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1.
Cell ; 163(5): 1237-1251, 2015 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-26590425

RESUMO

K-Ras and H-Ras share identical effectors and have similar properties; however, the high degree of tumor-type specificity associated with K-Ras and H-Ras mutations suggests that they have unique roles in oncogenesis. Here, we report that oncogenic K-Ras, but not H-Ras, suppresses non-canonical Wnt/Ca(2+) signaling, an effect that contributes strongly to its tumorigenic properties. K-Ras does this by binding to calmodulin and so reducing CaMKii activity and expression of Fzd8. Restoring Fzd8 in K-Ras mutant pancreatic cells suppresses malignancy, whereas depletion of Fzd8 in H-Ras(V12)-transformed cells enhances their tumor initiating capacity. Interrupting K-Ras-calmodulin binding using genetic means or by treatment with an orally active protein kinase C (PKC)-activator, prostratin, represses tumorigenesis in K-Ras mutant pancreatic cancer cells. These findings provide an alternative way to selectively target this "undruggable" protein.


Assuntos
Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Receptores de Superfície Celular/metabolismo , Via de Sinalização Wnt , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Calmodulina/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Genes ras , Humanos , Camundongos , Dados de Sequência Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Papiloma/metabolismo , Ésteres de Forbol/administração & dosagem , Fosforilação , Ligação Proteica/efeitos dos fármacos
2.
Am J Obstet Gynecol ; 231(1): 67-91, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38336124

RESUMO

OBJECTIVE: Care bundles are a promising approach to reducing postpartum hemorrhage-related morbidity and mortality. We assessed the effectiveness and safety of care bundles for postpartum hemorrhage prevention and/or treatment. DATA SOURCES: We searched MEDLINE, Embase, Cochrane CENTRAL, Maternity and Infant Care Database, and Global Index Medicus (inception to June 9, 2023) and ClinicalTrials.gov and the International Clinical Trials Registry Platform (last 5 years) using a phased search strategy, combining terms for postpartum hemorrhage and care bundles. STUDY ELIGIBILITY CRITERIA: Peer-reviewed studies evaluating postpartum hemorrhage-related care bundles were included. Care bundles were defined as interventions comprising ≥3 components implemented collectively, concurrently, or in rapid succession. Randomized and nonrandomized controlled trials, interrupted time series, and before-after studies (controlled or uncontrolled) were eligible. METHODS: Risk of bias was assessed using RoB 2 (randomized trials) and ROBINS-I (nonrandomized studies). For controlled studies, we reported risk ratios for dichotomous outcomes and mean differences for continuous outcomes, with certainty of evidence determined using GRADE. For uncontrolled studies, we used effect direction tables and summarized results narratively. RESULTS: Twenty-two studies were included for analysis. For prevention-only bundles (2 studies), low-certainty evidence suggests possible benefits in reducing blood loss, duration of hospitalization, and intensive care unit stay, and maternal well-being. For treatment-only bundles (9 studies), high-certainty evidence shows that the E-MOTIVE intervention reduced risks of composite severe morbidity (risk ratio, 0.40; 95% confidence interval, 0.32-0.50) and blood transfusion for bleeding, postpartum hemorrhage, severe postpartum hemorrhage, and mean blood loss. One nonrandomized trial and 7 uncontrolled studies suggest that other postpartum hemorrhage treatment bundles might reduce blood loss and severe postpartum hemorrhage, but this is uncertain. For combined prevention/treatment bundles (11 studies), low-certainty evidence shows that the California Maternal Quality Care Collaborative care bundle may reduce severe maternal morbidity (risk ratio, 0.64; 95% confidence interval, 0.57-0.72). Ten uncontrolled studies variably showed possible benefits, no effects, or harms for other bundle types. Nearly all uncontrolled studies did not use suitable statistical methods for single-group pretest-posttest comparisons and should thus be interpreted with caution. CONCLUSION: The E-MOTIVE intervention improves postpartum hemorrhage-related outcomes among women delivering vaginally, and the California Maternal Quality Care Collaborative bundle may reduce severe maternal morbidity. Other bundle designs warrant further effectiveness research before implementation is contemplated.


Assuntos
Pacotes de Assistência ao Paciente , Hemorragia Pós-Parto , Humanos , Hemorragia Pós-Parto/prevenção & controle , Hemorragia Pós-Parto/terapia , Feminino , Gravidez
3.
Eur J Orthop Surg Traumatol ; 34(4): 1893-1899, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38451337

RESUMO

PURPOSE: Rotational malalignment and leg length discrepancy after intramedullary nailing of femoral shaft are frequent. This study has three objectives: evaluate the rate of femoral rotational malalignment and leg length discrepancy using EOS imaging after antegrade intramedullary nailing of femoral shaft fracture, find a relevant clinical examination to detect malrotation and identified risk factors. METHODS: We performed a retrospective single-centre study between January 2014 and January 2022. Fifty-eight patients were clinically and radiographically assessed at a minimum of three months. RESULTS: The femoral rotation of the operated side was significantly greater by a mean of 15.4° in internal rotation compared to the healthy side. There was no statically significant difference for the femoral length (p = 0.08). CONCLUSION: When using EOS stereography following antegrade intramedullary nailing of post-traumatic diaphyseal femur fractures, a statistically significant difference of more than 15.4° in internal rotation was found for femoral rotation on the operated side compared to the healthy side.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [B. Poirot] Last name [Seynaeve]. Also, kindly confirm the details in the metadata are correct.The last name of the first author was corrected : Given name = B. and last name = Poirot Seynaeve The details in matadata are correct LEVEL OF EVIDENCE: III.


Assuntos
Fraturas do Fêmur , Fixação Intramedular de Fraturas , Humanos , Fixação Intramedular de Fraturas/métodos , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/instrumentação , Fraturas do Fêmur/cirurgia , Fraturas do Fêmur/diagnóstico por imagem , Estudos Retrospectivos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Rotação , Desigualdade de Membros Inferiores/etiologia , Desigualdade de Membros Inferiores/diagnóstico por imagem , Fraturas Mal-Unidas/diagnóstico por imagem , Fraturas Mal-Unidas/cirurgia , Imageamento Tridimensional/métodos , Adulto Jovem , Mau Alinhamento Ósseo/diagnóstico por imagem , Mau Alinhamento Ósseo/etiologia , Idoso , Fêmur/diagnóstico por imagem , Fêmur/cirurgia
4.
Biophys J ; 122(11): 2242-2255, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-36639867

RESUMO

Biological and model membranes are frequently subjected to fluid shear stress. However, membrane mechanical responses to flow remain incompletely described. This is particularly true of membranes supported on a solid substrate, and the influences of membrane composition and substrate roughness on membrane flow responses remain poorly understood. Here, we combine microfluidics, fluorescence microscopy, and neutron reflectivity to explore how supported lipid bilayer patches respond to controlled shear stress. We demonstrate that lipid membranes undergo a significant, passive, and partially reversible increase in membrane area due to flow. We show that these fluctuations in membrane area can be constrained, but not prevented, by increasing substrate roughness. Similar flow-induced changes to membrane structure may contribute to the ability of living cells to sense and respond to flow.


Assuntos
Bicamadas Lipídicas , Bicamadas Lipídicas/química , Microscopia de Fluorescência , Fenômenos Físicos
5.
Liver Int ; 43(5): 989-999, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36719055

RESUMO

BACKGROUND: Alanine aminotransferase (ALT) measurement is essential for evaluation of liver disease. We validated a novel rapid point-of-care (POC) test for ALT1 against laboratory ALT. METHODS: Stored plasma samples from adults with chronic liver disease (Test cohort n = 240; Validation cohort n = 491) were analysed using the BioPoint® antigen immunoassay POC ALT1 lateral flow test, which provides quantitative ALT results (Axxin handheld reader) or semi-quantitative results (visual read, cut off 40 IU/ml). The accuracy of POC ALT1 to detect ALT > 40 IU/L was determined by ROC analysis. In patients with chronic hepatitis B, treatment eligibility (EASL criteria) was determined using POC ALT1 and compared to laboratory ALT. RESULTS: POC ALT1 test had good accuracy for laboratory ALT > 40 IU/L: AUROC 0.93 (95% CI: 0.89-0.96) in the Test cohort and AUROC 0.92 (95% CI: 0.88-0.95) in the Validation cohort. POC ALT1 cut off of 0.8 for ALT > 40 IU/L maximised sensitivity (97%) and specificity (71%) in the Test cohort (42% laboratory ALT > 40 IU/L) and yielded PPV 84% and NPV 91% in the Validation cohort (19% laboratory ALT > 40 IU/L). Semi-quantitative POC ALT1 had good accuracy for laboratory ALT in the Validation cohort (AUROC 0.85, 95% CI: 0.81-0.99; sensitivity 77% and specificity 93%). Combined with HBV DNA and transient elastography, both quantitative and semi-quantitative POC ALT1 tests had good accuracy for excluding hepatitis B treatment needs (sensitivity 96%, specificity 78% and NPV 99%). CONCLUSION: The POC ALT1 test had good accuracy for elevated ALT levels and for determining treatment eligibility among people with chronic hepatitis B.


Assuntos
Hepatite B Crônica , Hepatite B , Adulto , Humanos , Alanina Transaminase , Hepatite B Crônica/diagnóstico , Projetos Piloto , Estudos de Coortes , DNA Viral
6.
BMC Public Health ; 23(1): 972, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37237349

RESUMO

BACKGROUND: Perceived stigma is a complex societal phenomenon that is harboured especially by female sex workers because of the interplay of a myriad of factors. As such, a precise measure of the contribution of different social practices and characteristics is necessary for both understanding and intervening in matters related to perceived stigma. We developed a Perceived Stigma Index that measures the factors that greatly contribute to the stigma among sex workers in Kenya, and thereby inform a framework for future interventions. METHODS: Social Practice Theory was adopted in the development of the Perceived Stigma Index in which three social domains were extracted from data collected in the WHISPER or SHOUT study conducted among female sex workers (FSW), aged 16-35 years in Mombasa, Kenya. The three domains included: Social demographics, Relationship Control and Sexual and Gender-based Violence, and Society awareness of sexual and reproductive history. The factor assessment entailed Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), and the internal consistency of the index was measured using Cronbach's alpha coefficient. RESULTS: We developed a perceived stigma index to measure perceived stigma among 882 FSWs with a median age of 26 years. A Cronbach's alpha coefficient of 0.86 (95% confidence interval (CI) 0.85-0.88) was obtained as a measure of the internal consistency of our index using the Social Practice Theory. In regression analysis, we identified three major factors that contribute to the perceived stigma and consists of : (i) income and family support (ß = 1.69; 95% CI); (ii) society's awareness of the sex workers' sexual and reproductive history (ß = 3.54; 95% CI); and (iii) different forms of relationship control e.g. physical abuse (ß = 1.48; 95%CI that propagate the perceived stigma among the FSWs. CONCLUSION: Social practice theory has solid properties that support and capture the multi-dimensional nature of perceived stigma. The findings support the fact that social practices contribute or provoke this fear of being discriminated against. Thus, in offering interventions to curb perceived stigma, focus should fall on the education of the society on the importance of acceptance and integration of the FSWs as part of the society and the eradication of sexual and gender based violence meted out on them. TRIAL REGISTRATION: The trial was registered in the Australian New Zealand Clinical Trials Registry, ACTRN12616000852459.


Assuntos
Infecções por HIV , Profissionais do Sexo , Humanos , Feminino , Adulto , Quênia , Austrália , Comportamento Sexual , Estigma Social
7.
Eur J Gynaecol Oncol ; 44(1): 17-25, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36874058

RESUMO

Bevacizumab has demonstrated significant benefit in recurrent ovarian, fallopian tube and peritoneal cancer (OC), but its optimal position within the sequence of systemic therapies remains controversial. Since rebound progression after bevacizumab has been observed in other cancers, and because bevacizumab is incorporated in several regimens used in the recurrent setting, the duration of treatment may impact survival. We sought to identify whether earlier bevacizumab exposure is associated with prolonged bevacizumab therapy and survival by conducting a multi-institution retrospective study of recurrent OC patients treated with bevacizumab from 2004-2014. Multivariate logistic regression identified factors associated with receiving more than six bevacizumab cycles. Overall survival by duration and ordinal sequence of bevacizumab therapy were evaluated using logrank testing and Cox regression. In total, 318 patients were identified. 89.1% had stage III or IV disease; 36% had primary platinum resistance; 40.5% received two or fewer prior chemotherapy regimens. Multivariate logistic regression demonstrated that primary platinum sensitivity (Odds Ratio (OR) 2.34, p = 0.001) or initiating bevacizumab at the first or second recurrence (OR 2.73, p < 0.001) were independently associated with receiving more than six cycles of bevacizumab. Receiving more cycles of bevacizumab was associated with improved overall survival whether measured from time of diagnosis (logrank p < 0.001), bevacizumab initiation (logrank p < 0.001), or bevacizumab discontinuation (logrank p = 0.017). Waiting one additional recurrence to initiate bevacizumab resulted in a 27% increased hazard of death (Hazard Ratio (HR) 1.27, p < 0.001) by multivariate analysis. In conclusion, patients with primary platinum sensitive disease who received fewer prior lines of chemotherapy were able to receive more cycles of bevacizumab, which was associated with improved overall survival. Survival worsened when bevacizumab was initiated later in the ordinal sequence of therapies.

8.
Sex Transm Infect ; 98(8): 608-616, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36180209

RESUMO

BACKGROUND: Current rapid tests for syphilis and yaws can detect treponemal and non-treponemal antibodies. We aimed to critically appraise the literature for rapid diagnostic tests (RDTs) which can better distinguish an active infection of syphilis or yaws. METHODS: We conducted a systematic review and meta-analysis, searching five databases between January 2010 and October 2021 (with an update in July 2022). A generalised linear mixed model was used to conduct a bivariate meta-analysis for the pooled sensitivity and specificity. Heterogeneity was assessed using the I2 statistic. We used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) to assess the risk of bias and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) to evaluate the certainty of evidence. RESULTS: We included 17 studies for meta-analyses. For syphilis, the pooled sensitivity and specificity of the treponemal component were 0.93 (95% CI: 0.86 to 0.97) and 0.98 (95% CI: 0.96 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.90 (95% CI: 0.82 to 0.95) and 0.97 (95% CI: 0.92 to 0.99), respectively. For yaws, the pooled sensitivity and specificity of the treponemal component were 0.86 (95% CI: 0.66 to 0.95) and 0.97 (95% CI: 0.94 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.80 (95% CI: 0.55 to 0.93) and 0.96 (95% CI: 0.92 to 0.98), respectively. CONCLUSIONS: RDTs that can differentiate between active and previously treated infections could optimise management by providing same-day treatment and reducing unnecessary treatment. PROSPERO REGISTRATION NUMBER: CRD42021279587.


Assuntos
Sífilis , Bouba , Humanos , Bouba/diagnóstico , Sífilis/diagnóstico , Testes Diagnósticos de Rotina , Sensibilidade e Especificidade
9.
BMC Public Health ; 22(1): 1203, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710413

RESUMO

BACKGROUND: In 2016, we conducted a systematic review to assess the feasibility of treatment monitoring for people living with HIV (PLHIV) receiving antiretroviral therapy (ART) in low and middle-income countries (LMICs), in line with the 90-90-90 treatment target. By 2020, global estimates suggest the 90-90-90 target, particularly the last 90, remains unattainable in many LMICs. This study aims to review the progress and identify needs for public health interventions to improve viral load monitoring and viral suppression for PLHIV in LMICs. METHODS: A literature search was conducted using an update of the initial search strategy developed for the 2016 review. Electronic databases (Medline and PubMed) were searched to identify relevant literature published in English between Dec 2015 and August 2021. The primary outcome was initial viral load (VL) monitoring (the proportion of PLHIV on ART and eligible for VL monitoring who received a VL test). Secondary outcomes included follow-up VL monitoring (the proportion of PLHIV who received a follow-up VL after an initial elevated VL test), confirmation of treatment failure (the proportion of PLHIV who had two consecutive elevated VL results) and switching treatment regimen rates (the proportion of PLHIV who switched treatment regimen after confirmation of treatment failure). RESULTS: The search strategy identified 1984 non-duplicate records, of which 34 studies were included in the review. Marked variations in initial VL monitoring coverage were reported across study settings/countries (range: 12-93% median: 74% IQR: 46-82%) and study populations (adults (range: 25-96%, median: 67% IQR: 50-84%), children, adolescents/young people (range: 2-94%, median: 72% IQR: 47-85%), and pregnant women (range: 32-82%, median: 57% IQR: 43-71%)). Community-based models reported higher VL monitoring (median: 85%, IQR: 82-88%) compared to decentralised care at primary health facility (median: 64%, IRQ: 48-82%). Suboptimal uptake of follow-up VL monitoring and low regimen switching rates were observed. CONCLUSIONS: Substantial gaps in VL coverage across study settings and study populations were evident, with limited data availability outside of sub-Saharan Africa. Further research is needed to fill the data gaps. Development and implementation of innovative, community-based interventions are required to improve VL monitoring and address the "failure cascade" in PLHIV on ART who fail to achieve viral suppression.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Criança , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Gravidez , Testes Sorológicos , Falha de Tratamento , Carga Viral
10.
Aesthetic Plast Surg ; 46(2): 907-911, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34767060

RESUMO

With the increase of cosmetic injectable hyaluronic acid (HA), there have been more cases with serious complications, including skin necrosis, blindness, and cerebral embolism. Patients who have recovered from HA filler-induced total vision loss are extremely rare. We report a case of a 27-year-old female who developed severe ocular pain on the right side and total vision loss following a 1.0 ml HA filler injection in the nasal dorsum. She arrived at our hospital 4 hours later. Her visual acuity was no light perception (NLP), and she exhibited eyelid ptosis, ophthalmoplegia, and frontal and nasal ecchymosis. She was promptly treated with subcutaneous and retrobulbar hyaluronidase injections, as well as intra-arterial 1500 IU hyaluronidase injections into the right ophthalmic artery with DSA assistance. Her vision improved from NLP to counting fingers at 1.0 meters. Unfortunately, 13 hours later, she felt an intense headache, and her vision again decreased to NLP. We immediately performed an injection of 1500 IU hyaluronidase combined with 8 mg alteplase for intra-arterial thrombolysis (IAT) into the right ophthalmic artery. Her vision improved immediately afterward. After 3 months, her visual acuity had significantly recovered from NLP (admission vision status) to 20/50 (Snellen chart with glasses). Similarly, skin, conjunctival, eye movement, and ptosis symptoms completely recovered. This case demonstrates that reversal of complete blindness due to embolism of the ophthalmic and central retinal arteries could be accomplished through multidisciplinary therapies, especially IAT using fibrinolytic agents combined with hyaluronidase followed by an anticoagulant regimen.Level of evidence VThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Adulto , Cegueira/etiologia , Técnicas Cosméticas/efeitos adversos , Feminino , Fibrinolíticos/efeitos adversos , Humanos , Ácido Hialurônico/efeitos adversos , Hialuronoglucosaminidase , Injeções Intra-Arteriais
11.
Kidney Int ; 99(1): 218-226, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898570

RESUMO

We have previously shown that ultrasonography can detect hyperechogenic crystal deposits in the kidney medulla of patients with gout. In this cross-sectional study we investigated the frequency and clinical correlates of hyperechogenic kidney medulla in 502 consecutive primary consultants for gout (ACR/EULAR criteria) at the Vien Gut medical center in Ho Chi Minh City, Vietnam. None of these patients received urate-lowering drugs. Kidney medulla echogenicity on B-mode ultrasonography was compared to that of the kidney cortex. Overall, 36% patients showed a hyperechoic pattern of Malpighi pyramids. On univariate analysis, the pattern was significantly associated with age, estimated gout duration, steroid-dependency, clinical tophi, urate arthropathy, double contour thickness at the scanned joints, coronary heart disease, arterial hypertension, hyperuricemia, proteinuria, leukocyturia, and decreased estimated glomerular filtration rate. On multivariable analysis, the hyperechoic pattern was associated with estimated disease duration, clinical tophi, urate arthropathy, double contour thickness and decreased estimated glomerular filtration rate. No hyperechoic pattern was observed in 515 consecutive consultants without gout. Thus, hyperechoic kidney medulla was frequently demonstrated in Vietnamese patients with tophaceous gout and associated with features of tubulointerstitial nephritis. This finding revives the hypothesis of microcrystalline nephropathy of gout, predominantly seen in untreated gouty patients, which could be an important target for urate-lowering therapy.


Assuntos
Gota , Hiperuricemia , Estudos Transversais , Gota/diagnóstico por imagem , Gota/tratamento farmacológico , Gota/epidemiologia , Humanos , Medula Renal , Ácido Úrico
13.
Nature ; 517(7535): 489-92, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25363767

RESUMO

Next-generation sequencing of human tumours has refined our understanding of the mutational processes operative in cancer initiation and progression, yet major questions remain regarding the factors that induce driver mutations and the processes that shape mutation selection during tumorigenesis. Here we performed whole-exome sequencing on adenomas from three mouse models of non-small-cell lung cancer, which were induced either by exposure to carcinogens (methyl-nitrosourea (MNU) and urethane) or by genetic activation of Kras (Kras(LA2)). Although the MNU-induced tumours carried exactly the same initiating mutation in Kras as seen in the Kras(LA2) model (G12D), MNU tumours had an average of 192 non-synonymous, somatic single-nucleotide variants, compared with only six in tumours from the Kras(LA2) model. By contrast, the Kras(LA2) tumours exhibited a significantly higher level of aneuploidy and copy number alterations compared with the carcinogen-induced tumours, suggesting that carcinogen-induced and genetically engineered models lead to tumour development through different routes. The wild-type allele of Kras has been shown to act as a tumour suppressor in mouse models of non-small-cell lung cancer. We demonstrate that urethane-induced tumours from wild-type mice carry mostly (94%) Kras Q61R mutations, whereas those from Kras heterozygous animals carry mostly (92%) Kras Q61L mutations, indicating a major role for germline Kras status in mutation selection during initiation. The exome-wide mutation spectra in carcinogen-induced tumours overwhelmingly display signatures of the initiating carcinogen, while adenocarcinomas acquire additional C > T mutations at CpG sites. These data provide a basis for understanding results from human tumour genome sequencing, which has identified two broad categories of tumours based on the relative frequency of single-nucleotide variations and copy number alterations, and underline the importance of carcinogen models for understanding the complex mutation spectra seen in human cancers.


Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Genes ras/genética , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Mutação/genética , Proteína Oncogênica p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/genética , Animais , Carcinógenos/toxicidade , Carcinoma Pulmonar de Células não Pequenas/induzido quimicamente , Carcinoma Pulmonar de Células não Pequenas/genética , Variações do Número de Cópias de DNA/genética , Progressão da Doença , Feminino , Instabilidade Genômica/genética , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Metilnitrosoureia/toxicidade , Camundongos , Modelos Genéticos , Mutação Puntual/genética , Uretana/toxicidade
14.
Am J Primatol ; 83(6): e23255, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33792947

RESUMO

The novel coronavirus SARS-CoV-2, which in humans leads to the disease COVID-19, has caused global disruption and more than 2 million fatalities since it first emerged in late 2019. As we write, infection rates are at their highest point globally and are rising extremely rapidly in some areas due to more infectious variants. The primary target of SARS-CoV-2 is the cellular receptor angiotensin-converting enzyme-2 (ACE2). Recent sequence analyses of the ACE2 gene predict that many nonhuman primates are also likely to be highly susceptible to infection. However, the anticipated risk is not equal across the Order. Furthermore, some taxonomic groups show high ACE2 amino acid conservation, while others exhibit high variability at this locus. As an example of the latter, analyses of strepsirrhine primate ACE2 sequences to date indicate large variation among lemurs and lorises compared to other primate clades despite low sampling effort. Here, we report ACE2 gene and protein sequences for 71 individual strepsirrhines, spanning 51 species and 19 genera. Our study reinforces previous results while finding additional variability in other strepsirrhine species, and suggests several clades of lemurs have high potential susceptibility to SARS-CoV-2 infection. Troublingly, some species, including the rare and endangered aye-aye (Daubentonia madagascariensis), as well as those in the genera Avahi and Propithecus, may be at high risk. Given that lemurs are endemic to Madagascar and among the primates at highest risk of extinction globally, further understanding of the potential threat of COVID-19 to their health should be a conservation priority. All feasible actions should be taken to limit their exposure to SARS-CoV-2.


Assuntos
COVID-19/veterinária , Lemur , Lorisidae , Doenças dos Primatas/epidemiologia , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/genética , Animais , COVID-19/epidemiologia , Lemur/genética , Lorisidae/genética , Doenças dos Primatas/virologia , Fatores de Risco
15.
Genes Dev ; 27(6): 670-82, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23512660

RESUMO

Epithelial-mesenchymal transition (EMT) is thought to be an important, possibly essential, component of the process of tumor dissemination and metastasis. About 20%-30% of Hras mutant mouse skin carcinomas induced by chemical initiation/promotion protocols have undergone EMT. Reduced exposure to TPA-induced chronic inflammation causes a dramatic reduction in classical papillomas and squamous cell carcinomas (SCCs), but the mice still develop highly invasive carcinomas with EMT properties, reduced levels of Hras and Egfr signaling, and frequent Ink4/Arf deletions. Deletion of Hras from the mouse germline also leads to a strong reduction in squamous tumor development, but tumors now acquire activating Kras mutations and exhibit more aggressive metastatic properties. We propose that invasive carcinomas can arise by different genetic and biological routes dependent on exposure to chronic inflammation and possibly from different target cell populations within the skin. Our data have implications for the use of inhibitors of inflammation or of Ras/Egfr pathway signaling for prevention or treatment of invasive cancers.


Assuntos
Carcinoma de Células Escamosas/patologia , Inflamação/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/patologia , Animais , Carcinoma de Células Escamosas/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Transição Epitelial-Mesenquimal , Receptores ErbB/metabolismo , Dosagem de Genes , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Marcadores Genéticos/genética , Camundongos , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Cutâneas/genética
16.
Adv Funct Mater ; 30(28): 2001800, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32684909

RESUMO

Carrier mobility in doped conjugated polymers is limited by Coulomb interactions with dopant counterions. This complicates studying the effect of the dopant's oxidation potential on carrier generation because different dopants have different Coulomb interactions with polarons on the polymer backbone. Here, dodecaborane (DDB)-based dopants are used, which electrostatically shield counterions from carriers and have tunable redox potentials at constant size and shape. DDB dopants produce mobile carriers due to spatial separation of the counterion, and those with greater energetic offsets produce more carriers. Neutron reflectometry indicates that dopant infiltration into conjugated polymer films is redox-potential-driven. Remarkably, X-ray scattering shows that despite their large 2-nm size, DDBs intercalate into the crystalline polymer lamellae like small molecules, indicating that this is the preferred location for dopants of any size. These findings elucidate why doping conjugated polymers usually produces integer, rather than partial charge transfer: dopant counterions effectively intercalate into the lamellae, far from the polarons on the polymer backbone. Finally, it is shown that the IR spectrum provides a simple way to determine polaron mobility. Overall, higher oxidation potentials lead to higher doping efficiencies, with values reaching 100% for driving forces sufficient to dope poorly crystalline regions of the film.

17.
Bioscience ; 70(9): 794-803, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32973409

RESUMO

Threats to biodiversity are well documented. However, to effectively conserve species and their habitats, we need to know which conservation interventions do (or do not) work. Evidence-based conservation evaluates interventions within a scientific framework. The Conservation Evidence project has summarized thousands of studies testing conservation interventions and compiled these as synopses for various habitats and taxa. In the present article, we analyzed the interventions assessed in the primate synopsis and compared these with other taxa. We found that despite intensive efforts to study primates and the extensive threats they face, less than 1% of primate studies evaluated conservation effectiveness. The studies often lacked quantitative data, failed to undertake postimplementation monitoring of populations or individuals, or implemented several interventions at once. Furthermore, the studies were biased toward specific taxa, geographic regions, and interventions. We describe barriers for testing primate conservation interventions and propose actions to improve the conservation evidence base to protect this endangered and globally important taxon.

18.
Langmuir ; 36(26): 7259-7267, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32460498

RESUMO

Collagen is a skeleton of native extracellular matrix (ECM) that is known to provide mechanical and structural stability. In an attempt to develop a new connective cellular model with the surrounding ECM without further experimental complications, such as the reconstitution of ECM receptors, we designed the experiments and discovered that the fibrillogenesis of membrane-bound collagen is not spontaneous as it is in the form of free collagen in bulk solution. The confocal microscopic results suggest that cholesterol is a crucial component that facilitates the fibril formation on the membrane surface. In situ X-ray and neutron reflectivity on Langmuir monolayer and solid-supported lipid bilayer models, respectively, reveal two features of cholesterol effects on the collagen fibril formation. Mainly, cholesterol increases the lateral lipid headgroup separation on the membrane surface, which promotes the association degree of collagen monomers. It also enhances the elastic modulus of the membrane to impede membrane filtration by the collagen assemblies.


Assuntos
Colágeno , Matriz Extracelular , Colesterol , Citoesqueleto , Módulo de Elasticidade
19.
Langmuir ; 36(14): 3970-3980, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32207953

RESUMO

Styrene-maleic acid (SMA) copolymers have recently gained attention for their ability to facilitate the detergent-free solubilization of membrane protein complexes and their native boundary lipids into polymer-encapsulated, nanosized lipid particles, referred to as SMALPs. However, the interfacial interactions between SMA and lipids, which dictate the mechanism, efficiency, and selectivity of lipid and membrane protein extraction, are barely understood. Our recent finding has shown that SMA 1440, a chemical derivative of the SMA family with a functionalized butoxyethanol group, was most active in galactolipid-rich membranes, as opposed to phospholipid membranes. In the present work, we have performed X-ray reflectometry (XRR) and neutron reflectometry (NR) on the lipid monolayers at the liquid-air interface followed by the SMA copolymer adsorption. XRR and Langmuir Π-A isotherms captured the fluidifying effect of galactolipids, which allowed SMA copolymers to infiltrate easily into the lipid membranes. NR results revealed the detailed structural arrangement of SMA 1440 copolymers within the membranes and highlighted the partition of butoxyethanol group into the lipid tail region. This work allows us to propose a possible mechanism for the membrane solubilization by SMA.

20.
J Clin Microbiol ; 57(2)2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30463898

RESUMO

Measuring CD4 counts remains an important component of HIV care. The Visitect CD4 is the first instrument-free low-cost point-of-care CD4 test with results interpreted visually after 40 min, providing a result of ≥350 CD4 cells/mm3 The field performance and diagnostic accuracy of the test was assessed among HIV-infected pregnant women in South Africa. A nurse performed testing at the point-of-care using both venous and finger-prick blood, and a counselor and laboratory staff tested venous blood in the clinic laboratory (four Visitect CD4 tests/participant). Performance was compared to the mean CD4 count from duplicate flow cytometry tests on venous blood (FACSCalibur Trucount). In 2017, 156 patients were enrolled, providing a total of 624 Visitect CD4 tests (468 venous and 156 finger-prick samples). Of 624 tests, 28 (4.5%) were inconclusive. Generalized linear mixed modeling showed better performance of the test on venous blood (sensitivity = 81.7%; 95% confidence interval [CI] = 72.3 to 91.1]; specificity = 82.6%, 95% CI = 77.1 to 88.1) than on finger-prick specimens (sensitivity = 60.7%; 95% CI = 45.0 to 76.3; specificity = 89.5%, 95% CI = 83.2 to 95.8; P = 0.001). No difference in performance was detected by cadre of health worker (P = 0.113) or between point-of-care versus laboratory-based testing (P = 0.108). Adequate performance of Visitect CD4 with different operators and at the point of care, with no need of electricity or instrument, shows the potential utility of this device, especially for facilitating decentralization of CD4 testing services in rural areas.


Assuntos
Contagem de Linfócito CD4/métodos , Infecções por HIV/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Complicações Infecciosas na Gravidez/diagnóstico , Adolescente , Adulto , Contagem de Linfócito CD4/economia , Estudos Transversais , Feminino , Custos de Cuidados de Saúde , Humanos , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Sensibilidade e Especificidade , África do Sul , Fatores de Tempo , Adulto Jovem
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