Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 527
Filtrar
1.
Expert Rev Hematol ; 17(7): 361-374, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38841813

RESUMO

INTRODUCTION: Comprehensive information about atypical hemolytic uremic syndrome (aHUS) is relatively scarce outside of Europe and North America. This narrative review assembles available published data about the clinical presentation and management of aHUS in Latin America. AREAS COVERED: A search conducted in February 2023 of the MEDLINE (from inception), Embase (from inception), and LILACS/IBECS (1950 to 2023) databases using search terms 'atypical hemolytic uremic syndrome' and 'Latin America' and their variations retrieved 51 records (full papers and conference abstracts) published in English, Spanish, or Portuguese. After de-duplication, manual screening of titles/abstracts and addition of author-known articles, 25 articles were included of which 17 (68%) are full papers. All articles were published during the years 2013-2022. Articles include cohort studies, a registry analysis, and case reports from Argentina, Brazil, Chile and Columbia. Overall, Latin American patients with aHUS present the classic epidemiological, clinical, and genetic characteristics associated with this condition as described in other world regions. Depending on the country and time of reporting, aHUS in Latin America was treated mainly with plasma therapy and/or eculizumab. Where reported, eculizumab substantially improved aHUS-related outcomes in almost all adult and pediatric patients. EXPERT OPINION: Eculizumab has dramatically altered the natural course of aHUS, improving prognosis and patient outcomes. Addressing economic challenges and investing in healthcare infrastructure will be essential to implement strategies for timely detection and early treatment of aHUS in Latin America.


Assuntos
Síndrome Hemolítico-Urêmica Atípica , Gerenciamento Clínico , Humanos , América Latina/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/terapia , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Anticorpos Monoclonais Humanizados/uso terapêutico
2.
J Psychiatr Res ; 173: 151-156, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38531145

RESUMO

Treatment response is hard to predict and detailed mechanisms unknown. Lower levels of the dehydroepiandrosterone sulphate (DHEA(S)) - a precursor to testosterone and estrogen - have been associated to depression and to response to antidepressant treatment. Previous studies however may have been ridden by confounding and reverse causation. The aim of this study is to evaluate whether higher levels of DHEA(S) are causally linked to response to antidepressants using mendelian randomization (MR). We performed a Two-sample MR analysis using data the largest publicly available GWAS of DHEA(S) levels (n = 14,846) using eight common genetic variants associated to DHEA(S) (seven single nucleotide polymorphisms and one variant rs2497306) and the largest GWAS of antidepressant response (n = 5218) using various MR methods (IVW, MR Egger, Weighted mean, weighted mode, MR-PRESSO) and single SNP analysis. We further investigated for pleiotropy conducting a look up on PhenoScanner and GWAS Catalog. Results show no evidence for DHEA(S) gene risk score from any of MR methods, however, we found a significant association on individual variant analysis for rs11761538, rs17277546, and rs2497306. There was some evidence for heterogeneity and pleiotropy. This is the first paper to show some evidence for a causal association of genetically-predicted DHEA and improvement of depressive symptoms. The effect is not a simple linear effect, and we were unable to dissect whether the effect was direct effect of DHEA(S), mediated by DHEA(S) or on the pathway is not yet clear. Further studies using more refined instrumental variables will help clarify this association.


Assuntos
Antidepressivos , Análise da Randomização Mendeliana , Humanos , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Estratificação de Risco Genético , Polimorfismo de Nucleotídeo Único/genética , Desidroepiandrosterona , Estudo de Associação Genômica Ampla
3.
Braz J Med Biol Res ; 56: e12781, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37878883

RESUMO

Treatments that attenuate the effects of hypoestrogenism in menopausal women have been gaining visibility. This study investigated the skin response to a phytoestrogen-enriched cosmetic formulation created by incorporating a biotransformed soybean extract (BE) into a cream-like matrix. Collagen-I expression was analyzed both in vitro (fibroblast cells) and ex vivo (skin explants). The results revealed an increased amount of collagen-I both in fibroblasts and human skin when treated with BE and BE-incorporated cream. Also, this collagen-I overexpression was inhibited by PHTPP, indicating a dependence on estrogen hormone receptor beta (ERß) signaling. Moreover, BE was not harmful to skin microbiota, showing a promising nutricosmetic potential. Thus, this work presented a fully functional cream-like formulation that was shown to be safe and effectively increase collagen-I levels both in vitro and ex vivo.


Assuntos
Colágeno , Glycine max , Feminino , Humanos , Glycine max/metabolismo , Colágeno/metabolismo , Pele/metabolismo , Higiene da Pele , Suplementos Nutricionais , Fibroblastos
4.
Braz J Med Biol Res ; 56: e12636, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37493768

RESUMO

The indirect immunofluorescence (IIF) technique for antineutrophil cytoplasmic antibodies (ANCA) detection is subject to substantial differences across laboratories. This study aimed to assess the impact of improvements in the IIF-ANCA technique on the positivity rate of ANCA tests. A cross-sectional study was performed with serum samples from patients with ANCA-associated vasculitis (AAV), autoimmune hepatitis (AIH), and ulcerative colitis (UC). A paired analysis was performed for IIF-ANCA results using the traditional method and a modified protocol after a series of specific adjustments in the technique based on the protocol of IIF-ANCA test performed at a nation-wide private laboratory in Brazil. ANCA specificity was assessed by ELISA for anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) antibodies. Sixty-one patients were evaluated. The positivity rate of IIF-ANCA tests at disease presentation performed at the University reference laboratory was 32.3% in AAV, AIH, and UC patients, whereas the positivity rates of IIF-ANCA and ELISA tests in other laboratories were 75.0 and 72.7%, respectively. After modifications in the IIF-ANCA technique, there was a significant increase in the positivity rate (14.8 vs 34.3%; P=0.0002) and in median titers [1/40 (1/30-1/160) vs 1/80 (1/40-1/80); P=0.0003] in AAV, AIH, and UC patients. UC had the highest increment in positive results from 5.3 to 36.8%. There was poor agreement between MPO- or PR3-ANCA and both IIF-ANCA techniques. In conclusion, modifications in the IIF-ANCA protocol led to a significant improvement in its positivity rate and titers.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos , Peroxidase , Humanos , Técnica Indireta de Fluorescência para Anticorpo , Estudos Transversais , Mieloblastina , Ensaio de Imunoadsorção Enzimática
5.
Med Oral Patol Oral Cir Bucal ; 28(1): e1-e8, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36565219

RESUMO

BACKGROUND: Oral cancer (OC) is a growing public health problem worldwide. In Brazil, the National Oral Health Policy, implemented in 2004, expanded access to oral health services and prioritized OC care. However, it is not known whether this expansion resulted in a reduction in hospital admissions with death. This study aimed to analyze the proportion of hospital admissions who progressed to death due to OC in Brazil from 2007 to 2019 and its correlation with the coverage of health services. MATERIAL AND METHODS: This study is an ecological, longitudinal, and analytical study of hospital admissions with death due to OC recorded in the Brazilian Hospital Information System. The following analyses were performed: descriptive, spatial (choropleth maps and Moran index), and negative binomial regression, with a hierarchical approach, estimating crude and adjusted regression coefficients (ß) and respective 95% confidence intervals (95% CI) (alpha=5%). RESULTS: In 2019, Moran's index (I) of spatial autocorrelation showed a negative association between hospital admissions with death and dentist surgeon/inhabitant rate (I=-0.176), physician/inhabitant rate (I=-0.157), family health strategy (FHS) coverage (I=-0.080), oral health team (OHT) coverage (I= -0.129), dental specialty centers (DSC)/inhabitant rate (I= -0.200), and oncology bed/inhabitant rate (I= -0.101). In the adjusted regression analysis, the proportion of hospitalizations with deaths caused by OC was higher in Brazilian states with a lower medical ̸inhabitant ratio (ß= -0.014; p=0.040), a lower dentists/inhabitant ratio (ß= -0.720; p=0.045), a lower number of DSC (ß= -0.004; p<0.000), a lower amount paid per hospitalization (ß= -10.350; p<0.001), and a lower number of biopsies (ß= -0.00008; p=0.010). The proportion of hospitalizations that progressed to death showed a positive association with the number of days of hospitalization (ß= 0.00002; p=0.002). CONCLUSIONS: Increased health care coverage has decreased serious hospital admissions with deaths caused by OC in Brazil.


Assuntos
Hospitalização , Neoplasias Bucais , Humanos , Brasil/epidemiologia , Atenção à Saúde , Instalações de Saúde , Neoplasias Bucais/mortalidade , Neoplasias Bucais/terapia , Análise Espaço-Temporal , Estudos Longitudinais
6.
Braz. j. med. biol. res ; 56: e12781, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1520480

RESUMO

Treatments that attenuate the effects of hypoestrogenism in menopausal women have been gaining visibility. This study investigated the skin response to a phytoestrogen-enriched cosmetic formulation created by incorporating a biotransformed soybean extract (BE) into a cream-like matrix. Collagen-I expression was analyzed both in vitro (fibroblast cells) and ex vivo (skin explants). The results revealed an increased amount of collagen-I both in fibroblasts and human skin when treated with BE and BE-incorporated cream. Also, this collagen-I overexpression was inhibited by PHTPP, indicating a dependence on estrogen hormone receptor beta (ERβ) signaling. Moreover, BE was not harmful to skin microbiota, showing a promising nutricosmetic potential. Thus, this work presented a fully functional cream-like formulation that was shown to be safe and effectively increase collagen-I levels both in vitro and ex vivo.

7.
Braz. j. med. biol. res ; 56: e12636, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1447692

RESUMO

The indirect immunofluorescence (IIF) technique for antineutrophil cytoplasmic antibodies (ANCA) detection is subject to substantial differences across laboratories. This study aimed to assess the impact of improvements in the IIF-ANCA technique on the positivity rate of ANCA tests. A cross-sectional study was performed with serum samples from patients with ANCA-associated vasculitis (AAV), autoimmune hepatitis (AIH), and ulcerative colitis (UC). A paired analysis was performed for IIF-ANCA results using the traditional method and a modified protocol after a series of specific adjustments in the technique based on the protocol of IIF-ANCA test performed at a nation-wide private laboratory in Brazil. ANCA specificity was assessed by ELISA for anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) antibodies. Sixty-one patients were evaluated. The positivity rate of IIF-ANCA tests at disease presentation performed at the University reference laboratory was 32.3% in AAV, AIH, and UC patients, whereas the positivity rates of IIF-ANCA and ELISA tests in other laboratories were 75.0 and 72.7%, respectively. After modifications in the IIF-ANCA technique, there was a significant increase in the positivity rate (14.8 vs 34.3%; P=0.0002) and in median titers [1/40 (1/30-1/160) vs 1/80 (1/40-1/80); P=0.0003] in AAV, AIH, and UC patients. UC had the highest increment in positive results from 5.3 to 36.8%. There was poor agreement between MPO- or PR3-ANCA and both IIF-ANCA techniques. In conclusion, modifications in the IIF-ANCA protocol led to a significant improvement in its positivity rate and titers.

10.
J Photochem Photobiol B ; 227: 112379, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34998114

RESUMO

In this work the thermal diffusivity (D) of Astyanax lacustris fish scale is investigated aiming to use it for environmental integrity certification. The D values were obtained by a relatively simple procedure by a photoacoustic method. The chosen fish species is from wide occurrence in Brasil's basins. It has short migration, and it has also been used as environmental bioindicator. The results obtained in 195 scales sampled from three different streams in the Midwest region in Brazil gives an average value of D ~ 4 × 10-3 cm2/s. ANCOVA analysis demonstrated that D values are able to differentiate among the three basins and indicates that it is dependent on the scales thickness and water conductivity. This last one is strongly affected by biotic and abiotic actions, so that D values measured by photoacoustic method can be used for interpreting the environmental integrity from where the fishes were sampled.


Assuntos
Monitoramento Ambiental , Peixes , Animais , Brasil , Ecossistema , Monitoramento Ambiental/métodos , Análise Espectral
13.
Ultrasound Obstet Gynecol ; 59(2): 202-208, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34664753

RESUMO

OBJECTIVE: In addition to the lungs, the placenta and the endothelium can be affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are markers of endothelial dysfunction and could potentially serve as predictors of severe coronavirus disease 2019 (COVID-19). We aimed to investigate the association of serum concentrations of sFlt-1 and PlGF with the severity of COVID-19 in pregnancy. METHODS: This was a prospective cohort study carried out in a tertiary care hospital in Mexico City, Mexico. Symptomatic pregnant women with a positive reverse-transcription quantitative polymerase chain reaction test for SARS-CoV-2 infection who fulfilled the criteria for hospitalization were included. The primary outcome was severe pneumonia due to COVID-19. Secondary outcomes were intensive care unit (ICU) admission, viral sepsis and maternal death. sFlt-1 levels were expressed as multiples of the median (MoM). The association between sFlt-1 and each adverse outcome was explored by logistic regression analysis, adjusted for gestational age for outcomes occurring in more than five patients, and the predictive performance was assessed by receiver-operating-characteristics-curve analysis. RESULTS: Among 113 pregnant women with COVID-19, higher sFlt-1 MoM was associated with an increased probability of severe pneumonia (adjusted odds ratio (aOR), 1.817 (95% CI, 1.365-2.418)), ICU admission (aOR, 2.195 (95% CI, 1.582-3.047)), viral sepsis (aOR, 2.318 (95% CI, 1.407-3.820)) and maternal death (unadjusted OR, 5.504 (95% CI, 1.079-28.076)). At a 10% false-positive rate, sFlt-1 MoM had detection rates of 45.2%, 66.7%, 83.3% and 100% for severe COVID-19 pneumonia, ICU admission, viral sepsis and maternal death, respectively. PlGF values were similar between women with severe and those with non-severe COVID-19 pneumonia. CONCLUSION: sFlt-1 MoM is higher in pregnant women with severe COVID-19 and has the capability to predict serious adverse pregnancy events, such as severe pneumonia, ICU admission, viral sepsis and maternal death. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
COVID-19 , Unidades de Terapia Intensiva/estatística & dados numéricos , Pneumonia Viral , Complicações Infecciosas na Gravidez , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Adulto , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/terapia , Estudos de Coortes , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Idade Gestacional , Humanos , México/epidemiologia , Mortalidade , Placenta/metabolismo , Placenta/fisiopatologia , Fator de Crescimento Placentário/sangue , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/etiologia , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/terapia , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença
14.
Braz. j. biol ; 82: e234471, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1153460

RESUMO

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.


Assuntos
Esgotos , Bactérias/genética , Fenótipo , Brasil , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária
15.
Braz. j. biol ; 82: 1-6, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468419

RESUMO

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.


Assuntos
Enterococcus/patogenicidade , Esgotos/análise , Microbiologia da Água/normas , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Resistência Microbiana a Medicamentos , Staphylococcus aureus/patogenicidade
16.
Braz. j. biol ; 822022.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468606

RESUMO

Abstract High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Resumo Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.

17.
Plant Biol (Stuttg) ; 23(6): 981-991, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34532932

RESUMO

The coexistence of plant species in tropical rainforests is related to specific abiotic resources, varying according to the occurrence microhabitat of each species. Light quality is the main abiotic factor influencing germination of small seeds; however, studies often do not discriminate its effect from that of light irradiance. This study compared specific requirements for seed germination of ten small-seeded species, with restricted occurrence in only one of three contrasting microhabitats: forest understorey, edge of clearings and open areas. Laboratory experiments were carried out to test temperature regime (constant or fluctuating), light quality (R:FR) and light irradiance (PAR), which reproduce high and low conditions commonly found in the microhabitats. Seed germination of all species occurred between 20 and 30 °C, only seeds of open area species were able to germinate at 35 °C and no species required alternating temperatures to germinate. Irrespective of species and microhabitat, a decrease in the R:FR reduced the germination percentage; however, there were differences in the capacity to germinate at low R:FR. The values of R:FR50% were higher for open area and edge species (0.441-0.345) than for understorey species (0.181-0.109), with few exceptions. For all species and most of the tests, germination was not influenced by PAR. Light quality is the most important light signal for germination of small seeds; irradiance has little effect. Our results suggest two distinct patterns of germination for small-seeded species: open area and edge species are light-demanding and require high R:FR to germinate, while understorey species are shade-tolerant and germinate at low R:FR. These differences are responsible for distinct microhabitat occurrence and help to explain the coexistence of species in tropical forests.


Assuntos
Germinação , Sementes , Florestas , Temperatura
18.
Ann Oncol ; 32(8): 994-1004, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34219000

RESUMO

BACKGROUND: In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-bound-paclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumab-paclitaxel in aTNBC. PATIENTS AND METHODS: Eligible patients [no prior systemic therapy or ≥12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m2 (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression ≥1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint. RESULTS: Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P = 0.20; median PFS 6.0 months with atezolizumab-paclitaxel versus 5.7 months with placebo-paclitaxel]. In the PD-L1-positive population, atezolizumab-paclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placebo-paclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumab-paclitaxel versus 28.3 months with placebo-paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug. CONCLUSION: Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. CLINICALTRIALS.GOV: NCT03125902.


Assuntos
Neoplasias de Mama Triplo Negativas , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Humanos , Paclitaxel/uso terapêutico , Intervalo Livre de Progressão , Neoplasias de Mama Triplo Negativas/tratamento farmacológico
19.
Plant Biol (Stuttg) ; 23(5): 735-742, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33884724

RESUMO

To mitigate anthropogenic impacts on plant diversity in tropical montane grasslands, one of the most threatened ecosystems in Brazil, it will be essential to develop ex situ conservation strategies to preserve wild species. The lack of basic research on the seed storage behaviour of grassland species may, however, limit their use for reintroduction and restoration projects. We investigated seed storage behaviour at the community level by comparing the effects of cold-low RH (10 °C; 10% RH) and freezing-low RH (20 °C; 10% RH) conditions on seed viability, germination and dormancy of 47 species. Fresh seeds of 43% of the species showed primary dormancy. More than half of the species showed high seed survival responses (viability >60%) under both storage temperatures. Despite a variety of dormancy responses among the different species, the low RH storage conditions tested released dormancy for most species during 12- and 30-month storage times. Multivariate analysis of the best (freezing-low RH, 30 months) storage condition evidenced the formation of five distinct groups, three with species having high conservation potential in seed banks. Although further studies are needed to test dormancy-breaking treatments and improve seed conservation practices, this first approach to assessing seed banking techniques could contribute to demand for locally adapted seeds for ecological restoration projects in tropical montane grasslands.


Assuntos
Germinação , Dormência de Plantas , Brasil , Ecossistema , Pradaria , Sementes , Temperatura
20.
Braz J Biol ; 82: e234471, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33681897

RESUMO

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Assuntos
Bactérias , Esgotos , Bactérias/genética , Brasil , Testes de Sensibilidade Microbiana , Fenótipo , Centros de Atenção Terciária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA