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1.
Clinics (Sao Paulo) ; 78: 100296, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38043345

RESUMEN

In this review, we describe recent advances in understanding the relationship between epigenetic changes, especially DNA methylation (DNAm), with hypersensitivity and respiratory disorders such as asthma in childhood. It is clearly described that epigenetic mechanisms can induce short to long-term changes in cells, tissues, and organs. Through the growing number of studies on the Origins of Health Development and Diseases, more and more data exist on how environmental and genomic aspects in early life can induce allergies and asthma. The lack of biomarkers, standardized assays, and access to more accessible tools for data collection and analysis are still a challenge for future studies. Through this review, the authors draw a panorama with the available information that can assist in the establishment of an epigenetic approach for the risk analysis of these pathologies.


Asunto(s)
Asma , Hipersensibilidad , Humanos , Asma/genética , Epigénesis Genética/genética , Hipersensibilidad/genética , Metilación de ADN , Biomarcadores/metabolismo
2.
Heliyon ; 9(7): e17717, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37483797

RESUMEN

Leptin concentrations in breast milk can influence metabolic programming during the first months of life. Small for gestational age (SGA) newborns show a peculiar growth pattern after birth, which can lead to adulthood diseases. This study aims to assess an association between leptin concentration in mature breast milk and the infant anthropometric indicators of the SGA and the non-SGA groups, in addition, to comparing the hormone level between these groups. A longitudinal study was performed with mother-infant pairs. The maternal sociodemographic information was collected in the first 48 h postpartum. Breast milk was collected at one month postpartum and leptin concentrations were obtained by immunoassays. The infant anthropometric measurements were collected at three and six months postpartum and included weight, height (to body mass index-BMI calculated), triceps skinfold (TSF), and subscapular skinfold (SSF). The BMI for age (BMI/A), TSF, and SSF were calculated by Z-score indicators. Data from 67 mother-infant pairs (n = 16 SGA and n = 51 non-SGA) were analyzed. In univariate analyses, the breast milk of the SGA group had lower leptin concentrations than the non-SGA group (p = 0.006), however, after adjustment, there was no difference between groups (p = 0.181). In the SGA group, there was a significant association between leptin concentrations and lower SSF at six months in infants, after adjustment (p = 0.003). In the non-SGA group, the breast milk leptin was associated with lower BMI/A at three and six months in infants, after adjustment (p = 0.002 and p = 0.010, respectively). The association between breast milk leptin concentrations with SSF in the SGA group and BMI/A in the non-SGA group suggests that leptin may be a modulating factor in infant growth in the first months of life.

3.
PLoS One ; 18(4): e0282423, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37023037

RESUMEN

OBJECTIVE: To analyze the outcomes of children with sickle cell disease (SCD) and COVID-19. METHOD: A multicenter prospective study was conducted in five hematological centers from Central and Southeast Brazil, starting in April 2020. The variables recorded include clinical symptoms, diagnostic methods, therapeutic measures, and treatment sites. The clinical repercussions of the infection on the initial treatment and the overall prognosis were also evaluated. RESULTS: Twenty-five unvaccinated children, aged 4 to 17 years, with SCD and a positive SARS-CoV-2 RT-PCR result participated in this study. Patients were classified as SCD types SS (n = 20, 80%) and SC (n = 5, 20%). Clinical characteristics and evolution were similar in both groups (p>0.05), except for the fetal hemoglobin value which was higher among the SC patients (p = 0.025). The most frequent symptoms were hyperthermia (72%) and cough (40%). Three children were admitted to the intensive care unit, all of whom were overweight/obese (p = 0.078). No deaths were observed. CONCLUSIONS: Although SCD leads to specific complications, the results found in this sample suggest that COVID-19 does not seem to carry an increased mortality risk in pediatric patients with this disease.


Asunto(s)
Anemia de Células Falciformes , COVID-19 , Humanos , Niño , COVID-19/complicaciones , Estudios Prospectivos , SARS-CoV-2 , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/terapia , Anemia de Células Falciformes/diagnóstico , Sistema de Registros
4.
Braz J Infect Dis ; 27(2): 102745, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36750202

RESUMEN

BACKGROUND: Despite high cure rates, treatment-related mortality in children with acute lymphoblastic leukemia (ALL) remains significant. About 4% of patients die during remission induction therapy and approximately two-thirds of treatment-related deaths are due to infectious complications. METHODS: From May 2021 to June 2022, children aged one through 18 years, with a recent diagnosis of ALL, admitted to three pediatric oncology centers in Brazil, were enrolled in this multicenter, open-label, randomized, phase 3 clinical trial. Eligible patients were randomly divided into two groups, based on a 1:1 allocation ratio, to receive, or not, levofloxacin as a prophylactic agent during the induction phase. All patients were treated according to the IC-BFM 2009 chemotherapy protocol. Primary endpoints were carbapenemase-producing Enterobacteriaceae (CPE) colonization, Clostridioides difficile diarrhea, and other adverse events related to the use of levofloxacin. The secondary endpoint was febrile neutropenia during induction. The median follow-up was 289 days. RESULTS: Twenty patients were included in this trial, 10 in each group (control and levofloxacin). Mild adverse reactions related to levofloxacin were observed in three patients (30%). Three patients had Clostridioides difficile diarrhea, two in the levofloxacin group and one in the control group (p > 0.99). Only one patient presented colonization by CPE. This patient belonged to the levofloxacin group (p > 0.99). Nine patients presented febrile neutropenia, five in the control group and four in the levofloxacin intervention group (p > 0.99), one patient died due to febrile neutropenia. CONCLUSION: The use of levofloxacin was shown to be safe in the induction phase in children with de novo ALL. The use of this medication did not increase the rate of colonization by CPE nor the rate of diarrhea by C. difficile. All adverse reactions were mild and remitted either spontaneously or after switching medicine administration from oral to intravenous route.


Asunto(s)
Clostridioides difficile , Neutropenia Febril , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Niño , Adolescente , Levofloxacino/efectos adversos , Profilaxis Antibiótica/métodos , Antibacterianos/efectos adversos , Brasil , Neutropenia Febril/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Diarrea/complicaciones , Diarrea/tratamiento farmacológico
5.
Braz. j. infect. dis ; 27(2): 102745, 2023. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1439690

RESUMEN

ABSTRACT Background: Despite high cure rates, treatment-related mortality in children with acute lymphoblastic leukemia (ALL) remains significant. About 4% of patients die during remission induction therapy and approximately two-thirds of treatment-related deaths are due to infectious complications. Methods: From May 2021 to June 2022, children aged one through 18 years, with a recent diagnosis of ALL, admitted to three pediatric oncology centers in Brazil, were enrolled in this multicenter, open-label, randomized, phase 3 clinical trial. Eligible patients were randomly divided into two groups, based on a 1:1 allocation ratio, to receive, or not, levofloxacin as a prophylactic agent during the induction phase. All patients were treated according to the IC-BFM 2009 chemotherapy protocol. Primary endpoints were carbapenemase-producing Enterobacteriaceae (CPE) colonization, Clostridioides difficile diarrhea, and other adverse events related to the use of levofloxacin. The secondary endpoint was febrile neutropenia during induction. The median follow-up was 289 days. Results: Twenty patients were included in this trial, 10 in each group (control and levofloxacin). Mild adverse reactions related to levofloxacin were observed in three patients (30%). Three patients had Clostridioides difficile diarrhea, two in the levofloxacin group and one in the control group (p > 0.99). Only one patient presented colonization by CPE. This patient belonged to the levofloxacin group (p > 0.99). Nine patients presented febrile neutropenia, five in the control group and four in the levofloxacin intervention group (p > 0.99), one patient died due to febrile neutropenia. Conclusion: The use of levofloxacin was shown to be safe in the induction phase in children with de novo ALL. The use of this medication did not increase the rate of colonization by CPE nor the rate of diarrhea by C. difficile. All adverse reactions were mild and remitted either spontaneously or after switching medicine administration from oral to intravenous route.

6.
Clinics ; 78: 100296, 2023. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1528413

RESUMEN

Abstract In this review, we describe recent advances in understanding the relationship between epigenetic changes, especially DNA methylation (DNAm), with hypersensitivity and respiratory disorders such as asthma in childhood. It is clearly described that epigenetic mechanisms can induce short to long-term changes in cells, tissues, and organs. Through the growing number of studies on the Origins of Health Development and Diseases, more and more data exist on how environmental and genomic aspects in early life can induce allergies and asthma. The lack of biomarkers, standardized assays, and access to more accessible tools for data collection and analysis are still a challenge for future studies. Through this review, the authors draw a panorama with the available information that can assist in the establishment of an epigenetic approach for the risk analysis of these pathologies.

7.
Exp Hematol Oncol ; 11(1): 86, 2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36333762

RESUMEN

Acute lymphoblastic leukemia is the most common childhood malignancy. One of the drugs used in the treatment is Asparaginase, and monitoring of its activity levels enables better outcomes. Since 2018, our laboratory has been working to establish a regular analysis of activity. This implementation allowed to qualify care by detecting silent inactivation and also establishing desensitization as a safe way to overcome the lack of Erwinia. We were able to monitor children aged 0 to 18 years who were being treated with PEG-ASNase. The activity was assessed on days 7 (90 samples) and 14 (52 samples) after ASNase infusions. 142 samples were analyzed. 95.7% reached an adequate activity level (≥ 0.1 IU/mL). Patients treated with ASNase can develop allergic reactions. With the activity monitoring, is possible to circumvent situations like these and implement desensitization protocols for patients who had clinical hypersensitivity without inactivation. Desensitization induces temporary unresponsiveness to drug antigens, allowing the patients to proceed with the prescribed chemotherapy. We have received samples from four patients being treated with different desensitization protocols. Patients tolerated the protocols well. Only one had a grade 2 reaction during the infusion and activity < 0.1 IU/mL, which resulted in the switch to Erwinia. The dose adaptation is a possible and more recent use of ASNase monitoring and we were able to confirm the feasibility of PEG-ASNase desensitization protocols.

8.
Clinics (Sao Paulo) ; 77: 100004, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35113785

RESUMEN

This work aimed to better understand the impact of pandemics of respiratory viruses on children with hemoglobinopathies through a comprehensive review of the literature. MEDLINE, SCIELO, LILACS, and PUBMED were used as data sources to find articles without time period restrictions. Previous observations suggest that patients with hemoglobinopathies are a group especially susceptible to the complications of viral respiratory infections, with greater morbidity and mortality related to them. Within this context, this review found that, during the 2009 H1N1 pandemic, the risk of hospitalization in children and adults increased, especially in patients with a history of complications such as acute chest syndrome. In addition, the Coronavirus Disease 2019 (COVID-19) pandemic appears to have less repercussion among children with hemoglobinopathies compared to adults, similar to what is seen in the general population. In the H1N1 pandemic, patients with hemoglobinopathies behaved as a group more susceptible to complications, with increased morbidity and mortality. However, for COVID-19, the existing data to date on these patients do not show the same clinical impact. Thus, although these children deserve attention in case of infection due to their potential risks, they seem to have a favorable evolution.


Asunto(s)
COVID-19 , Hemoglobinopatías , Subtipo H1N1 del Virus de la Influenza A , Adulto , Niño , Hemoglobinopatías/complicaciones , Hemoglobinopatías/epidemiología , Humanos , Pandemias , SARS-CoV-2
9.
Bone Marrow Transplant ; 57(3): 453-459, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35027676

RESUMEN

In the COVID-19 scenario, patients undergoing hematopoietic stem cell transplantation (HSCT) infected with SARS-CoV-2 may have an increased risk of death. Through a national multicenter study, we aimed to describe the impact of COVID-19 on the survival of HSCT recipients in Brazil. Eighty-six patients with a confirmed diagnosis of SARS-CoV-2 (92% by RT-PCR) were included. There were 24 children and 62 adults receiving an autologous (n = 25) and allogeneic (n = 61) HSCT for malignant (n = 72) and non-malignant (n = 14) disorders. Twenty-six patients died, (10 on autologous (38%) and 16 patients (62%) on allogeneic group). The estimated overall survival (OS) at day 40 was 69%. Adults had decreased OS compared to children (66% vs 79%, p = 0.03). The severity of symptoms at the time of diagnosis, ECOG score, laboratory tests (C-reactive protein, urea values) were higher in patients who died (p < 0.05). In conclusion, HSCT recipients infected with SARS-CoV-2 have a high mortality rate mainly in adults and patients with critical initial COVID-19 presentation. These findings show the fragility of HSCT recipients with SARS-CoV-2 infection. Therefore, the importance of adherence to preventive measures is evident, in addition to prioritizing the vaccination of family members and the HSCT team.


Asunto(s)
COVID-19 , Trasplante de Células Madre Hematopoyéticas , Adulto , Brasil/epidemiología , COVID-19/complicaciones , Niño , Humanos , SARS-CoV-2 , Tasa de Supervivencia
10.
Clinics ; 77: 100004, 2022. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1364743

RESUMEN

Abstract This work aimed to better understand the impact of pandemics of respiratory viruses on children with hemoglobinopathies through a comprehensive review of the literature. MEDLINE, SCIELO, LILACS, and PUBMED were used as data sources to find articles without time period restrictions. Previous observations suggest that patients with hemoglobinopathies are a group especially susceptible to the complications of viral respiratory infections, with greater morbidity and mortality related to them. Within this context, this review found that, during the 2009 H1N1 pandemic, the risk of hospitalization in children and adults increased, especially in patients with a history of complications such as acute chest syndrome. In addition, the Coronavirus Disease 2019 (COVID-19) pandemic appears to have less repercussion among children with hemoglobinopathies compared to adults, similar to what is seen in the general population. In the H1N1 pandemic, patients with hemoglobinopathies behaved as a group more susceptible to complications, with increased morbidity and mortality. However, for COVID-19, the existing data to date on these patients do not show the same clinical impact. Thus, although these children deserve attention in case of infection due to their potential risks, they seem to have a favorable evolution. Highlights Children with hemoglobinopathies have less severe conditions with Coronavirus 2019 Disease (COVID-19) compared to adults, which is similar to that observed in the general population In the H1N1 pandemic, patients with hemoglobinopathies behaved as the group most susceptible to complications, with increased morbidity and mortality

11.
Genet Mol Biol ; 44(4): e20200411, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34874050

RESUMEN

Different intrauterine exposures are associated with different metabolic profiles leading to growth and development characteristics in children and also relate to health and disease patterns in adult life. The objective of this work was to evaluate the impact of four different intrauterine environments on the telomere length of newborns. This is a longitudinal observational study using a convenience sample of 222 mothers and their term newborns (>37 weeks of gestational age) from hospitals in Porto Alegre, Rio Grande do Sul (Brazil), from September 2011 to January 2016. Sample was divided into four groups: pregnant women with Gestational Diabetes Mellitus (DM) (n=38), smoking pregnant women (TOBACCO) (n=52), mothers with small-for-gestational age (SGA) children due to idiopathic intrauterine growth restriction (n=33), and a control group (n=99). Maternal and newborn genomic DNA were obtained from epithelial mucosal cells. Telomere length was assessed by qPCR, with the calculation of the telomere and single copy gene (T/S ratio). In this sample, there was no significant difference in telomere length between groups (p>0.05). There was also no association between childbirth weight and telomere length in children (p>0.05). For term newborns different intrauterine environments seems not to influence telomere length at birth.

12.
Front Genet ; 12: 632685, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34249077

RESUMEN

Osmotins are multifunctional proteins belonging to the thaumatin-like family related to plant stress responses. To better understand the functions of soybean osmotins in drought stress response, the current study presents the characterisation of four previously described proteins and a novel putative soybean osmotin (GmOLPa-like). Gene and protein structure as well as gene expression analyses were conducted on different tissues and developmental stages of two soybean cultivars with varying dehydration sensitivities (BR16 and EMB48 are highly and slightly sensitive, respectively). The analysed osmotin sequences share the conserved amino acid signature and 3D structure of the thaumatin-like family. Some differences were observed in the conserved regions of protein sequences and in the electrostatic surface potential. P21-like present the most similar electrostatic potential to osmotins previously characterised as promoters of drought tolerance in Nicotiana tabacum and Solanum nigrum. Gene expression analysis indicated that soybean osmotins were differentially expressed in different organs (leaves and roots), developmental stages (R1 and V3), and cultivars in response to dehydration. In addition, under dehydration conditions, the highest level of gene expression was detected for GmOLPa-like and P21-like osmotins in the leaves and roots, respectively, of the less drought sensitive cultivar. Altogether, the results suggest an involvement of these genes in drought stress tolerance.

13.
Pediatr Blood Cancer ; 68(12): e29223, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34288386

RESUMEN

BACKGROUND: Strategies to mitigate the impact of COVID-19 in special populations are complex and challenging. Few studies have addressed the impact of COVID-19 on pediatric patients with cancer in low- and middle-income countries. METHODS: Multicenter observational cohort study with prospective records and retrospective analyses starting in April 2020 in 21 pediatric oncology centers distributed throughout Brazil. PARTICIPANTS: Patients under 18 years of age who are infected by the SARS-CoV-2 virus (confirmed diagnosis through reverse transcriptase-polymerase chain reaction [RT-PCR]) while under treatment at pediatric oncology centers. The variables of interest included clinical symptoms, diagnostic and therapeutic measures. The repercussions of SARS-CoV-2 infection on cancer treatment and general prognosis were monitored. RESULTS: One hundred seventy-nine patients were included (median age 6 [4-13] years, 58% male). Of these, 55.9% had acute leukemia and 34.1% had solid tumors. The presence of SARS-CoV-2 was diagnosed by RT-PCR. Various laboratory markers were analyzed, but showed no correlation with outcome. Children with low or high BMI for age had lower overall survival (71.4% and 82.6%, respectively) than those with age-appropriate BMI (92.7%) (p = .007). The severity of presentation at diagnosis was significantly associated with outcome (p < .001). Overall mortality in the presence of infection was 12.3% (n = 22). CONCLUSION: In children with cancer and COVID-19, lower BMI was associated with worse prognosis. The mortality in this group of patients (12.3%) was significantly higher than that described in the pediatric population overall (∼1%).


Asunto(s)
COVID-19/complicaciones , Neoplasias/complicaciones , Adolescente , Índice de Masa Corporal , Brasil/epidemiología , COVID-19/epidemiología , Niño , Preescolar , Femenino , Humanos , Masculino , Neoplasias/epidemiología , Sistema de Registros , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2/aislamiento & purificación , Análisis de Supervivencia
14.
Br J Haematol ; 194(1): 168-173, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33993488

RESUMEN

Our group recently showed that the (ASNase) formulation available in Brazil from 2017 to 2018 when used at the same dose and frequency as the formulation provided previously did not reach the activity considered therapeutic. Based on these, our goal was to assess the impact of these facts on the prognosis of children with ALL at different oncology centers. A multicentre retrospective observational study followed by a prospective follow-up. Patients aged >1 and <18 years in first-line treatment followed up at 10 referral centres, between 2014 and 2018 who received the formulation Leuginase® were identified (Group B). For each patient, the centre registered 2 patients who received ASNase in the presentation of Aginasa® exclusively (Group A). Data collection was registered using (Redcap® ). A total of 419 patients were included; 282 in Group A and 137 in B. Group A had a 3-year OS and EFS of 91·8% and 84·8% respectively, while Group B had a 3-year OS of 83·8% (P = 0·003) and EFS of 76·1% (P = 0·008). There was an impact on 3-year OS and EFS of children who received a formulation. This result highlights the importance of evaluating ASNase and monitoring its activity.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Asparaginasa/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Asparaginasa/administración & dosificación , Brasil/epidemiología , Niño , Preescolar , Composición de Medicamentos , Femenino , Estudios de Seguimiento , Humanos , Lactante , Estimación de Kaplan-Meier , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Supervivencia sin Progresión , Estudios Prospectivos , Estudios Retrospectivos
15.
Clin. biomed. res ; 41(3): 192-198, 20210000. graf
Artículo en Inglés | LILACS | ID: biblio-1344765

RESUMEN

Introduction: Treatment of childhood acute lymphoblastic leukemia (ALL) is based on risk stratification. This study aimed to assess the agreement between risk group classifications in the different childhood ALL treatment protocols used in a referral hospital in southern Brazil. Methods: We retrospectively reviewed the medical records of patients aged 1 to 18 years with B-cell ALL treated at a hospital from January 2013 to April 2017. Agreement between risk classifications was assessed by the kappa coefficient. Results: Seventy-five patients were analyzed. There was poor agreement between risk stratification by GBTLI 2009 and BFM 95 protocols (kappa = 0.22; p = 0.003) and by GBTLI 2009 and IC-BFM 2002 protocols (kappa = 0.24; p = 0.002). Risk group distribution was 13.3% for low risk, 32.0% for intermediate risk, and 54.7% for high risk based on stratification by the GBTLI 2009 protocol, and 28.0% for low risk, 42.7% for intermediate risk, and 29.3% for high risk based on stratification by the IC-BFM 2002 protocol. Overall survival was 68.6%. Conclusion: This study provides numerous points to ponder about the treatment of leukemia in Brazil. The percentage of patients classified as high risk in our sample was higher than that reported in the international literature. This difference, however, had no impact on overall survival, which was shorter than that reported in the international literature. (AU)


Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Adolescente , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidad , Protocolos de Quimioterapia Combinada Antineoplásica , Factores de Riesgo , Supervivientes de Cáncer
16.
Sci Rep ; 10(1): 21481, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33293625

RESUMEN

Acute lymphoid leukemia is a childhood cancer that in high-income countries has event-free survival rates of 80% and global survival rates of 90%. In Brazil these rates are under 70%. This difference may be due to the implementation of supportive care, including the assessment of asparaginase (ASNase) activity. ASNase may cause hypersensitivity reactions and silent drug inactivation. For this reason, ASNase activity monitoring is an essential tool to ensure an effective treatment. Our aim was to implement an ASNase activity measurement technique at a hospital setting. samples from children who were given Escherichia coli-derived ASNase were collected. The results of the analyses conducted in our laboratory Hospital de Clínicas de Porto Alegre were compared to those of two institutions: Centro Infantil Boldrini and University of Munster. 262 samples were assessed. The results of the first analyses were compared with those obtained at Centro Infantil Boldrini and showed an ICC of 0.954. Thirty samples were sent to the University of Munster and presented an ICC was 0.960. Our results, when compared to those of national and international centers, showed an excellent agreement. The study was able to implement an ASNase activity test to monitor the treatment.


Asunto(s)
Asparaginasa/análisis , Monitoreo Fisiológico/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Antineoplásicos/uso terapéutico , Asparaginasa/metabolismo , Asparaginasa/uso terapéutico , Brasil/epidemiología , Niño , Preescolar , Hipersensibilidad a las Drogas , Femenino , Humanos , Masculino , Polietilenglicoles/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Resultado del Tratamiento
18.
Genet Mol Biol ; 40(1 suppl 1): 209-216, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28257524

RESUMEN

Urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide. The ammonia (nitrogen (N) product of urease activity) is incorporated into organic compounds. Thus, urease is involved in N remobilization, as well as in primary N assimilation. Two urease isoforms have been described for soybean: the embryo-specific, encoded by the Eu1 gene, and the ubiquitous urease, encoded by Eu4. A third urease-encoding gene was recently identified, designated Eu5, which encodes the putative protein product SBU-III. The present study aimed to evaluate the contribution of soybean ureases to seed germination and plant development. Analyses were performed using Eu1/Eu4/Eu5-co-suppressed transgenic plants and mutants of the Eu1 and Eu4 urease structural genes, as well as a urease-null mutant (eu3-a) that activates neither the ubiquitous nor embryo-specific ureases. The co-suppressed plants presented a developmental delay during the first month after germination; shoots and roots were significantly smaller and lighter. Slower development was observed for the double eu1-a/eu4-a mutant and the eu3-a single mutant. The N content in transgenic plants was significantly lower than in non-transgenic plants. Among the mutants, eu3-a presented the lowest and eu1-a the highest N content. Altogether, these results indicate that increased ureolytic activity plays an important role in plant development.

19.
Genet. mol. biol ; 40(1,supl.1): 209-216, 2017. tab, graf
Artículo en Inglés | LILACS | ID: biblio-892383

RESUMEN

Abstract Urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide. The ammonia (nitrogen (N) product of urease activity) is incorporated into organic compounds. Thus, urease is involved in N remobilization, as well as in primary N assimilation. Two urease isoforms have been described for soybean: the embryo-specific, encoded by the Eu1 gene, and the ubiquitous urease, encoded by Eu4. A third urease-encoding gene was recently identified, designated Eu5, which encodes the putative protein product SBU-III. The present study aimed to evaluate the contribution of soybean ureases to seed germination and plant development. Analyses were performed using Eu1/Eu4/Eu5-co-suppressed transgenic plants and mutants of the Eu1 and Eu4 urease structural genes, as well as a urease-null mutant (eu3-a) that activates neither the ubiquitous nor embryo-specific ureases. The co-suppressed plants presented a developmental delay during the first month after germination; shoots and roots were significantly smaller and lighter. Slower development was observed for the double eu1-a/eu4-a mutant and the eu3-a single mutant. The N content in transgenic plants was significantly lower than in non-transgenic plants. Among the mutants, eu3-a presented the lowest and eu1-a the highest N content. Altogether, these results indicate that increased ureolytic activity plays an important role in plant development.

20.
Plant Physiol Biochem ; 101: 96-104, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26874294

RESUMEN

In plants, ureases have been related to urea degradation, to defense against pathogenic fungi and phytophagous insects, and to the soybean-Bradyrhizobium japonicum symbiosis. Two urease isoforms have been described for soybean: the embryo-specific, encoded by Eu1 gene, and the ubiquitous urease, encoded by Eu4. A third urease-encoding locus exists in the completed soybean genome. The gene was designated Eu5 and the putative product of its ORF as SBU-III. Phylogenetic analysis shows that 41 plant, moss and algal ureases have diverged from a common ancestor protein, but ureases from monocots, eudicots and ancient species have evolved independently. Genomes of ancient organisms present a single urease-encoding gene and urease-encoding gene duplication has occurred independently along the evolution of some eudicot species. SBU-III has a shorter amino acid sequence, since many gaps are found when compared to other sequences. A mutation in a highly conserved amino acid residue suggests absence of ureolytic activity, but the overall protein architecture remains very similar to the other ureases. The expression profile of urease-encoding genes in different organs and developmental stages was determined by RT-qPCR. Eu5 transcripts were detected in seeds one day after dormancy break, roots of young plants and embryos of developing seeds. Eu1 and Eu4 transcripts were found in all analyzed organs, but Eu4 expression was more prominent in seeds one day after dormancy break whereas Eu1 predominated in developing seeds. The evidence suggests that SBU-III may not be involved in nitrogen availability to plants, but it could be involved in other biological role(s).


Asunto(s)
Regulación Enzimológica de la Expresión Génica/fisiología , Regulación de la Expresión Génica de las Plantas/fisiología , Glycine max , Proteínas de Plantas , Transcripción Genética/fisiología , Ureasa , Secuencia de Aminoácidos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/química , Proteínas de Plantas/genética , Glycine max/enzimología , Glycine max/genética , Ureasa/biosíntesis , Ureasa/química , Ureasa/genética
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