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1.
Proc Natl Acad Sci U S A ; 121(21): e2402116121, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38739803

RESUMO

Pyrite is the most common sulfide mineral in hydrothermal ore-forming systems. The ubiquity and abundance of pyrite, combined with its ability to record and preserve a history of fluid evolution in crustal environments, make it an ideal mineral for studying the genesis of hydrothermal ore deposits, including those that host critical metals. However, with the exception of boiling, few studies have been able to directly link changes in pyrite chemistry to the processes responsible for bonanza-style gold mineralization. Here, we report the results of high-resolution secondary-ion mass spectrometry and electron microprobe analyses conducted on pyrite from the Brucejack epithermal gold deposit, British Columbia. Our δ34S and trace element results reveal that the Brucejack hydrothermal system experienced abrupt fluctuations in fluid chemistry, which preceded and ultimately coincided with the onset of ultra-high-grade mineralization. We argue that these fluctuations, which include the occurrence of extraordinarily negative δ34S values (e.g., -36.1‰) in zones of auriferous, arsenian pyrite, followed by sharp increases of δ34S values in syn-electrum zones of nonarsenian pyrite, were caused by vigorous, fault valve-induced episodic boiling (flashing) and subsequent inundation of the hydrothermal system by seawater. We conclude that the influx of seawater was the essential step to forming bonanza-grade electrum mineralization by triggering, through the addition of cationic flocculants and cooling, the aggregation of colloidal gold suspensions. Moreover, our study demonstrates the efficacy of employing high-resolution, in situ analytical techniques to map out individual ore-forming events in a hydrothermal system.

2.
Dalton Trans ; 53(18): 8005-8010, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38651270

RESUMO

Efficient catalysts for Guerbet-type ethanol/methanol upgrading to iso-butanol have been developed via Michael addition of a variety of amines to ruthenium-coordinated dppen (1,1-bis(diphenylphosphino)ethylene). All catalysts produce over 50% iso-butanol yield with >90% selectivity in 2 h with catalyst 1 showing the best activity (74% yield after this time). The selectivity and turnover number approach 100% and 1000 respectively using catalyst 6. The presence of uncoordinated functionalised donor groups in these complexes results in a more stable catalyst compared to unfunctionalised analogues.

3.
Arthritis Care Res (Hoboken) ; 76(3): 311-317, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37691427

RESUMO

OBJECTIVE: There is limited literature describing the overlap of systemic sclerosis (SSc) and systemic lupus erythematosus (SLE), and the studies have employed a range of case definitions. Our study used the new EULAR/American College of Rheumatology (ACR) SLE classification criteria to define SSc-SLE cases among our center's SSc cohort. METHODS: This is a single-center, retrospective study of a previously described cohort of patients with SSc. Patient data were re-abstracted to evaluate for fulfillment of the 2019 EULAR/ACR classification criteria for SLE. Demographic, laboratory, clinical features, and mortality were compared among patients with SSc-SLE and patients with SSc alone. RESULTS: Among the 402 patients with SSc that were analyzed, 40 (10%) fulfilled the 2019 EULAR/ACR SLE classification criteria. Neuropsychiatric and renal involvement were rare. An initial SLE diagnosis was purported in 43% of the patients with SSc-SLE and 7% of patients with SSc alone (P < 0.001). Patients with SSc-SLE were more likely to be female, African American, and with limited cutaneous SSc. Anti-U1-RNP antibody positivity prevalence was 30% among patients with SSc-SLE and 6.6% among patients with SSc alone (P < 0.001). Death during follow-up occurred in 12 patients (30%) with SSc-SLE and in 81 patients (22%) with SSc alone, but there was no difference in survival among the groups per log rank test (P = 0.404). CONCLUSION: Ten percent of patients with SSc fulfill the 2019 EULAR/ACR classification criteria for SLE. These patients comprise a distinct demographic, serologic, and clinical phenotype but have similar severe SSc-specific end-organ damage and mortality as patients with SSc alone. Patients with SLE with Raynaud phenomenon should be evaluated for SSc-specific autoantibodies and scleroderma organ involvement.


Assuntos
Lúpus Eritematoso Sistêmico , Reumatologia , Escleroderma Sistêmico , Humanos , Feminino , Estados Unidos/epidemiologia , Masculino , Estudos Retrospectivos , Prevalência , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/epidemiologia , Escleroderma Sistêmico/diagnóstico , Escleroderma Sistêmico/epidemiologia
4.
J Vasc Interv Radiol ; 34(11): 1922-1928, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37517463

RESUMO

PURPOSE: To evaluate the feasibility and safety of early and proactive involvement of interventional radiology (IR) in the management of placenta accreta spectrum (PAS) by performing the cesarean operation and prophylactic uterine artery embolization in the IR angiography suite as a combined procedure. MATERIALS AND METHODS: This study evaluated the effectiveness and safety of prophylactic uterine artery embolization prior to placental separation in cases of antenatally proven or suspected abnormal placentation. Over a 5-year period, 16 consecutive patients with PAS underwent combined IR and obstetric intervention. In all cases, cesarean delivery was performed in the IR angiography suite. Vascular access was obtained prior to surgery with balloon placement into both internal iliac arteries. These balloons were inflated after delivery, followed by uterine artery embolization (14 of 16) if there was evidence of active postpartum bleeding or inability to deliver the placenta. RESULTS: There was no fetal or maternal mortality and no significant IR or surgical adverse events. Mean blood loss was 1900 mL. Seven patients (44%) underwent hysterectomy. CONCLUSIONS: In patients with PAS, cesarean section in the angiography suite preceded by prophylactic balloon placement and followed by uterine artery embolization was feasible, safe, and effective in preventing massive blood loss, with a 56% uterine sparing rate.


Assuntos
Oclusão com Balão , Placenta Acreta , Hemorragia Pós-Parto , Embolização da Artéria Uterina , Gravidez , Humanos , Feminino , Placenta Acreta/terapia , Placenta Acreta/cirurgia , Embolização da Artéria Uterina/efeitos adversos , Cesárea/efeitos adversos , Placenta , Oclusão com Balão/efeitos adversos , Oclusão com Balão/métodos , Histerectomia , Artéria Ilíaca , Hemorragia Pós-Parto/etiologia , Hemorragia Pós-Parto/prevenção & controle , Morbidade , Estudos Retrospectivos , Perda Sanguínea Cirúrgica/prevenção & controle
5.
JCI Insight ; 8(14)2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37347545

RESUMO

Vincristine is a widely used chemotherapeutic drug for the treatment of multiple malignant diseases that causes a dose-limiting peripheral neurotoxicity. There is no clinically effective preventative treatment for vincristine-induced sensory peripheral neurotoxicity (VIPN), and mechanistic details of this side effect remain poorly understood. We hypothesized that VIPN is dependent on transporter-mediated vincristine accumulation in dorsal root ganglion neurons. Using a xenobiotic transporter screen, we identified OATP1B3 as a neuronal transporter regulating the uptake of vincristine. In addition, genetic or pharmacological inhibition of the murine orthologue transporter OATP1B2 protected mice from various hallmarks of VIPN - including mechanical allodynia, thermal hyperalgesia, and changes in digital maximal action potential amplitudes and neuronal morphology - without negatively affecting plasma levels or antitumor effects of vincristine. Finally, we identified α-tocopherol from an untargeted metabolomics analysis as a circulating endogenous biomarker of neuronal OATP1B2 function, and it could serve as a companion diagnostic to guide dose selection of OATP1B-type transport modulators given in combination with vincristine to prevent VIPN. Collectively, our findings shed light on the fundamental basis of VIPN and provide a rationale for the clinical development of transporter inhibitors to prevent this debilitating side effect.


Assuntos
Doenças do Sistema Nervoso Periférico , Xenobióticos , Camundongos , Animais , Vincristina/toxicidade , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/prevenção & controle , Hiperalgesia/induzido quimicamente , Gânglios Espinais , Proteínas de Membrana Transportadoras
6.
Rheumatology (Oxford) ; 62(10): 3433-3438, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37079727

RESUMO

OBJECTIVES: SSc is associated with increased health-care resource utilization and economic burden. The Collaborative National Quality and Efficacy Registry (CONQUER) is a US-based collaborative that collects longitudinal follow-up data on SSc patients with <5 years of disease duration enrolled at scleroderma centres in the USA. The objective of this study was to investigate the relationship between gastrointestinal tract symptoms and self-reported resource utilization in CONQUER participants. METHODS: CONQUER participants who had completed a baseline and 12-month Gastrointestinal Tract Questionnaire (GIT 2.0) and a Resource Utilization Questionnaire (RUQ) were included in this analysis. Patients were categorized by total GIT 2.0 severity: none-to-mild (0-0.49); moderate (0.50-1.00), and severe-to-very severe (1.01-3.00). Clinical features and medication exposures were examined in each of these categories. The 12-month RUQ responses were summarized by GIT 2.0 score categories at 12 months. RESULTS: Among the 211 CONQUER participants who met the inclusion criteria, most (64%) had mild GIT symptoms, 26% had moderate symptoms, and 10% severe GIT symptoms at 12 months. The categorization of GIT total severity score by RUQ showed that more upper endoscopy procedures and inpatient hospitalization occurred in the CONQUER participants with severe GIT symptoms. These patients with severe GIT symptoms also reported the use of more adaptive equipment. CONCLUSION: This report from the CONQUER cohort suggests that severe GIT symptoms result in more resource utilization. It is especially important to understand resource utilization in early disease cohorts when disease activity, rather than damage, primarily contributes to health-related costs of SSc.


Assuntos
Gastroenteropatias , Escleroderma Sistêmico , Humanos , Gastroenteropatias/etiologia , Inquéritos e Questionários , Autorrelato , Sistema de Registros , Escleroderma Sistêmico/complicações
7.
Cancer Res Commun ; 2(11): 1334-1343, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36506732

RESUMO

Oxaliplatin-induced peripheral neurotoxicity (OIPN) is a debilitating side effect that afflicts ~90% of patients that is initiated by OCT2-dependent uptake of oxaliplatin in DRG neurons. The antidepressant drug duloxetine has been used to treat OIPN, although its usefulness in preventing this side effect remains unclear. We hypothesized that duloxetine has OCT2-inhibitory properties and can be used as an adjunct to oxaliplatin-based regimens to prevent OIPN. Transport studies were performed in cells stably transfected with mouse or human OCT2 and in isolated mouse DRG neurons ex vivo. Wild-type and OCT2-deficient mice were used to assess effects of duloxetine on hallmarks of OIPN, endogenous OCT2 biomarkers, and the pharmacokinetics of oxaliplatin, and the translational feasibility of a duloxetine-oxaliplatin combination was evaluated in various models of colorectal cancer. We found that duloxetine potently inhibited the OCT2-mediated transport of several xenobiotic substrates, including oxaliplatin, in a reversible, concentration-dependent manner, and independent of species and cell context. Furthermore, duloxetine restricted access of these substrates to DRG neurons ex vivo and prevented OIPN in wild-type mice to a degree similar to the complete protection observed in OCT2-deficient mice, without affecting the plasma levels of oxaliplatin. Importantly, the uptake and cytotoxicity of oxaliplatin in tumor cell lines in vitro and in vivo were not negatively influenced by duloxetine. The observed OCT2-targeting properties of duloxetine, combined with the potential for clinical translation, provide support for its further exploration as a therapeutic candidate for studies aimed at preventing OIPN in cancer patients requiring treatment with oxaliplatin. Significance: We found that duloxetine has potent OCT2-inhibitory properties and can diminish excessive accumulation of oxaliplatin into DRG neurons. In addition, pre-treatment of mice with duloxetine prevented OIPN without significantly altering the plasma pharmacokinetics and antitumor properties of oxaliplatin. These results suggest that intentional inhibition of OCT2-mediated transport by duloxetine can be employed as a prevention strategy to ameliorate OIPN without compromising the effectiveness of oxaliplatin-based treatment.


Assuntos
Antineoplásicos , Síndromes Neurotóxicas , Doenças do Sistema Nervoso Periférico , Humanos , Camundongos , Animais , Oxaliplatina/efeitos adversos , Antineoplásicos/toxicidade , Cloridrato de Duloxetina/farmacologia , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Síndromes Neurotóxicas/tratamento farmacológico
9.
J Assist Reprod Genet ; 39(8): 1693-1712, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35870095

RESUMO

Since 2007, the Oncofertility Consortium Annual Conference has brought together a diverse network of individuals from a wide range of backgrounds and professional levels to disseminate emerging basic and clinical research findings in fertility preservation. This network also developed enduring educational materials to accelerate the pace and quality of field-wide scientific communication. Between 2007 and 2019, the Oncofertility Consortium Annual Conference was held as an in-person event in Chicago, IL. The conference attracted approximately 250 attendees each year representing 20 countries around the world. In 2020, however, the COVID-19 pandemic disrupted this paradigm and precluded an in-person meeting. Nevertheless, there remained an undeniable demand for the oncofertility community to convene. To maintain the momentum of the field, the Oncofertility Consortium hosted a day-long virtual meeting on March 5, 2021, with the theme of "Oncofertility Around the Globe" to highlight the diversity of clinical care and translational research that is ongoing around the world in this discipline. This virtual meeting was hosted using the vFairs ® conference platform and allowed over 700 people to participate, many of whom were first-time conference attendees. The agenda featured concurrent sessions from presenters in six continents which provided attendees a complete overview of the field and furthered our mission to create a global community of oncofertility practice. This paper provides a synopsis of talks delivered at this event and highlights the new advances and frontiers in the fields of oncofertility and fertility preservation around the globe from clinical practice and patient-centered efforts to translational research.


Assuntos
COVID-19 , Preservação da Fertilidade , Neoplasias , COVID-19/epidemiologia , Humanos , Pandemias
10.
Dalton Trans ; 51(22): 8906-8913, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35638731

RESUMO

The reactions of R2P-PR2 with R'E-ER', (where E = Se, S, O, Te) to give R2P-ER' have been explored experimentally and computationally. The reaction of Ph2P-PPh2 with PhSe-SePh gives Ph2P-SePh (1) rapidly and quantitatively. The P-P/Se-Se reaction is inhibited by the addition of the radical scavenger TEMPO which is consistent with a radical mechanism for the heterometathesis reaction. Compound 1 has been fully characterised, including by X-ray crystallography. A range of other Ar2P-SeR (R = Ph, nBu or CH2CH2CO2H) have also been prepared and characterised. The reaction of 1 with [Mo(CO)4(nbd)] (nbd = norbornadiene) gives two products which, from their characteristic 31P NMR data, have been identified as cis-[Mo(CO)4(Ph2PSePh-P)2] (8) and the mixed-donor complex cis-[Mo(CO)4(Ph2P-SePh-P)(Ph2P-SePh-Se)] (9). It is deduced that the P and Se atoms in ligand 1 have comparable capacity to coordinate to Mo(0). The reaction of Ph2P-PPh2 with PhS-SPh gives Ph2P-SPh (2) quantitatively but no reaction was observed between Ph2P-PPh2 and PhTe-TePh. Heterometathesis between Ph2P-PPh2 and tBuO-OtBu does not occur thermally but has been observed under UV irradiation to give Ph2P-OtBu along with P(V) oxidation by-products. DFT calculations have been carried out to illuminate why heterometatheses with dichalcogenides R'E-ER' occur readily when E = S and Se but not when E = O and Te. The calculations show that heterometathesis is predicted to be thermodynamically favourable for E = O, S and Se and unfavourable for E = Te. The fact that a metathesis reaction between Ph2P-PPh2 with tBuO-OtBu is not observed in the absence of UV radiation, is therefore due to kinetics.

12.
Eur Phys J C Part Fields ; 81(9): 823, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720726

RESUMO

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

13.
Nutr Res ; 94: 10-24, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34571215

RESUMO

Topical 17-beta-estradiol (E2) regulates the hair cycle, hair shaft differentiation, and sebum production. Vitamin A also regulates sebum production. Vitamin A metabolism proteins localized to the pilosebaceous unit (PSU; hair follicle and sebaceous gland); and were regulated by E2 in other tissues. This study tests the hypothesis that E2 also regulates vitamin A metabolism in the PSU. First, aromatase and estrogen receptors localized to similar sites as retinoid metabolism proteins during mid-anagen. Next, female and male wax stripped C57BL/6J mice were topically treated with E2, the estrogen receptor antagonist ICI 182,780 (ICI), letrozole, E2 plus letrozole, or vehicle control (acetone) during mid-anagen. E2 or one of its inhibitors regulated most of the vitamin A metabolism genes and proteins examined in a sex-dependent manner. Most components were higher in females and reduced with ICI in females. ICI reductions occurred in the premedulla, sebaceous gland, and epidermis. Reduced E2 also reduced RA receptors in the sebaceous gland and bulge in females. However, reduced E2 increased the number of retinal dehydrogenase 2 positive hair follicle associated dermal dendritic cells in males. These results suggest that estrogen regulates vitamin A metabolism in the skin. Interactions between E2 and vitamin A have implications in acne treatment, hair loss, and skin immunity.


Assuntos
Proteínas de Transporte/metabolismo , Estradiol/metabolismo , Estrogênios/metabolismo , Pele/metabolismo , Tretinoína/metabolismo , Animais , Aromatase/metabolismo , Células Dendríticas/metabolismo , Epiderme , Antagonistas do Receptor de Estrogênio/farmacologia , Feminino , Fulvestranto/farmacologia , Cabelo , Folículo Piloso/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Oxirredutases/metabolismo , Receptores de Estrogênio/metabolismo , Glândulas Sebáceas/metabolismo , Fatores Sexuais
14.
Organometallics ; 40(16): 2844-2851, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34483434

RESUMO

We report a variety of rhenium complexes supported by bidentate and tridentate phosphinoamine ligands and their use in the formation of the advanced biofuel isobutanol from methanol and ethanol. Rhenium pincer complexes 1-3 are effective catalysts for this process, with 2 giving isobutanol in 35% yields, with 97% selectivity in the liquid fraction, over 16 h with catalyst loadings as low as 0.07 mol %. However, these catalysts show poorer overall selectivity, with the formation of a significant amount of carboxylate salt solid byproduct also being observed. Production of the active catalyst 1d has been followed by 31P NMR spectroscopy, and the importance of the presence of base and elevated temperatures to catalyst activation has been established. Complexes supported by diphosphine ligands are inactive for Guerbet chemistry; however, complexes supported by bidentate phosphinoamine ligands show greater selectivity for isobutanol formation over carboxylate salts. The novel complex 7 was able to produce isobutanol in 28% yield over 17 h. The importance of the N-H moiety to the catalytic performance has also been established, giving further weight to the hypothesis that these catalysts operate via a cooperative mechanism.

15.
BMC Public Health ; 21(1): 1691, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34530779

RESUMO

BACKGROUND: Public mental health (PMH) aims to improve wellbeing and prevent poor mental health at the population level. It is a global challenge and a UK priority area for action. Communities play an important role in the provision of PMH interventions. However, the evidence base concerning community-based PMH interventions is limited, meaning it is challenging to compare service provision to need. Without this, the efficient and equitable provision of services is hindered. Here, we sought to map the current range of community-based interventions for improving mental health and wellbeing currently provided in England to inform priority areas for policy and service intervention. METHOD: We adopted an established mapping exercise methodology, comparing service provision with demographic and deprivation statistics. Five local authority areas of England were selected based on differing demographics, mental health needs and wider challenging circumstances (i.e. high deprivation). Community-based interventions were identified through: 1) desk-based research 2) established professional networks 3) chain-referral sampling of individuals involved in local mental health promotion and prevention and 4) peer researchers' insight. We included all community-based, non-clinical interventions aimed at adult residents operating between July 2019 and May 2020. RESULTS: 407 interventions were identified across the five areas addressing 16 risk/protective factors for PMH. Interventions for social isolation and loneliness were most prevalent, most commonly through social activities and/or befriending services. The most common subpopulations targeted were older adults and people from minority ethnic backgrounds. Interventions focusing on broader structural and environmental determinants were uncommon. There was some evidence of service provision being tailored to local need, though this was inconsistent, meaning some at-risk groups such as men or LGBTQ+ people from minority ethnic backgrounds were missed. Interventions were not consistently evaluated. CONCLUSIONS: There was evidence of partial responsiveness to national and local prioritising. Provision was geared mainly towards addressing social and individual determinants of PMH, suggesting more integration is needed to engage wider service providers and policy-makers in PMH strategy and delivery at the community level. The lack of comprehensive evaluation of services to improve PMH needs to be urgently addressed to determine the extent of their effectiveness in communities they serve.


Assuntos
Promoção da Saúde , Saúde Mental , Idoso , Inglaterra , Exercício Físico , Humanos , Masculino , Políticas
16.
Dalton Trans ; 50(20): 7094-7104, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-33950053

RESUMO

By combining the diphosphanes Ar2P-PAr2, where Ar = C6H5, 4-C6H4Me, 4-C6H4OMe, 3,5-C6H3(CF3)2, it has been shown that P,P-metathesis generally occurs rapidly under ambient conditions. DFT calculations have shown that the stability of unsymmetrical diphosphanes Z2P-PZ'2 is a function of the difference between the Z and Z' substituents in terms of size and electronegativity. Of the mechanisms that were calculated for the P,P-metathesis, the most likely was considered to be one involving Ar2P˙ radicals. The observations that photolysis increases the rate of the P,P-metatheses and TEMPO inhibits it, are consistent with a radical chain process. The P,P-metathesis reactions that involve (o-Tol)2P-P(o-Tol)2 are anomalously slow and, in the absence of photolysis, were only observed to take place in CHCl3 and CH2Cl2. The role of the chlorinated solvent is ascribed to the formation of Ar2PCl which catalyses the P,P-metathesis. The slow kinetics observed with (o-Tol)2P-P(o-Tol)2 is tentatively attributed to the o-CH3 groups quenching the (o-Tol)2P˙ radicals or inhibiting the metathesis reaction sterically.

17.
Proc Natl Acad Sci U S A ; 118(20)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33975954

RESUMO

Aqueous complexation has long been considered the only viable means of transporting gold to depositional sites in hydrothermal ore-forming systems. A major weakness of this hypothesis is that it cannot readily explain the formation of ultrahigh-grade gold veins. This is a consequence of the relatively low gold concentrations typical of ore fluids (tens of parts per billion [ppb]) and the fact that these "bonanza" veins can contain weight-percent levels of gold in some epithermal and orogenic deposits. Here, we present direct evidence for a hypothesis that could explain these veins, namely, the transport of the gold as colloidal particles and their flocculation in nanoscale calcite veinlets. These gold-bearing nanoveinlets bear a remarkable resemblance to centimeter-scale ore veins in many hydrothermal gold deposits and give unique insight into the scale invariability of colloidal flocculation in forming hyperenriched gold deposits. Using this evidence, we propose a model for the development of bonanza gold veins in high-grade deposits. We argue that gold transport in these systems is largely mechanical and is the result of exceptionally high degrees of supersaturation that preclude precipitation of gold crystals and instead lead to the formation of colloidal particles, which flocculate and form much larger masses. These flocculated masses aggregate locally, where they are seismically pumped into fractures to locally form veins composed largely of gold. This model explains how bonanza veins may form from fluids containing ppb concentrations of gold and does not require prior encapsulation of colloidal gold particles in silica gel, as proposed by previous studies.

18.
Proc Natl Acad Sci U S A ; 118(5)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33495337

RESUMO

Doxorubicin is a commonly used anticancer agent that can cause debilitating and irreversible cardiac injury. The initiating mechanisms contributing to this side effect remain unknown, and current preventative strategies offer only modest protection. Using stem-cell-derived cardiomyocytes from patients receiving doxorubicin, we probed the transcriptomic landscape of solute carriers and identified organic cation transporter 3 (OCT3) (SLC22A3) as a critical transporter regulating the cardiac accumulation of doxorubicin. Functional validation studies in heterologous overexpression models confirmed that doxorubicin is transported into cardiomyocytes by OCT3 and that deficiency of OCT3 protected mice from acute and chronic doxorubicin-related changes in cardiovascular function and genetic pathways associated with cardiac damage. To provide proof-of-principle and demonstrate translational relevance of this transport mechanism, we identified several pharmacological inhibitors of OCT3, including nilotinib, and found that pharmacological targeting of OCT3 can also preserve cardiovascular function following treatment with doxorubicin without affecting its plasma levels or antitumor effects in multiple models of leukemia and breast cancer. Finally, we identified a previously unrecognized, OCT3-dependent pathway of doxorubicin-induced cardiotoxicity that results in a downstream signaling cascade involving the calcium-binding proteins S100A8 and S100A9. These collective findings not only shed light on the etiology of doxorubicin-induced cardiotoxicity, but also are of potential translational relevance and provide a rationale for the implementation of a targeted intervention strategy to prevent this debilitating side effect.


Assuntos
Doxorrubicina/efeitos adversos , Traumatismos Cardíacos/induzido quimicamente , Traumatismos Cardíacos/tratamento farmacológico , Terapia de Alvo Molecular , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Animais , Criança , Regulação da Expressão Gênica , Traumatismos Cardíacos/fisiopatologia , Humanos , Camundongos , Miócitos Cardíacos/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/deficiência , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Análise de Sequência de RNA
19.
J Scleroderma Relat Disord ; 6(1): 3-10, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35382244

RESUMO

Systemic sclerosis is a highly morbid, complex autoimmune disease that is variable both in its phenotype and the attendant mortality driven by such manifestations. This review article synthesizes mortality data from the best available meta-analyses, subgroup analyses of single cohorts, and subjective comparisons of individual cohort studies, which in aggregate suggest that mortality in systemic sclerosis has been gradually improving over the past several decades. This review also summarizes the literature describing various risk factors for mortality in systemic sclerosis.

20.
Rheum Dis Clin North Am ; 46(4): 705-712, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32981647

RESUMO

Racial and ethnic disparities in systemic sclerosis are abundant. The incidence, severity of end-organ manifestations, functional impairment, quality of life, and mortality of systemic sclerosis vary by ethnic group. This article summarizes such disparities and explores the role of socioeconomic status in their development and persistence.


Assuntos
Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Racismo , Escleroderma Sistêmico , Etnicidade , Humanos , Qualidade de Vida , Escleroderma Sistêmico/epidemiologia , Escleroderma Sistêmico/etnologia , Escleroderma Sistêmico/terapia , Fatores Socioeconômicos
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