Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
2.
J Thromb Haemost ; 22(2): 466-469, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37981048

RESUMO

All newborns need extra phylloquinone (vitamin K1; K1) to prevent vitamin K deficiency bleeding (VKDB). In preterm babies, the main sources are prophylactic K1 given at birth and parenteral and/or enteral feeding thereafter. Preterm babies are at risk of late-onset VKDB if ongoing K1 supplementation is inadequate. For extremely preterm infants fed an exclusive human milk diet, the low K1 content of human milk may predispose them to vitamin K deficiency. Human milk fortification with either bovine milk-derived fortifier or human milk-based fortifier (HMF) made from pooled donor milk is a widely used strategy to improve the micronutrient and growth status of preterm infants. However, the K1 content of HMF is markedly lower than that of bovine-based preparations. We present an unusual case of late-onset VKDB in an extremely preterm infant who received an exclusive human milk diet and HMF and quantify total K1 intake prior to the bleeding.


Assuntos
Leite Humano , Sangramento por Deficiência de Vitamina K , Lactente , Recém-Nascido , Humanos , Lactente Extremamente Prematuro , Sangramento por Deficiência de Vitamina K/prevenção & controle , Vitamina K 1 , Dieta , Vitamina K
3.
J Thromb Haemost ; 20(12): 2773-2785, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36087073

RESUMO

BACKGROUND: There is near-global consensus that all newborns be given parenteral vitamin K1 (VK1 ) at birth as prophylaxis against VK deficiency bleeding (VKDB). Breastmilk has a low VK content and cases of late VKDB are reported in exclusively breastmilk-fed preterm infants despite VK prophylaxis at birth. OBJECTIVES: To assess the prevalence of functional VK insufficiency in preterm infants based on elevated under-γ-carboxylated (Glu) species of Gla proteins, factor II (PIVKA-II), and osteocalcin (GluOC), synthesized by liver and bone, respectively. PATIENTS/METHODS: Prospective, multicenter, observational study in preterm infants born <33 weeks' gestation. Blood samples and dietary history were collected before hospital discharge, and after discharge at 2-3 months' corrected age. Outcome measures were serum VK1 , PIVKA-II, and %GluOC (GluOC as a percentage of the sum of GluOC plus GlaOC) compared between exclusively breastmilk-fed and formula/mixed-fed infants after discharge. RESULTS: After discharge, breastmilk-fed babies had significantly lower serum VK1 (0.15 vs. 1.81 µg/L), higher PIVKA-II (0.10 vs. 0.02 AU/ml) and higher %GluOC (63.6% vs. 8.1%) than those receiving a formula/mixed-feed diet. Pre-discharge (based on elevated PIVKA-II), only one (2%) of 45 breastmilk-fed infants was VK insufficient. After discharge, eight (67%) of 12 exclusively breastmilk-fed babies were VK insufficient versus only one (4%) of 25 formula/mixed-fed babies. CONCLUSIONS: Preterm infants who remain exclusively or predominantly human breastmilk-fed after neonatal unit discharge are at high risk of developing subclinical VK deficiency in early infancy. Routine postdischarge VK1 supplementation of breastfed infants to provide intakes comparable to those from formula milks should prevent this deficiency.


Assuntos
Leite Humano , Deficiência de Vitamina K , Lactente , Recém-Nascido , Humanos , Recém-Nascido Prematuro , Assistência ao Convalescente , Estudos Prospectivos , Alta do Paciente , Deficiência de Vitamina K/diagnóstico , Deficiência de Vitamina K/epidemiologia , Deficiência de Vitamina K/prevenção & controle , Vitamina K 1 , Hemorragia , Vitamina K
4.
Cell Rep Med ; 1(5): 100077, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32904427

RESUMO

Supplementation with members of the early-life microbiota as "probiotics" is increasingly used in attempts to beneficially manipulate the preterm infant gut microbiota. We performed a large observational longitudinal study comprising two preterm groups: 101 infants orally supplemented with Bifidobacterium and Lactobacillus (Bif/Lacto) and 133 infants non-supplemented (control) matched by age, sex, and delivery method. 16S rRNA gene profiling on fecal samples (n = 592) showed a predominance of Bifidobacterium and a lower abundance of pathobionts in the Bif/Lacto group. Metabolomic analysis showed higher fecal acetate and lactate and a lower fecal pH in the Bif/Lacto group compared to the control group. Fecal acetate positively correlated with relative abundance of Bifidobacterium, consistent with the ability of the supplemented Bifidobacterium strain to metabolize human milk oligosaccharides into acetate. This study demonstrates that microbiota supplementation is associated with a Bifidobacterium-dominated preterm microbiota and gastrointestinal environment more closely resembling that of full-term infants.


Assuntos
Bifidobacterium/fisiologia , Microbioma Gastrointestinal/fisiologia , Recém-Nascido Prematuro/metabolismo , Recém-Nascido Prematuro/fisiologia , Lactobacillus/fisiologia , Metaboloma/fisiologia , Bifidobacterium/genética , Aleitamento Materno/métodos , Suplementos Nutricionais/microbiologia , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Humanos , Lactente , Recém-Nascido , Lactobacillus/genética , Estudos Longitudinais , Leite Humano/microbiologia , Probióticos/administração & dosagem , RNA Ribossômico 16S/genética
5.
Lancet Neurol ; 18(1): 35-45, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30447969

RESUMO

BACKGROUND: In neonatal encephalopathy, the clinical manifestations of injury can only be reliably assessed several years after an intervention, complicating early prognostication and rendering trials of promising neuroprotectants slow and expensive. We aimed to determine the accuracy of thalamic proton magnetic resonance (MR) spectroscopy (MRS) biomarkers as early predictors of the neurodevelopmental abnormalities observed years after neonatal encephalopathy. METHODS: We did a prospective multicentre cohort study across eight neonatal intensive care units in the UK and USA, recruiting term and near-term neonates who received therapeutic hypothermia for neonatal encephalopathy. We excluded infants with life-threatening congenital malformations, syndromic disorders, neurometabolic diseases, or any alternative diagnoses for encephalopathy that were apparent within 6 h of birth. We obtained T1-weighted, T2-weighted, and diffusion-weighted MRI and thalamic proton MRS 4-14 days after birth. Clinical neurodevelopmental tests were done 18-24 months later. The primary outcome was the association between MR biomarkers and an adverse neurodevelopmental outcome, defined as death or moderate or severe disability, measured using a multivariable prognostic model. We used receiver operating characteristic (ROC) curves to examine the prognostic accuracy of the individual biomarkers. This trial is registered with ClinicalTrials.gov, number NCT01309711. FINDINGS: Between Jan 29, 2013, and June 25, 2016, we recruited 223 infants who all underwent MRI and MRS at a median age of 7 days (IQR 5-10), with 190 (85%) followed up for neurological examination at a median age of 23 months (20-25). Of those followed up, 31 (16%) had moderate or severe disability, including one death. Multiple logistic regression analysis could not be done because thalamic N-acetylaspartate (NAA) concentration alone accurately predicted an adverse neurodevelopmental outcome (area under the curve [AUC] of 0·99 [95% CI 0·94-1·00]; sensitivity 100% [74-100]; specificity 97% [90-100]; n=82); the models would not converge when any additional variable was examined. The AUC (95% CI) of clinical examination at 6 h (n=190) and at discharge (n=167) were 0·72 (0·65-0·78) and 0·60 (0·53-0·68), respectively, and the AUC of abnormal amplitude integrated EEG at 6 h (n=169) was 0·73 (0·65-0·79). On conventional MRI (n=190), cortical injury had an AUC of 0·67 (0·60-0·73), basal ganglia or thalamic injury had an AUC of 0·81 (0·75-0·87), and abnormal signal in the posterior limb of internal capsule (PLIC) had an AUC of 0·82 (0·76-0·87). Fractional anisotropy of PLIC (n=65) had an AUC of 0·82 (0·76-0·87). MRS metabolite peak-area ratios (n=160) of NAA-creatine (<1·29) had an AUC of 0·79 (0·72-0·85), of NAA-choline had an AUC of 0·74 (0·66-0·80), and of lactate-NAA (>0·22) had an AUC of 0·94 (0·89-0·97). INTERPRETATION: Thalamic proton MRS measures acquired soon after birth in neonatal encephalopathy had the highest accuracy to predict neurdevelopment 2 years later. These methods could be applied to increase the power of neuroprotection trials while reducing their duration. FUNDING: National Institute for Health Research UK.


Assuntos
Encéfalo/diagnóstico por imagem , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/terapia , Espectroscopia de Ressonância Magnética , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/metabolismo , Feminino , Humanos , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Hipóxia-Isquemia Encefálica/metabolismo , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Tálamo , Resultado do Tratamento
6.
Arch Dis Child Fetal Neonatal Ed ; 102(5): F451-F455, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28456753

RESUMO

OBJECTIVE: To compare in two epochs of differing phosphate provision serum calcium, phosphate, potassium, and sodium concentrations and the frequency of abnormality of these electrolytes and of sepsis in preterm infants who received an optimised higher amino acid-content formulation. DESIGN AND SETTING: Retrospective cohort study at a single tertiary-level neonatal unit. PATIENTS: Preterm infants given parenteral nutrition (PN) in the first postnatal week during two discrete 6-month epochs in 2013-2014. INTERVENTIONS: In epoch 1 the Ca2+:PO4 molar ratio of the PN formulation was ~1.3-1.5:1 (1.7 mmol Ca2+ and 1.1 mmol PO4 per 100 mL aqueous phase) and in epoch 2 was 1.0:1 via extra phosphate supplementation (1.7 mmol Ca2+ and 1.7 mmol PO4 per 100 mL). MAIN OUTCOME MEASURES: Peak calcium and nadir phosphate and potassium concentrations, and proportions with severe hypercalcaemia (Ca2+ >3.0 mmol/L), hypophosphataemia (PO4<1.5 mmol/L), and hypokalaemia (K+ <3.5 mmol/L) within the first postnatal week. RESULTS: In epoch 2, peak calcium concentrations were lower than in epoch 1 (geometric means: 2.83 mmol/L vs 3.09 mmol/L, p value<0.0001), fewer babies were severely hypercalcaemic (10/49, 20%, vs 31/51, 61%, p value<0.0001); nadir plasma phosphate concentrations were higher (means: 1.54 mmol/L vs 1.32 mmol/L, p value=0.006), and there were fewer cases of hypophosphataemia (17/49, 35% vs 31/51, 61%, p value=0.009) and hypokalaemia (12/49, 25% vs 23/51, 45%, p value=0.03). CONCLUSIONS: Reverting from a PN Ca2+:PO4 molar ratio of 1.3-1.5:1 to a ratio of 1.0:1 was associated with a lower incidence and severity of hypophosphataemia and hypercalcaemia. For preterm infants given higher concentrations of amino acids (≥2.5 g/kg/day) from postnatal day 1, an equimolar Ca2+:PO4 ratio may be preferable during the first postnatal week.


Assuntos
Cálcio/análise , Hipercalcemia/prevenção & controle , Hipofosfatemia/prevenção & controle , Recém-Nascido Prematuro , Soluções de Nutrição Parenteral/química , Fosfatos/análise , Aminoácidos/análise , Estudos de Coortes , Feminino , Humanos , Hipercalcemia/etiologia , Hipopotassemia/prevenção & controle , Hipofosfatemia/etiologia , Recém-Nascido , Masculino , Nutrição Parenteral , Potássio/análise , Estudos Retrospectivos , Índice de Gravidade de Doença
7.
Nutrients ; 7(10): 8308-20, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26426042

RESUMO

All newborns require phylloquinone after birth to prevent vitamin K deficiency bleeding. Babies born prematurely may be at particular risk of deficiency without adequate supplementation during infancy. The main sources of phylloquinone in preterm babies during the neonatal period are the prophylactic dose of phylloquinone given at birth, and that derived from parenteral and/or enteral feeding. This observational study formed part of a prospective, multicentre, randomised, controlled trial that examined the vitamin K status of preterm infants after random allocation to one of three phylloquinone prophylactic regimens at birth (0.5 or 0.2 mg intramuscularly or 0.2 mg intravenously). In this nutritional sub-study we quantified the proportional and total phylloquinone intakes of preterm infants within the neonatal period from all sources. Almost all infants had average daily phylloquinone intakes that were in excess of the currently recommended amounts. In infants who did not receive parenteral nutrition, the bolus dose of phylloquinone given at birth was the major source of phylloquinone intake, whereas in infants who received parenteral nutrition, the intake from the parenteral preparation exceeded that from the bolus dose by a ratio of approximately 3:1. Our study supports the concern of others that preterm infants who receive current parenteral nutrition formulations may be receiving excessive vitamin K.


Assuntos
Recém-Nascido Prematuro/fisiologia , Vitamina K 1/administração & dosagem , Nutrição Enteral , Idade Gestacional , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Nutrição Parenteral , Recomendações Nutricionais , Deficiência de Vitamina K/complicações , Deficiência de Vitamina K/prevenção & controle
8.
J Med Chem ; 58(4): 1717-35, 2015 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-25680029

RESUMO

WNT signaling is frequently deregulated in malignancy, particularly in colon cancer, and plays a key role in the generation and maintenance of cancer stem cells. We report the discovery and optimization of a 3,4,5-trisubstituted pyridine 9 using a high-throughput cell-based reporter assay of WNT pathway activity. We demonstrate a twisted conformation about the pyridine-piperidine bond of 9 by small-molecule X-ray crystallography. Medicinal chemistry optimization to maintain this twisted conformation, cognisant of physicochemical properties likely to maintain good cell permeability, led to 74 (CCT251545), a potent small-molecule inhibitor of WNT signaling with good oral pharmacokinetics. We demonstrate inhibition of WNT pathway activity in a solid human tumor xenograft model with evidence for tumor growth inhibition following oral dosing. This work provides a successful example of hypothesis-driven medicinal chemistry optimization from a singleton hit against a cell-based pathway assay without knowledge of the biochemical target.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos/métodos , Luciferases/antagonistas & inibidores , Piridinas/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Compostos de Espiro/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Bioensaio/métodos , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Cristalografia por Raios X , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Luciferases/metabolismo , Camundongos , Modelos Moleculares , Estrutura Molecular , Piridinas/administração & dosagem , Piridinas/química , Bibliotecas de Moléculas Pequenas/administração & dosagem , Bibliotecas de Moléculas Pequenas/química , Compostos de Espiro/administração & dosagem , Compostos de Espiro/química , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto
9.
J Fam Plann Reprod Health Care ; 33(3): 183-7, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17609077

RESUMO

BACKGROUND AND METHODOLOGY: Although men are identified as a priority group for sexual health initiatives, limitations in other data sources mean little is known about their use of general practitioners (GPs) or family planning clinics (FPCs) for family planning services. This paper provides a unique profile of which men have increased their use of GPs or FPCs for family planning services over the 1990s. Data were taken from the repeated cross-sectional British Omnibus Survey, 1991-2000. In total, 16 470 men aged 16-49 years were asked which health service they had used for family planning purposes within the last 5 years. RESULTS: Although around two-thirds of men cite general practice as their preferred source for professional advice on contraception, in 2000 only 12.5% (95% CI 11-14) had used this source for family planning purposes in the past 5 years. Between 1991 and 2000, the greatest growth was in use of FPCs, particularly among men aged 16-24 years, of single or cohabiting marital status, or of professional or unskilled social class. The greatest growth in use of GPs relative to use in 1991 was among men aged 35-44 years and those in the skilled non-manual and skilled manual social classes. DISCUSSION AND CONCLUSIONS: As the 1990s progressed, an increasing percentage of men attended GPs and FPCs for family planning purposes. Differential rates of growth by age group, marital status and social class have occurred, but levels of use are still much lower than for women.


Assuntos
Atitude Frente a Saúde , Serviços de Planejamento Familiar/estatística & dados numéricos , Serviços de Planejamento Familiar/tendências , Medicina de Família e Comunidade/estatística & dados numéricos , Infecções Sexualmente Transmissíveis/prevenção & controle , Adolescente , Adulto , Medicina de Família e Comunidade/tendências , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Fatores de Tempo , Reino Unido
10.
Pediatrics ; 118(6): e1657-66, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17101711

RESUMO

OBJECTIVE: Preterm infants may be at particular risk from either inadequate or excessive vitamin K prophylaxis. Our goal was to assess vitamin K status and metabolism in preterm infants after 3 regimens of prophylaxis. METHODS: Infants <32 weeks' gestation were randomized to receive 0.5 mg (control) or 0.2 mg of vitamin K1 intramuscularly or 0.2 mg intravenously after delivery. Primary outcome measures were serum vitamin K1, its epoxide metabolite (vitamin K1 2,3-epoxide), and undercarboxylated prothrombin assessed at birth, 5 days, and after 2 weeks of full enteral feeds. Secondary outcome measures included prothrombin time and factor II concentrations. RESULTS: On day 5, serum vitamin K1 concentrations in the 3 groups ranged widely (2.9-388.0 ng/mL) but were consistently higher than the adult range (0.15-1.55 ng/mL). Presence of vitamin K1 2,3-epoxide on day 5 was strongly associated with higher vitamin K1 bolus doses. Vitamin K1 2,3-epoxide was detected in 7 of 29 and 4 of 29 infants from the groups that received 0.5 mg intramuscularly and 0.2 mg intravenously, respectively, but in none of 32 infants from group that received 0.2 mg intramuscularly. After 2 weeks of full enteral feeding, serum vitamin K1 was lower in the infants who received 0.2 mg intravenously compared with the infants in the control group. Three infants from the 0.2-mg groups had undetectable serum vitamin K1 as early as the third postnatal week but without any evidence of even mild functional deficiency, as shown by their normal undercarboxylated prothrombin concentrations. CONCLUSIONS: Vitamin K1 prophylaxis with 0.2 mg administered intramuscularly maintained adequate vitamin K status of preterm infants until a median age of 25 postnatal days and did not cause early vitamin K1 2,3-epoxide accumulation. In contrast, 0.2 mg administered intravenously and 0.5 mg administered intramuscularly led to vitamin K1 2,3-epoxide accumulation, possibly indicating overload of the immature liver. To protect against late vitamin K1 deficiency bleeding, breastfed preterm infants given a 0.2-mg dose of prophylaxis should receive additional supplementation when feeding has been established.


Assuntos
Doenças do Prematuro/prevenção & controle , Deficiência de Vitamina K/prevenção & controle , Vitamina K/administração & dosagem , Vitaminas/administração & dosagem , Feminino , Humanos , Recém-Nascido , Masculino , Vitamina K/sangue , Vitaminas/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA