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1.
Soft Matter ; 20(9): 2040-2051, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38343290

RESUMO

Toric focal conic domains (TFCDs) in smectic liquid crystals exhibit distinct topological characteristics, featuring torus-shaped molecular alignment patterns with rotational symmetry around a central core. TFCDs have attracted much interest due to their unique topological structures and properties, enabling not only fundamental studies but also potential applications in liquid crystal (LC)-based devices. Here, we investigated the precise spatial control of the arrangement of TFCDs using micropatterns and sublimation of TFCDs to estimate the energy states of the torus-like structures. Through simulations, we observed that the arrangement of TFCDs strongly depends on the shape of the topographies of underlying substrates. To accurately estimate the energetic effects of non-zero eccentricity and evaluate their thermodynamic stability, we propose a geometric model. Our findings provide valuable insights into the behavior of smectic LCs, offering opportunities for developing novel LC-based devices with precise control over their topological properties.

2.
Environ Res ; 231(Pt 2): 116196, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37211184

RESUMO

BACKGROUND: On August 5, 2015, the Gold King Mine Spill (GKMS) resulted in 3 million gallons of acid mine drainage spilling into the San Juan River impacting the Diné Bikeyah (traditional homelands of the Navajo people). The Gold King Mine Spill Diné Exposure Project was formed to understand the impacts of the GKMS on the Diné (Navajo). Reporting individualized household results in an exposure study is becoming more common; however, materials are often developed with limited community input with knowledge flowing in one direction - from researcher to participant. In this study we examined the development, dissemination, and evaluation of individualized results materials. METHODS: In August 2016, Navajo Nation Community Health Representatives (Navajo CHRs) sampled household water, dust, and soil, and resident blood and urine for lead and arsenic, respectively. From May-July 2017, iterative dialogue with a wide range of community partners and a community focus groups guided the development of a culturally-based dissemination process. In August 2017, Navajo CHRs reported individualized results and they surveyed the participants on the report-back process at that time. RESULTS: All of the 63 Diné adults (100%) who participated in the exposure study received their results by a CHR in person and 42 (67%) completed an evaluation. Most of those participants (83%) were satisfied with the result packets. Respondents ranked the individual and overall household results as the most important information they received (69% and 57%, respectively), while information on metals exposures and their health effects were the least helpful. CONCLUSIONS: Our project illustrates how a model of environmental health dialogue, defined by iterative, multidirectional communication among Indigenous community members, trusted Indigenous leaders, Indigenous researchers, non-Indigenous researchers, can improve reporting individualized study results. Findings can inform future research to encourage multi-directional environmental health dialogue to craft more culturally responsive and effective dissemination and communication materials.


Assuntos
Ouro , Indígenas Norte-Americanos , Humanos , Exposição Ambiental/análise , Saúde Ambiental , Saúde Pública
3.
J Rural Stud ; 97: 449-457, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36908972

RESUMO

This paper explores how Indigenous-led research reframes the impacts and response to environmental disasters in the context of acid mine spills in rural communities of the Southwest United States. The collaborative research project addressing the Gold King Mine Spill (GKMS) designed qualitative methodologies that center Indigenous worldviews and contribute to broader understandings of environmental justice. The research team, led by Diné scholars and community leaders, gathered qualitative responses from 123 adult participants in twelve focus groups from three rural communities on the Navajo Nation. The project incorporated fluent Diné speakers and cultural consultants to lead focus groups in a manner consistent with cultural worldviews. The analysis of the focus group data resulted in original findings that reframe previous understandings of environmental harm by broadening the boundaries to include: 1) social relations across time; 2) social relations across space; 3) spiritual relations; and 4) restoring balance. The findings allow for greater insight into the colonial context of disaster on rural and Indigenous lands and confronts colonial-rooted disasters through Indigenous-informed political action.

4.
Ultrasound Obstet Gynecol ; 59(5): 613-618, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34529288

RESUMO

OBJECTIVE: Non-invasive assessment of maternal cardiovascular potential and kinetic energy can be used to derive potential-to-kinetic-energy ratio (PKR) and Smith-Madigan inotropic index (SMII), which reflect the balance between blood pressure and blood flow. The aim of this study was to evaluate PKR and SMII in pregnancies complicated by hypertensive disorders of pregnancy (HDP) and/or small-for-gestational-age (SGA) birth. METHODS: This was a prospective study that enrolled women with a singleton pregnancy between 5 and 41 weeks' gestation. Women who developed HDP and/or SGA underwent cardiovascular profiling from 20 weeks. To establish reference ranges for PKR and SMII, women without any pre-existing medical problems at the time of booking who did not develop HDP, SGA or other complications during pregnancy were also recruited for cardiovascular profiling. Measurements of cardiovascular parameters were obtained using a non-imaging ultrasound cardiac output monitor. RESULTS: A total of 688 women completed the study, including 626 controls, 21 cases with HDP, 19 cases with SGA and 22 cases with HDP and SGA. PKR was significantly elevated in pregnancies with placental dysfunction compared with controls (HDP only, 29.81 ± 9.5; HDP and SGA, 44.33 ± 24.27; SGA only, 31.05 ± 13.14; vs controls, 22.30 ± 7.93; all P < 0.05). SMII values were significantly lower only in cases affected by SGA alone when compared with controls (1.47 ± 0.23 W/m2 vs 1.75 ± 0.40 W/m2 ; P < 0.005). These differences remained statistically significant when the analysis was undertaken using multiples of the median values corrected for gestational age. CONCLUSIONS: The findings of this study suggest that point-of-care non-invasive cardiovascular profiling using PKR and SMII may help distinguish between pregnancies affected by specific placental disorders and those exhibiting healthy cardiovascular adaptation to pregnancy. Women with HDP and/or SGA appear to have distinctive PKR and SMII profiles that reflect low kinetic energy in pregnancies with SGA and high potential energy in pregnancies affected by HDP. Finally, non-invasive assessment of potential and kinetic cardiovascular energy demonstrates physiological high-flow and low-resistance adaptation in uncomplicated pregnancies. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Placenta , Pré-Eclâmpsia , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Masculino , Pré-Eclâmpsia/diagnóstico por imagem , Gravidez , Estudos Prospectivos
5.
Soft Matter ; 17(25): 6140-6159, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34080608

RESUMO

A coupled phase-field and hydrodynamic model is introduced to describe a two-phase, weakly compressible smectic (layered phase) in contact with an isotropic fluid of different density. A non-conserved smectic order parameter is coupled to a conserved mass density in order to accommodate non-solenoidal flows near the smectic-isotropic boundary arising from density contrast between the two phases. The model aims to describe morphological transitions in smectic thin films under heat treatment, in which arrays of focal conic defects evolve into conical pyramids and concentric rings through curvature dependent evaporation of smectic layers. The model leads to an extended thermodynamic relation at a curved surface that includes its Gaussian curvature, non-classical stresses at the boundary and flows arising from density gradients. The temporal evolution given by the model conserves the overall mass of the liquid crystal while still allowing for the modulated smectic structure to grow or shrink. A numerical solution of the governing equations reveals that pyramidal domains are sculpted at the center of focal conics upon a temperature increase, which display tangential flows at their surface. Other cases investigated include the possible coalescence of two cylindrical stacks of smectic layers, formation of droplets, and the interactions between focal conic domains through flow.

6.
BJOG ; 128(2): 167-175, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32314535

RESUMO

OBJECTIVE: To describe maternal haemodynamic differences in gestational hypertension with small-for-gestational-age babies (HDP + SGA), gestational hypertension with appropriate-for-gestational-age babies (HDP-only) and control pregnancies. DESIGN: Prospective cohort study. SETTING: Tertiary Hospital, UK. POPULATION: Women with gestational hypertension and healthy pregnant women. METHODS: Maternal haemodynamic indices were measured using a non-invasive Ultrasound Cardiac Output Monitor (USCOM-1A® ) and corrected for gestational age and maternal characteristics using device-specific reference ranges. MAIN OUTCOME MEASURES: Maternal cardiac output, stroke volume, systemic vascular resistance. RESULTS: We included 114 HDP + SGA, 202 HDP-only and 401 control pregnancies at 26-41 weeks of gestation. There was no significant difference in the mean arterial blood pressure (110 versus 107 mmHg, P = 0.445) between the two HDP groups at presentation. Pregnancies complicated by HDP + SGA had significantly lower median heart rate (76 versus 85 bpm versus 83 bpm), lower cardiac output (0.85 versus 0.98 versus 0.97 MoM) and higher systemic vascular resistance (1.4 versus 1.0 versus 1.2 MoM) compared with control and HDP-only pregnancies, respectively (all P < 0.05). CONCLUSION: Women with HDP + SGA present with more severe haemodynamic dysfunction than HDP-only. Even HDP-only pregnancies exhibit impaired haemodynamic indices compared with normal pregnancies, supporting a role of the maternal cardiovascular system in gestational hypertension irrespective of fetal size. Central haemodynamic changes may play a role in the pathogenesis of pre-eclampsia and should be considered alongside placental aetiology. TWEETABLE ABSTRACT: Hypertensive disorders of pregnancy are associated with worse maternal haemodynamic function when associated with small-for-gestational-age birth.


Assuntos
Débito Cardíaco/fisiologia , Frequência Cardíaca/fisiologia , Pré-Eclâmpsia/fisiopatologia , Resistência Vascular/fisiologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Estudos Prospectivos , Fatores de Risco , Reino Unido
7.
J Environ Health ; 84(3): 44-48, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35350769

RESUMO

Beginning in 2016, the Agency for Toxic Substances and Disease Registry (ATSDR) and the National Environmental Health Association (NEHA) launched a partnership to create a free online course with the goal of building capacity within communities to help remediate and redevelop brownfields sites. Brownfields are land reuse sites often contaminated by harmful chemicals or redeveloped without proper environmental oversight. Due to their potentially hazardous status, brownfields sites can lead to harmful exposures in humans while accentuating and often exacerbating socioeconomic disparities within their communities. As a result of this partnership, NEHA and ATSDR launched the Environmental Health and Land Reuse (EHLR) Certificate Program in 2020. The Journal is pleased to feature this column to highlight an example of how the EHLR Certificate Program was used to build understanding and increase knowledge on this important topic within environmental health students. The findings and conclusions in this column are those of the authors and do not necessarily represent the views or official position of NEHA, ATSDR, or the Centers for Disease Control and Prevention. Furthermore, verbal permission was given by the students to use their work in this column.

8.
Ultrasound Obstet Gynecol ; 55(2): 210-216, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31381215

RESUMO

OBJECTIVE: Pregnancies complicated by fetal growth restriction (FGR) have a worse outcome than those with a small-for-gestational-age (SGA) fetus. There is increasing evidence of a maternal cardiovascular role in the pathophysiology of FGR. We aimed to compare maternal hemodynamic indices between pregnancies complicated by FGR and those delivering a SGA neonate, using a non-invasive device. METHODS: This was a prospective study of normotensive pregnancies complicated by FGR (defined as estimated fetal weight (EFW) < 3rd centile or Doppler evidence of impaired placental-fetal blood flow), those with a SGA fetus (defined as EFW < 10th centile) and control pregnancies with an appropriately grown fetus. Assessment of maternal hemodynamics (heart rate (HR), cardiac output (CO), mean arterial pressure (MAP), systemic vascular resistance (SVR) and stroke volume) was performed using a non-invasive device (USCOM-1A®). Uterine artery (UtA) pulsatility index (PI) was measured using transabdominal ultrasound. Hemodynamic variables that are affected by gestational age and maternal characteristics were corrected for using device-specific reference ranges. Comparison between groups was performed using the chi-square test or the Mann-Whitney U-test, as appropriate. RESULTS: A total of 102 FGR, 64 SGA and 401 control pregnancies, with a median gestational age of 36 weeks, were included in the analysis. Women with a pregnancy complicated by FGR and those with a SGA fetus were shorter and weighed less than did controls. Compared with controls, the FGR group had significantly lower median maternal HR (80 beats per min (bpm) vs 85 bpm; P = 0.001) and CO multiples of the median (MoM; 0.91 vs 0.98; P = 0.003), and higher median maternal MAP (90 mmHg vs 87 mmHg; P = 0.040), SVR MoM (1.2 vs 1.0; P < 0.001) and UtA-PI MoM (1.1 vs 0.96; P < 0.001), but there was no significant difference in stroke volume MoM (1.0 vs 0.98; P = 0.647). Compared with the SGA group, the FGR group had a significantly lower median HR (80 bpm vs 87 bpm; P = 0.022), and higher median maternal MAP (90 mmHg vs 85 mmHg; P = 0.025), SVR MoM (1.2 vs 1.0; P = 0.002) and UtA-PI MoM (1.1 vs 0.98; P = 0.005), but there was no significant difference in CO MoM (0.91 vs 0.96; P = 0.092) or stroke volume MoM (1.0 vs 1.0; P = 0.806). There were no significant differences in adjusted maternal hemodynamic indices between the SGA group and controls. CONCLUSION: Pregnancies complicated by FGR presented with impaired maternal hemodynamic function, as evidenced by lower HR and CO, as well as higher MAP, SVR and UtA resistance. Pregnancies delivering a SGA neonate, without evidence of FGR, had normal maternal hemodynamic function. Maternal hemodynamic indices may therefore be of value in distinguishing FGR from SGA pregnancies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Retardo do Crescimento Fetal/diagnóstico , Hemodinâmica , Complicações Cardiovasculares na Gravidez/fisiopatologia , Ultrassonografia Doppler , Ultrassonografia Pré-Natal , Adulto , Pressão Arterial , Biomarcadores/análise , Débito Cardíaco , Feminino , Retardo do Crescimento Fetal/etiologia , Peso Fetal , Feto/irrigação sanguínea , Feto/diagnóstico por imagem , Idade Gestacional , Frequência Cardíaca , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Circulação Placentária , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico por imagem , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Fluxo Pulsátil , Volume Sistólico , Artéria Uterina/diagnóstico por imagem , Artéria Uterina/fisiopatologia , Resistência Vascular
9.
Ultrasound Obstet Gynecol ; 56(1): 44-50, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31613410

RESUMO

OBJECTIVE: Pregnancies complicated by pre-eclampsia with a small-for-gestational-age (SGA) neonate have poorer maternal hemodynamic function compared to those with hypertensive disorders of pregnancy (HDP) and an appropriately grown neonate. Arterial stiffness is a recognized prognostic marker of cardiovascular disease in the general population. The aim of this study was to compare maternal arterial stiffness between hypertensive pregnancies with, and those without, a SGA neonate and normotensive control pregnancies. METHODS: This was a prospective cohort study of pregnancies complicated by pre-eclampsia or gestational hypertension and healthy normotensive control pregnancies, presenting to a tertiary referral hospital between January 2012 and May 2018. Maternal arterial stiffness was assessed by aortic pulse-wave velocity (PWV) and aortic augmentation index (AIx), which were recorded using a non-invasive device (Arteriograph®). Maternal and hemodynamic factors were adjusted for using linear regression analysis. Pregnancies with HDP were divided into those that delivered a SGA (birth weight < 10th percentile) neonate (HDP + SGA group) and those that delivered an appropriately grown neonate (HDP-only group). Comparisons between groups were carried out using the Mann-Whitney U-test for continuous variables and the chi-square (or Fisher's exact) test for categorical variables. RESULTS: Included in the analysis were 69 patients with HDP who delivered a SGA neonate, 129 with HDP who delivered a normally grown neonate and 220 healthy controls. Maternal age, weight, height and heart rate were associated significantly with brachial and aortic AIx. Maternal weight, height, mean arterial pressure, heart rate and gestational age were significant predictors of aortic PWV. Adjusted aortic AIx was significantly higher in both the HDP + SGA and HDP-only groups, compared with in controls (12.5% and 10.0% vs 7.6%; both P < 0.01), and was significantly different between the two HDP groups (P = 0.002). Adjusted PWV was significantly higher in the HDP-only group compared with in controls and the HDP + SGA group (7.7 m/s vs 7.1 m/s and 7.1 m/s; both P < 0.001). Conversely, unadjusted PWV was not significantly different between the two HDP groups (P = 0.414). CONCLUSIONS: Pregnancies complicated by HDP with, and those without, a SGA neonate have significantly higher aortic AIx compared with uncomplicated normotensive pregnancies. Aortic AIx was highest in those pregnancies complicated by HDP with a SGA neonate, reflecting a progression in severity of arterial stiffness abnormality with a worsening clinical picture. These findings most likely reflect systemic reduced vascular compliance and increased systemic vascular resistance in pregnancy complicated by HDP. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Recém-Nascido Pequeno para a Idade Gestacional , Pré-Eclâmpsia/fisiopatologia , Ultrassonografia Pré-Natal , Artéria Uterina/fisiopatologia , Rigidez Vascular , Adulto , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos Prospectivos , Fluxo Pulsátil
10.
Ultrasound Obstet Gynecol ; 55(5): 652-660, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31273879

RESUMO

OBJECTIVE: Selective fetal growth restriction (sFGR) occurs in monochorionic twin pregnancies when unequal placental sharing leads to restriction in the growth of just one twin. Management options include laser separation of the fetal circulations, selective reduction or expectant management, but what constitutes the best treatment is not yet known. New trials in this area are urgently needed but, in this rare and complex group, maximizing the relevance and utility of clinical research design and outputs is paramount. A core outcome set ensures standardized outcome collection and reporting in future research. The objective of this study was to develop a core outcome set for studies evaluating treatments for sFGR in monochorionic twins. METHODS: An international steering group of clinicians, researchers and patients with experience of sFGR was established to oversee the process of development of a core outcome set for studies investigating the management of sFGR. Outcomes reported in the literature were identified through a systematic review and informed the design of a three-round Delphi survey. Clinicians, researchers, and patients and family representatives participated in the survey. Outcomes were scored on a Likert scale from 1 (limited importance for making a decision) to 9 (critical for making a decision). Consensus was defined a priori as a Likert score of ≥ 8 in the third round of the Delphi survey. Participants were then invited to take part in an international meeting of stakeholders in which the modified nominal group technique was used to consider the consensus outcomes and agree on a final core outcome set. RESULTS: Ninety-six outcomes were identified from 39 studies in the systematic review. One hundred and three participants from 23 countries completed the first round of the Delphi survey, of whom 88 completed all three rounds. Twenty-nine outcomes met the a priori criteria for consensus and, along with six additional outcomes, were prioritized in a consensus development meeting, using the modified nominal group technique. Twenty-five stakeholders participated in this meeting, including researchers (n = 3), fetal medicine specialists (n = 3), obstetricians (n = 2), neonatologists (n = 3), midwives (n = 4), parents and family members (n = 6), patient group representatives (n = 3), and a sonographer. Eleven core outcomes were agreed upon. These were live birth, gestational age at birth, birth weight, intertwin birth-weight discordance, death of surviving twin after death of cotwin, loss during pregnancy or before final hospital discharge, parental stress, procedure-related adverse maternal outcome, length of neonatal stay in hospital, neurological abnormality on postnatal imaging and childhood disability. CONCLUSIONS: This core outcome set for studies investigating the management of sFGR represents the consensus of a large and diverse group of international collaborators. Use of these outcomes in future trials should help to increase the clinical relevance of research on this condition. Consensus agreement on core outcome definitions and measures is now required. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Determinação de Ponto Final , Retardo do Crescimento Fetal/terapia , Procedimentos Cirúrgicos Obstétricos/estatística & dados numéricos , Avaliação de Resultados em Cuidados de Saúde/métodos , Peso ao Nascer , Consenso , Técnica Delphi , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Nascido Vivo , Procedimentos Cirúrgicos Obstétricos/métodos , Gravidez , Gravidez de Gêmeos , Resultado do Tratamento , Gêmeos Monozigóticos/estatística & dados numéricos
11.
Ultrasound Obstet Gynecol ; 54(1): 58-63, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30084237

RESUMO

OBJECTIVE: Pregnancies affected by a hypertensive disorder (HDP) have increased uterine artery pulsatility index (UtA-PI) compared with that in healthy pregnancies. Women with HDP are also known to have lower cardiac output and increased systemic vascular resistance. The aim of this study was to investigate the relationship between central and uterine hemodynamics in HDP and uncomplicated pregnancy. METHODS: This was a prospective study of HDP and normotensive control singleton pregnancies presenting at a tertiary referral hospital between January 2012 and December 2017. Paired measurements of maternal hemodynamics, using a non-invasive device (USCOM-1A®), and UtA-PI were performed in the third trimester. HDP pregnancies were divided into preterm (onset < 37 weeks' gestation) and term (onset ≥ 37 weeks). Spearman's rank coefficient was used to assess the correlation between the central and uteroplacental hemodynamics. Regression analysis was performed to assess the association of UtA-PI with independent variables. RESULTS: We included 231 women with HDP (152 with preterm and 79 with term HDP) and 378 controls with normotensive pregnancy. Compared with controls, women with preterm HDP had significantly lower cardiac output (median (interquartile range (IQR)), 6.0 (5.1-7.2) vs 6.6 (5.8-7.5) L/min; P < 0.001) and significantly higher systemic vascular resistance (median (IQR), 1394 (1189-1670) vs 1063 (915-1222) dynes × s/cm5 ; P < 0.001) and UtA-PI (median (IQR), 1.0 (0.75-1.4) vs 0.67 (0.58-0.83); P < 0.001). Conversely, in women with term HDP, there were no significant differences in heart rate, cardiac output or UtA-PI compared with controls (all P > 0.05), while systemic vascular resistance was significantly higher (median (IQR), 1315 (1099-1527) vs 1063 (915-1222) dynes × s/cm5 ; P < 0.001). On multiple regression analysis, heart rate, mean arterial pressure and stroke volume were associated significantly with mean UtA-PI (all P < 0.001). CONCLUSIONS: Differences observed between HDP and normotensive pregnancies in third-trimester UtA resistance are mirrored in the central maternal hemodynamic parameters. Late pregnancy differences in the uteroplacental circulation in preterm and term HDP are an index of maternal cardiovascular function rather than being related to inadequate spiral artery remodeling and impaired placentation. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Hemodinâmica/fisiologia , Hipertensão Induzida pela Gravidez/fisiopatologia , Artéria Uterina/diagnóstico por imagem , Adulto , Pressão Arterial , Débito Cardíaco/fisiologia , Feminino , Idade Gestacional , Frequência Cardíaca/fisiologia , Humanos , Hipertensão Induzida pela Gravidez/classificação , Circulação Placentária/fisiologia , Placentação/fisiologia , Gravidez , Terceiro Trimestre da Gravidez/fisiologia , Estudos Prospectivos , Fluxo Pulsátil/fisiologia , Volume Sistólico/fisiologia , Ultrassonografia Doppler/métodos , Resistência Vascular/fisiologia
12.
Ultrasound Obstet Gynecol ; 53(4): 496-502, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29516615

RESUMO

OBJECTIVE: Traditional blood-pressure monitoring in hypertensive pregnant women requires frequent visits to the maternity outpatient services. Home blood-pressure monitoring (HBPM) could offer a cost-saving alternative that is acceptable to patients. The aim of this study was to undertake a health economic analysis of HBPM compared with traditional monitoring in hypertensive pregnant women. METHODS: This was a cost-minimization study of hypertensive pregnant women who had HBPM with or without the adjunct of a smartphone application (App), via a specially designed pathway, and a control group managed according to the local protocol of regular hospital visits for blood-pressure monitoring. Outcome measures were the number of outpatient visits, inpatient bed stays and investigations performed. Maternal, fetal and neonatal adverse outcomes were also recorded. Health economic analysis was performed using direct cost comparison of the study dataset and process scenario modeling. RESULTS: The HBPM group included 108 women, of whom 29 recorded their results on the smartphone App and 79 in their notes. The control group comprised 58 patients. There were significantly more women with chronic hypertension in the HBPM group than in the control group (49.1% vs 25.9%, P = 0.004). The HBPM group had significantly longer duration of monitoring (9 weeks vs 5 weeks, P = 0.004) and started monitoring at an earlier gestational age (30.0 weeks vs 33.6 weeks, P = 0.001) compared with the control group. Despite these differences, the mean saving per week for each patient using HBPM compared with traditional monitoring was £200.69, while for each HBPM patient using the smartphone App, the weekly saving was £286.53 compared with the control group. The process modeling method predicted weekly savings of between £98.32 and £245.80 per patient using HBPM compared with traditional monitoring. CONCLUSION: HBPM in hypertensive pregnancy appears to be cost saving compared with traditional monitoring, without compromising maternal, fetal or neonatal safety. Larger studies are required to confirm these findings. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Monitorização Ambulatorial da Pressão Arterial/economia , Hipertensão Induzida pela Gravidez/economia , Adulto , Estudos de Casos e Controles , Estudos de Coortes , Análise Custo-Benefício , Feminino , Humanos , Hipertensão Induzida pela Gravidez/diagnóstico , Aplicativos Móveis , Gravidez , Cuidado Pré-Natal/economia , Smartphone
13.
Ultrasound Obstet Gynecol ; 54(5): 670-675, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30548496

RESUMO

OBJECTIVES: To construct reference ranges for stroke volume, cardiac output and systemic vascular resistance (SVR) in normal pregnancy for the NICOM® device, and to explore associations between maternal characteristics and these hemodynamic variables. METHODS: This was a prospective cohort study of healthy singleton pregnancies between 10 and 40 weeks' gestation attending a tertiary referral hospital between September 2012 and May 2018. Measurements of stroke volume, cardiac output and SVR were obtained throughout pregnancy using NICOM, a non-invasive device based on bioreactance technology. NICOM device-specific reference ranges were created with respect to gestational age and maternal characteristics. Once the distribution of the data had been determined with respect to the gestational age, patient characteristics were added to the model to test whether they provided a significant improvement in prediction of the median value. The effect was assessed of maternal weight, height, smoking status, conception using assisted reproductive technology, nulliparity and ethnicity. RESULTS: We included 411 women in this study. The relationships between cardiac variables and gestational age observed in the NICOM-specific reference ranges are consistent with previous findings, with increasing cardiac output values until around 35 weeks and a decrease thereafter until term, and decreasing SVR until around 36 weeks, followed by an increase towards 40 weeks. Stroke volume showed a small linear increase across gestation with lower variability in observations close to term. Maternal weight, height and age were associated with cardiac output (all P < 0.05) and SVR (all P < 0.01), whilst maternal weight and height were associated with stroke volume (both P < 0.001). Ethnicity was significantly associated with stroke volume (P = 0.001) but not with cardiac output or SVR. CONCLUSIONS: This study presents device-specific reference ranges for stroke volume, cardiac output and SVR for the NICOM device in healthy pregnancy and describes the maternal characteristics that are associated with the values of these hemodynamic measurements. Studies using NICOM in pregnancy can use these ranges in order to evaluate observations relative to those expected in uncomplicated pregnancy conditional on maternal characteristics. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Débito Cardíaco/fisiologia , Monitorização Fisiológica/instrumentação , Gravidez/fisiologia , Volume Sistólico/fisiologia , Resistência Vascular/fisiologia , Adulto , Estatura , Peso Corporal , Feminino , Idade Gestacional , Humanos , Idade Materna , Estudos Prospectivos , Valores de Referência
14.
Ultrasound Obstet Gynecol ; 54(2): 232-238, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30302868

RESUMO

OBJECTIVE: Maternal hemodynamics change significantly during Cesarean section complicated by massive hemorrhage or severe hypertensive disease. Cardiac output (CO) monitoring aids early, goal-directed hemodynamic therapy. The aim of this study was to record hemodynamic changes observed during Cesarean section in pregnancies at high risk of hemodynamic instability, using invasive (LiDCOrapid™) and non-invasive (NICOM®) devices, and to assess agreement between the two devices in measuring CO. METHODS: Simultaneous intraoperative hemodynamic measurements were taken using the LiDCOrapid and NICOM devices, following standardized techniques, in women at high risk of hemodynamic instability undergoing Cesarean section. Agreement in CO measurements between the two devices was assessed using Bland-Altman plots and the agreement:tolerability index (ATI). Agreement analyses were performed for repeated measures in subjects, using centiles. RESULTS: From 10 women, 307 paired measurements were analyzed. Mean bias (defined as the mean difference in CO measurements between the LiDCOrapid and NICOM devices) was 3.05 (95% CI, 1.89 to 4.21) L/min. Limits of agreement ranged from -1.58 (95% CI, -4.47 to -0.14) to 7.68 (95% CI, 6.24 to 10.56) L/min. The resulting agreement interval was 9.26 L/min which returned an ATI of 2.3. CONCLUSIONS: There are large mean differences between CO measurements obtained during Cesarean section using the LiDCOrapid and NICOM hemodynamic monitors in pregnant women at high risk of hemodynamic instability, indicating that they should not be considered interchangeable clinically. There is an unacceptably low level of agreement (ATI > 2) in CO measurements between the devices, conferring a high risk of clinical misclassification during massive hemorrhage. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Débito Cardíaco/fisiologia , Cesárea/estatística & dados numéricos , Gravidez de Alto Risco/fisiologia , Adulto , Feminino , Idade Gestacional , Hemodinâmica/fisiologia , Hemorragia/complicações , Humanos , Monitorização Intraoperatória/instrumentação , Monitorização Fisiológica , Gravidez , Estudos Prospectivos
15.
Ultrasound Obstet Gynecol ; 54(2): 255-261, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30520170

RESUMO

OBJECTIVE: To develop, using a Delphi procedure and a nominal group technique, a core outcome set (COS) for studies evaluating treatments for twin-twin transfusion syndrome (TTTS), which should assist in standardizing outcome selection, collection and reporting in future research studies. METHODS: An international steering group comprising healthcare professionals, researchers and patients with experience of TTTS guided the development of this COS. Potential core outcomes, identified through a comprehensive literature review and supplemented by outcomes suggested by the steering group, were entered into a three-round Delphi survey. Healthcare professionals, researchers, and patients or relatives of patients who had experienced TTTS were invited to participate. Consensus was defined a priori using the 15%/70% definition of the Core Outcome Measures in Effectiveness Trials (COMET) initiative. The modified nominal group technique was used to evaluate the consensus outcomes in a face-to-face consultation meeting and identify the final COS. RESULTS: One hundred and three participants, from 29 countries, participated in the three-round Delphi survey. Of those, 88 completed all three rounds. Twenty-two consensus outcomes were identified through the Delphi procedure and entered into the modified nominal group technique. The consensus meeting was attended by 11 healthcare professionals, two researchers and three patients; 12 core outcomes were prioritized for inclusion in the COS. Fetal core outcomes included live birth, pregnancy loss (including miscarriage, stillbirth, termination of pregnancy and neonatal mortality), subsequent death of a cotwin following single-twin demise at the time of treatment, recurrence of TTTS, twin anemia-polycythemia sequence and amniotic band syndrome. Neonatal core outcomes included gestational age at delivery, birth weight, brain injury syndromes and ischemic limb injury. Maternal core outcomes included maternal mortality and admission to Level-2 or -3 care setting. One aspirational outcome, neurodevelopment at 18-24 months of age, was also prioritized. CONCLUSIONS: Implementing the COS for TTTS within future research studies could make a substantial contribution to advancing the usefulness of research in TTTS. Standardized definitions and measurement instruments are now required for individual core outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Determinação de Ponto Final/métodos , Transfusão Feto-Fetal/terapia , Avaliação de Resultados em Cuidados de Saúde/tendências , Resultado da Gravidez/epidemiologia , Adolescente , Adulto , Consenso , Técnica Delphi , Feminino , Transfusão Feto-Fetal/diagnóstico , Idade Gestacional , Ocupações em Saúde , Humanos , Masculino , Mortalidade Materna , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Projetos de Pesquisa , Participação dos Interessados , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
16.
Ultrasound Obstet Gynecol ; 51(4): 524-530, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29468771

RESUMO

OBJECTIVE: The majority of patients with chronic or gestational hypertension do not develop pre-eclampsia. Home blood-pressure monitoring (HBPM) has the potential to offer a more accurate and acceptable means of monitoring hypertensive patients during pregnancy compared with traditional pathways of frequent outpatient monitoring. The aim of this study was to determine whether HBPM reduces visits to antenatal services and is safe in pregnancy. METHODS: This was a case-control study of 166 hypertensive pregnant women, which took place at St George's Hospital, University of London. Inclusion criteria were: chronic hypertension, gestational hypertension or high risk of developing pre-eclampsia, no significant proteinuria (≤ 1+ proteinuria on dipstick testing) and normal biochemical and hematological markers. Exclusion criteria were maternal age < 16 years, systolic blood pressure > 155 mmHg or diastolic blood pressure > 100 mmHg, significant proteinuria (≥ 2+ proteinuria on dipstick testing or protein/creatinine ratio > 30 mg/mmol), evidence of small-for-gestational age (estimated fetal weight < 10th centile), signs of severe pre-eclampsia, significant mental health concerns or insufficient understanding of the English language. Pregnant women in the HBPM group were taught how to measure and record their blood pressure using a validated machine at home and attended every 1-2 weeks for assessment depending on clinical need. The control group was managed as per the local protocol prior to the implementation of HBPM. The two groups were compared with respect to number of visits to antenatal services and outcome. RESULTS: There were 108 women in the HBPM group and 58 in the control group. There was no difference in maternal age, parity, body mass index, ethnicity or smoking status between the groups, but there were more women with chronic hypertension in the HBPM group compared with the control group (49.1% vs 25.9%, P = 0.004). The HBPM group had significantly fewer outpatient attendances per patient (6.5 vs 8.0, P = 0.003) and this difference persisted when taking into account differences in duration of monitoring (0.8 vs 1.6 attendances per week, P < 0.001). There was no difference in the incidence of adverse maternal, fetal or neonatal outcome between the two groups. CONCLUSION: HBPM in hypertensive pregnancies has the potential to reduce the number of hospital visits required by patients without compromising maternal and pregnancy outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Monitorização Ambulatorial da Pressão Arterial/métodos , Hipertensão Induzida pela Gravidez/diagnóstico , Cuidado Pré-Natal/estatística & dados numéricos , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão Induzida pela Gravidez/fisiopatologia , Aplicativos Móveis , Pré-Eclâmpsia/prevenção & controle , Gravidez , Resultado da Gravidez/epidemiologia , Estudos Retrospectivos , Autocuidado
17.
Ultrasound Obstet Gynecol ; 52(5): 577-585, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29607558

RESUMO

OBJECTIVE: Twin-twin transfusion syndrome (TTTS) is associated with significant mortality and morbidity. Potential treatments for the condition require robust evaluation. The aim of this study was to evaluate outcome reporting across observational studies and randomized controlled trials assessing treatments for TTTS. METHODS: Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE were searched from inception to August 2016. Observational studies and randomized controlled trials reporting outcome following treatment for TTTS in monochorionic-diamniotic twin pregnancy and monochorionic-triamniotic or dichorionic-triamniotic triplet pregnancy were included. Outcome reporting was systematically extracted and categorized. RESULTS: Six randomized trials and 94 observational studies were included, reporting data from 20 071 maternal participants and 3199 children. Six different treatments were evaluated. Included studies reported 62 different outcomes, including six fetal, seven offspring mortality, 25 neonatal, six early childhood and 18 maternal/operative outcomes. Outcomes were reported inconsistently across trials. For example, when considering offspring mortality, 31 (31%) studies reported live birth, 31 (31%) reported intrauterine death, 49 (49%) reported neonatal mortality and 17 (17%) reported perinatal mortality. Four (4%) studies reported respiratory distress syndrome. Only 19 (19%) studies were designed for long-term follow-up and 11 (11%) of these reported cerebral palsy. CONCLUSIONS: Studies evaluating treatments for TTTS have often neglected to report clinically important outcomes, especially neonatal morbidity outcomes, and most are not designed for long-term follow-up. The development of a core outcome set could help standardize outcome collection and reporting in TTTS studies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Transfusão Feto-Fetal/terapia , Avaliação de Resultados em Cuidados de Saúde , Assistência Perinatal/normas , Feminino , Transfusão Feto-Fetal/mortalidade , Humanos , Estudos Observacionais como Assunto , Gravidez , Resultado da Gravidez , Gravidez de Gêmeos , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
Ultrasound Obstet Gynecol ; 52(4): 515-521, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29786155

RESUMO

OBJECTIVE: To assess the agreement between home blood-pressure monitoring (HBPM) and blood-pressure measurements in a clinic setting, in a cohort of pregnant women with hypertensive disorders of pregnancy (HDP). METHODS: This was a cohort study of 147 pregnant women with HDP conducted at St George's Hospital, University of London, London, UK, between 2016 and 2017. Inclusion criteria were chronic hypertension, gestational hypertension or high risk of developing pre-eclampsia, no significant proteinuria and no hematological or biochemical abnormalities. Each included patient was prescribed a personalized schedule of hospital visits and blood-pressure measurements, according to their individual risk as per UK National Institute for Health and Care Excellence guidelines. The blood-pressure measurement at the clinic and the HBPM reading obtained closest to that hospital visit were paired for analysis. Only one pair of measurements was used per patient. Differences between home and clinic blood-pressure measurements were tested using the Wilcoxon signed rank test or paired t-test, and were also assessed visually using Bland-Altman plots. Comparison of the binary outcomes was performed using McNemar's chi-square test. Subgroup analysis was performed in the following gestational-age windows: < 14 weeks, 15-22 weeks, 23-32 weeks and 33-42 weeks' gestation. RESULTS: A total of 294 blood-pressure measurements from 147 women were included in the analysis. Median systolic HBPM measurements were significantly lower than clinic measurements (132.0 (interquartile range (IQR), 123.0-140.0) mmHg vs 138.0 (IQR, 132.0-146.5) mmHg; P < 0.001). When stratified according to gestational age, systolic blood-pressure measurements obtained at home were significantly lower than those at clinic in all gestational-age periods except 23-32 weeks' gestation (P = 0.057). Median diastolic blood-pressure measurements at home were also significantly lower than those at clinic (85.0 (IQR, 77.0-90.0) mmHg vs 89.0 (IQR, 82.0-94.0) mmHg; P < 0.001). When stratified according to gestational age, diastolic HBPM measurements were significantly lower in the periods 5-14 weeks (P < 0.001), 15-22 weeks (P = 0.008) and 33-42 weeks (P < 0.001), compared with clinic measurements. The incidence of clinically significant systolic and diastolic hypertension based on clinic blood-pressure measurements was four to five times higher than that based on HBPM measurements (P < 0.001 and P = 0.005, respectively). CONCLUSIONS: Our study shows that, in women with HDP, blood pressure measured at home is lower than that measured in a clinic setting. This is consistent with observations in non-pregnant adults, in whom home and ambulatory monitoring of hypertensive patients is recommended. As such, HBPM has the potential to reduce the number of false-positive diagnoses of severe hypertension and unnecessary medical interventions in women with HDP. This must be carefully weighed against the risk of missing true-positive diagnoses. Prospective studies investigating the use of HBPM in pregnant women are urgently needed to determine the relevant blood-pressure thresholds for HBPM, and interval and frequency of monitoring. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Hipertensão Induzida pela Gravidez/diagnóstico , Pré-Eclâmpsia/prevenção & controle , Adulto , Pressão Sanguínea , Monitorização Ambulatorial da Pressão Arterial/economia , Monitorização Ambulatorial da Pressão Arterial/instrumentação , Análise Custo-Benefício , Feminino , Humanos , Hipertensão Induzida pela Gravidez/fisiopatologia , Cooperação do Paciente , Gravidez , Reprodutibilidade dos Testes
19.
Soft Matter ; 13(37): 6529-6541, 2017 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-28895608

RESUMO

A coarse-grained lattice gas model is developed to study pattern forming processes in drying drops containing surfactant. By performing Monte Carlo simulations of the model, the coupled dynamics of surfactant and liquid evaporation and the resulting oscillatory dynamics at the contact line are elucidated. We show that the coupled drop dynamics and the resulting final deposition patterns can be altered by adsorption kinetics. For slow adsorption rates, surfactant molecules recirculate along with colloidal particles and the area covered by the surfactant on the surface grows from the contact line as the initial concentration of the surfactant increases. This leads to coffee-ring patterns with wide rim areas upon drying or to multi-ring patterns depending on the surfactant concentration. For fast adsorption rates, a surfactant skin covers the entire surface area during the early phase of evaporation. This suppresses the coffee ring effect, and uniform patterns are obtained independent of surfactant concentration. The results suggest that the distribution of surfactant on the surface is critical in determining final deposition patterns and that understanding of the skin-forming process of the surfactant on the surface can help in manipulating the delicate pattern forming process of particles in evaporating drops.

20.
J Autoimmun ; 50: 67-76, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24365380

RESUMO

B-cell depletion therapy (BCDT) based on rituximab (RTX) induces clinical remission in a majority of seropositive patients with Rheumatoid arthritis (RA). However, all patients eventually relapse. The aim of this study was to determine whether dynamic changes in combinations of serological measures of B-cell activation were associated over up to three cycles of BCDT. We included only RA patients who gave an adequate clinical response, as measured by DAS28. Twenty three patients were studied over 1 cycle, 21 over 2, and 15 over 3 cycles of BCDT. Serum analytes including isotypes of Rheumatoid factors (RhF) and anti-citrullinated protein/peptide antibodies (ACPA), B-cell activating factor (BAFF), serum free light chains (SFLC), soluble CD23 (sCD23), antibodies to tetanus toxoid (TT) and to pneumococcal capsular polysaccharide (PCP) were measured by ELISA at 4 key points in each cycle, namely: Baseline (pre-RTX in each cycle); when B-cell depleted (CD19+B-cells < 5/µl); at B-cell return (CD19+B-cells ≥ 5/µl); and at clinical relapse (ΔDAS28 > 1.2). SFLC were used as a measure of plasmablast activity. As sCD23 is cleaved from naïve B-cells coincident with attaining CD27 expression, levels were used as a novel measure of maturation of B-cells to CD27+. The most consistent changes between baseline and B-cell depletion within all 3 cycles were in SFLC, sCD23 and IgM-RhF which fell and in BAFF levels which rose. After 3 complete cycles of BCDT, both IgM autoantibodies and IgG-CCP had decreased, BAFF levels were higher (all p < 0.05); other analytes remained unchanged compared with baseline. Dynamic changes in λSFLC, sCD23, IgM-RhF and BAFF were also consistently associated with relapse in patients with longer clinical responses after B-cell return. Incremental rises in sCD23 levels in cycles 2 and 3 were correlated with time to relapse. Repopulation of the periphery after BCDT is initiated by naïve B-cells and precedes relapse. Our study showed that differentiation into plasmablasts, attended by sCD23 and SFLC production and IgM-RhF specificity may be required to precipitate relapse in patients experiencing longer responses after RTX. These studies also provide novel information related to the resumption of autoimmune responses and their association with B-cell kinetics following BCDT.


Assuntos
Artrite Reumatoide/terapia , Subpopulações de Linfócitos B/imunologia , Depleção Linfocítica , Plasmócitos/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Murinos/uso terapêutico , Antirreumáticos/uso terapêutico , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Autoanticorpos/sangue , Fator Ativador de Células B/genética , Fator Ativador de Células B/imunologia , Subpopulações de Linfócitos B/efeitos dos fármacos , Subpopulações de Linfócitos B/patologia , Biomarcadores/metabolismo , Diferenciação Celular , Expressão Gênica , Humanos , Imunoglobulina M/genética , Imunoglobulina M/imunologia , Ativação Linfocitária , Pessoa de Meia-Idade , Plasmócitos/efeitos dos fármacos , Plasmócitos/patologia , Receptores de IgE/genética , Receptores de IgE/imunologia , Recidiva , Indução de Remissão , Rituximab , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia
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