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1.
Pulm Circ ; 13(4): e12305, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37915400

RESUMO

Pulmonary hypertension (PH) is a significant health problem that contributes to high morbidity and mortality in diverse cardiac, pulmonary, and systemic diseases in children. Evidence-based advances in PH care have been challenged by a paucity of quality endpoints for assessing clinical course and the lack of robust clinical trial data to guide pharmacologic therapies in children. While the landmark adult AMBITION trial demonstrated the benefit of up-front combination PH therapy with ambrisentan and tadalafil, it remains unknown whether upfront combination therapy leads to more rapid and sustained clinical benefits in children with various categories of PH. In this article, we describe the inception of the Kids Mod PAH Trial, a multicenter Phase III trial, to address whether upfront combination therapy (sildenafil and bosentan vs. sildenafil alone) improves PH outcomes in children, recognizing that marked differences between the etiology and therapeutic response between adults and children exist. The primary endpoint of this study is WHO functional class (FC) 12 months after initiation of study drug therapy. In addition to the primary outcome, secondary endpoints are being assessed, including a composite measure of time to clinical worsening, WHO FC at 24 months, echocardiographic assessment of PH and quantitative assessment of right ventricular function, 6-min walk distance, and NT-proBNP levels. Exploratory endpoints include selected biomarkers, actigraphy, and assessments of quality of life. This study is designed to pave the way for additional clinical trials by establishing a robust infrastructure through the development of a PPHNet Clinical Trials Network.

3.
Artigo em Inglês | MEDLINE | ID: mdl-37502242

RESUMO

Bacterial superinfection and antibiotic prescribing in the setting of the current mpox outbreak are not well described in the literature. This retrospective observational study revealed low prevalence (11%) of outpatient antibiotic prescribing for bacterial superinfection of mpox lesions; at least 3 prescriptions (23%) were unnecessary.

4.
Nucleic Acids Res ; 51(8): 3631-3649, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36808431

RESUMO

PBRM1 is a subunit of the PBAF chromatin remodeling complex, which is mutated in 40-50% of clear cell renal cell carcinoma patients. It is thought to largely function as a chromatin binding subunit of the PBAF complex, but the molecular mechanism underlying this activity is not fully known. PBRM1 contains six tandem bromodomains which are known to cooperate in binding of nucleosomes acetylated at histone H3 lysine 14 (H3K14ac). Here, we demonstrate that the second and fourth bromodomains from PBRM1 also bind nucleic acids, selectively associating with double stranded RNA elements. Disruption of the RNA binding pocket is found to compromise PBRM1 chromatin binding and inhibit PBRM1-mediated cellular growth effects.


Assuntos
Cromatina , Neoplasias Renais , Humanos , Cromatina/genética , RNA/genética , Proteínas Nucleares/metabolismo , Histonas/metabolismo , Neoplasias Renais/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo
6.
BMJ Case Rep ; 15(10)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192031

RESUMO

Improving maternal and child health is a global priority. Although infection with Listeria monocytogenes (LM), a small facultative anaerobic, gram-positive motile bacillus is rare, when it infects the maternal-fetoplacental unit, it can result in adverse fetal sequelae such as chorioamnionitis, preterm labour, neonatal sepsis, meningitis and neonatal death. Pregnancy-associated listeriosis may present with a plethora of diverse, non-specific symptoms such as fever, influenza-like or gastrointestinal symptoms, premature contractions and preterm labour. It has a predilection for the second and third trimester of pregnancy, occurring sporadically or as part of an outbreak, most of which have involved unpasteurised dairy products, long shelf life products, contaminated ready-to-eat food, deli meats and soft cheeses. Strains belonging to the clonal complexes 1, 4 and 6 are hypervigilant and are commonly associated with maternal-neonatal infections. Maternal listeriosis occurs as a direct consequence of LM-specific placental tropism, which is mediated by the conjugated action of internalin A and internalin B at the placental barrier. The diagnosis is established from placental culture. Penicillin, ampicillin and amoxicillin are the antimicrobials of choice. It has a high fetal morbidity of up to 30%. The authors present the case of a multiparous woman in her early 20s presenting with sepsis and preterm premature rupture of her membranes at 21 weeks gestation. A live baby was delivered spontaneously and died shortly after birth. Placental cultures and postmortem examination were consistent with the diagnosis of disseminated Listeria infection. Due to the increased susceptibility of pregnant women for LM, a high index of clinical suspicion is required to establish the diagnosis and initiate appropriate antimicrobial therapy to reduce adverse fetal outcomes.


Assuntos
Listeria monocytogenes , Listeriose , Trabalho de Parto Prematuro , Pré-Eclâmpsia , Complicações Infecciosas na Gravidez , Sepse , Amoxicilina , Criança , Feminino , Humanos , Recém-Nascido , Listeriose/complicações , Listeriose/diagnóstico , Listeriose/tratamento farmacológico , Penicilinas , Placenta , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Sepse/complicações
7.
EClinicalMedicine ; 47: 101389, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35465646

RESUMO

Background: Pregnant women with SARS-CoV-2 infection experience higher rates of stillbirth and preterm birth. A unique pattern of chronic histiocytic intervillositis (CHI) and/or massive perivillous fibrin deposition (MPFD) has emerged, coined as SARS-CoV-2 placentitis. Methods: The aim of this study was to describe a cohort of placentas diagnosed with SARS-CoV-2 placentitis during October 2020-March 2021. Cases with a histological diagnosis of SARS-CoV-2 placentitis and confirmatory immunohistochemistry were reported. Maternal demographic data, pregnancy outcomes and placental findings were collected. Findings: 59 mothers delivered 61 infants with SARS-CoV-2 placentitis. The gestational age ranged from 19 to 41 weeks with most cases (78.6%) being third trimester. 30 infants (49.1%) were stillborn or late miscarriages. Obese mothers had higher rates of pregnancy loss when compared with those with a BMI <30 [67% (10/15) versus 41% (14/34)]. 47/59 (79.7%) mothers had a positive SARS-CoV-2 PCR test either at the time of labour or in the months before, of which 12 (25.5%) were reported to be asymptomatic. Ten reported only CHI, two cases showed MPFD only and in 48 placentas both CHI and MPFD was described. Interpretation: SARS-CoV2 placentitis is a distinct entity associated with increased risk of pregnancy loss, particularly in the third trimester. Women can be completely asymptomatic and still experience severe placentitis. Unlike 'classical' MPFD, placentas with SARS-CoV-2 are generally normal in size with adequate fetoplacental weight ratios. Further work should establish the significance of the timing of maternal SARS-CoV-2 infection and placentitis, the significance of SARS-CoV2 variants, and rates of vertical transmission associated with this pattern of placental inflammation. Funding: There was not funding associated with this study.

8.
J Pharmacol Exp Ther ; 380(3): 220-229, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34980660

RESUMO

During a myocardial infarction or ischemic stroke, blood flow to the heart or brain is partially blocked. This results in reduced delivery of oxygen and nutrients and, ultimately, tissue damage. Initial treatment involves removing the clot and restoring blood flow (reperfusion). However, this treatment is not as effective as one would hope because the reperfusion process itself can cause a different type of damage (reperfusion injury) that contributes up to 50% of the total damage. Bradykinin is an autocoid that is released from blood vessel endothelial cells during ischemia and reperfusion and has the potential to prevent reperfusion injury. However, bradykinin is rapidly inactivated by enzymes on endothelial cells, limiting its beneficial effects. One of these enzymes is aminopeptidase P2. We designed a potent and specific inhibitor of aminopeptidase P2 called ST-115, [(S)-2-mercapto-4-methylpentanoyl]-4(S)-fluoro-Pro-Pro-3(R)-beta-Pro. When ST-115 is administered intravenously at the start of reperfusion, it reduces bradykinin degradation. This increases bradykinin's concentration in the capillaries and enhances its protective effects. We tested ST-115 in a mouse model of myocardial infarction and found that the damaged area of the heart was reduced by 58% compared with mice given saline. In a rat model of ischemic stroke, ST-115 reduced functional deficits in a skilled walking test by 60% and reduced brain edema by 51%. It reduced brain infarct size by 48% in a major subset of rats with small strokes. The results indicate that ST-115 can ameliorate reperfusion injury and can ultimately serve as a therapeutic for acute myocardial infarction and ischemic stroke. SIGNIFICANCE STATEMENT: We have shown that our aminopeptidase P2 inhibitor, ST-115, can reduce tissue injury caused by episodes of ischemia followed by reperfusion. It was successful in rodent models of myocardial infarction and stroke. The clinical use would involve the intravenous administration of ST-115 at the induction of reperfusion. In the case of stroke, the successful technique of thrombectomy could be combined with ST-115 administration to simultaneously reduce both ischemic and reperfusion injury.


Assuntos
AVC Isquêmico , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Acidente Vascular Cerebral , Aminopeptidases , Animais , Bradicinina/farmacologia , Bradicinina/uso terapêutico , Células Endoteliais/metabolismo , Camundongos , Infarto do Miocárdio/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Ratos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico
9.
Pediatr Dev Pathol ; 25(2): 99-106, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34492208

RESUMO

BACKGROUND: Accurate measurements of mucosal eosinophil concentrations in gastrointestinal tracts of healthy children are necessary to differentiate health and disease states in general, and better define eosinophilic gastrointestinal diseases. STUDY: We retrospectively reviewed gastrointestinal biopsies from children with macroscopically normal endoscopies, who, after a minimal follow-up of one year, were not diagnosed with any organic disease. Peak eosinophil concentrations and distributions were assessed from each segment of the gastrointestinal tract. RESULTS: Three centers (Italy, United Kingdom, and Israel) contributed 202 patients (median age 13 years IQR 9.5-15.5, range 1-18 years). Median (IQR, range) eosinophil concentrations (eos/mm2) were: esophagus 0 (0-0, 0-84), stomach 0 (0-4, 0-84), duodenal bulb 20 (13-30, 7-67), second part of duodenum 20 (13-29, 0-105), terminal ileum 29 (14-51, 0-247), cecum 53 (37-89, 10-232), ascending colon 55 (25-84, 0-236), transverse colon 38 (21-67, 4-181), descending colon 29 (17-59, 0-114), sigmoid colon 25 (13-40, 0-215) and rectum 13 (4-28, 0-152). Significant geographical variance was present, however, no differences in eosinophil concentrations were identified between children with resolving symptoms vs. those with functional diagnoses, nor across age groups. CONCLUSIONS: Standardized eosinophil concentrations from the gastrointestinal tracts of children without organic disease will serve to better define both health and disease states. No differences were found between resolved symptoms vs. functional diagnoses nor between age groups in this pediatric cohort.


Assuntos
Eosinofilia , Gastrite , Adolescente , Criança , Pré-Escolar , Eosinofilia/patologia , Eosinófilos/patologia , Gastrite/patologia , Humanos , Lactente , Estudos Retrospectivos
10.
Curr Probl Diagn Radiol ; 51(2): 171-175, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33840576

RESUMO

INTRODUCTION: Assimilate a general radiology division into a subspecialty-focused radiology department at an academic medical center. METHODS: This Institutional Review Board-approved quality improvement initiative was performed at an academic medical centers' subspecialty-focused academic radiology department, aiming to assimilate a general radiology division providing interpretive services for a distributed set of community ambulatory practices. An Oversight Committee charged by the department chair created a charter with unambiguous goal, timelines, clear decision-making, and conflict resolution processes. The Committee assessed the resources and clinical capabilities of the general radiologists, and the anticipated shift in exam volume from the community into subspecialty divisions. Primary outcome, percentage of targeted organ systems-specific interpretations by general radiologists based on assigned subspecialty division, and secondary outcome of report turnaround time (TAT) for all ambulatory exams, were compared before and after sub-specialization. RESULTS: Among 10 general radiologists, 4.5 were assigned to subspecialty divisions; 5.5 continued to cover an independent general radiology practice in a for-profit delivery network. In the 5 months' post-transition, a total 86.6% (11,668/13,477) of reports by the integrated general radiologists were within designated subspecialty divisions vs 23.9% (2,586/10,829) pre-transition (P < 0.01). There was no change in ambulatory radiology report TAT for non-urgent care center (UCC) or UCC exams pre- vs post-integration. DISCUSSION: A quality improvement initiative with unambiguous decision-making and conflict resolution processes incorporated a general radiology practice (radiologists and exams) into a subspecialty-focused academic radiology practice without negatively impacting TAT metrics. Future studies would be needed to assess impact on quality of interpretations.


Assuntos
Radiologia , Centros Médicos Acadêmicos , Humanos , Melhoria de Qualidade , Radiografia , Radiologistas
11.
J Clin Transl Sci ; 5(1): e178, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858640

RESUMO

Clinical research coordinators are increasingly tasked with a multitude of complex study activities critical to scientific rigor and participant safety, though more than half report not receiving appropriate training. To determine the reproducibility of an established clinical research workforce orientation program, collaborative partners across Clinical and Translational Science Award institutions seeded core principles and structure from Mayo Clinic's Clinical Research Orientation program within Penn State University and the University of Mississippi Medical Center from 2019 to 2021. Training concepts were established and tied to those domains deemed critical by the Joint Task Force for Clinical Trial Competency for the conduct of clinical research at the highest levels of safety and quality possible. Significant knowledge and confidence gains and high overall program satisfaction were reported across participants and partner sites, despite programs being required to pivot from traditional, in-person formats to entirely virtual platforms as a result of the COVID-19 pandemic. The successful standardization and translation of foundational clinical research training has important efficiency and efficacy implications for research enterprises across the USA.

13.
Appl Environ Microbiol ; 87(13): e0043321, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33858836

RESUMO

Wastewater-based monitoring for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the individual building level could be an efficient, passive means of early detection of new cases in congregate living settings, but this approach has not been validated. Preliminary samples were collected from a hospital and a local municipal wastewater treatment plant. Molecular diagnostic methods were compared side by side to assess feasibility, performance, and sensitivity. Refined sample collection and processing protocols were then used to monitor two occupied dormitory complexes (n = 105 and 66) over 8 weeks. Wastewater results were validated using known case counts from external clinical testing of building occupants. Results confirm that ultracentrifugation from a 24-h composite collection had a sensitivity of 96.2% and a specificity of 100%. However, the method could not distinguish new infectious cases from persistent convalescent shedding of SARS-CoV-2 RNA. If the detection of convalescent shedding is considered a false positive, then the sensitivity is 100% and specificity drops to 45%. It was determined that the proposed approach constitutes a highly sensitive wastewater surveillance method for detecting SARS-CoV-2, but it could not distinguish new infectious cases from persistent convalescent shedding. Future work must focus on approaches to distinguish new infections from convalescent shedding to fully realize the potential of building wastewater as a surveillance tool for congregate living. IMPORTANCE Some of the most severe outbreaks of COVID-19 have taken place in places where persons live together, such as nursing homes. Wastewater testing from individual buildings could be used for frequent pooled surveillance of virus from all occupants, including those who are contagious, with or without symptoms. This work provides a sensitive practical method for detecting infected individuals, as validated in two building complexes housing occupants who underwent frequent clinical testing performed by external entities. Although this sensitive method could be deployed now for pooled surveillance as an early warning system to limit outbreaks, the study shows that the approach will require further refinement to differentiate contagious, newly infected individuals from persons who have persistent viral fragments shedding in their stool outside the contagious period.


Assuntos
COVID-19/epidemiologia , Instituições Residenciais , SARS-CoV-2/isolamento & purificação , Águas Residuárias/virologia , COVID-19/diagnóstico , Humanos , Técnicas de Diagnóstico Molecular , Reprodutibilidade dos Testes , SARS-CoV-2/genética , Vigilância Epidemiológica Baseada em Águas Residuárias
14.
Sustain Sci ; 16(4): 1201-1213, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33897904

RESUMO

Because of ethnic and cultural violence in Myanmar, approximately a million Rohingya fled to neighboring Bangladesh starting from August 2017, in what the UN has called a "textbook example of ethnic cleansing". Those arriving in Bangladesh were able to escape decade-long ethnic violence in Myanmar, but the Rohingya's immediate destination, Cox's Bazar district is one of the most climate-vulnerable and disaster-prone areas in Bangladesh. Currently, they have been subjected to extreme rainfalls, landslides, and flashfloods. With the COVID-19 pandemic, they continue to face fear and further marginalization in resource-constrained Bangladesh, as well as increased vulnerability due to tropical cyclones, flashfloods, and landslides. The Rohingya in southeast Bangladesh are now at the epicenter of a humanitarian and sustainability crisis. However, their situation is not entirely unique. Millions of displaced, stateless or refugees around the world are facing multi-dimensional crises in various complex geopolitical, and climatic situations. Using the theoretical lens of political ecology and critical development studies, this paper analyzes the sustainability-peace nexus for millions of Rohingya in Myanmar and in Bangladesh. This paper is based on information from various sources, including three ethnographic field visits in recent years, which helped to get local insights into the current sustainability challenges in this humanitarian context. The core arguments of this paper suggest that sustainability-peace nexus will especially be compromised in climate-vulnerable resource-constrained conditions. To overcome this challenge, decolonizing Rohingya solutions would be critical, by engaging the Rohingya in the process of development and meaningful change, which can affect their lives, livelihoods, and wellbeing. Even though this paper has a specific geographical focus, the insights are relevant in parts of the world facing similar social, economic, political, and environmental challenges.

15.
Int Migr Rev ; 55(1): 108-134, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36518224

RESUMO

The 2017 revitalization of the controversial Security Communities program, which requires local law enforcement to cooperate with federal immigration officials in the United States, has made it urgent to better understand such enforcement programs' effects on the well-being of Latinas/os, especially the foreign-born. Social isolation from increased immigration enforcement can have significant impacts on economic, social, and health outcomes among Latina/o immigrants and non-immigrants. This article analyzes the gendered impacts of different levels of increased local involvement in immigration enforcement on social isolation, using a survey of over 2000 Latinas/os in four large US cities, all considered to be traditional destinations. Unsurprisingly, respondents reported increased social isolation resulting from local law enforcement's involvement in immigration enforcement. In contrast to results from previous research, our analysis found that women and men were equally likely to feel socially isolated and that having children led to more social isolation for both women and men. Personal and vicarious experiences with immigration enforcement, as well as living in Phoenix and Houston - two urban areas with the strictest enforcement regimes - were strongly related to social isolation. Our results indicate that local authorities' increased involvement in immigration enforcement can lead to more social isolation for Latina immigrants, particularly those who have children, aligning their experiences with men's and, thus, undermining Latinas' previously recognized role as bridges between their families and social institutions and as community builders.

16.
Front Genome Ed ; 2: 8, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34713217

RESUMO

In mammals over 65% of the total body iron is located within erythrocytes in the heme moieties of hemoglobin. Iron homeostasis requires iron absorbed from the diet by the gut as well as recycling of iron after the destruction of senescent erythrocytes. Senescent erythrocytes are engulfed by reticuloendothelial system macrophages where hemoglobin is broken down in the lysosomes, releasing heme for iron recovery in the cytoplasm. We recently showed that the SLC48A1 protein is responsible for transporting heme from the lysosome to the cytoplasm. CRISPR generated SLC48A1-deficient mice accumulate heme in their reticuloendothelial system macrophages as hemozoin crystals. Here we describe additional features of SLC48A1-deficient mice. We show that visible hemozoin first appears in the reticuloendothelial system macrophages of SLC48A1-deficient mice at 8 days of age, indicating the onset of erythrocyte recycling. Evaluation of normal and SLC48A1-deficient mice on iron-controlled diets show that SLC48A1-mediated iron recycling is equivalent to at least 10 parts per million of dietary iron. We propose that mutations in human SLC48A1 could contribute to idiopathic iron disorders.

17.
Elife ; 82019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31571584

RESUMO

Free heme is cytotoxic as exemplified by hemolytic diseases and genetic deficiencies in heme recycling and detoxifying pathways. Thus, intracellular accumulation of heme has not been observed in mammalian cells to date. Here we show that mice deficient for the heme transporter SLC48A1 (also known as HRG1) accumulate over ten-fold excess heme in reticuloendothelial macrophage lysosomes that are 10 to 100 times larger than normal. Macrophages tolerate these high concentrations of heme by crystallizing them into hemozoin, which heretofore has only been found in blood-feeding organisms. SLC48A1 deficiency results in impaired erythroid maturation and an inability to systemically respond to iron deficiency. Complete heme tolerance requires a fully-operational heme degradation pathway as haplo insufficiency of HMOX1 combined with SLC48A1 inactivation causes perinatal lethality demonstrating synthetic lethal interactions between heme transport and degradation. Our studies establish the formation of hemozoin by mammals as a previously unsuspected heme tolerance pathway.


Specialized cells, known as red blood cells, are responsible for transporting oxygen to various organs in the body. Each red blood cell contains over a billion molecules of heme which make up the iron containing portion of the hemoglobin protein that binds and transports oxygen. When red blood cells reach the end of their life, they are degraded, and the heme and iron inside them is recycled to produce new red blood cells. Heme, however, is highly toxic to cells, and can cause severe tissue damage if not properly removed. Scavenger cells called macrophages perform this recycling role in the spleen, liver and bone marrow. Collectively, macrophages can process around five million red blood cells every second or about 100 trillion heme molecules. But, it is unclear how they are able to handle such enormous volumes. Macrophages isolated from human and mice have been shown to transport heme from damaged red blood cells using a protein called HRG1. To investigate the role HRG1 plays in heme-iron recycling, Pek et al. used a gene editing tool known an CRISPR/Cas9 to remove the gene for HRG1 from the macrophages of mice. If HRG1 is a major part of this process, removing the gene should result in a build-up of toxic heme and eventual death of the mouse. But, rather than dying of heme-iron overload as expected, these mutant mice managed to survive. Pek et al. found that despite being unable to recycle heme, these mice were still able to make new red blood cells as long as they had a diet that was rich in iron. However, the darkening color of the spleen, bone marrow, and liver in these HRG1 deficient mice indicated that these mice were still accumulating high levels of heme. Further experiments revealed that these mice protected themselves from toxicity by converting the excess heme into crystals called hemozoin. This method of detoxification is commonly seen in blood-feeding parasites, and this is the first time it has been observed in a mammal. These crystals invite new questions about how mammals recycle heme and what happens when this process goes wrong. The next step is to ask whether humans also start to make hemozoin if the gene for HRG1 is faulty. If so, this could open a new avenue of exploration into treatments for red blood cell diseases like anemia and iron overload.


Assuntos
Heme/toxicidade , Hemeproteínas/metabolismo , Macrófagos/metabolismo , Animais , Heme Oxigenase-1/metabolismo , Hemeproteínas/deficiência , Proteínas de Membrana/metabolismo , Camundongos
18.
Sci Adv ; 5(5): eaaw4466, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31149638

RESUMO

The tight coupling between cerebral blood flow and neural activity is a key feature of normal brain function and forms the basis of functional hyperemia. The mechanisms coupling neural activity to vascular responses, however, remain elusive despite decades of research. Recent studies have shown that cerebral functional hyperemia begins in capillaries, and red blood cells (RBCs) act as autonomous regulators of brain capillary perfusion. RBCs then respond to local changes of oxygen tension (PO2) and regulate their capillary velocity. Using ex vivo microfluidics and in vivo two-photon microscopy, we examined RBC capillary velocity as a function of PO2 and showed that deoxygenated hemoglobin and band 3 interactions on RBC membrane are the molecular switch that responds to local PO2 changes and controls RBC capillary velocity. Capillary hyperemia can be controlled by manipulating RBC properties independent of the neurovascular unit, providing an effective strategy to treat or prevent impaired functional hyperemia.


Assuntos
Encéfalo/irrigação sanguínea , Membrana Eritrocítica/fisiologia , Hiperemia/sangue , Oxigênio/sangue , Animais , Proteína 1 de Troca de Ânion do Eritrócito/genética , Proteína 1 de Troca de Ânion do Eritrócito/metabolismo , Velocidade do Fluxo Sanguíneo/fisiologia , Circulação Cerebrovascular , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Hiperemia/fisiopatologia , Dispositivos Lab-On-A-Chip , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
19.
Leukemia ; 33(12): 2884-2897, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31097785

RESUMO

Although the over-expression of angiogenic factors is reported in diffuse large B-cell lymphoma (DLBCL), the poor response to anti-VEGF drugs observed in clinical trials suggests that angiogenesis in these tumours might be driven by VEGF-independent pathways. We show that sphingosine kinase-1 (SPHK1), which generates the potent bioactive sphingolipid sphingosine-1-phosphate (S1P), is over-expressed in DLBCL. A meta-analysis of over 2000 cases revealed that genes correlated with SPHK1 mRNA expression in DLBCL were significantly enriched for tumour angiogenesis meta-signature genes; an effect evident in both major cell of origin (COO) and stromal subtypes. Moreover, we found that S1P induces angiogenic signalling and a gene expression programme that is present within the tumour vasculature of SPHK1-expressing DLBCL. Importantly, S1PR1 functional antagonists, including Siponimod, and the S1P neutralising antibody, Sphingomab, inhibited S1P signalling in DLBCL cells in vitro. Furthermore, Siponimod, also reduced angiogenesis and tumour growth in an S1P-producing mouse model of angiogenic DLBCL. Our data define a potential role for S1P signalling in driving an angiogenic gene expression programme in the tumour vasculature of DLBCL and suggest novel opportunities to target S1P-mediated angiogenesis in patients with DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Lisofosfolipídeos/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Transdução de Sinais , Esfingosina/análogos & derivados , Transcriptoma , Animais , Linhagem Celular Tumoral , Biologia Computacional/métodos , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/patologia , Lisofosfolipídeos/genética , Camundongos , RNA Mensageiro/genética , Esfingosina/genética , Esfingosina/metabolismo
20.
Pathol Oncol Res ; 25(3): 1223-1231, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30739251

RESUMO

SLIT2 has been classified as a major tumour suppressor gene due to its frequent inactivation in different cancer types. However, alterations of SLIT2 expression and relation to patient outcomes in diffuse large B cell lymphoma (DLBCL) remain undefined. The aim of this study was to investigate the expression and the methylation status of SLIT2 gene as well as its relation to patient outcomes in DLBCL. Immunohistochemical (IHC) staining was carried out to detect the expression of SLIT2 in a series of 108 DLBCL cases. Re-analysis of previously published dataset (GSE10846) that measured gene expression in DLBCL patients who had received CHOP or R-CHOP therapy was performed to identify associations between SLIT2 and patients survival. Laser capture microdissection was performed to isolate GC B cells and DLBCL primary tumor cells. Bisulfite treatment and methylation-specific PCR (MSP) analysis were done to assess SLIT2 promotor methylation status. We report that the expression of SLIT2 protein was reduced in a subset of DLBCL cases and this was significantly correlated with advanced clinical stage (p = 0.041) and was an independent predictor of worse overall survival (OS) (p = 0.012). Re-analysis of published gene expression data showed that reduced SLIT2 mRNA expression was significantly correlated with worse OS in R-CHOP-treated ABC DLBCL patients (p = <0.01). Hypermethylation of the SLIT2 promotor was significantly correlated with low SLIT2 expression (p = 0.009). Our results provide a novel evidence of reduced expression of SLIT2 that is associated with promoter hypermethylation and adverse outcomes in patients with DLBCL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/metabolismo , Metilação de DNA , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Regiões Promotoras Genéticas , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Prognóstico , Estudos Retrospectivos , Rituximab/administração & dosagem , Taxa de Sobrevida , Vincristina/administração & dosagem
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