Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 401
Filtrar
1.
Theriogenology ; 221: 1-8, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38518659

RESUMO

The aim of the study was to determine the effect of carbetocin administration (a long-acting analog of oxytocin) 20 or 10 min before electroejaculation (EE) on the duration of semen collection procedure, quantitative and qualitative characteristics of the ejaculate, and stress biomarkers in rams. Semen was collected from 12 Corriedale rams (age, 2.5-5.5 years old) with EE, in a Latin-square design, administrating carbetocin (0.2 mg/100 kg of body weight i.v.) 20 or 10 min before EE, or without carbetocin administration (CB-20, CB-10, and CON treatments, respectively). Each treatment was applied to different rams every 3-4 days, allowing all the rams to receive all three treatments. Carbetocin administered 20 or 10 min before EE increased the number of sperm ejaculated (P = 0.01), the semen concentration (P = 0.02), the number of insemination doses collected in a single collection (P = 0.01), and the number of insemination doses collected/electrical pulses administered (P = 0.05) compared to control rams. Carbetocin administered 20 or 10 min before semen collection prolonged the time required for EE and the number of pulses administered during EE compared to CON rams (P < 0.03 for both). The CB-10 rams required the administration of more electrical pulses during ejaculation than CON rams (P = 0.001), and CB-20 treatment tended to require more electrical pulses than CON rams (P = 0.06). The volume of the ejaculate was greater in CB-10 than in CON rams (P = 0.01), and that of CB-20 treatment tended to be greater than CON rams (P = 0.08). The percentage of sperm with intact membrane was greater in CB-20 than in CON rams (P = 0.01). Total protein, albumin, and globulin concentrations were lower immediately after carbetocin administration 20 or 10 min before EE. The treatments did not affect cortisol concentration, glycemia, rectal and surface temperatures, heart rate, and facial expressions. Carbetocin administration before EE of rams improved the quantitative and qualitative characteristics of the ejaculate, duplicating the number of insemination doses collected. It can be a promising treatment to obtain a greater quantity of doses to inseminate with a lower frequency of semen collections, reducing the negative impacts of EE on animal welfare.


Assuntos
Ocitocina , Ocitocina/análogos & derivados , Sêmen , Masculino , Ovinos , Animais , Sêmen/fisiologia , Ocitocina/farmacologia , Carneiro Doméstico , Espermatozoides/fisiologia , Ejaculação/fisiologia , Inseminação
2.
Braz J Biol ; 83: e277329, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055508

RESUMO

West Indian cherry cultivation has proved to be an important economic activity in northeastern Brazil. However, irrigation with brackish waters limits cultivation, requiring new strategies to minimize the effect of salt stress. In this context, the present study aimed to evaluate the effect of nitrogen (N), phosphorus (P), and potassium (K) combinations on the photosynthetic pigments and quantum yield of West Indian cherry cultivated under salt stress, in the second year of production. The assay was conducted in a protected environment by adopting an experimental design in randomized blocks, with treatments distributed in a 2×10 factorial arrangement referring to two electrical conductivity levels of irrigation water - ECw (0.6 and 4.0 dS m-1) and 10 NPK fertilization combinations - FC (80-100-100; 100-100-100; 120-100-100; 140-100-100; 100-80-100; 100-120-100; 100-140-100; 100-100-80; 100-100-120, and 100-100-140% of the recommendation, in the second year of production), with three replications, each consisting of one plant. Irrigation with the electrical conductivity of 4.0 dS m-1 negatively affected the synthesis of photosynthetic pigments and the photochemical efficiency of the West Indian cherry cv. Flor Branca. The NPK combinations did not attenuate the effects of salt stress on the analyzed variables. However, the combinations referring to 120-100-100%, 140-100-100%, and 100-120-100% of NPK recommendation improved the quantum yield of photosystem II by reducing the initial fluorescence and increasing the maximum fluorescence of the West Indian cherry cv. Flor Branca.


Assuntos
Nitrogênio , Fotossíntese , Estresse Salino , Brasil
3.
J Mater Cycles Waste Manag ; : 1-17, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37360946

RESUMO

Construction and demolition waste (CDW) is an environmental problem that affects all regions of the world. Particularly in the Brazilian Amazon Forest region, the volume of CDW generated almost doubled between 2007 and 2019. Indeed, despite Brazil having environmental regulations for waste management, these have been insufficient to solve the environmental problem because there is no CDW reverse supply chain (RSC) properly developed in the Amazon region. Previous studies have proposed a conceptual model of a CDW RSC but have hitherto failed to apply them against real world practice. This paper, therefore, attempts to test existing conceptual models that describe a CDW RSC against real industry practice prior to developing an applied model of a CDW RSC for the Brazilian Amazon. To modify the conceptual model for CDW RSC, qualitative data through 15 semi-structured interviews with five different types of stakeholders of the Amazonian CDW RSC were collected and analyzed using qualitative content analysis methods using NVivo software. The proposed applied model includes present and future reverse logistics (RL) practices, and strategies and tasks necessary for the implementation of a CDW RSC in the city of Belém of Pará, in the Brazilian Amazon. Findings reveal that several overlooked problems, particularly the limitations of the existing legal framework in Brazil, are not enough to promote a robust CDW RSC. This is perhaps the first study to examine CDW RSC in the Amazonian rainforest. Arguments provided in this study highlight the necessity for an Amazonian CDW RSC that must be promoted and regulated by the government. This can be addressed by the utilizing public-private partnership (PPP) for developing a CDW RSC.

4.
Domest Anim Endocrinol ; 82: 106753, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36027631

RESUMO

High circulating progesterone concentrations decrease the responses to stressful situations in farm ruminants. We hypothesized that administering a single dose of long-acting progesterone formulation reduces the stress response of anestrous ewes to weaning. The aim of this study was to compare the behavioral, cortisol, and blood protein responses to weaning of anestrous ewes treated or not, with a single dose of a long-acting progesterone formulation. A complementary aim was to characterize the bioavailability of progesterone after this treatment. Thirty-six multiparous single-lambing Corriedale ewes and their lambs were used in this study. The lambs were weaned at 6:30 h when they were 65 d old (d0), and were taken to another paddock without chemical, visual or auditory contact with their mothers, while the ewes remained in the same paddock. Immediately before weaning, while 19 ewes received oil based long-acting progesterone formulation, other 17 ewes remained as controls, receiving sunflower oil. Twelve ewes from each group were used for behavioral recordings, the other 5 untreated ewes and 7 treated ewes were used to characterize the cortisol response and the progesterone profile. Behaviors were recorded every 10th min for 3 h in the morning and 3 h in the afternoon on day minus 3, d0 and d2, and expressed as percentage of recordings each animal displayed each behavior on each day. Treated ewes were recorded more times standing up than ewes on the day of weaning (P < 0.05), but the reverse result was found 2 d after (P < 0.01). Treated ewes were recorded more times lying down than control ewes on d2 after weaning (P < 0.0001), when treated ewes were observed fewer times walking than control ewes (P = 0.0004), as also happened the day of weaning (P < 0.0001). On the day of weaning, treated ewes grazed and paced less than control ewes (P = 0.001 and P = 0.009). Treated ewes ruminated more than control ewes on the day of weaning (P = 0.02) and 2 d later (P = 0.0002). Control ewes also secreted more cortisol than progesterone-treated ewes (P = 0.03), with no effect of the treatment on the concentration of total proteins, albumin or globulins. While control ewes never had luteal progesterone concentrations (>0.5 ng/mL), treated ewes achieved luteal progesterone concentrations 2 h after its administration, and remained well above luteal levels until 15 h after administration. The administration of a single dose of long-acting progesterone formulation appears to be a viable choice in reducing the stress to weaning in ewes. Ewes treated with progesterone coped better with weaning, returning to their normal basal behavior earlier than untreated ones, and secreting lower cortisol levels.


Assuntos
Hidrocortisona , Progesterona , Ovinos , Animais , Feminino , Desmame , Corpo Lúteo , Transporte Biológico
5.
Braz J Biol ; 84: e255836, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35507962

RESUMO

Improving plant germination is essential to guarantee better quality seedlings. Thus, this research aimed to evaluate whether the seed priming with light quality (LIQ) and the aqueous extract of Cyperus rotundus (AEC) tuber could modulate the germination and initial growth of Moringa oleifera L. seedlings. The experimental design was a completely randomized in the 4x4 factorial scheme, composed of four LIQ conditions (white, blue, red, and distant red light) and four AEC concentrations (0, 25, 50 and 100%). Seed priming with red light reduced the average emergence time, while blue, red, and extreme red lights associated with 50% of aqueous extract of C. rotundus increased shoot initial length and photosynthetic pigment accumulation. Seed priming with blue light resulted in seedlings with a shorter final shoot length. However, application of 100% of aqueous extract of C. rotundus reversed this. The white light in combination with concentrations of 50 and 100% of AEC promoted a higher relative shoot growth rate of seedlings. The research revealed that seed priming with light quality and aqueous extracts of C. rotundus tubers modulates the germination and initial growth of M. oleifera seedlings. More work needs to be done to determine the responsible compounds in AEC that is responsible for priming growth as phytohormones.


Assuntos
Cyperus , Moringa oleifera , Germinação , Plântula , Sementes , Água
6.
Public Health Action ; 12(1): 48-52, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35317540

RESUMO

BACKGROUND: The level of antibiotic resistance of pathogens causing uncomplicated urinary tract infections (UTIs) is increasing. The 2017-2018 GLASS (Global Antimicrobial Resistance and Use Surveillance System) report indicated >70% resistance to ceftriaxone and ciprofloxacin in Escherichia coli in Pakistan. METHODS: A prospective study was conducted in the Médecins Sans Frontières (MSF) supported Timurgara District Hospital, Timurgara, Pakistan, from September 2017 to December 2018. Women aged 18-65 years presenting to the Emergency Department with symptoms of uncomplicated UTI (cystitis/pyelonephritis) were invited to participate. We conducted microbiological culture and sensitivity testing for samples with positive dipstick or nitrite test. RESULTS: Of the 200 patients who participated, 109 (54.5%) were diagnosed with pyelonephritis and 91 (45.5%) with cystitis. Forty-three samples (21.5%) were culture-positive: E. coli was isolated in 27 samples, Enterococcus spp. in 7 and Klebsiella pneumoniae in 6. Overall resistance to ciprofloxacin was observed in 51.8% of E. coli isolates, and ceftriaxone resistance in 66.7% of E. coli isolates and in 33.3% of K. pneumoniae. Resistance to fosfomycin was low (one E. coli isolate). CONCLUSIONS: This study found resistance to first- and second-line antibiotics for treating UTIs as per the MSF protocol. Heightened awareness and potential changes to local prescription practices are necessary to curb the spread of antimicrobial resistance pathogens causing UTIs.


OBJECTIF: Le taux de résistance aux antibiotiques des pathogènes responsables d'infections urinaires non compliquées (UTI) est en hausse. Le rapport GLASS (Global Antimicrobial Resistance and Use Surveillance System) 2017­2018 a indiqué un taux de résistance >70% à la ceftriaxone et à la ciprofloxacine chez Escherichia coli (Pakistan). MÉTHODES: Une étude prospective a été réalisée dans l'hôpital du district de Timurgara géré par Médecins Sans Frontières (MSF), de septembre 2017 à décembre 2018. Les femmes de 18­65 ans consultant aux Urgences avec des symptômes d'UTI non compliquée (cystite/pyélonéphrite) ont été invitées à participer. Nous avons réalisé une culture microbiologique et un test de sensibilité pour les échantillons positifs à la bandelette urinaire et au test de détection des nitrites. RÉSULTATS: Deux cents patients ont participé, dont 109 (54,5%) avaient un diagnostic de pyélonéphrite et 91 (45,5%) un diagnostic de cystite. Quarante-trois échantillons (21,5%) étaient positifs à la culture ; E. coli a été isolé de 27 échantillons, Enterococcus spp. de sept échantillons et Klebsiella pneumoniae de six échantillons. Une résistance à la ciprofloxacine a été observée chez 51,8% des isolats de E. coli, et une résistance à la ceftriaxone chez 66,7% des isolats de E. coli et chez 33,3% des isolats de K. pneumoniae. La résistance à la fosfomycine était faible (un isolat de E. coli). CONCLUSIONS: Cette étude a rapporté une résistance aux antibiotiques de première et deuxième intention utilisés dans le traitement des UTI, conformément au protocole de MSF. Une sensibilisation accrue et un éventuel changement des pratiques locales de prescription sont nécessaires pour freiner la propagation des pathogènes responsables d'UTI résistants aux antimicrobiens.

7.
J Dairy Sci ; 105(5): 4083-4098, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35221070

RESUMO

Previous research has shown that the brown seaweed Ascophyllum nodosum (ASCO) has antimicrobial and antioxidant properties and also increases milk I concentration. We aimed to investigate the effects of supplementing ASCO meal or monensin (MON) on ruminal fermentation, diversity and relative abundance of ruminal bacterial taxa, metabolism of I and As, and blood concentrations of thyroid hormones, antioxidant enzymes, and cortisol in lactating dairy cows. Five multiparous ruminally cannulated Jersey cows averaging (mean ± standard deviation) 102 ± 15 d in milk and 450 ± 33 kg of body weight at the beginning of the study were used in a Latin square design with 28-d periods (21 d for diet adaptation and 7 d for data and sample collection). Cows were fed ad libitum a basal diet containing (dry matter basis) 65% forage as haylage and corn silage and 35% concentrate and were randomly assigned to 1 of the following 5 dietary treatments: 0, 57, 113, or 170 g/d of ASCO meal, or 300 mg/d of MON. Supplements were placed directly into the rumen once daily after the morning feeding. Diets had no effect on ruminal pH and NH3-N concentration, which averaged 6.02 and 6.86 mg/dL, respectively. Total volatile fatty acid concentration decreased linearly in cows fed incremental amounts of ASCO meal. Supplementation with ASCO meal did not change the ruminal molar proportions of volatile fatty acids apart from butyrate, which responded quadratically with the lowest values observed at 56 and 113 g/d of ASCO supplementation. Compared with the control diet or diets containing ASCO meal, cows fed MON showed greater molar proportion of propionate. Diets did not affect the α diversity indices Shannon, Simpson, and Fisher for ruminal bacteria. However, feeding incremental levels of ASCO meal linearly decreased the relative abundance of Tenericutes in ruminal fluid. Monensin increased the relative abundance of the CAG:352 bacterial genus in ruminal fluid compared with the control diet. Linear increases in response to ASCO meal supplementation were observed for the concentrations and output of I in serum, milk, urine, and feces. Fecal excretion of As increased linearly in cows fed varying amounts of ASCO meal, but ASCO did not affect the concentration and secretion of As in milk. The plasma activities of the antioxidant enzymes and the serum concentrations of thyroid hormones did not change. In contrast, circulating cortisol decreased linearly in diets containing ASCO meal. The apparent total-tract digestibilities of dry matter, organic matter, and crude protein increased linearly with ASCO meal, but those of neutral and acid detergent fiber were not affected. In summary, feeding incremental amounts of ASCO meal decreased serum cortisol concentration, and increased I concentrations and output in serum, milk, feces, and urine.


Assuntos
Arsênio , Ascophyllum , Iodo , Animais , Antioxidantes/metabolismo , Arsênio/metabolismo , Arsênio/farmacologia , Ascophyllum/metabolismo , Bactérias/metabolismo , Bovinos , Suplementos Nutricionais , Digestão , Ácidos Graxos Voláteis/metabolismo , Feminino , Hidrocortisona/metabolismo , Iodo/metabolismo , Lactação , Monensin/metabolismo , Monensin/farmacologia , Rúmen/metabolismo
8.
Braz. j. biol ; 82: e233550, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278499

Assuntos
Phaseolus , Sementes
9.
Braz. j. biol ; 82: e233567, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1249220

RESUMO

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3 - and ammonium - NH4 + ) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4 + form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+ /K+ , Na+ /Ca++ and Na+ /Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4 + under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3 - form the most suitable for the cultivation of the species.


Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3 - e amônio - NH4 + ) e cinco níveis de condutividade elétrica da água de irrigação (CEa ) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-1). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4 + promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+ /K+ , Na+ /Ca++ e Na+ /Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-1 reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4 + sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3 - a mais adequada para o cultivo da espécie.


Assuntos
Compostos de Amônio , Nitrogênio , Raízes de Plantas/química , Estresse Salino , Homeostase , Itália , Nitratos
11.
Braz. j. biol ; 82: 1-10, 2022. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468479

RESUMO

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-¹ reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.


Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-¹). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-¹ reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.


Assuntos
Cucurbita pepo , Estresse Salino , Hidroponia , Hidróxido de Amônia/administração & dosagem , Hidróxido de Amônia/efeitos adversos , Hidróxido de Amônia/toxicidade , Homeostase , Nitrogênio/administração & dosagem , Nitrogênio/efeitos adversos
14.
Braz. j. biol ; 822022.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468666

RESUMO

Abstract This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.


Resumo Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-1). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-1 reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.

17.
Braz J Biol ; 82: e233567, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105657

RESUMO

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.


Assuntos
Compostos de Amônio , Nitrogênio , Homeostase , Itália , Nitratos , Raízes de Plantas/química , Estresse Salino
20.
Braz J Med Biol Res ; 54(6): e10754, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33886813

RESUMO

Epidermal growth factor receptor (EGFR) signaling and components of the fibrinolytic system, including urokinase-type plasminogen activator (uPA) and thrombomodulin (TM), have been implicated in tumor progression. In the present study, we employed cBioPortal platform (http://www.cbioportal.org/), cancer cell lines, and an in vivo model of immunocompromised mice to evaluate a possible cooperation between EGFR signaling, uPA, and TM expression/function in the context of cervical cancer. cBioPortal analysis revealed that EGFR, uPA, and TM are positively correlated in tumor samples of cervical cancer patients, showing a negative prognostic impact. Aggressive human cervical cancer cells (CASKI) presented higher gene expression levels of EGFR, uPA, and TM compared to its less aggressive counterpart (C-33A cells). EGFR induces uPA expression in CASKI cells through both PI3K-Akt and MEK1/2-ERK1/2 downstream effectors, whereas TM expression induced by EGFR was dependent on PI3K/Akt signaling alone. uPA induced cell-morphology modifications and cell migration in an EGFR-dependent and -independent manner, respectively. Finally, treatment with cetuximab reduced in vivo CASKI xenografted-tumor growth in nude mice, and decreased intratumoral uPA expression, while TM expression was unaltered. In conclusion, we showed that EGFR signaling regulated expression of the fibrinolytic system component uPA in both in vitro and in vivo settings, while uPA also participated in cell-morphology modifications and migration in a human cervical cancer model.


Assuntos
Fosfatidilinositol 3-Quinases , Neoplasias do Colo do Útero , Animais , Linhagem Celular Tumoral , Movimento Celular , Receptores ErbB , Feminino , Humanos , Camundongos , Camundongos Nus , Prognóstico , Neoplasias do Colo do Útero/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...