Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 691
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Mol Ther ; 31(8): 2360-2375, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37403357

RESUMO

RNA vaccines possess significant clinical promise in counteracting human diseases caused by infectious or cancerous threats. Self-amplifying replicon RNA (repRNA) has been thought to offer the potential for enhanced potency and dose sparing. However, repRNA is a potent trigger of innate immune responses in vivo, which can cause reduced transgene expression and dose-limiting reactogenicity, as highlighted by recent clinical trials. Here, we report that multivalent repRNA vaccination, necessitating higher doses of total RNA, could be safely achieved in mice by delivering multiple repRNAs with a localizing cationic nanocarrier formulation (LION). Intramuscular delivery of multivalent repRNA by LION resulted in localized biodistribution accompanied by significantly upregulated local innate immune responses and the induction of antigen-specific adaptive immune responses in the absence of systemic inflammatory responses. In contrast, repRNA delivered by lipid nanoparticles (LNPs) showed generalized biodistribution, a systemic inflammatory state, an increased body weight loss, and failed to induce neutralizing antibody responses in a multivalent composition. These findings suggest that in vivo delivery of repRNA by LION is a platform technology for safe and effective multivalent vaccination through mechanisms distinct from LNP-formulated repRNA vaccines.


Assuntos
Nanopartículas , RNA , Humanos , Camundongos , Animais , Distribuição Tecidual , RNA/genética , Antígenos , Imunidade Humoral , Inflamação
2.
Palliat Support Care ; 22(2): 281-288, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37559193

RESUMO

OBJECTIVES: The COVID-19 pandemic posed new challenges to physical and psychological well-being. Families with pediatric cancer patients were particularly vulnerable due to changes like children staying at home, hospital policy shifts, and caring for an immunocompromised child. Limited research exists on COVID-19's effects on these families. This study aimed to assess the pandemic's impact and identify psychosocial support gaps. METHODS: Participants (N = 256) were parents of children with cancer recruited via Facebook in partnership with Momcology®, a community-based organization for pediatric cancer, between February and May 2021. Qualitative analyses used open-ended responses about the pandemic's impact on the family. RESULTS: Analysis revealed 6 themes, with positive and negative sentiments: family changes (n = 169; 61% negative), social isolation (n = 154; 100% negative), emotional impact (n = 143; 89% negative), school changes (n = 126; 80% negative), health-care changes (n = 111; 96% negative), and physical health (n = 49; 73% negative). Family changes overarched all themes and included financial strains, at-home schooling, and family bonding. Parents highlighted social isolation and the emotional impact of pandemic-related changes. School changes forced parents to balance remote-work and childcare. Health-care changes limited resources and visitation. Parents reported their children were less active and slept less but had fewer illnesses. SIGNIFICANCE OF RESULTS: Many common pandemic challenges were exacerbated by the stress of caring for a child with cancer. Parents struggled most with loss of social support and feelings of isolation. Careful consideration should be given to providing resources for parents of children with cancer and their families.


Assuntos
COVID-19 , Neoplasias , Criança , Humanos , Pandemias , Estresse Psicológico/psicologia , Apoio Social , Pais/psicologia , Neoplasias/complicações
3.
Support Care Cancer ; 31(6): 364, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37249650

RESUMO

PURPOSE: This study examined the relationship between the presence of chronic disease conditions and mental and physical health among cancer survivors in the United States. METHODS: We conducted a cross-sectional analysis utilizing survey data from the 2016-2017 Behavioral Risk Factor Surveillance System (BRFSS) on 65,673 eligible cancer survivors. The primary outcomes of interest were self-rated metal/physical health in the past 30 days. Descriptive statistics and multivariate logistic regression were used to examine the mentioned association. RESULTS: 15.3% and 24.8% of survivors reported having several days of poor mental and physical health (14-30 days compared to 0-13 days), and 42.4% of survivors reported having one to two chronic diseases. In multivariate analysis, survivors with one to two chronic diseases were more likely to report several days of poor mental (OR, 2.74; 95% CI, 2.22-3.38) and physical (OR, 1.95; 95% CI, 1.72-2.22) health. Survivors with 3+ chronic diseases had markedly higher odds of having several days of poor mental (OR, 6.41; 95% CI, 5.19-7.91) and physical health (OR, 4.71; 95% CI, 4.16-5.34). Among survivors with at least one chronic disease, older age, insured, and more perceived social/emotional support were negatively associated with mental health (p value <0.05). Similarly, older age was related to fewer days of poor physical health (p value <0.05) regardless of chronic disease conditions. CONCLUSION: Having chronic diseases was associated with more days of poor mental and physical health among cancer survivors. Integrated, extensive care should include mental/physical health components and chronic disease management in cancer survivorship care.


Assuntos
Sobreviventes de Câncer , Neoplasias , Humanos , Estados Unidos/epidemiologia , Estudos Transversais , Saúde Mental , Sobreviventes/psicologia , Doença Crônica , Neoplasias/epidemiologia , Neoplasias/psicologia , Qualidade de Vida
4.
Am J Primatol ; 85(2): e23458, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36504317

RESUMO

The relevance of emerging infectious diseases continues to grow worldwide as human activities increasingly extend into formerly remote natural areas. This is particularly noticeable on the island of Madagascar. As closest relatives to humans on the island, lemurs are of particular relevance as a potential origin of zoonotic pathogen spillover. Knowledge of pathogens circulating in lemur populations is, however, very poor. Particularly little is known about lemur hemoparasites. To infer host range, ecological and geographic spread of the recently described hemoparasitic nematode Lemurfilaria lemuris in northwestern Madagascar, a total of 942 individuals of two mouse lemur species (Microcebus murinus [n = 207] and Microcebus ravelobensis [n = 433]) and two rodent species (the endemic Eliurus myoxinus [n = 118] and the invasive Rattus rattus [n = 184]) were captured in two fragmented forest landscapes (Ankarafantsika National Park and Mariarano Classified Forest) in northwestern Madagascar for blood sample examination. No protozoan hemoparasites were detected by microscopic blood smear screening. Microfilaria were present in 1.0% (2/207) of M. murinus and 2.1% (9/433) of M. ravelobensis blood samples but not in rodent samples. Internal transcribed spacer 1 (ITS-1) sequences were identical to an unnamed Onchocercidae species previously described to infect a larger lemur species, Propithecus verreauxi, about 650 km further south. In contrast to expectations, L. lemuris was not detected. The finding of a pathogen in a distantly related host species, at a considerable geographic distance from the location of its original detection, instead of a microfilaria species previously described for one of the studied host species in the same region, illustrates our low level of knowledge of lemur hemoparasites, their host ranges, distribution, modes of transmission, and their zoonotic potential. Our findings shall stimulate new research that will be of relevance for both conservation medicine and human epidemiology.


Assuntos
Cheirogaleidae , Lemur , Lemuridae , Strepsirhini , Ratos , Animais , Humanos , Especificidade de Hospedeiro , Roedores , Madagáscar , Especificidade da Espécie
5.
Hum Mol Genet ; 29(2): 202-215, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31696228

RESUMO

Transcriptional and epigenetic alterations occur early in Huntington's disease (HD), and treatment with epigenetic modulators is beneficial in several HD animal models. The drug JQ1, which inhibits histone acetyl-lysine reader bromodomains, has shown promise for multiple cancers and neurodegenerative disease. We tested whether JQ1 could improve behavioral phenotypes in the R6/2 mouse model of HD and modulate HD-associated changes in transcription and epigenomics. R6/2 and non-transgenic (NT) mice were treated with JQ1 daily from 5 to 11 weeks of age and behavioral phenotypes evaluated over this period. Following the trial, cortex and striatum were isolated and subjected to mRNA-seq and ChIP-seq for the histone marks H3K4me3 and H3K27ac. Initially, JQ1 enhanced motor performance in NT mice. In R6/2 mice, however, JQ1 had no effect on rotarod or grip strength but exacerbated weight loss and worsened performance on the pole test. JQ1-induced gene expression changes in NT mice were distinct from those in R6/2 and primarily involved protein translation and bioenergetics pathways. Dysregulation of HD-related pathways in striatum was exacerbated by JQ1 in R6/2 mice, but not in NTs, and JQ1 caused a corresponding increase in the formation of a mutant huntingtin protein-dependent high molecular weight species associated with pathogenesis. This study suggests that drugs predicted to be beneficial based on their mode of action and effects in wild-type or in other neurodegenerative disease models may have an altered impact in the HD context. These observations have important implications in the development of epigenetic modulators as therapies for HD.


Assuntos
Azepinas/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Triazóis/farmacologia , Acetilação , Animais , Escala de Avaliação Comportamental , Sintomas Comportamentais/tratamento farmacológico , Córtex Cerebral/patologia , Sequenciamento de Cromatina por Imunoprecipitação , Corpo Estriado/patologia , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Ontologia Genética , Histonas/metabolismo , Proteína Huntingtina/genética , Doença de Huntington/tratamento farmacológico , Doença de Huntington/genética , Doença de Huntington/patologia , Masculino , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , RNA-Seq , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
6.
Chemistry ; 28(51): e202200995, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35697660

RESUMO

Tuberculosis (TB) is a leading source of infectious disease mortality globally. Antibiotic-resistant strains comprise an estimated 10 % of new TB cases and present an urgent need for novel therapeutics. ß-lactam antibiotics have traditionally been ineffective against M. tuberculosis (Mtb), the causative agent of TB, due to the organism's inherent expression of ß-lactamases that destroy the electrophilic ß-lactam warhead. We have developed novel ß-lactam conjugates, which exploit this inherent ß-lactamase activity to achieve selective release of pyrazinoic acid (POA), the active form of a first-line TB drug. These conjugates are selectively active against M. tuberculosis and related mycobacteria, and activity is retained or even potentiated in multiple resistant strains and models. Preliminary mechanistic investigations suggest that both the POA "warhead" as well as the ß-lactam "promoiety" contribute to the observed activity, demonstrating a codrug strategy with important implications for future TB therapy.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Pirazinamida/análogos & derivados , Pirazinamida/farmacologia , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia , beta-Lactamas/farmacologia
7.
Bioorg Med Chem ; 74: 117046, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36228522

RESUMO

Tuberculosis (TB) remains a leading cause of infectious disease-related mortality and morbidity. Pyrazinamide (PZA) is a critical component of the first-line TB treatment regimen because of its sterilizing activity against non-replicating Mycobacterium tuberculosis (Mtb), but its mechanism of action has remained enigmatic. PZA is a prodrug converted by pyrazinamidase encoded by pncA within Mtb to the active moiety, pyrazinoic acid (POA) and PZA resistance is caused by loss-of-function mutations to pyrazinamidase. We have recently shown that POA induces targeted protein degradation of the enzyme PanD, a crucial component of the coenzyme A biosynthetic pathway essential in Mtb. Based on the newly identified mechanism of action of POA, along with the crystal structure of PanD bound to POA, we designed several POA analogs using structure for interpretation to improve potency and overcome PZA resistance. We prepared and tested ring and carboxylic acid bioisosteres as well as 3, 5, 6 substitutions on the ring to study the structure activity relationships of the POA scaffold. All the analogs were evaluated for their whole cell antimycobacterial activity, and a few representative molecules were evaluated for their binding affinity, towards PanD, through isothermal titration calorimetry. We report that analogs with ring and carboxylic acid bioisosteres did not significantly enhance the antimicrobial activity, whereas the alkylamino-group substitutions at the 3 and 5 position of POA were found to be up to 5 to 10-fold more potent than POA. Further development and mechanistic analysis of these analogs may lead to a next generation POA analog for treating TB.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Pirazinamida/farmacologia , Pirazinamida/metabolismo , Antituberculosos/farmacologia , Antituberculosos/metabolismo , Amidoidrolases/metabolismo , Tuberculose/microbiologia , Mutação , Relação Estrutura-Atividade , Ácidos Carboxílicos/metabolismo , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana
8.
Semin Immunol ; 39: 22-29, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30366662

RESUMO

Lipopolysaccharide (LPS) is a well-defined agonist of Toll-like receptor (TLR) 4 that activates innate immune responses and influences the development of the adaptive response during infection with Gram-negative bacteria. Many years ago, Dr. Edgar Ribi separated the adjuvant activity of LPS from its toxic effects, an effort that led to the development of monophosphoryl lipid A (MPL). MPL, derived from Salmonella minnesota R595, has progressed through clinical development and is now used in various product-enabling formulations to support the generation of antigen-specific responses in several commercial and preclinical vaccines. We have generated several synthetic lipid A molecules, foremost glucopyranosyl lipid adjuvant (GLA) and second-generation lipid adjuvant (SLA), and have advanced these to clinical trial for various indications. In this review we summarize the potential and current positioning of TLR4-based adjuvant formulations in approved and emerging vaccines.


Assuntos
Adjuvantes Imunológicos/farmacologia , Compostos de Alúmen/farmacologia , Glucosídeos/farmacologia , Imunogenicidade da Vacina , Lipídeo A/análogos & derivados , Tuberculose/prevenção & controle , Adjuvantes Imunológicos/química , Compostos de Alúmen/química , Animais , Glucosídeos/química , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Leishmaniose/imunologia , Leishmaniose/parasitologia , Leishmaniose/prevenção & controle , Hanseníase/imunologia , Hanseníase/parasitologia , Hanseníase/prevenção & controle , Lipídeo A/química , Lipídeo A/farmacologia , Lipossomos/administração & dosagem , Lipossomos/química , Lipossomos/imunologia , Malária/imunologia , Malária/parasitologia , Malária/prevenção & controle , Camundongos , Esquistossomose/imunologia , Esquistossomose/parasitologia , Esquistossomose/prevenção & controle , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/microbiologia , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Tuberculose/imunologia , Tuberculose/microbiologia , Vacinas/administração & dosagem , Vacinas/química , Vacinas/imunologia
9.
Proc Natl Acad Sci U S A ; 116(35): 17207-17212, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31405980

RESUMO

It has been hypothesized that the overall size of-or efficiency of carbon export from-the biosphere decreased at the end of the Great Oxidation Event (GOE) (ca. 2,400 to 2,050 Ma). However, the timing, tempo, and trigger for this decrease remain poorly constrained. Here we test this hypothesis by studying the isotope geochemistry of sulfate minerals from the Belcher Group, in subarctic Canada. Using insights from sulfur and barium isotope measurements, combined with radiometric ages from bracketing strata, we infer that the sulfate minerals studied here record ambient sulfate in the immediate aftermath of the GOE (ca. 2,018 Ma). These sulfate minerals captured negative triple-oxygen isotope anomalies as low as ∼ -0.8‰. Such negative values occurring shortly after the GOE require a rapid reduction in primary productivity of >80%, although even larger reductions are plausible. Given that these data imply a collapse in primary productivity rather than export efficiency, the trigger for this shift in the Earth system must reflect a change in the availability of nutrients, such as phosphorus. Cumulatively, these data highlight that Earth's GOE is a tale of feast and famine: A geologically unprecedented reduction in the size of the biosphere occurred across the end-GOE transition.

10.
Arch Gynecol Obstet ; 305(2): 439-447, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34392396

RESUMO

OBJECTIVE: To validate our previous findings of high-level EGFR expression in GCCC using an expanded cohort of specimens and to further examine the molecular and cellular features of this aggressive malignancy to identify potentially actionable therapeutic targets. METHODS: The SEER database was queried to obtain the epidemiological data regarding the current national survival trends for GCCC. Immunohistochemistry (IHC) was used to examine the expression of EGFR, PD-1, and PD-L1. CiberSort analysis was used to analyze a previously published RNA-sequencing dataset obtained from a single patient diagnosed with GCCC. RESULTS: In comparison to squamous cell carcinomas and adenocarcinoma/adenosquamous carcinomas, GCCC was observed in younger patients (p < 0.001) and demonstrated inferior survival (p < 0.001). All (100%) of the specimens (8/8) exhibited immunoreactivity when stained for CD3ε (T-cell marker), EGFR, PD-1, and PD-L1 whereas CTLA4 expression was not detected. Analysis of RNA-sequencing data revealed that cetuximab and erlotinib altered the chemokine profile, lymphocyte abundance, and expression of inhibitory immune checkpoints in a single patient when combined with cytotoxic chemotherapy in a single patient. CONCLUSIONS: The data from this descriptive study suggests that immune checkpoint blockade, whether single agent or in combination, may be a suitable therapeutic option for a disease for which targeted approaches do not currently exist.


Assuntos
Carcinoma Adenoescamoso , Carcinoma de Células Escamosas , Neoplasias do Colo do Útero , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/patologia , Colo do Útero/patologia , Feminino , Humanos , Neoplasias do Colo do Útero/patologia
11.
Curr Top Microbiol Immunol ; 428: 103-127, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30043342

RESUMO

Developing new vaccines against emerging pathogens or pathogens where variability of antigenic sites presents a challenge, the inclusion of stimulators of the innate immune system is critical to mature the immune response in a way that allows high avidity recognition while preserving the ability to react to drifted serovars. The innate immune system is an ancient mechanism for recognition of nonself and the first line of defense against pathogen insult. By triggering innate receptors, adjuvants can boost responses to vaccines and enhance the quality and magnitude of the resulting immune response. This chapter: (1) describes the innate immune system, (2) provides examples of how adjuvants are formulated to optimize their effectiveness, and (3) presents examples of how adjuvants can improve outcomes of immunization.


Assuntos
Adjuvantes Imunológicos , Vacinas/imunologia , Humanos , Vacinação , Vacinologia
12.
Parasite Immunol ; 43(4): e12814, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33351204

RESUMO

AIMS: Despite immunization appearing to be the most appropriate strategy for long-term control of the vector-borne leishmaniases, no sustainable vaccine is currently available against any form of leishmaniasis. We therefore evaluated, in the context of vaccine antigen candidates, antigen-specific immune response at various stages of cutaneous leishmaniasis (CL). METHODS AND RESULTS: Peripheral blood mononuclear cells (PBMC) isolated from healthy volunteers and CL patients (caused by either Leishmania major or L tropica) were incubated with crude Leishmania proteins (soluble Leishmania antigen; SLA), single recombinant proteins (TSA, LeIF, LmSTI1) or chimeric fusion proteins (LEISH-F2 and LEISH-F3). The concentrations of immune modulatory cytokines were then determined. While we did not detect appreciable antigen-specific IL-5 secretion, SLA induced secretion of interleukin (IL)-10 in cultures from early active lesion CL patients and even from healthy individuals. Conversely, interferon (IFN)-γ responses to SLA and recombinant proteins followed a similar pattern, developing only in the late active CL lesion phase. Once established, antigen-specific IFN-γ responses persisted in cured CL patients. CONCLUSION: Together, our results provide further insight into the development of immune responses during CL and further validate the selection of LEISH-F2 and LEISH-F3 as vaccine antigen candidates.


Assuntos
Antígenos de Protozoários/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/prevenção & controle , Leucócitos Mononucleares , Proteínas de Protozoários/imunologia , Citocinas/imunologia , Humanos , Interferon gama
13.
Prev Med ; 147: 106483, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33640399

RESUMO

The objective of this study is to provide an assessment of allostatic load (AL) burden among US adults across race/ethnicity, gender, and age groups over a 30-year time period. We analyzed data from 50,671 participants of the National Health and Nutrition Examination Survey (NHANES) years 1988 through 2018. AL score was defined as the sum total for abnormal measures of the following components: serum albumin, body mass index, serum C - reactive protein, serum creatinine, diastolic blood pressure, glycated hemoglobin, systolic blood pressure, total cholesterol, and serum triglycerides. We performed modified Poisson regression to estimate the adjusted Relative Risks (aRRs) of allostatic load, and generalized linear models to determine adjusted mean differences accounting for NHANES sampling weights. Among US adults aged 18 or older, the prevalence of high AL increased by more than 45% from 1988 to 1991 to 2015-2018, from 33.5% to 48.6%. By the latest period, 2015-2018, Non-Hispanic Black women (aRR: 1.292; 95% CI: 1.290-1.293) and Latina women (aRR: 1.266; 95% CI: 1.265-1.267) had higher risks of AL than non-Hispanic White women. Similar trends were observed among men. Age-adjusted mean AL score among NH-Black and Latinx adults was higher than for NH-Whites of up to a decade older regardless of gender. From 1988 through 2018, Adults aged 40 years old and older had over 2-fold increased risks of high AL when compared to adults 18-29 years old. After 30-years of collective data, racial disparities in allostatic load persist for NH-Black and Latinx adults.


Assuntos
Alostase , Adolescente , Adulto , Negro ou Afro-Americano , Etnicidade , Feminino , Hispânico ou Latino , Humanos , Masculino , Inquéritos Nutricionais , Estados Unidos , Adulto Jovem
14.
Appl Microbiol Biotechnol ; 105(2): 503-508, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33394146

RESUMO

Immunological and molecular advances have modernized diagnostic testing for many diseases. Although interferon gamma-release and polymerase chain reaction assays have been developed to detect Mycobacterium tuberculosis (Mtb) infection, purified protein derivative (PPD)-based tuberculin skin testing (TST) remains the most widely used method. Indeed, the TST is a simple and cost-effective tool that can be easily applied for widespread screening for Mtb infection. However, the lack of specificity has been a limitation of these tests, and, more recently, supply issues have arisen. Building upon the skin tests that historically have been used within TB and leprosy control programs, we discuss recent developments using modern technologies for improving mycobacterial skin testing as well as practical advantages inherent to the technique. Furthermore, we outline how this knowledge could be applied to develop similar tests that could benefit diagnostic strategies for other infections. KEY POINTS: • Skin testing provides a significantly cheaper alternative to most modern technologies. • Skin tests provide a lab-independent diagnostic strategy that can be widely administered. • Diseases for which T cell responses are more robust or durable than antibody responses are accessible for skin testing.


Assuntos
Mycobacterium tuberculosis , Teste Tuberculínico , Interferon gama , Programas de Rastreamento , Linfócitos T
15.
Folia Primatol (Basel) ; 92(1): 1-11, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33291109

RESUMO

Madagascar is home to many threatened and endemic primate species, yet this island has seen dramatic declines in lemur habitat due to forest loss. This forest loss has resulted in an increasingly fragmented forest landscape, with fragments isolated from each other by grasslands (i.e., matrix). The grassland matrix is not entirely homogeneous containing matrix elements such as isolated trees and shrubs and linear features such as drainage lines. Because most lemurs are predominantly arboreal, they may preferentially use matrix elements to facilitate dispersal between fragments for access to mates or reduce feeding competition, allowing gene flow between fragments of habitat. Therefore, it is important to understand to what degree they use the matrix. We investigated matrix use in two mouse lemurs, the grey mouse lemur (Microcebus murinus) and the golden-brown mouse lemur (Microcebus ravelobensis) in a fragmented landscape in northwest Madagascar. We tested the predictions that: (1) lemurs use matrix less often than forest fragments, (2) if they use the matrix, then they will preferentially use matrix elements compared to grassland, and (3) M. murinus will disperse into the matrix further than M. ravelobensis. In 2011, we visually surveyed line transects in four areas containing matrix elements and four adjacent forest fragments during nocturnal walks. In 2017, we set up traplines in four areas of the matrix containing matrix elements, three areas that were grassland, and six traplines in adjacent fragments. We compared the relative abundance of mouse lemurs in matrix transects to fragmented forest transects, and the relative abundance of captured lemurs in matrix elements, grassland, and fragment traplines. We found that encounter rates of mouse lemurs did not significantly differ between the matrix and fragmented forest transects or traplines. Our sample size was too low to determine if the mean distance from the forest was greater for either Microcebus spp. Our study highlights that mouse lemurs do use matrix elements and there may be interspecific differences in use. Further research is needed to confirm species-specific matrix use, why mouse lemurs use matrix, and how much matrix elements facilitate movement for each species in fragmented landscapes.


Assuntos
Cheirogaleidae/fisiologia , Ecossistema , Animais , Comportamento Animal , Florestas , Pradaria , Madagáscar
16.
Br J Cancer ; 122(6): 749-758, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31932755

RESUMO

BACKGROUND: We evaluated oncological changes in patients with squamous cell carcinoma of the anus (SCCA) treated by chemoradiotherapy (CRT) from a large UK institute, to derive estimates of contemporary outcomes. METHODS: We performed a treatment-cohort analysis in 560 patients with non-metastatic SCCA treated with CRT over 25 years. The primary outcomes were 3-year loco-regional failure (LRF), 5-year overall survival (OS), and 5-year cancer-specific survival (CSS). We developed prediction models; and overlaid estimates on published results from historic trials. RESULTS: Age distributions, proportions by gender and cT stage remained stable over time. The median follow-up was 61 (IQR: 36-79) months. Comparing the first period (1990-1994) with the last period (2010-2014), 3-year LRF declined from 33 to 16% (Ptrends < 0.001); 5-year OS increased from 60% to 76% (Ptrends = 0.001); and 5-year CCS increased from 62% in to 80% (Ptrends = 0.001). For 2020, the models predicted a 3-year LRF of 14.7% (95% CIs: 0-31.3); 5-year OS of 74.7% (95% CIs: 54.6-94.9); and 5-year CSS of 85.7% (95% CIs: 75.3-96.0). Reported oncological outcomes from historic trials generally underestimated contemporary outcomes. CONCLUSIONS: Current and predicted rates for 3-year LRF and 5-year survivals are considerably improved compared with those in historic trials.


Assuntos
Neoplasias do Ânus/tratamento farmacológico , Neoplasias do Ânus/radioterapia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias do Ânus/mortalidade , Carcinoma de Células Escamosas/mortalidade , Estudos de Coortes , Feminino , Humanos , Masculino , Estudos Prospectivos , Análise de Sobrevida , Resultado do Tratamento
17.
Glob Chang Biol ; 26(10): 5574-5587, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32506810

RESUMO

Continental margins are disproportionally important for global primary production, fisheries and CO2 uptake. However, across the Northeast Atlantic shelves, there has been an ongoing summertime decline of key biota-large diatoms, dinoflagellates and copepods-that traditionally fuel higher tropic levels such as fish, sea birds and marine mammals. Here, we combine multiple time series with in situ process studies to link these declines to summer nutrient stress and increasing proportions of picophytoplankton that can comprise up to 90% of the combined pico- and nanophytoplankton biomass in coastal areas. Among the pico-fraction, it is the cyanobacterium Synechococcus that flourishes when iron and nitrogen resupply to surface waters are diminished. Our field data show how traits beyond small size give Synechococcus a competitive edge over pico- and nanoeukaryotes. Key is their ability to grow at low irradiances near the nutricline, which is aided by their superior light-harvesting system and high affinity to iron. However, minute size and lack of essential biomolecules (e.g. omega-3 polyunsaturated fatty acids and sterols) render Synechococcus poor primary producers to sustain shelf sea food webs efficiently. The combination of earlier spring blooms and lower summer food quantity and quality creates an increasing period of suboptimal feeding conditions for zooplankton at a time of year when their metabolic demand is highest. We suggest that this nutrition-related mismatch has contributed to the widespread, ~50% decline in summer copepod abundance we observe over the last 60 years. With Synechococcus clades being prominent from the tropics to the Arctic and their abundances increasing worldwide, our study informs projections of future food web dynamics in coastal and shelf areas where droughts and stratification lead to increasing nutrient starvation of surface waters.


Assuntos
Diatomáceas , Cadeia Alimentar , Animais , Regiões Árticas , Biomassa , Zooplâncton
18.
J Immunol ; 201(11): 3383-3391, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30348734

RESUMO

Toll-like receptor 4 plays an important role in the regulation of the innate and adaptive immune response. The majority of TLR4 activators currently in clinical use are derivatives of its prototypic ligand LPS. The discovery of innovative TLR4 activators has the potential of providing new therapeutic immunomodulators and adjuvants. We used computational design methods to predict and optimize a total of 53 cyclic and linear peptides targeting myeloid differentiation 2 (MD2) and cluster of differentiation 14 (CD14), both coreceptors of human TLR4. Activity of the designed peptides was first assessed using NF-κB reporter cell lines expressing either TLR4/MD2 or TLR4/CD14 receptors, then binding to CD14 and MD2 confirmed and quantified using MicroScale Thermophoresis. Finally, we incubated select peptides in human whole blood and observed their ability to induce cytokine production, either alone or in synergy with LPS. Our data demonstrate the advantage of computational design for the discovery of new TLR4 peptide activators with little structural resemblance to known ligands and indicate an efficient strategy with which to identify TLR4 targeting peptides that could be used as easy-to-produce alternatives to LPS-derived molecules in a variety of settings.


Assuntos
Anticorpos Biespecíficos/genética , Sítios de Ligação de Anticorpos/genética , Receptores de Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/imunologia , Receptor 4 Toll-Like/agonistas , Anticorpos Biespecíficos/metabolismo , Células Cultivadas , Biologia Computacional , Humanos , Ligantes , Estrutura Molecular , NF-kappa B/metabolismo , Ligação Proteica , Conformação Proteica , Engenharia de Proteínas , Transdução de Sinais
19.
Surg Endosc ; 34(12): 5516-5521, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31993814

RESUMO

INTRODUCTION: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an established treatment for pseudomyxoma peritonei (PMP) from perforated low-grade appendiceal mucinous neoplasms (LAMN II). In a selected group of LAMN II patients without established PMP, CRS/HIPEC can be performed laparoscopically (L-CRS/HIPEC); however the short-term benefits and safety of this approach have yet to be determined. This study aims to determine the short-term outcomes from a series of L-CRS/HIPEC LAMN II patients compared to those who have undergone a similar open operation (O-CRS/HIPEC) for low-volume PMP. METHODS: LAMN II patients undergoing L-CRS/HIPEC at a UK national peritoneal tumour centre were compared to O-CRS/HIPEC patients (peritoneal cancer index ≤ 7). Outcomes of interest included Clavien-Dindo complication grade, operative time, blood transfusions, high dependency unit (HDU) admission, length of hospital stay, and histopathological findings. RESULTS: 55 L-CRS/HIPEC were compared to 29 O-CRS/HIPEC patients (2003-2017). Groups were matched for age, sex, and procedures. Median operative time was 8.8 (IQR 8.1-9.5) h for L-CRS/HIPEC versus 7.3 (IQR 6.7-8) h for O-CRS/HIPEC (Mann-Whitney test p < 0.001). Post-operative HDU admission was 56% versus 97% (OR 0.04 95% CI 0.01-0.34) and median length of stay = 6 (IQR 5-8) versus 10 (IQR 8-11) days (p < 0.001) for L- versus O-CRS/HIPEC. Despite a normal pre-operative CT scan, 13/55 (23.6%) L-CRS/HIPEC patients had acellular mucin and 2/55 (3.5%) had mucin with epithelium present in their specimens. Residual appendix tumour was identified in 2/55 patients (3.6%). Clavien-Dindo Grade 1-4 complications were similar in both groups with no mortality. CONCLUSION: L-CRS/HIPEC for LAMN II takes longer; however patients have significantly reduced length of HDU and overall stay, without increased post-operative complications. A significant proportion of LAMN II patients undergoing L-CRS/HIPEC have extra-appendiceal acellular mucin with some cases demonstrating residual cellular epithelium from the LAMN II. The risk of these patients developing PMP without surgery is under current review.


Assuntos
Neoplasias do Apêndice/cirurgia , Procedimentos Cirúrgicos de Citorredução/métodos , Quimioterapia Intraperitoneal Hipertérmica/métodos , Laparoscopia/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
20.
Appl Microbiol Biotechnol ; 104(9): 3971-3979, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32157423

RESUMO

The persistence of new leprosy cases in endemic areas such as India, Brazil, Bangladesh, and the Philippines has encouraged studies of chemoprophylaxis among contacts of patients. Epidemiological screening tools to enable early detection of infected individuals in endemic populations would be critical to target individuals most in need of intervention. Despite decades of attempts, however, there still are no tests available for the early detection of low-level infection with Mycobacterium leprae. In this report, we describe the development of a leprosy skin test using M. leprae-specific antigens. We selected the chimeric LID-1 fusion protein, formulated to achieve maximum performance at a minimal dose, as a skin test candidate based on its ability to elicit delayed-type hypersensitivity (DTH) reactions in M. leprae immune guinea pigs in a sensitive and specific manner, i.e., with no cross-reactivity observed with other mycobacterial species. Importantly, evaluations in armadillos indicated that intradermal inoculation of formulated LID-1 could distinguish uninfected from M. leprae-infected animals manifesting with symptoms distinctly similar to the PB presentation of patients. Together, our data provide strong proof-of-concept for developing an antigen-specific skin test to detect low-level M. leprae infection. Such a test could, when applied with appropriate use of chemo- and/or immunoprophylaxis, be instrumental in altering the evolution of clinical disease and M. leprae transmission, thus furthering the objective of zero leprosy.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Hipersensibilidade Tardia , Hanseníase Paucibacilar/diagnóstico , Testes Cutâneos/métodos , Animais , Antígenos de Bactérias/farmacologia , Tatus , Proteínas de Bactérias/farmacologia , Diagnóstico Precoce , Feminino , Cobaias , Injeções Intradérmicas , Hanseníase Paucibacilar/imunologia , Mycobacterium leprae , Estudo de Prova de Conceito , Pele/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA