the S1S2 protein with a strong ability to block S1S2-ACE2 interactions. The daily addition of rhRod decreased viral replication in Vero E6 cells starting at 48 h at concentrations >1 µM. Finally, SARS-CoV-2-infected mice receiving rhRod had decreased lung inflammation compared to mock-treated animals. Based on our data, rhRod decreases SARS-CoV-2 replication in vitro and lung inflammation in vivo. Future studies will need to evaluate the protective effects of rhRod against additional viral variants and identify the optimal dosing scheme that both prevents viral replication and host lung injury.


Assuntos
COVID-19 , Pneumonia , Humanos , Camundongos , Animais , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/farmacologia , Vimentina , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas contra COVID-19/farmacologia , Escherichia coli/metabolismo , Replicação Viral
3.
EMBO J ; 38(13): e100532, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31268606

RESUMO

Lung cancer remains the leading cause of cancer-related death due to poor treatment responses and resistance arising from tumour heterogeneity. Here, we show that adverse prognosis associated with epigenetic silencing of the tumour suppressor RASSF1A is due to increased deposition of extracellular matrix (ECM), tumour stiffness and metastatic dissemination in vitro and in vivo. We find that lung cancer cells with RASSF1A promoter methylation display constitutive nuclear YAP1 accumulation and expression of prolyl 4-hydroxylase alpha-2 (P4HA2) which increases collagen deposition. Furthermore, we identify that elevated collagen creates a stiff ECM which in turn triggers cancer stem-like programming and metastatic dissemination in vivo. Re-expression of RASSF1A or inhibition of P4HA2 activity reverses these effects and increases markers of lung differentiation (TTF-1 and Mucin 5B). Our study identifies RASSF1A as a clinical biomarker associated with mechanical properties of ECM which increases the levels of cancer stemness and risk of metastatic progression in lung adenocarcinoma. Moreover, we highlight P4HA2 as a potential target for uncoupling ECM signals that support cancer stemness.


Assuntos
Adenocarcinoma de Pulmão/patologia , Metilação de DNA , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/metabolismo , Proteínas Supressoras de Tumor/genética , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Animais , Linhagem Celular Tumoral , Progressão da Doença , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Camundongos , Metástase Neoplásica , Transplante de Neoplasias , Prolil Hidroxilases/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Proteínas de Sinalização YAP
4.
Phys Rev Lett ; 130(11): 116105, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-37001088

RESUMO

We present our discovery of switchable high explosives (HEs) as a new class of energetic material that cannot detonate unless filled with a fluid. The performance of fluid-filled additive-manufactured HE lattices is herein evaluated by analysis of detonation velocity and Gurney energy. The Gurney energy of the unfilled lattice was 98% lower than that of the equivalent water-filled lattice and changing the fluid mechanical properties allowed tuning of the Gurney energy and detonation velocity by 8.5% and 13.4%, respectively. These results provide, for the first time since the development of HEs, a method to completely remove the hazard of unplanned detonations during storage and transport.

5.
Clin Anat ; 36(1): 110-117, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35951617

RESUMO

The safety and effectiveness of facial cosmetic surgery procedures are dependent on detailed 3D understanding of the complex surgical anatomy of the face. Traditional, small sample size anatomical dissection studies have limitations in providing definitive clarification of the fascial layers of the face, and especially in their relationship with the facial nerve, and their reaction to surgical manipulation. The objective study of large tissue areas is required to effectively demonstrate the broader architecture. Conventional histology techniques were modified to handle extraordinarily large tissue samples to fulfill this requirement. Full-thickness soft tissue samples (skin to bone) of maximum length 18 cm, width 4 cm, and tissue thickness 1 cm, were harvested from 20 hemifaces of 15 fresh human cadavers (mean age at death = 81 years). After fixation, the samples were processed with an automated processor using paraffin wax for 156 h, sectioned at 30 µm, collected on gelatin-chromium-coated glass slides, stained with a Masson's Trichrome technique and photographed. Using this technique, excellent visualization was obtained of the fascial connective tissue and its relationship with the facial mimetic muscles, muscles of mastication and salivary glands in 73 large histological slides. The resulting slides improved the study of the platysma and superficial musculo-aponeurotic system (SMAS), the spaces and ligaments, the malar fat pad, and the facial nerve in relations to the deep fascia. Additionally, surgically induced changes in the soft-tissue organization were successfully visualized. This technique enables improved insight into the broad structural architecture and histomorphology of large-scale facial tissues.


Assuntos
Ritidoplastia , Sistema Musculoaponeurótico Superficial , Humanos , Idoso de 80 Anos ou mais , Ritidoplastia/métodos , Fáscia/anatomia & histologia , Bochecha , Músculos Faciais
6.
Aesthet Surg J ; 43(9): 941-954, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37130080

RESUMO

BACKGROUND: A limitation of current facelift techniques is the early postoperative reappearance of anterior midcheek laxity associated with recurrence of the nasolabial fold (NLF). OBJECTIVES: This study was undertaken to examine the regional anatomy of the anterior midcheek and NLF with a focus on explaining the early recurrence phenomenon and to explore the possibility of alternative surgical methods that prolong NLF correction. METHODS: Fifty cadaver heads were studied (16 embalmed, 34 fresh; mean age, 75 years). Following preliminary dissections and macrosectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination, and microcomputed tomography. Mechanical testing of the melo fat pad (MFP) and skin was performed to gain insight on which structure is responsible for transmission of the lifting tension in a composite facelift procedure. RESULTS: Anatomic dissections, sheet plastination, and microcomputed tomography demonstrated the 3-dimensional architecture and borders of the MFP. Histology of a lifted midcheek demonstrated that a composite MFP lift causes a change in connective tissue organization from a hanging-down pattern into a pulled-upward pattern, suggesting traction on the skin. Mechanical testing confirmed that, in a composite lift, despite the sutures being placed directly into the deep aspect of the MFP, the lifting tension distal to the suture is transmitted through the skin and not through the MFP. CONCLUSIONS: The usual method of performing a composite midcheek lift results in the skin, and not the MFP itself, bearing the load of the nondissected tissues distal to the lifting suture. For this reason, early recurrence of the NLF occurs following skin relaxation in the postoperative period. Accordingly, specific surgical procedures for remodeling the MFP should be explored, possibly in combination with volume restoration of the fat and bone, for more lasting improvement of the NLF.


Assuntos
Sulco Nasogeniano , Ritidoplastia , Idoso , Humanos , Tecido Adiposo/cirurgia , Sulco Nasogeniano/cirurgia , Ritidoplastia/métodos , Microtomografia por Raio-X
7.
J Am Chem Soc ; 144(50): 22865-22869, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36479874

RESUMO

We report the mechanochemical reactivity of the highly strained pentacyclic hydrocarbon cubane. The mechanical reactivity of cubane is explored for three regioisomers with 1,2-, 1,3-, and 1,4-substituted pulling attachments. Whereas all compounds can be activated thermally, mechanical activation is observed via pulsed ultrasonication of cubane-containing polymers only when force is applied via 1,2-attachment. The single observed product of the force-coupled reaction is a thermally inaccessible syn-tricyclooctadiene, in contrast to cyclooctatetraene (observed thermally) or a pair of cyclobutadienes that would result from sequential cyclobutane scission. We further quantify the mechanochemical reactivity of cubane by single molecule force spectroscopy, and force-coupled rate constants for ring opening reach ∼33 s-1 at a force of ∼1.55 nN, lower than forces of 1.8-2.0 nN that are typical of conventional cyclobutanes.


Assuntos
Fenômenos Mecânicos , Polímeros , Polímeros/química
8.
MMWR Morb Mortal Wkly Rep ; 71(44): 1412-1417, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36327164

RESUMO

As of October 21, 2022, a total of 27,884 monkeypox cases (confirmed and probable) have been reported in the United States.§ Gay, bisexual, and other men who have sex with men have constituted a majority of cases, and persons with HIV infection and those from racial and ethnic minority groups have been disproportionately affected (1,2). During previous monkeypox outbreaks, severe manifestations of disease and poor outcomes have been reported among persons with HIV infection, particularly those with AIDS (3-5). This report summarizes findings from CDC clinical consultations provided for 57 patients aged ≥18 years who were hospitalized with severe manifestations of monkeypox¶ during August 10-October 10, 2022, and highlights three clinically representative cases. Overall, 47 (82%) patients had HIV infection, four (9%) of whom were receiving antiretroviral therapy (ART) before monkeypox diagnosis. Most patients were male (95%) and 68% were non-Hispanic Black (Black). Overall, 17 (30%) patients received intensive care unit (ICU)-level care, and 12 (21%) have died. As of this report, monkeypox was a cause of death or contributing factor in five of these deaths; six deaths remain under investigation to determine whether monkeypox was a causal or contributing factor; and in one death, monkeypox was not a cause or contributing factor.** Health care providers and public health professionals should be aware that severe morbidity and mortality associated with monkeypox have been observed during the current outbreak in the United States (6,7), particularly among highly immunocompromised persons. Providers should test all sexually active patients with suspected monkeypox for HIV at the time of monkeypox testing unless a patient is already known to have HIV infection. Providers should consider early commencement and extended duration of monkeypox-directed therapy†† in highly immunocompromised patients with suspected or laboratory-diagnosed monkeypox.§§ Engaging all persons with HIV in sustained care remains a critical public health priority.


Assuntos
Infecções por HIV , Mpox , Minorias Sexuais e de Gênero , Estados Unidos/epidemiologia , Humanos , Masculino , Adolescente , Adulto , Feminino , Infecções por HIV/diagnóstico , Homossexualidade Masculina , Etnicidade , Vigilância da População , Grupos Minoritários , Mpox/epidemiologia
9.
South Med J ; 115(4): 270-275, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35365844

RESUMO

OBJECTIVES: Treating chronic migraine (CM) effectively is one of the greatest challenges a primary care provider (PCP) may encounter. Many patients with CM report dissatisfaction and minimal gains from treatment, despite using the best medical interventions available. For this study, patients with CM and their partners provided insight into how PCPs could improve CM treatment. METHODS: Using the immersion/crystallization phenomenological method, we collected data from 11 patients with CM and 8 of their partners (N = 19). We analyzed open-ended survey responses about migraine treatment from patients with CM, as well as transcripts from interviews with patients with CM and their partners (14 interviews total) about their medical experiences. RESULTS: Participants used a variety of pharmacological and alternative treatments in search of a cure; wanted to be treated more collaboratively; and repeatedly gave up on medical care, but then sought treatment again. CONCLUSIONS: PCPs could be trained to encourage patients with CM to shift toward accepting and managing migraines rather than endlessly hoping for a cure. Patients could be taught to manage CM using a holistic, biopsychosocial approach.


Assuntos
Transtornos de Enxaqueca , Assistência ao Paciente , Humanos , Transtornos de Enxaqueca/psicologia , Transtornos de Enxaqueca/terapia , Inquéritos e Questionários
10.
BMC Med Educ ; 22(1): 158, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260154

RESUMO

BACKGROUND: As the field of education was adapting to virtual learning during the COVID-19 pandemic, a need quickly emerged for a course to prepare medical students for future clinical practice. This call to action was answered by creating an innovative Fundamentals of COVID-19 course at the Indiana University School of Medicine (IUSM). As a group of medical student leaders at IUSM, we developed this online course in order to support our fellow students and the community. METHODS: The study examined the educational effects of completing the Fundamentals of COVID-19 course. In order to examine these effects, the study asked enrolled students to complete both a pre- and post-course self-assessment survey. Students were asked an identical set of questions on each survey about their knowledge, skills, and abilities (KSA) regarding COVID-19. Composite scores were created for each KSA learning domain. Responses were provided using a five-point Likert scale ranging from 1 = strongly disagree to 5 = strongly agree. RESULTS: Out of the 724 students enrolled, 645 students completed both the pre- and post-course assessment surveys. Findings show that there were both meaningful and statistically significant differences in students' responses to the pre- and post-course surveys. Results show 1.) a significant mean increase in the knowledge composite score of 1.01, 95% CI [0.95, 1.06], t(644) = 36.4, p < .001, d = 1.43; 2.) a significant mean increase in the skills composite score of .55, 95% CI [0.50, 0.60], t(644) = 20.70, p < .001, d = 0.81. and 3.) a significant mean increase of the abilities composite score of 1.02, 95% CI [.97, 1.07], t(644) = 36.56, p < .001, d = 1.44. CONCLUSIONS: These findings demonstrate that the student-developed, online Fundamentals of COVID-19 course resulted in notable and statistically significant educational effects. The increase in students' self-reported ratings, especially in the knowledge and abilities domains, indicate that meaningful learning occurred within the course. These findings have notable implications for medical student training during healthcare emergencies, such as a pandemic, as well as within modern clerkship environments. Overall, our findings provide evidence that student-led curricular design and virtual delivery of course content can be effective tools in undergraduate medical education.


Assuntos
COVID-19 , Educação de Graduação em Medicina , Educação Médica , Estudantes de Medicina , COVID-19/epidemiologia , Currículo , Educação Médica/métodos , Humanos , Pandemias , SARS-CoV-2
11.
Adv Skin Wound Care ; 35(10): 535-543, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36125453

RESUMO

GENERAL PURPOSE: To provide information about the management of infected wounds in wound care settings. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Identify a host factor that may predispose a patient to a wound infection as well as characteristics of each stage of wound infection.2. Distinguish a common organism that causes early, acute wound infections and explain the preferred method for obtaining a wound specimen for culture.3. Apply knowledge of commonly prescribed antibiotics in wound care settings.


Although all chronic wounds are colonized by microbes and not all wounds are infected, antibiotics are widely prescribed in wound care settings. Antibiotic misuse in wound care occurs for many reasons, including diagnostic uncertainty regarding the presence of a bacterial infection, insufficient clinician knowledge about when antibiotics are necessary, clinicians' fear of achieving unfavorable patient outcomes, and patient demand. Understanding wound infection stages and proper wound assessment are essential to differentiate infected wounds from colonized wounds. Adequate knowledge of microbiology and commonly prescribed antibiotics in wound care settings is critical to optimize antimicrobial management. In this article, the authors review wound infection stages, host resistant factors, and microbial virulence factors that affect the progression of wound infection, specimen collection, common causative organisms, and commonly prescribed antibiotics in wound care settings.


Assuntos
Doenças Transmissíveis , Infecção dos Ferimentos , Antibacterianos/uso terapêutico , Humanos , Pele , Cicatrização , Infecção dos Ferimentos/tratamento farmacológico
12.
J Biol Chem ; 295(21): 7376-7390, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32299911

RESUMO

CTX-M ß-lactamases are widespread in Gram-negative bacterial pathogens and provide resistance to the cephalosporin cefotaxime but not to the related antibiotic ceftazidime. Nevertheless, variants have emerged that confer resistance to ceftazidime. Two natural mutations, causing P167S and D240G substitutions in the CTX-M enzyme, result in 10-fold increased hydrolysis of ceftazidime. Although the combination of these mutations would be predicted to increase ceftazidime hydrolysis further, the P167S/D240G combination has not been observed in a naturally occurring CTX-M variant. Here, using recombinantly expressed enzymes, minimum inhibitory concentration measurements, steady-state enzyme kinetics, and X-ray crystallography, we show that the P167S/D240G double mutant enzyme exhibits decreased ceftazidime hydrolysis, lower thermostability, and decreased protein expression levels compared with each of the single mutants, indicating negative epistasis. X-ray structures of mutant enzymes with covalently trapped ceftazidime suggested that a change of an active-site Ω-loop to an open conformation accommodates ceftazidime leading to enhanced catalysis. 10-µs molecular dynamics simulations further correlated Ω-loop opening with catalytic activity. We observed that the WT and P167S/D240G variant with acylated ceftazidime both favor a closed conformation not conducive for catalysis. In contrast, the single substitutions dramatically increased the probability of open conformations. We conclude that the antagonism is due to restricting the conformation of the Ω-loop. These results reveal the importance of conformational heterogeneity of active-site loops in controlling catalytic activity and directing evolutionary trajectories.


Assuntos
Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Evolução Molecular , Mutação de Sentido Incorreto , Resistência beta-Lactâmica , beta-Lactamases/química , Substituição de Aminoácidos , Catálise , Ceftazidima/química , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , beta-Lactamases/genética , beta-Lactamases/metabolismo
13.
J Am Chem Soc ; 143(10): 3846-3855, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33667078

RESUMO

Woodward and Hoffman once jested that a very powerful Maxwell demon could seize a molecule of cyclobutene at its methylene groups and tear it open in a disrotatory fashion to obtain butadiene (Woodward, R. B.; Hoffmann, R. The Conservation of Orbital Symmetry. Angew. Chem., Int. Ed. 1969, 8, 781-853). Nearly 40 years later, that demon was discovered, and the field of covalent polymer mechanochemistry was born. In the decade since our demon was befriended, many fundamental investigations have been undertaken to build up our understanding of force-modified pathways for electrocyclic ring-opening reactions. Here, we seek to extend that fundamental understanding by exploring substituent effects in allowed and forbidden ring-opening reactions of cyclobutene (CBE) and benzocyclobutene (BCB) using a combination of single-molecule force spectroscopy (SMFS) and computation. We show that, while the forbidden ring-opening of cis-BCB occurs at a lower force than the allowed ring-opening of trans-BCB on the time scale of the SMFS experiment, the opposite is true for cis- and trans-CBE. Such a reactivity flip is explained through computational analysis and discussion of the so-called allowed/forbidden gap.

14.
J Clin Microbiol ; 59(1)2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33093026

RESUMO

The distribution of upper respiratory viral loads (VL) in asymptomatic children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. We assessed PCR cycle threshold (Ct) values and estimated VL in infected asymptomatic children diagnosed in nine pediatric hospital testing programs. Records for asymptomatic and symptomatic patients with positive clinical SARS-CoV-2 tests were reviewed. Ct values were (i) adjusted by centering each value around the institutional median Ct value from symptomatic children tested with that assay and (ii) converted to estimated VL (numbers of copies per milliliter) using internal or manufacturer data. Adjusted Ct values and estimated VL for asymptomatic versus symptomatic children (118 asymptomatic versus 197 symptomatic children aged 0 to 4 years, 79 asymptomatic versus 97 symptomatic children aged 5 to 9 years, 69 asymptomatic versus 75 symptomatic children aged 10 to 13 years, 73 asymptomatic versus 109 symptomatic children aged 14 to 17 years) were compared. The median adjusted Ct value for asymptomatic children was 10.3 cycles higher than for symptomatic children (P < 0.0001), and VL were 3 to 4 logs lower than for symptomatic children (P < 0.0001); differences were consistent (P < 0.0001) across all four age brackets. These differences were consistent across all institutions and by sex, ethnicity, and race. Asymptomatic children with diabetes (odds ratio [OR], 6.5; P = 0.01), a recent contact (OR, 2.3; P = 0.02), and testing for surveillance (OR, 2.7; P = 0.005) had higher estimated risks of having a Ct value in the lowest quartile than children without, while an immunocompromised status had no effect. Children with asymptomatic SARS-CoV-2 infection had lower levels of virus in their nasopharynx/oropharynx than symptomatic children, but the timing of infection relative to diagnosis likely impacted levels in asymptomatic children. Caution is recommended when choosing diagnostic tests for screening of asymptomatic children.


Assuntos
Infecções Assintomáticas/epidemiologia , COVID-19/diagnóstico , COVID-19/epidemiologia , Carga Viral , Adolescente , Teste para COVID-19/métodos , Criança , Pré-Escolar , Feminino , Hospitais Pediátricos , Humanos , Lactente , Recém-Nascido , Masculino , Nasofaringe/virologia , Orofaringe/virologia , SARS-CoV-2/isolamento & purificação
15.
J Biol Chem ; 293(46): 17971-17984, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30275013

RESUMO

The CTX-M ß-lactamases have emerged as the most widespread extended-spectrum ß-lactamases (ESBLs) in Gram-negative bacteria. These enzymes rapidly hydrolyze cefotaxime, but not the related cephalosporin, ceftazidime. ESBL variants have evolved, however, that provide enhanced ceftazidime resistance. We show here that a natural variant at a nonactive site, i.e. second-shell residue N106S, enhances enzyme stability but reduces catalytic efficiency for cefotaxime and ceftazidime and decreases resistance levels. However, when the N106S variant was combined with an active-site variant, D240G, that enhances enzyme catalytic efficiency, but decreases stability, the resultant double mutant exhibited higher resistance levels than predicted on the basis of the phenotypes of each variant. We found that this epistasis is due to compensatory effects, whereby increased stability provided by N106S overrides its cost of decreased catalytic activity. X-ray structures of the variant enzymes in complex with cefotaxime revealed conformational changes in the active-site loop spanning residues 103-106 that were caused by the N106S substitution and relieve steric strain to stabilize the enzyme, but also alter contacts with cefotaxime and thereby reduce catalytic activity. We noted that the 103-106 loop conformation in the N106S-containing variants is different from that of WT CTX-M but nearly identical to that of the non-ESBL, TEM-1 ß-lactamase, having a serine at the 106 position. Therefore, residue 106 may serve as a "switch" that toggles the conformations of the 103-106 loop. When it is serine, the loop is in the non-ESBL, TEM-like conformation, and when it is asparagine, the loop is in a CTX-M-like, cefotaximase-favorable conformation.


Assuntos
Resistência às Cefalosporinas/genética , beta-Lactamases/genética , Substituição de Aminoácidos , Cefotaxima/química , Ceftazidima/química , Cristalografia por Raios X , Estabilidade Enzimática , Epistasia Genética , Escherichia coli/genética , Hidrólise , Cinética , Testes de Sensibilidade Microbiana , Mutagênese Sítio-Dirigida , Conformação Proteica , beta-Lactamases/química
16.
Arch Sex Behav ; 46(2): 575-584, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27091186

RESUMO

Using matched, heterosexual couple data from the Relationship Evaluation Questionnaire (RELATE; n = 326 couples), an adapted common-fate approach was used to examine both common and unique attributes of husbands' and wives' acceptance of pornography and sexual satisfaction as well as husbands' and wives' pornography use. It was expected that spouses' unique as well as shared variance of pornography acceptance would be significantly associated with husbands' and wives' levels of personal pornography use and that these use patterns would be significantly associated with husbands' and wives' unique as well as shared variance of sexual satisfaction. It was also expected that pornography use would significantly mediate the relationship between pornography acceptance and sexual satisfaction. Results indicated that the shared variance of pornography acceptance was positively associated with both spouses' pornography use and that spouses' pornography use was negatively associated with their own sexual satisfaction. Wives' pornography use was found to be positively associated with the couple's shared variance of sexual satisfaction, but pornography use did not significantly mediate the relationship between pornography acceptance and sexual satisfaction. These findings emphasize the complexity of pornography use in couple relationships and the importance of studying pornography acceptance and use as a coupling dynamic within marriages rather than just an individual behavior.


Assuntos
Literatura Erótica/psicologia , Heterossexualidade/psicologia , Satisfação Pessoal , Cônjuges/psicologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Casamento , Cônjuges/estatística & dados numéricos , Inquéritos e Questionários
17.
J Shoulder Elbow Surg ; 26(11): 2038-2046, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28865966

RESUMO

BACKGROUND: Retearing after rotator cuff surgery is a major clinical problem. Numerous scaffolds are being used to try to reduce retear rates. However, few have demonstrated clinical efficacy. We hypothesize that this lack of efficacy is due to insufficient mechanical properties. Therefore, we compared the macro and nano/micro mechanical properties of 7 commercially available scaffolds to those of the human supraspinatus tendons, whose function they seek to restore. METHODS: The clinically approved scaffolds tested were X-Repair, LARS ligament, Poly-Tape, BioFiber, GraftJacket, Permacol, and Conexa. Fresh frozen cadaveric human supraspinatus tendon samples were used. Macro mechanical properties were determined through tensile testing and rheometry. Scanning probe microscopy and scanning electron microscopy were performed to assess properties of materials at the nano/microscale (morphology, Young modulus, loss tangent). RESULTS: None of the scaffolds tested adequately approximated both the macro and micro mechanical properties of human supraspinatus tendon. Macroscale mechanical properties were insufficient to restore load-bearing function. The best-performing scaffolds on the macroscale (X-Repair, LARS ligament) had poor nano/microscale properties. Scaffolds approximating tendon properties on the nano/microscale (BioFiber, biologic scaffolds) had poor macroscale properties. CONCLUSION: Existing scaffolds failed to adequately approximate the mechanical properties of human supraspinatus tendons. Combining the macroscopic mechanical properties of a synthetic scaffold with the micro mechanical properties of biologic scaffold could better achieve this goal. Future work should focus on advancing techniques to create new scaffolds with more desirable mechanical properties. This may help improve outcomes for rotator cuff surgery patients.


Assuntos
Materiais Biocompatíveis , Teste de Materiais , Lesões do Manguito Rotador/cirurgia , Alicerces Teciduais , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Cadáver , Humanos , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Tendões/transplante , Resistência à Tração
18.
J Child Sex Abus ; 26(1): 58-77, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28212063

RESUMO

Trauma from female incestuous child sexual abuse may result in negative psychological consequences affecting adult relationships. This study explored relational consequences of incestuous child sexual abuse, focusing on conflict resolution styles, relationship satisfaction, and relationship stability. Using the RELATionship Evaluation dataset, 457 heterosexual couples in which female partners experienced incestuous child sexual abuse were compared to a group of 1,827 couples with no sexual abuse history. Analyses tested differences in the frequencies of reported conflict resolution styles for incestuous child sexual abuse and non-incestuous child sexual abuse groups, the mediating effects of conflict resolution styles on the relationship between incestuous child sexual abuse, and self- and partner-reported relationship satisfaction and stability. Significant differences in the reports of types of conflict resolution styles were found for incestuous child sexual abuse versus non-incestuous child sexual abuse groups. Incestuous child sexual abuse and conflict resolution styles were negatively related to relationship satisfaction and stability and there was a significant indirect effect between female incestuous child sexual abuse, female volatility, and relationship instability. Clinical applications for couple relationships are discussed.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis/psicologia , Características da Família , Incesto/psicologia , Relações Interpessoais , Negociação/psicologia , Satisfação Pessoal , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Arch Sex Behav ; 45(1): 145-58, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26228990

RESUMO

The present study utilized a sample of 1755 adult couples in heterosexual romantic relationships to examine how different patterns of pornography use between romantic partners may be associated with relationship outcomes. While pornography use has been generally associated with some negative and some positive couple outcomes, no study has yet explored how differences between partners may uniquely be associated with relationship well-being. Results suggested that greater discrepancies between partners in pornography use were related to less relationship satisfaction, less stability, less positive communication, and more relational aggression. Mediation analyses suggested that greater pornography use discrepancies were primarily associated with elevated levels of male relational aggression, lower female sexual desire, and less positive communication for both partners which then predicted lower relational satisfaction and stability for both partners. Results generally suggest that discrepancies in pornography use at the couple level are related to negative couple outcomes. Specifically, pornography differences may alter specific couple interaction processes which, in turn, may influence relationship satisfaction and stability. Implications for scholars and clinicians interested in how pornography use is associated with couple process are discussed.


Assuntos
Literatura Erótica , Casamento/psicologia , Satisfação Pessoal , Comportamento Sexual/psicologia , Cônjuges/psicologia , Adulto , Comunicação , Características da Família , Feminino , Heterossexualidade , Humanos , Libido , Masculino , Parceiros Sexuais , Inquéritos e Questionários , Estados Unidos
20.
Biophys J ; 109(12): 2501-2510, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26682809

RESUMO

In this work, we report the implementation of interferometric second harmonic generation (SHG) microscopy with femtosecond pulses. As a proof of concept, we imaged the phase distribution of SHG signal from the complex collagen architecture of juvenile equine growth cartilage. The results are analyzed in respect to numerical simulations to extract the relative orientation of collagen fibrils within the tissue. Our results reveal large domains of constant phase together with regions of quasi-random phase, which are correlated to respectively high- and low-intensity regions in the standard SHG images. A comparison with polarization-resolved SHG highlights the crucial role of relative fibril polarity in determining the SHG signal intensity. Indeed, it appears that even a well-organized noncentrosymmetric structure emits low SHG signal intensity if it has no predominant local polarity. This work illustrates how the complex architecture of noncentrosymmetric scatterers at the nanoscale governs the coherent building of SHG signal within the focal volume and is a key advance toward a complete understanding of the structural origin of SHG signals from tissues.


Assuntos
Colágeno/química , Microscopia , Multimerização Proteica , Animais , Cartilagem/química , Cavalos , Modelos Biológicos , Estrutura Secundária de Proteína
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