RESUMO
Chlorophyll is essential in photosynthesis, converting sunlight into chemical energy in plants, algae, and certain bacteria. Its structure, featuring a porphyrin ring enclosing a central magnesium ion, varies in forms like chlorophyll a, b, c, d, and f, allowing light absorption at a broader spectrum. With a 20-carbon phytyl tail (except for chlorophyll c), chlorophyll is anchored to proteins. Previous findings suggested the presence of chlorophyll with a modified farnesyl tail in thermophilic cyanobacteria Thermosynechoccocus vestitus. In our Arabidopsis thaliana PSII cryo-EM map, specific chlorophylls showed incomplete phytyl tails, suggesting potential farnesyl modifications. However, further high-resolution mass spectrometry (HRMS) analysis in A. thaliana and T. vestitus did not confirm the presence of any farnesyl tails. Instead, we propose the truncated tails in PSII models may result from binding pocket flexibility rather than actual modifications.
Assuntos
Arabidopsis , Clorofila , Complexo de Proteína do Fotossistema II , Clorofila/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Arabidopsis/metabolismo , Espectrometria de Massas , Thermosynechococcus/metabolismo , Microscopia CrioeletrônicaRESUMO
Photosystem II starts the photosynthetic electron transport chain that converts solar energy into chemical energy and thus sustains life on Earth. It catalyzes two chemical reactions: water oxidation to molecular oxygen and plastoquinone reduction. Coupling of electron and proton transfer is crucial for efficiency; however, the molecular basis of these processes remains speculative owing to uncertain water binding sites and the lack of experimentally determined hydrogen positions. We thus collected high-resolution cryo-electron microscopy data of fully hydrated photosystem II from the thermophilic cyanobacterium Thermosynechococcus vestitus to a final resolution of 1.71 angstroms. The structure reveals several previously undetected partially occupied water binding sites and more than half of the hydrogen and proton positions. This clarifies the pathways of substrate water binding and plastoquinone B protonation.
Assuntos
Hidrogênio , Complexo de Proteína do Fotossistema II , Prótons , Thermosynechococcus , Água , Sítios de Ligação , Microscopia Crioeletrônica , Transporte de Elétrons , Hidrogênio/química , Oxirredução , Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/ultraestrutura , Complexo de Proteína do Fotossistema II/metabolismo , Plastoquinona/metabolismo , Plastoquinona/química , Thermosynechococcus/enzimologia , Água/químicaRESUMO
OBJECTIVE: Pregnancy in women with lupus poses a higher risk of complications compared with the general population. The present study aimed to determine and describe the obstetric and neonatal outcomes of pregnant women with lupus. MATERIALS AND METHODS: We conducted an observational retrospective study of pregnant women with the diagnosis of lupus, who were selected and followed at the Maternal-Fetal Medicine Clinic of our institution between January 2013 and July 2018. We analyzed 59 pregnancies and 52 newborns, and collected data regarding sociodemographic features, the preconception period, pregnancy, childbirth, postpartum and the newborn. A descriptive analysis of the variables was performed. RESULTS: In 58% of the cases, the pregnancy was uneventful. We registered flares in 25% of the cases, preeclampsia in 3%, fetal growth restriction in 12%, gestational loss in 10%, preterm labor in 10%, postpartum complications in 20%, and small for gestational age newborns in 17% of the cases. CONCLUSIONS: Most pregnancies in women with lupus have favorable obstetric and neonatal outcomes. Prenatal counseling, adequate multidisciplinary surveillance, and optimized treatment of the disease are fundamental pillars for these good results.
OBJETIVO: A gravidez em mulheres com lúpus representa um risco maior de complicações em comparação com a população em geral. O presente estudo teve como objetivo determinar e descrever os resultados obstétricos e neonatais de gestantes com lúpus. MATERIAIS E MéTODOS: Realizamos um estudo retrospectivo observacional de gestantes com diagnóstico de lúpus, selecionadas e acompanhadas no Ambulatório de Medicina Materno-Fetal de nossa instituição entre janeiro de 2013 e julho de 2018. Analisamos 59 gestações e 52 recém-nascidos e coletamos dados referentes às características sociodemográficas, período pré-concepcional, gravidez, parto, pós-parto e nascimento. Foi realizada uma análise descritiva das variáveis. RESULTADOS: Em 58% dos casos, a gravidez transcorreu sem intercorrências. Registramos surtos em 25% dos casos, pré-eclâmpsia em 3%, restrição do crescimento fetal em 12%, perda gestacional em 10%, trabalho de parto prematuro em 10%, complicações pós-parto em 20% e recém-nascidos pequenos para a idade gestacional em 17% dos casos. CONCLUSõES: A maioria das gestações em mulheres com lúpus tem resultados obstétricos e neonatais favoráveis. Aconselhamento pré-natal, vigilância multidisciplinar adequada e tratamento otimizado da doença são pilares fundamentais para esses bons resultados.
Assuntos
Complicações na Gravidez , Resultado da Gravidez , Gravidez , Feminino , Recém-Nascido , Humanos , Resultado da Gravidez/epidemiologia , Estudos Retrospectivos , Gestantes , Portugal/epidemiologia , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/diagnóstico , Retardo do Crescimento Fetal/epidemiologiaRESUMO
OBJECTIVE: Compare the neonatal outcomes of two protocols of diagnosis and surveillance of pregnancies complicated by early-onset FGR in a tertiary hospital. METHODS: This is a retrospective cohort study of pregnant women diagnosed with early-onset FGR between 2017 and 2020. We compared the obstetric and perinatal outcomes between two different management protocols (before and after 2019). RESULTS: Seventy-two cases of early-onset FGR were diagnosed in the forementioned period: 45 (62.5%) were managed according to protocol 1 and 27 (37.5%) according to protocol 2. Mean gestational age at delivery was significantly different between groups: 34.9 ± 3.1 weeks (95% CI 34.0-35.9) in group 1 and 32.3 ± 4.4 weeks (95% CI 30.4-33.9) in group 2. 74.1% (20) of newborns in group 2 were admitted in de NICU, a significant difference when compared with 46.7% of group 1. There were no statistically significant differences in the remaining serious neonatal adverse outcomes. CONCLUSIONS: This is the first study published comparing two different protocols of management of FGR. The implementation of the new protocol seems to have led to a decrease in the number of fetuses labeled as growth restricted and to a decrease in the gestational age of delivery of such fetuses, but without increasing the rate of serious neonatal adverse outcomes. SYNOPSIS: The implementation of the 2016 ISUOG guidelines for the diagnosis of fetal growth restriction seems to have led to a decrease in the number of fetuses labeled as growth restricted and to a decrease in the gestational age of delivery of such fetuses, but without increasing the rate of serious neonatal adverse outcomes.
Assuntos
Retardo do Crescimento Fetal , Feto , Recém-Nascido , Gravidez , Humanos , Feminino , Lactente , Estudos Retrospectivos , Idade Gestacional , HospitalizaçãoRESUMO
Deinococcus radiodurans is known for its remarkable ability to withstand harsh stressful conditions. The outermost layer of its cell envelope is a proteinaceous coat, the S-layer, essential for resistance to and interactions with the environment. The S-layer Deinoxanthin-binding complex (SDBC), one of the main units of the characteristic multilayered cell envelope of this bacterium, protects against environmental stressors and allows exchanges with the environment. So far, specific regions of this complex, the collar and the stalk, remained unassigned. Here, these regions are resolved by cryo-EM and locally refined. The resulting 3D map shows that the collar region of this multiprotein complex is a trimer of the protein DR_0644, a Cu-only superoxide dismutase (SOD) identified here to be efficient in quenching reactive oxygen species. The same data also showed that the stalk region consists of a coiled coil that extends into the cell envelope for â¼280 Å, reaching the inner membrane. Finally, the orientation and localization of the complex are defined by in situ cryo-electron crystallography. The structural organization of the SDBC couples fundamental UV antenna properties with the presence of a Cu-only SOD, showing here coexisting photoprotective and chemoprotective functions. These features suggests how the SDBC and similar protein complexes, might have played a primary role as evolutive templates for the origin of photoautotrophic processes by combining primary protective needs with more independent energetic strategies.
Assuntos
Deinococcus , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Deinococcus/química , Deinococcus/citologia , Deinococcus/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismoRESUMO
Abstract Objective Pregnancy in women with lupus poses a higher risk of complications compared with the general population. The present study aimed to determine and describe the obstetric and neonatal outcomes of pregnant women with lupus. Materials and Methods We conducted an observational retrospective study of pregnant women with the diagnosis of lupus, who were selected and followed at the Maternal-Fetal Medicine Clinic of our institution between January 2013 and July 2018. We analyzed 59 pregnancies and 52 newborns, and collected data regarding sociodemographic features, the preconception period, pregnancy, childbirth, postpartum and the newborn. A descriptive analysis of the variables was performed. Results In 58% of the cases, the pregnancy was uneventful. We registered flares in 25% of the cases, preeclampsia in 3%, fetal growth restriction in 12%, gestational loss in 10%, preterm labor in 10%, postpartum complications in 20%, and small for gestational age newborns in 17% of the cases. Conclusions Most pregnancies in women with lupus have favorable obstetric and neonatal outcomes. Prenatal counseling, adequate multidisciplinary surveillance, and optimized treatment of the disease are fundamental pillars for these good results.
Resumo Objetivo A gravidez em mulheres com lúpus representa um risco maior de complicações em comparação com a população em geral. O presente estudo teve como objetivo determinar e descrever os resultados obstétricos e neonatais de gestantes com lúpus. Materiais e Métodos Realizamos um estudo retrospectivo observacional de gestantes com diagnóstico de lúpus, selecionadas e acompanhadas no Ambulatório de Medicina Materno-Fetal de nossa instituição entre janeiro de 2013 e julho de 2018. Analisamos 59 gestações e 52 recém-nascidos e coletamos dados referentes às características sociodemográficas, período pré-concepcional, gravidez, parto, pós-parto e nascimento. Foi realizada uma análise descritiva das variáveis. Resultados Em 58% dos casos, a gravidez transcorreu sem intercorrências. Registramos surtos em 25% dos casos, pré-eclâmpsia em 3%, restrição do crescimento fetal em 12%, perda gestacional em 10%, trabalho de parto prematuro em 10%, complicações pós-parto em 20% e recém-nascidos pequenos para a idade gestacional em 17% dos casos. Conclusões A maioria das gestações em mulheres com lúpus tem resultados obstétricos e neonatais favoráveis. Aconselhamento pré-natal, vigilância multidisciplinar adequada e tratamento otimizado da doença são pilares fundamentais para esses bons resultados.
Assuntos
Humanos , Feminino , Gravidez , Resultado da Gravidez , Lúpus Eritematoso SistêmicoRESUMO
OBJECTIVE: The risk of intraventricular hemorrhage (IVH) and periventricular leukomalacia is associated with low birth weight and gestational age. Caesarean section (CS) may reduce the risk of IVH, although it has been a matter of debate. The aim of this study was to evaluate the influence of the mode of delivery (MOD) on the development of IVH and cystic periventricular leukomalacia (cPVL). STUDY DESIGN: We analyzed an initial cohort of 11,023 very low birth weight (VLBW) infants born between January 2010 and December 2019. Infants with major malformations and gestational age <23 weeks and ≥32 weeks were excluded. A final cohort of 8,251 newborns was analyzed. Data was collected from Portuguese National very low birth weight registry. Cases were classified as vaginal delivery (VD) or CS. Outcome was assessed in univariate and logistic regression analyses. RESULTS: The median gestational age was 29 weeks (IQR 3.3) and the median weight was 1,100 g (IQR 555). The prevalence of IVH was significantly higher in the VD group versus the CS group, across all grading levels:1,144 newborns had grade I IVH (16% VD vs. 14% CS, p <0.01), 706 had grade II IVH (12% VD vs. 7.6% CS, p <0.01), and 777 had grade III IVH (14% VD vs. 7.9% CS, p <0.01). Post-hemorrhagic ventricular dilatation occurred in 457 newborns (8.3% VD vs. 4.6% CS, p <0.01) and 456 newborns had periventricular hemorrhagic infarction (8.4% VD vs. 4.5% CS, p <0.01). There was no association between MOD and cPVL. After applying a logistic regression analysis, including known risk factors for IVH and cPVL, VD was independently associated with an increased risk of IVH (odds ratio [OR] 1.600[1.423-1.799], p <0.001) and its complications (OR 1.440[1.195-1.735], p <0.001). MOD was not associated with an increased risk of cPVL. CONCLUSION: Our study suggests that CS is associated with a reduced risk of IVH and its complications in preterm VLBW infants < 32 weeks of gestational age. A CS should be considered in this group of infants to prevent the development of IVH and its complications. KEY POINTS: · IVH and cPVL are risk factors for neurological disabilities.. · CS may decrease the risk of IVH in preterms <32 weeks GA.. · There is no association between the MOD and cPVL..
RESUMO
In higher plants, the photosynthetic process is performed and regulated by Photosystem II (PSII). Arabidopsis thaliana was the first higher plant with a fully sequenced genome, conferring it the status of a model organism; nonetheless, a high-resolution structure of its Photosystem II is missing. We present the first Cryo-EM high-resolution structure of Arabidopsis PSII supercomplex with average resolution of 2.79 Å, an important model for future PSII studies. The digitonin extracted PSII complexes demonstrate the importance of: the LHG2630-lipid-headgroup in the trimerization of the light-harvesting complex II; the stabilization of the PsbJ subunit and the CP43-loop E by DGD520-lipid; the choice of detergent for the integrity of membrane protein complexes. Furthermore, our data shows at the anticipated Mn4CaO5-site a single metal ion density as a reminiscent early stage of Photosystem II photoactivation.
Assuntos
Arabidopsis/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Arabidopsis/ultraestrutura , Microscopia Crioeletrônica , Digitonina/metabolismoRESUMO
INTRODUCTION: Sudden and unexpected postnatal collapse is a rare event with potentially dramatic consequences. Intervention approaches are limited, but hypothermia has been considered after postnatal collapse. The aim of this study was to analyse sudden and unexpected postnatal collapse cases that underwent therapeutic hypothermia in the five Portuguese hypothermia centres. MATERIAL AND METHODS: In this multicentre, retrospective and descriptive study, clinical, ultrasonography, amplitude-integrated electroencephalography and brain magnetic resonance findings of newborns with postnatal collapse that underwent therapeutic hypothermia are reported (2010 - 2018). Statistical analysis was performed by using IBM SPSS Statistics version 21. RESULTS: Twenty-two cases of sudden and unexpected postnatal collapse were referred for therapeutic hypothermia (82% outborn), all ≥ 36 weeks, with Apgar 5´ ≥ 8. Collapse occurred during the first two hours in 73% (all < 24 hours), 50% during skin-to-skin care, 55% related to feeding and 23% during co-bedding. Moderate-severe encephalopathy and severe acidosis were observed (median: Thompson score 16, pH 6.90, base deficit 22 mmol/L). Amplitude-integrated electroencephalogram was abnormal in 95% and magnetic resonance imaging showed severe brain injury in 46%. The mortality rate was 50%. A possible cause was identified in 27%. DISCUSSION: The incidence rate of 2.7 sudden cases of postnatal collapse per 100 000 births, is possibly under-estimated. All infants suffered the collapse in the first day, mostly within the first two hours, as reported before. Possible causes were identified in less than a third of cases, but multiple predisposing conditions were identified, suggesting that prevention may be possible. Newborn positioning and skin-to-skin care have been the most discussed practices. A significant proportion of infants had poor outcomes. Lower Thompson score, electroencephalogram amplitude normalization and normal magnetic resonance imaging seemed to indicate better outcomes. Although conclusive trials on therapeutic hypothermia after postnatal collapse are not available, its use has been considered individually. No severe adverse effects directly related to hypothermia were registered in this study, but the results do not allow drawing meaningful conclusions. CONCLUSION: In our national sample of 22 infants who suffered sudden and unexpected postnatal collapse and underwent therapeutic hypothermia, a significant proportion had poor outcomes. Absolute conclusions from our experience with hypothermia in postnatal collapse cannot be drawn, but systematic reporting of cases and long-term clinical evaluation would facilitate understanding of the real benefits of hypothermia. As this procedure has not been validated with clinical trials for this indication, its use should be considered on a case-by-case approach. The potentially avoidable nature of unexpected postnatal collapse is evident from its association with certain behaviours and risk factors. Surveillance practices during the first hours should be implemented, whilst the benefits of breastfeeding and skin-to-skin care should continue to be widely promoted.
Introdução: O colapso pós-natal súbito inesperado, apesar de raro, condiciona potenciais consequências dramáticas. As intervenções terapêuticas são limitadas, mas a hipotermia induzida tem sido considerada após estes eventos. O objetivo deste estudo foi analisar os casos de colapso pós-natal súbito inesperado submetidos a hipotermia induzida nos cinco centros portugueses que a realizam. Material e Métodos: Estudo descritivo retrospetivo multicêntrico dos recém-nascidos submetidos a hipotermia induzida após colapso pós-natal entre 2010 e 2018. Foram analisadas as variáveis clínicas, a monitorização por eletroencefalograma de amplitude integrada e imagem por ultrassonografia e a ressonância magnética cerebral. A análise estatística foi efetuada com apoio do IBM SPSS Statistics version 21. Resultados: Foram submetidos a hipotermia terapêutica por colapso súbito 22 recém-nascidos, 82% outborn, todos com 36 ou mais semanas de gestação e Apgar 5´ ≥ 8. A situação ocorreu nas primeiras duas horas de vida em 73% (todos com menos de 24 horas de vida), 50% no contacto pele-a-pele, 55% associados à amamentação e 23% durante partilha de cama. Os recém-nascidos observados apresentaram encefalopatia moderada a grave e acidose grave (mediana: Thompson 16, pH 6,90, défice bases 22 mmol/L). Entre os recém-nascidos, 95% registaram alteração no eletroencefalograma e 46% padrões graves de ressonância cerebral. A taxa de mortalidade foi de 50%. Identificaram-se possíveis causas em 27%. Discussão: Estimou-se uma incidência de 2,7 casos de colapso pós-natal súbito inesperado por cada 100 000 nascimentos, um valor possivelmente subestimado. O colapso ocorreu no primeiro dia em todas as crianças, a maioria nas primeiras duas horas, tal como descrito em publicações anteriores. Identificaram-se possíveis causas em menos de um terço dos casos, mas múltiplas condições predisponentes foram referidas, o que sugere a possibilidade de adoção de medidas preventivas. O posicionamento do recém-nascido e o contacto pele-a-pele têm sido as práticas mais discutidas. Uma proporção significativa das crianças teve uma evolução desfavorável. Um desfecho mais positivo parece ter ocorrido nos casos em que se verificaram valores inferiores na escala de Thompson, normalização do eletroencefalograma de amplitude integrada e ressonância magnética normal. Embora não estejam disponíveis ensaios conclusivos sobre a utilização da hipotermia terapêutica após o colapso pós-natal, o seu uso tem sido considerado individualmente. Nesta revisão não foram observados efeitos adversos diretamente relacionados com o procedimento, mas os resultados não permitem obter conclusões significativas. Conclusão: Na nossa amostra nacional de 22 crianças que sofreram colapso súbito pós-natal e submetidas a hipotermia terapêutica, uma proporção significativa teve uma evolução desfavorável. A nossa experiência e a raridade da entidade clínica não permitem delinear conclusões precisas sobre a aplicação da hipotermia induzida no colapso pós-natal súbito inesperado, pelo que se considera essencial a prevenção. O benefício desta terapêutica poderá ser clarificado através do registo sistemático dos casos e do seguimento a longo prazo das crianças. Embora não existam ensaios clínicos que permitam a sua validação após estes eventos, a hipotermia induzida deve ser uma opção a considerar individualmente. A associação do colapso pós-natal com determinados comportamentos e fatores de risco evidenciam a sua potencial prevenção. Devem ser implementadas estratégias de monitorização nas primeiras horas de vida que permitam simultaneamente a contínua promoção da amamentação e do contacto pele-a-pele.
Assuntos
Hipotermia Induzida , Aleitamento Materno , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Estudos Retrospectivos , Fatores de RiscoRESUMO
BACKGROUND AND AIMS: Cerebral lesions detected using cerebral ultrasound (cUS) in very preterm infants are associated with increased risk for neurodevelopmental problems. However, uncomplicated intraventricular hemorrhage (IVH) has no consistent association with poor outcome. In this study we evaluate the effect of uncomplicated IVH on estimated brain volume at term-equivalent age (TEA), using a model based on measurements made from cUS. METHODS: We studied 2 groups of preterm infants (<32 weeks' gestational age (GA)) up to and at TEA: (1) infants with uncomplicated grades 2 or 3 IVH, (2) infants with consistently normal scans. Estimated cerebral volumes at TEA were calculated using a previously described model based on linear measurements and compared between the 2 groups using independent groups t-test or the Mann-Whitney test; p-value <0.05 was considered significant. RESULTS: We assessed 95 preterm infants (18 with uncomplicated IVH and 71 with normal scans). GA and birth weight were lower in infants with uncomplicated IVH (26.8/28.7weeks, p < 0.001, 944/1082g, p < 0.05, respectively); occipital-frontal circumference at TEA was smaller in the IVH infants (34.2 vs 35.3 cm, p < 0.05). However, no significant differences at TEA were found for estimated cranial volume (383/411cc3), estimated cerebral volume (337/341cc3), Levene ventricular index (13.5/12.2 mm) or thalamo-occipital distance (21.5/20.3 mm). Statistical adjustment for the lower GA in the IVH group confirmed the absence of a significant difference in the findings. CONCLUSIONS: In summary, we found that estimated cerebral volume at TEA, based on measurements made at the bedside using cranial US, is not different between very preterm infants with consistently normal scans and those with uncomplicated grades 2 and 3 IVH.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/crescimento & desenvolvimento , Hemorragia Cerebral/complicações , Doenças do Prematuro/diagnóstico por imagem , Ultrassonografia/métodos , Peso ao Nascer , Hemorragia Cerebral/diagnóstico por imagem , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso/crescimento & desenvolvimento , MasculinoRESUMO
INTRODUCTION: Prematurity and low birth weight have been associated with increased neonatal morbidity and mortality. This study aimed to evaluate possible risk factors for prematurity associated with fetal growth restriction and being small for gestational age and to determine the incidence of morbidity in these two groups of infants. MATERIAL AND METHODS: Retrospective case-control study of newborns with gestational age of less than 32 weeks, with obstetric diagnosis of fetal growth restriction and with the clinical diagnosis of small for gestational age, admitted to the Neonatal Intensive Care Unit of a tertiary hospital for a period of six years. RESULTS: A total of 356 newborns were studied, with an incidence of 11% of fetal growth restriction and 18% of small for gestational age. Pre-eclampsia was the risk factor for gestation with higher statistical significance (47% vs 16%, p < 0.001) in small for gestational age newborns. There was also a higher incidence of mild bronchopulmonary dysplasia (66% vs 38%, p = 0.005), late sepsis (59% vs 37%, p = 0.003), retinopathy of prematurity (58% vs 26%, p = 0.003) and necrotizing enterocolitis (20% vs 9%, p = 0.005). Mortality was similar in all three groups. DISCUSSION: There were fewer newborn males diagnosed with fetal growth restriction during pregnancy compared to women. Significant differences were observed in the group of these infants regarding the occurrence of chorioamnionitis and pre-eclampsia in comparison to the control group. Newborns with fetal growth restriction and small for age had higher scores on clinical risk indices compared to the control group. In general, small for gestational age newborns had a higher incidence of morbidity than infants with fetal growth restriction and the control group. CONCLUSION: Advances in neonatal intensive care decreased mortality in preterm infants. However, there are still significant differences in the incidence of morbidity in newborns with growth compromise. The collaboration between obstetricians and neonatologists provides the basis for a correct clinical evaluation, early signaling and global intervention on these newborns, with a significant impact on short and long-term prognosis.
Introdução: A prematuridade e o baixo peso ao nascer têm sido associados a maior morbilidade e mortalidade neonatais. Este estudo teve como objetivo avaliar possíveis fatores de risco para a prematuridade associada a restrição do crescimento fetal e a recém-nascidos leves para a idade gestacional e determinar a incidência da morbilidade nestes dois grupos de recém-nascidos.Material e Métodos: Estudo caso-controlo retrospetivo dos recém-nascidos com idade gestacional inferior a 32 semanas, com o diagnóstico obstétrico de restrição do crescimento fetal e com o diagnóstico clínico de leves para a idade gestacional, internados na Unidade de Cuidados Intensivos Neonatais de um hospital terciário, durante um período de seis anos.Resultados: Foram estudados 356 recém-nascidos, observando-se uma incidência de 11% de restrição do crescimento fetal e 18% de leves para a idade gestacional. A pré-eclâmpsia foi o fator de risco da gestação com maior significado estatístico (47% vs 16%, p < 0,001) nos recém-nascidos leves para a idade gestacional. Observou-se também, nestes recém-nascidos, maior incidência de displasia broncopulmonar ligeira (66% vs 38%, p = 0,005), de sépsis tardia (59% vs 37%, p = 0,003), de retinopatia da prematuridade (58% vs 26%, p = 0,003) e de enterocolite necrotizante (20% vs 9%, p = 0,005). A mortalidade foi idêntica nos três grupos.Discussão: Encontraram-se menos recém-nascidos do sexo masculino diagnosticados com restrição do crescimento fetal durante a gravidez comparativamente ao sexo feminino. Observaram-se diferenças significativas no grupo destes recém-nascidos, quanto à ocorrência de corioamnionite e de pré-eclâmpsia, face ao grupo controlo. Tanto os recém-nascidos com restrição do crescimento fetal como os leves para a idade gestacional apresentaram uma pontuação mais elevada nos índices de risco clínico comparativamente ao grupo controlo. De forma global, os recém-nascidos leves para a idade gestacional tiveram maior incidência de morbilidade que os recém-nascidos com restrição do crescimento fetal e que o grupo controlo.Conclusão: Os avanços nos cuidados intensivos neonatais diminuíram a mortalidade nos recém-nascidos prematuros. Contudo, observam-se ainda diferenças significativas na incidência da morbilidade nos recém-nascidos com compromisso do crescimento. A colaboração entre obstetras e neonatalogistas constitui a base para uma correta avaliação clínica, sinalização precoce e intervenção global sobre estes recém-nascidos, com impacto significativo no prognóstico a curto e longo prazo.
Assuntos
Retardo do Crescimento Fetal , Idade Gestacional , Recém-Nascido Pequeno para a Idade Gestacional , Adulto , Displasia Broncopulmonar/epidemiologia , Estudos de Casos e Controles , Enterocolite Necrosante/epidemiologia , Feminino , Retardo do Crescimento Fetal/epidemiologia , Humanos , Incidência , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Morbidade , Sepse Neonatal/epidemiologia , Portugal/epidemiologia , Pré-Eclâmpsia , Gravidez , Retinopatia da Prematuridade/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Centros de Atenção Terciária/estatística & dados numéricosRESUMO
BACKGROUND: Periventricular white matter (PWM) is particularly vulnerable in very preterm infants. Non-cystic white matter injury, known as non-cystic periventricular leukomalacia (ncPVL), is the commonest 'lesion' affecting the preterm brain. There is no consensus about whether ncPVL can be reliably identified from cerebral ultrasound (cUS) or whether there is any reliable correlate of ncPVL on cUS at term-equivalent age (TEA). OBJECTIVE: To compare brain volumes and linear measures at TEA in infants with and without a diagnosis of ncPVL. METHODS: Preterm infants of ≤32 weeks' gestation without major lesions were serially assessed using cUS. ncPVL was defined as PWM echogenicity comparable to the choroid plexus on two scans at least 2 weeks apart after the first postnatal week. At TEA, infants were scanned for the estimation of brain volume and ventricular and tissue dimensions. Head circumference was measured. The data were compared between those with/without ncPVL. Observer agreement was assessed using kappa statistic. RESULTS: Of 63 eligible infants 29% had ncPVL. Significant differences were found between those with/without ncPVL for 5 min Apgar score, CRIB score, invasive ventilation rates and chronic lung disease but not for other relevant clinical data. No significant differences were found for estimated brain volume, ventricular size, corpus callosum length/thickness or central grey matter width. Intra-observer reliability was moderate (kappa = 0.51-0.56); inter-observer reliability was poor (kappa = 0.20-0.32). CONCLUSIONS: This study indicates that an ultrasound diagnosis of ncPVL should not be used as a sole predictor of lower brain growth detectable at TEA.
Assuntos
Encéfalo/patologia , Doenças do Prematuro/patologia , Leucomalácia Periventricular/patologia , Encéfalo/anatomia & histologia , Estudos de Coortes , Idade Gestacional , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Doenças do Prematuro/diagnóstico por imagem , Leucomalácia Periventricular/diagnóstico por imagem , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , UltrassonografiaRESUMO
BACKGROUND: Reduced supratentorial brain growth has been shown in preterm-born infants at term-equivalent age (TEA), but cerebellar growth may be preserved in the absence of supratentorial injury. Our study aims to compare cerebellar size assessed using cerebral ultrasound (cUS) at TEA between preterm infants and term-born controls. METHODS: Cerebellar dimensions (including transverse cerebellar diameter (TCD), cerebellar vermis height, anteroposterior vermis diameter (APVD), and cerebellar vermis area (CVA)) were measured using Image Arena software (TomTec Imaging Systems, Unterschleissheim, Germany) in 71 infants <32-wk gestation without significant scan abnormality at TEA and in 58 term-born control infants. Intra- and interobserver agreement were evaluated. RESULTS: In comparison with controls, preterms at TEA had smaller TCDs (4.9 vs. 5.2 cm; P < 0.001) but larger CVAs (4.7 vs. 4.3 cm(2); P < 0.005) and APVDs (2.4 vs. 2.2 cm; P < 0.001); however, these differences were no longer seen after accounting for head shape. In <28-wk gestational age infants, CVA was statistically similar to controls, as were for small-for-gestational-age infants. CONCLUSION: Our data support neonatal sparing of preterm cerebellar growth that is measureable using cUS, and this includes the most immature and small-for-gestational-age infants. We suggest cUS can be used to assess cerebellar size at TEA, with measures of both width and height being taken into account, and thus may be a useful tool for detecting infants with poorer cerebellar growth who are at increased risk of disability.
Assuntos
Cerebelo/diagnóstico por imagem , Recém-Nascido Prematuro , Estudos de Casos e Controles , Humanos , Recém-Nascido , UltrassonografiaRESUMO
BACKGROUND AND AIMS: Very preterm infants are at particular risk of neurodevelopmental impairments. This risk can be anticipated when major lesions are seen on cerebral ultrasound (cUS). However, most preterm infants do not have such lesions yet many have a relatively poor outcome. Our study aims were to describe a tri-dimensional cUS model for measuring cranial and brain volume and to determine the range of brain volumes found in preterm infants without major cUS lesions at term equivalent age (TEA) compared to term-born control infants. We also aimed to evaluate whether gestational age (GA) at birth or being small for gestational age (SGA) influenced estimated brain size. METHODS: We scanned a cohort of very preterm infants at TEA and term-born controls. Infants with major cerebral lesions were excluded. Measurements of intracranial diameters (bi-parietal, longitudinal, cranial height), brain structures, ventricles and extracerebral space (ECS) were made. A mathematical model was built to estimate from the cUS measurements the axial area and volumes of the cranium and brain. Appropriate statistical methods were used for comparisons; a p-value under 0.05 was considered significant. SGA infants from both groups were analysed separately. RESULTS: We assessed 128 infants (72 preterms and 56 controls). The preterms' head was longer (11.5 vs. 10.5 cm, p < 0.001), narrower (7.8 vs. 8.4 cm, p < 0.001) and taller (8.9 vs. 8.6 cm, p < 0.01) than the controls'. Estimated intracranial volume was not statistically different between the groups (411 vs. 399 cm(3), NS), but preterms had larger estimated ECS volume (70 vs. 22 cm(3), p < 0.001), lateral ventricular coronal areas (33 vs. 12 mm(2), p < 0.001) and thalamo-occipital distances (20 vs. 16 mm, p < 0.001), but smaller estimated cerebral volume (340 vs. 377 cm(3), p < 0.001). Smaller brain volumes were associated with being of lower gestational age and birth weight and being small-for-gestational age. CONCLUSIONS: We have developed a model using cranial ultrasound for measuring cranial and brain volumes. Using this model our data suggest that even in the absence of major cerebral lesions, the average extrauterine cerebral growth of very preterm infants is compromised. Our model can help in identifying those preterm infants with smaller brains. Later follow-up data will determine the neurodevelopmental outcome of these preterm infants in relation to their estimated brain volumes.
Assuntos
Encéfalo/anatomia & histologia , Ecoencefalografia , Recém-Nascido Prematuro , Modelos Teóricos , Estudos de Casos e Controles , Interpretação Estatística de Dados , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Masculino , Tamanho do ÓrgãoRESUMO
BACKGROUND AND AIMS: Clinical assessment of gestational age (GA) in preterm infants can be challenging. Several ultrasound approaches for estimating GA using cerebellar measurements are reported, claiming to be simpler and more accurate than clinical assessment, but they are not widely used. We aimed to compare the accuracy of four previously described measurements and compare their use in preterm infants. METHODS: We studied infants <32weeks of GA defined by in-vitro fertilization date or early fetal ultrasound, excluding infants with neurological problems. Vermis anterior-posterior diameter (VAPD), vermis height (VH), and transverse cerebellar diameter via anterior (TCDa) and mastoid fontanelles (TCDm) were measured.Estimated PMA was calculated using published equations, and compared to known PMA using intraclass correlation coefficient (ICC). Intra and inter-observer reliability were determined. RESULTS: We studied 80 infants (mean GA 28.5weeks [range 24-32], mean post-natal age 5.7days). ICC was 0.761 (VAPD), 0.632 (VH), 0.115 (TCDa) and 0.825 (TCDm). The TCDm equation gave the best estimate of GA (mean estimate -2days; 95% CI±13.8days). TCDa and TCDm absolute measurements were similar for each infant. Accuracy for estimating GA was similar for appropriately grown and small-for-gestation infants. Inter and intra-observer reliability was very good for all measurements. CONCLUSIONS: Three previously described equations for estimating GA from cerebellar measurements gave good estimates of GA in preterms. The equation described for TCDm gave the narrowest 95% CI. We recommend the TCDm equation for the estimation of GA in VLBW infants but the TCD measurement can be made via either the anterior or mastoid fontanelle.
Assuntos
Cerebelo/diagnóstico por imagem , Idade Gestacional , Ultrassonografia Pré-Natal/métodos , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , GravidezRESUMO
OBJECTIVE: To determine whether prophylactic antibiotic administration in women presenting with premature rupture of membranes (PROM) at term can alter the rates of maternal and neonatal infections. METHODS: In a randomized, controlled, nonblinded trial, women at low risk with singleton term pregnancies presenting with PROM were assigned to either antibiotic administration or no treatment. Main outcomes evaluated were rates of maternal infection (chorioamnionitis and endometritis) and neonatal infection. RESULTS: A total of 161 patients were evaluated, 78 in the antibiotic group and 83 in the control group. Maternal infection was significantly lower when antibiotics were administered (2.6% compared with 13.2%; relative risk 0.89, 95% confidence interval 0.81-0.98; P=.013). All cases of maternal infection occurred in women with more than 12 hours of PROM. Newborns of mothers receiving antibiotics had fewer infections (3.8%) compared with those in the control group (6.0%), but the difference was not statistically significant (P=.375). CONCLUSION: Prophylactic use of antibiotics in PROM at term significantly reduced the risk of maternal infection in our population. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01633294. LEVEL OF EVIDENCE: I.
Assuntos
Antibacterianos/uso terapêutico , Antibioticoprofilaxia/métodos , Corioamnionite/tratamento farmacológico , Endometrite/tratamento farmacológico , Ruptura Prematura de Membranas Fetais/microbiologia , Complicações Infecciosas na Gravidez/prevenção & controle , Adolescente , Adulto , Corioamnionite/prevenção & controle , Endometrite/prevenção & controle , Feminino , Humanos , Recém-Nascido , Gravidez , Adulto JovemRESUMO
INTRODUCTION: In Portugal, since 1989, the rates of maternal, perinatal and neonatal mortality present a significant decrease, after the implemented perinatal network. The continuous assessment of the existing conditions at the different levels of perinatal care is essential to identify deviations from normality and may allow the optimization of quality of care. OBJECTIVES: To obtain information on and to evaluate the conditions and practices of neonatal resuscitation at the Portuguese delivery rooms, in order to propose measures for improvement of neonatal care. MATERIAL AND METHODS: An electronic questionnaire was sent to 35 hospitals with maternity. The survey included questions regarding to human and material resources, characteristics of delivery room practices used in stabilization / resuscitation of the newborn, number of deliveries and number of newborns transferred after birth per year, as well as issues related with the collaboration of obstetric teams. RESULTS: Thirty centres (86%) answered the questionnaire, 16 of the respondents were level III maternities/hospitals. In eight (27%) centres a paediatrician is present at all deliveries, whereas in the remaining centres a paediatrician is available only for risk situations. The material unavailable in some centres include cardio-respiratory monitoring equipment, support device with pressure controlled ventilation, oxygen blender, ventilator, CPAP (continuous positive airway pressure), neonatal transport incubators and equipments for thoracocentesis and paracentesis. The criteria used for prophylactic surfactant and oxygen use are very different among the various centres. All centres reported transferring newborns after birth, either because of lack of differentiation of care or vacant beds. The centres with perinatal support reported less cooperation of the obstetric teams. CONCLUSIONS: The care of the newborn in the national delivery rooms can and should be improved. It is necessary to adapt the equipment and human resources to the needs of each centre. Protocols and practices such as oxygen and "prophylactic" surfactant must be updated, transport after birth must be reduced and the communication with the obstetric teams should be improved.
Assuntos
Ressuscitação/estatística & dados numéricos , Ressuscitação/normas , Salas de Parto , Humanos , Recém-Nascido , Portugal , Inquéritos e QuestionáriosRESUMO
A questão da adesão aos regimes de tratamento tem sido abordada, nos últimos anos, numa perspectiva biopsicossocial pelos investigadores. Nesse sentido, o presente estudo procura investigar a prevalência de determinados comportamentos de saúde, nomeadamente a adesão terapêutica e em que medida a percepção de saúde influencia este componente. Para isso, construímos e aplicamos o QIAT (Questionário Informativo de Adesão Terapêutica) aos utentes dum centro de saúde (N = 273). Os resultados indicam que, de um modo geral, a não-adesão não se deve ao esquecimento ou a alterações na medicação. Em relação às crenças e atitudes face aos médicos e à Medicina por parte dos utentes, existe a crença de excesso de prescrição medicamentosa, assim como uma confiança exacerbada relativa ao efeito terapêutico dos fármacos e a culpabilização dos doentes por parte dos profissionais de saúde, aquando do insucesso do tratamento