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1.
Front Nutr ; 11: 1338392, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38577156

RESUMO

Background: Diets rich in minimally processed plant-based foods are recommended to breast cancer patients, and some may have an interest in whole-food, plant-based (WFPB) diets that avoid animal-based foods, added fats, and refined sugars. Within WFPB diets, the intakes of isoflavones, omega-6 polyunsaturated fatty acids (n-6 PUFAs), and omega-3 polyunsaturated FAs (n-3 PUFAs), which have been discussed in reference to breast cancer outcomes, have not been well characterized. Methods: Women with stage IV breast cancer on stable therapy were randomized 2:1 into (1) a WFPB intervention (N = 21) or (2) usual care (N = 11) for 8 weeks. Three meals per day were provided. Outcomes presented here include dietary intake of isoflavones, n-3 and n-6- PUFAs, which were assessed using three-day food records at baseline and 8 weeks. Baseline and 8-week mean intake within groups were compared using the Wilcoxon signed-rank test and between control and intervention groups by a two-sample t-test. Results: The WFPB intervention participants increased their daily consumption of total isoflavones from a mean of 0.8 mg/day to 14.5 mg/day (p < 0.0001) and decreased the n-6:n-3 ratio of their diet from a mean of 9.3 to 3.7 (p < 0.0001). Within the WFPB group, linoleic acid (n-6 PUFA) consumption decreased by a mean of 3.8 g (p = 0.0095), from 12.8 g/day to 9.0 g/day; total n-3 PUFA consumption increased by a mean of 1.1 g (p = 0.0005), from 1.6 g/day to 2.7 g/day. Conclusion: Transitioning to a WFPB diet resulted in significantly increased isoflavone intake and decreased n-6:n-3 ratio in women with breast cancer.

2.
Stem Cell Res Ther ; 15(1): 118, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659053

RESUMO

BACKGROUND: Cerebral organoids (COs) are the most advanced in vitro models that resemble the human brain. The use of COs as a model for Alzheimer's disease (AD), as well as other brain diseases, has recently gained attention. This study aimed to develop a human AD CO model using normal human pluripotent stem cells (hPSCs) that recapitulates the pathological phenotypes of AD and to determine the usefulness of this model for drug screening. METHODS: We established AD hPSC lines from normal hPSCs by introducing genes that harbor familial AD mutations, and the COs were generated using these hPSC lines. The pathological features of AD, including extensive amyloid-ß (Aß) accumulation, tauopathy, and neurodegeneration, were analyzed using enzyme-linked immunosorbent assay, Amylo-Glo staining, thioflavin-S staining, immunohistochemistry, Bielschowsky's staining, and western blot analysis. RESULTS: The AD COs exhibited extensive Aß accumulation. The levels of paired helical filament tau and neurofibrillary tangle-like silver deposits were highly increased in the AD COs. The number of cells immunoreactive for cleaved caspase-3 was significantly increased in the AD COs. In addition, treatment of AD COs with BACE1 inhibitor IV, a ß-secretase inhibitor, and compound E, a γ-secretase inhibitor, significantly attenuated the AD pathological features. CONCLUSION: Our model effectively recapitulates AD pathology. Hence, it is a valuable platform for understanding the mechanisms underlying AD pathogenesis and can be used to test the efficacy of anti-AD drugs.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Organoides , Células-Tronco Pluripotentes , Humanos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Organoides/metabolismo , Organoides/patologia , Células-Tronco Pluripotentes/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Proteínas tau/metabolismo , Proteínas tau/genética , Ácido Aspártico Endopeptidases/metabolismo , Ácido Aspártico Endopeptidases/genética , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Biológicos
3.
EJNMMI Res ; 14(1): 32, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38536511

RESUMO

BACKGROUND: Standard measures of response such as Response Evaluation Criteria in Solid Tumors are ineffective for bone lesions, often making breast cancer patients that have bone-dominant metastases ineligible for clinical trials with potentially helpful therapies. In this study we prospectively evaluated the test-retest uptake variability of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) in a cohort of breast cancer patients with bone-dominant metastases to determine response criteria. The thresholds for 95% specificity of change versus no-change were then applied to a second cohort of breast cancer patients with bone-dominant metastases. METHODS: For this study, nine patients with 38 bone lesions were imaged with 18F-FDG in the same calibrated scanner twice within 14 days. Tumor uptake was quantified by the most commonly used PET parameter, the maximum tumor voxel normalized by dose and body weight (SUVmax) and also by the mean of a 1-cc maximal uptake volume normalized by dose and lean-body-mass (SULpeak). The asymmetric repeatability coefficients with confidence intervals for SUVmax and SULpeak were used to determine the limits of 18F-FDG uptake variability. A second cohort of 28 breast cancer patients with bone-dominant metastases that had 146 metastatic bone lesions was imaged with 18F-FDG before and after standard-of-care therapy for response assessment. RESULTS: The mean relative difference of SUVmax and SULpeak in 38 bone tumors of the first cohort were 4.3% and 6.7%. The upper and lower asymmetric limits of the repeatability coefficient were 19.4% and - 16.3% for SUVmax, and 21.2% and - 17.5% for SULpeak. 18F-FDG repeatability coefficient confidence intervals resulted in the following patient stratification using SULpeak for the second patient cohort: 11-progressive disease, 5-stable disease, 7-partial response, and 1-complete response with three inevaluable patients. The asymmetric repeatability coefficients response criteria for SULpeak changed the status of 3 patients compared to the standard Positron Emission Tomography Response Criteria in Solid Tumors of ± 30% SULpeak. CONCLUSION: In evaluating bone tumor response for breast cancer patients with bone-dominant metastases using 18F-FDG SUVmax, the repeatability coefficients from test-retest studies show that reductions of more than 17% and increases of more than 20% are unlikely to be due to measurement variability. Serial 18F-FDG imaging in clinical trials investigating bone lesions in these patients, such as the ECOG-ACRIN EA1183 trial, benefit from confidence limits that allow interpretation of response.

4.
Cancers (Basel) ; 16(5)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38473237

RESUMO

Background: Hypoxia, a state of low oxygen level within a tissue, is often present in primary and secondary liver tumors. At the molecular level, the tumor cells' response to hypoxic stress induces proteomic and genomic changes which are largely regulated by proteins called hypoxia-induced factors (HIF). These proteins have been found to drive tumor progression and cause resistance to drug- and radiation-based therapies, ultimately contributing to a tumor's poor prognosis. Several imaging modalities have been developed to visualize tissue hypoxia, providing insight into a tumor's microbiology. Methods: A systematic literature search was conducted in PubMed, EMBASE, Cochrane, and Google Scholar for all reports related to hypoxia on liver tumors. All relevant studies were summarized. Results: This review will focus on the impact of hypoxia on liver tumors and review PET-, MRI-, and SPECT-based imaging modalities that have been developed to predict and assess a tumor's response to radiation therapy, with a focus on liver cancers. Conclusion: While there are numerous studies that have evaluated the impact of hypoxia on tumor outcomes, there remains a relative paucity of data evaluating and quantifying hypoxia within the liver. Novel and developing non-invasive imaging techniques able to provide functional and physiological information on tumor hypoxia within the liver may be able to assist in the treatment planning of primary and metastatic liver lesions.

5.
Res Sq ; 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38313279

RESUMO

BACKGROUND: Standard measures of response such as Response Evaluation Criteria in Solid Tumors are ineffective for bone lesions, often making breast cancer patients with bone-dominant metastases ineligible for clinical trials with potentially helpful therapies. In this study we prospectively evaluated the test-retest uptake variability of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) in a cohort of breast cancer patients with bone-dominant metastases to determine response criteria. The thresholds for 95% specificity of change versus no-change were then applied to a second cohort of breast cancer patients with bone-dominant metastases.In this study, nine patients with 38 bone lesions were imaged with 18F-FDG in the same calibrated scanner twice within 14 days. Tumor uptake was quantified as the maximum tumor voxel normalized by dose and body weight (SUVmax) and the mean of a 1-cc maximal uptake volume normalized by dose and lean-body-mass (SULpeak). The asymmetric repeatability coefficients with confidence intervals of SUVmax and SULpeak were used to determine limits of 18F-FDG uptake variability. A second cohort of 28 breast cancer patients with bone-dominant metastases that had 146 metastatic bone lesions was imaged with 18F-FDG before and after standard-of-care therapy for response assessment. RESULTS: The mean relative difference of SUVmax in 38 bone tumors of the first cohort was 4.3%. The upper and lower asymmetric limits of the repeatability coefficient were 19.4% and -16.3%, respectively. The 18F-FDG repeatability coefficient confidence intervals resulted in the following patient stratification for the second patient cohort: 11-progressive disease, 5-stable disease, 7-partial response, and 1-complete response with three inevaluable patients. The asymmetric repeatability coefficients response criteria changed the status of 3 patients compared to standard the standard Positron Emission Tomography Response Criteria in Solid Tumors of ±30% SULpeak. CONCLUSIONS: In evaluating bone tumor response for breast cancer patients with bone-dominant metastases using 18F-FDG uptake, the repeatability coefficients from test-retest studies show that reductions of more than 17% and increases of more than 20% are unlikely to be due to measurement variability. Serial 18F-FDG imaging in clinical trials investigating bone lesions from these patients, such as the ECOG-ACRIN EA1183 trial, benefit from confidence limits that allow interpretation of response.

6.
J Am Med Dir Assoc ; : 104924, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38310943

RESUMO

The exigencies of managing acutely ill residents within nursing homes have led to an increase in ambulance conveyances to the emergency department. This is further compounded by a shortage of adequately trained nursing staff and on-site physicians available around the clock. An acute regional hospital, strategically located in the epicenter of nursing home facilities in Singapore, encountered this challenge on its inception in 2018 within the northeast region. In response, the institution initiated a collaboration, EAGLEcareACT (Enhancing Advance Care Planning, Geriatrics, and End-of-Life Care Acute Care Team), aimed at rectifying the prevailing care disparities between neighboring nursing homes and the hospital. Within the EAGLEcareACT, a systematic and comprehensive approach was undertaken to engage diverse nursing homes, delineate precise needs, and establish mutually shared objectives. This encompassed the provisioning of monitoring of patients treated for acute medical conditions, structured training programs for nursing staff and aids in advance care planning. Teleconsultations with EAGLEcareACT team obviate the immediate necessity for conveyance to the emergency department.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38215460

RESUMO

PURPOSE: To delineate specific imaging characteristics of solitary fibrous tumors, schwannomas, cavernous venous malformations, and well-circumscribed orbital lymphoma. METHODS: Patients undergoing excisional biopsy of solitary fibrous tumor, schwannomas, cavernous venous malformations, or well-circumscribed orbital lymphoma with preoperative MRIs available for review were identified at 3 academic centers in the United States and Australia. An exploratory statistical analysis was performed to identify important radiologic features, which were subsequently included in a random forest model. Histopathologic correlates were evaluated in representative cases. RESULTS: A total of 91 cases were included with a mean age of 52.9 ± 17.2 years. Nearly all solitary fibrous tumors were located in the anterior or mid orbit (87.5%) and they more commonly demonstrated intralesional heterogeneity on T2-weighted imaging (45.5%) (p < 0.01). Compared with the other tumors, schwannomas tended to be intraconal (66.7%) and were often in the mid or posterior orbit (83.4%) (p < 0.01). Cavernous venous malformations characteristically demonstrated progressive contrast enhancement (93.9%; p < 0.01). Most lesions in all 4 groups were hypointense on T1-weighted imaging (80%-100%; p = 0.14) and only well-circumscribed orbital lymphoma tended to also be hypointense on T2 (81.8%) (p < 0.01). Finally, cases of lymphoma had significantly lower apparent diffusion coefficient ratios (0.9 ± 0.2) (p < 0.001), while the other 3 groups were not significantly different from one another (cavernous venous malformations: 1.8 ± 0.4; schwannomas: 1.8 ± 0.5; and solitary fibrous tumor: 1.6 ± 0.6) (p = 0.739). CONCLUSIONS: Key features that aid in the differentiation of these 4 tumors from one another include T2 intensity and homogeneity, early contrast-enhancement pattern, and ADC ratio.

8.
Breast Cancer Res Treat ; 203(3): 565-574, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37923962

RESUMO

PURPOSE: Most cytotoxic drugs are dosed using body surface area (BSA), yet not all cancer patients receive the full BSA-determined dose. Prior work suggests that breast cancer patients who are obese are more likely to experience dose reduction than normal weight patients. However, the factors driving dose reduction remain unclear. METHODS: In 452 women diagnosed with stage I-IIIA primary breast cancer at Kaiser Permanente Northern California, we evaluated the association between obesity and dose reduction, and further explored other factors in relation to dose reduction, including various sociodemographic characteristics, tumor characteristics, and comorbidities. Study participants were a part of the Pathways Study, diagnosed between 2006 and 2013 and treated with cyclophosphamide + doxorubicin, followed by paclitaxel (ACT). Dose reduction was assessed using first cycle dose proportion (FCDP) and average relative dose intensity (ARDI), a metric of dose intensity over the course of chemotherapy. RESULTS: Overall, 8% of participants received a FCDP < 90% and 21.2% had an ARDI < 90%, with dose reduction increasing with body mass index. In adjusted logistic regression models, obese women had 4.1-fold higher odds of receiving an ARDI < 90% than normal weight women (95% CI: 1.9-8.9; p-trend = 0.0006). Increasing age was positively associated with an ADRI < 90%, as was the presence of comorbidity. Dose reduction was less common in later calendar years. CONCLUSION: Results offer insight on factors associated with chemotherapy dosing for a common breast cancer regimen. Larger studies are required to evaluate relevance to other regimens, and further work will be needed to determine whether dose reductions impact outcomes in obese women.


Assuntos
Neoplasias da Mama , Prestação Integrada de Cuidados de Saúde , Fumaratos , beta-Alanina/análogos & derivados , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/complicações , Redução da Medicação , Estudos Retrospectivos , Ciclofosfamida , Obesidade/complicações , Obesidade/epidemiologia , Obesidade/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
9.
mBio ; : e0226223, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37850732

RESUMO

Among the 16 two-component systems in the opportunistic human pathogen Staphylococcus aureus, only WalKR is essential. Like the orthologous systems in other Bacillota, S. aureus WalKR controls autolysins involved in peptidoglycan remodeling and is therefore intimately involved in cell division. However, despite the importance of WalKR in S. aureus, the basis for its essentiality is not understood and the regulon is poorly defined. Here, we defined a consensus WalR DNA-binding motif and the direct WalKR regulon by using functional genomics, including chromatin immunoprecipitation sequencing, with a panel of isogenic walKR mutants that had a spectrum of altered activities. Consistent with prior findings, the direct regulon includes multiple autolysin genes. However, this work also revealed that WalR directly regulates at least five essential genes involved in lipoteichoic acid synthesis (ltaS): translation (rplK), DNA compaction (hup), initiation of DNA replication (dnaA, hup) and purine nucleotide metabolism (prs). Thus, WalKR in S. aureus serves as a polyfunctional regulator that contributes to fundamental control over critical cell processes by coordinately linking cell wall homeostasis with purine biosynthesis, protein biosynthesis, and DNA replication. Our findings further address the essentiality of this locus and highlight the importance of WalKR as a bona fide target for novel anti-staphylococcal therapeutics. IMPORTANCE The opportunistic human pathogen Staphylococcus aureus uses an array of protein sensing systems called two-component systems (TCS) to sense environmental signals and adapt its physiology in response by regulating different genes. This sensory network is key to S. aureus versatility and success as a pathogen. Here, we reveal for the first time the full extent of the regulatory network of WalKR, the only staphylococcal TCS that is indispensable for survival under laboratory conditions. We found that WalKR is a master regulator of cell growth, coordinating the expression of genes from multiple, fundamental S. aureus cellular processes, including those involved in maintaining cell wall metabolism, protein biosynthesis, nucleotide metabolism, and the initiation of DNA replication.

10.
mBio ; 14(5): e0174823, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37795985

RESUMO

IMPORTANCE: Extracellular membrane vesicles (MVs) produced by Staphylococcus aureus in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired S. aureus strains, and fibril formation was dependent on expression of the S. aureus δ-toxin gene (hld). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although S. aureus MVs were produced in vivo in a localized murine infection model, amyloid fibrils were not observed in the in vivo setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Animais , Camundongos , Staphylococcus aureus/metabolismo , Amiloide/metabolismo , Proteínas de Bactérias/metabolismo , Infecções Estafilocócicas/microbiologia
11.
Nat Commun ; 14(1): 6479, 2023 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-37838722

RESUMO

Global spread of multidrug-resistant, hospital-adapted Staphylococcus epidermidis lineages underscores the need for new therapeutic strategies. Here we show that many S. epidermidis isolates belonging to these lineages display cryptic susceptibility to penicillin/ß-lactamase inhibitor combinations under in vitro conditions, despite carrying the methicillin resistance gene mecA. Using a mouse thigh model of S. epidermidis infection, we demonstrate that single-dose treatment with amoxicillin/clavulanic acid significantly reduces methicillin-resistant S. epidermidis loads without leading to detectable resistance development. On the other hand, we also show that methicillin-resistant S. epidermidis is capable of developing increased resistance to amoxicillin/clavulanic acid during long-term in vitro exposure to these drugs. These findings suggest that penicillin/ß-lactamase inhibitor combinations could be a promising therapeutic candidate for treatment of a high proportion of methicillin-resistant S. epidermidis infections, although the in vivo risk of resistance development needs to be further addressed before they can be incorporated into clinical trials.


Assuntos
Penicilinas , Infecções Estafilocócicas , Humanos , Penicilinas/farmacologia , Penicilinas/uso terapêutico , Inibidores de beta-Lactamases/farmacologia , Staphylococcus epidermidis , Infecções Estafilocócicas/tratamento farmacológico , Ácido Clavulânico/farmacologia , Ácido Clavulânico/uso terapêutico , Amoxicilina/farmacologia , Amoxicilina/uso terapêutico , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
12.
Vaccines (Basel) ; 11(7)2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37515067

RESUMO

BACKGROUND: The longitudinal response to the COVID-19 vaccines among patients on hemodialysis with and without prior SARS-CoV-2 infection has not been well characterized. METHODS: To guide vaccination strategies in patients on hemodialysis, it is critical to characterize the longevity and efficacy of the vaccine; therefore, we conducted a prospective single-center monthly antibody surveillance study between March 2021 and March 2022 to investigate the dynamic humoral response to a series of COVID-19 mRNA vaccines in patients on hemodialysis with and without prior SARS-CoV-2 infection. Monthly quantitative antibody testing was performed using the Beckman Coulter Access SARS-CoV-2 IgG Antibody Test©, which detects IgG antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. RESULTS: This cohort of 30 participants (mean age: 61 ± 3 years) predominantly self-identified as African American (97%) and male (53%). Eight participants (27%) had recovered from COVID-19 (recovered) before the vaccine initiation. All participants received two vaccine doses, and 86.6% received a 6-month booster dose. Among patients naïve to COVID-19, the antibody positivity rate (APR) was 55% post-first-dose, 91% post-second-dose, 50% pre-booster at 6 months, 100% post-booster, and 89% at 6 months post-booster. Recovered patients sustained a consistent 100% APR throughout the year. The naïve patients demonstrated lower peak antibody levels post-second-dose than the recovered patients (17.9 ± 3.2 vs. 44.7 ± 5.6, p < 0.001). The peak antibody levels post-booster showed no significant difference between both groups (27.1 ± 3.9 vs. 37.9 ± 8.2, p = 0.20). Two naïve patients contracted COVID-19 during the follow-up period. CONCLUSIONS: The patients naïve to COVID-19 exhibited an attenuated and foreshortened antibody response following two doses of the mRNA vaccines compared with the recovered patients, who maintained 100% APR before the booster dose. The 6-month booster dose counteracted declining immunity and stimulated antibody responses in the naïve patients, even in previously non-responsive patients. This observation implies that different booster vaccination strategies might be required for COVID-19-naïve and -recovered patients. Post-vaccination antibody testing may serve as a valuable tool for guiding vaccination strategies.

13.
Singapore Med J ; 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37171447

RESUMO

It is crucial that policy makers, healthcare providers and relevant stakeholders understand how integrated care may be improved at our emergency departments (EDs) and what benefits that would bring. The potential that exists for right-siting care of special patient groups who could be managed in an ambulatory setting with the integration of a variety of hospital-based and community-based clinical support services is tremendous. This review describes the best practice and value of integrated care at the EDs. Local evidence is cited and compared with findings from overseas. The opportunities of care transition interventions among discharged patients are outlined, including that for paediatric patients, palliative care patients and patients with chronic diseases. This review also suggests ways to move forward to meet the aim of providing holistic care at EDs through integrated care programmes, innovation and research.

14.
Cell Host Microbe ; 31(4): 593-603.e7, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-37054679

RESUMO

The opportunistic pathogen Staphylococcus aureus frequently colonizes the inflamed skin of people with atopic dermatitis (AD) and worsens disease severity by promoting skin damage. Here, we show, by longitudinally tracking 23 children treated for AD, that S. aureus adapts via de novo mutations during colonization. Each patient's S. aureus population is dominated by a single lineage, with infrequent invasion by distant lineages. Mutations emerge within each lineage at rates similar to those of S. aureus in other contexts. Some variants spread across the body within months, with signatures of adaptive evolution. Most strikingly, mutations in capsule synthesis gene capD underwent parallel evolution in one patient and across-body sweeps in two patients. We confirm that capD negativity is more common in AD than in other contexts, via reanalysis of S. aureus genomes from 276 people. Together, these findings highlight the importance of the mutation level when dissecting the role of microbes in complex disease.


Assuntos
Dermatite Atópica , Infecções Estafilocócicas , Criança , Humanos , Staphylococcus aureus/genética , Pele , Mutação
15.
bioRxiv ; 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36993475

RESUMO

Staphylococcus aureus secretes phenol-soluble modulins (PSMs), a family of small, amphipathic, secreted peptides with multiple biologic activities. Community-acquired S. aureus strains produce high levels of PSMs in planktonic cultures, and PSM alpha peptides have been shown to augment the release of extracellular membrane vesicles (MVs). We observed that amyloids, aggregates of proteins characterized by a fibrillar morphology and stained with specific dyes, co-purified with MVs harvested from cell-free culture supernatants of community-acquired S. aureus strains. δ-toxin was a major component of amyloid fibrils that co-purified with strain LAC MVs, and δ-toxin promoted the production of MVs and amyloid fibrils in a dose-dependent manner. To determine whether MVs and amyloid fibrils were generated under in vivo conditions, we inoculated mice with S. aureus harvested from planktonic cultures. Bacterial MVs could be isolated and purified from lavage fluids recovered from infected animals. Although δ-toxin was the most abundant PSM in lavage fluids, amyloid fibrils could not be detected in these samples. Our findings expand our understanding of amyloid fibril formation in S. aureus cultures, reveal important roles of δ-toxin in amyloid fibril formation and MV biogenesis, and demonstrate that MVs are generated in vivo in a staphylococcal infection model. Importance: Extracellular membrane vesicles (MVs) produced by Staphylococcus aureus in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired S. aureus strains, and fibril formation was dependent on expression of the S. aureus δ-toxin gene ( hld ). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although S. aureus MVs were produced in vivo in a localized murine infection model, amyloid fibrils were not observed in the in vivo setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.

16.
mBio ; 14(1): e0357122, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36744901

RESUMO

The microbial secretome modulates how the organism interacts with its environment. Included in the Staphylococcus aureus secretome are extracellular membrane vesicles (MVs) that consist of cytoplasmic and membrane proteins, as well as exoproteins, some cell wall-associated proteins, and glycopolymers. The extent to which MVs contribute to the diverse composition of the secretome is not understood. We performed a proteomic analysis of MVs purified from the S. aureus strain MRSA252 along with a similar analysis of the whole secretome (culture supernatant) before and after depletion of MVs. The MRSA252 secretome was comprised of 1,001 proteins, of which 667 were also present in MVs. Cell membrane-associated proteins and lipoteichoic acid in the culture supernatant were highly associated with MVs, followed by cytoplasmic and extracellular proteins. Few cell wall-associated proteins were contained in MVs, and capsular polysaccharides were found both in the secretome and MVs. When MVs were removed from the culture supernatant by ultracentrifugation, 54 of the secretome proteins were significantly depleted in abundance. Proteins packaged in MVs were characterized by an isoelectric point that was significantly higher than that of proteins excluded from MVs. Our data indicate that the generation of S. aureus MVs is a mechanism by which lipoteichoic acid, cytoplasmic, and cell membrane-associated proteins are released into the secretome. IMPORTANCE The secretome of Staphylococcus aureus includes soluble molecules and nano-sized extracellular membrane vesicles (MVs). The protein composition of both the secretome and MVs includes cytoplasmic and membrane proteins, as well as exoproteins, some cell wall-associated proteins, and glycopolymers. How the MV cargo differs from the protein composition of the secretome has not yet been addressed. Although the compositions of the secretome and MVs were strikingly similar, we identified 54 proteins that were specifically packaged in MVs. Proteins highly associated with MVs were characterized by their abundance in the secretome, an association with the bacterial membrane, and a basic isoelectric point. This study deepens our limited understanding about the contribution of MVs to the secretome of S. aureus.


Assuntos
Vesículas Extracelulares , Infecções Estafilocócicas , Humanos , Staphylococcus aureus/metabolismo , Proteômica , Secretoma , Vesículas Extracelulares/metabolismo , Infecções Estafilocócicas/microbiologia , Proteínas de Membrana/metabolismo
17.
Proc Natl Acad Sci U S A ; 120(9): e2219394120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36802437

RESUMO

Vocal fatigue is a measurable form of performance fatigue resulting from overuse of the voice and is characterized by negative vocal adaptation. Vocal dose refers to cumulative exposure of the vocal fold tissue to vibration. Professionals with high vocal demands, such as singers and teachers, are especially prone to vocal fatigue. Failure to adjust habits can lead to compensatory lapses in vocal technique and an increased risk of vocal fold injury. Quantifying and recording vocal dose to inform individuals about potential overuse is an important step toward mitigating vocal fatigue. Previous work establishes vocal dosimetry methods, that is, processes to quantify vocal fold vibration dose but with bulky, wired devices that are not amenable to continuous use during natural daily activities; these previously reported systems also provide limited mechanisms for real-time user feedback. This study introduces a soft, wireless, skin-conformal technology that gently mounts on the upper chest to capture vibratory responses associated with vocalization in a manner that is immune to ambient noises. Pairing with a separate, wirelessly linked device supports haptic feedback to the user based on quantitative thresholds in vocal usage. A machine learning-based approach enables precise vocal dosimetry from the recorded data, to support personalized, real-time quantitation and feedback. These systems have strong potential to guide healthy behaviors in vocal use.


Assuntos
Canto , Distúrbios da Voz , Voz , Humanos , Retroalimentação , Distúrbios da Voz/etiologia , Voz/fisiologia , Prega Vocal/fisiologia
18.
Kidney Med ; 5(3): 100591, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36686274

RESUMO

Dobutamine is a weak beta-1 and a potent beta-2 adrenergic agonist commonly used to treat patients in cardiogenic shock. It enhances myocardial contractibility, increasing cardiac output. Myoclonus in patients receiving an infusion of dobutamine is rare and, although not fully understood, seems more common in patients with severe kidney failure. To our knowledge, this is the first reported case of dobutamine-induced myoclonus in a patient with kidney failure receiving peritoneal dialysis. Only 7% of the 518,749 patients of the United States requiring kidney replacement therapy receive peritoneal dialysis, with only a small unknown number of those with advanced heart failure manage with an infusion of inotropic medication. The low prevalence of combined advanced heart failure and kidney failure could partly explain this condition's rarity. In this study, we report the case of a 64-year-old woman with kidney failure receiving peritoneal dialysis in whom myoclonus developed 3 weeks after starting a dobutamine infusion for advanced refractory heart failure. Infectious and other pharmacologic causes of myoclonus were ruled out. Initially, uremia was suspected; however, despite increasing her peritoneal dialysis dose, it was only after discontinuing the dobutamine infusion that her myoclonus resolved.

19.
Cell Host Microbe ; 31(2): 213-227.e9, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36603588

RESUMO

Diet and commensals can affect the development of autoimmune diseases like type 1 diabetes (T1D). However, whether dietary interventions are microbe-mediated was unclear. We found that a diet based on hydrolyzed casein (HC) as a protein source protects non-obese diabetic (NOD) mice in conventional and germ-free (GF) conditions via improvement in the physiology of insulin-producing cells to reduce autoimmune activation. The addition of gluten (a cereal protein complex associated with celiac disease) facilitates autoimmunity dependent on microbial proteolysis of gluten: T1D develops in GF animals monocolonized with Enterococcus faecalis harboring secreted gluten-digesting proteases but not in mice colonized with protease deficient bacteria. Gluten digestion by E. faecalis generates T cell-activating peptides and promotes innate immunity by enhancing macrophage reactivity to lipopolysaccharide (LPS). Gnotobiotic NOD Toll4-negative mice monocolonized with E. faecalis on an HC + gluten diet are resistant to T1D. These findings provide insights into strategies to develop dietary interventions to help protect humans against autoimmunity.


Assuntos
Diabetes Mellitus Tipo 1 , Microbiota , Camundongos , Animais , Humanos , Diabetes Mellitus Tipo 1/prevenção & controle , Glutens , Camundongos Endogâmicos NOD , Proteólise , Dieta
20.
J Am Coll Surg ; 236(5): 1047-1053, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36719075

RESUMO

BACKGROUND: Breast MRI has been associated with significant rates of false positive findings. We aimed to determine the frequency of extramammary findings (EMFs) in newly diagnosed breast cancer patients on breast MRI with contrast and assess the significance of these findings and need for additional imaging and follow-up. STUDY DESIGN: A retrospective review of patients diagnosed with breast cancer from October 2018 to October 2019 was performed. Clinicopathologic features were collected, including type of breast cancer, size, stage, and whether the patients had a breast MRI. Those who had MRI were included, and the MRI was reviewed to determine if EMFs were identified. Further imaging and follow-up were assessed and recorded. RESULTS: Of the 480 patients included in this cohort, 353 (74%) had invasive cancer, and the remainder had ductal carcinoma in situ. Two hundred ninety patients (60%) underwent MRI, and 53 of 290 (18%) had EMFs on MRI. Of these, 28 of 53 (53%) underwent additional imaging to further evaluate findings. Two invasive procedures were performed (fine needle aspiration and thymectomy), and 1 malignancy was identified in the thymus. No metastatic breast cancer was identified in any patient. CONCLUSIONS: MRIs are frequently obtained for newly diagnosed breast cancer patients, and additional findings, especially extramammary, can be stressful for patients, and potentially lead to treatment delay if further evaluation is warranted. Our results demonstrate that incidental EMFs discovered via breast MRI are common and often lead to additional imaging studies. However, no metastatic lesions were found, and only 1 separate malignancy was identified, which did not affect breast cancer management. In patients with early-stage breast cancer, EMFs yield a very low rate of malignancy, providing high levels of reassurance and supporting the option of proceeding with surgery or treatment without delay.


Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Humanos , Feminino , Neoplasias da Mama/cirurgia , Neoplasias da Mama/diagnóstico por imagem , Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Imageamento por Ressonância Magnética/métodos , Radiografia , Estudos Retrospectivos
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