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1.
Soc Sci Med ; 330: 116054, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37399656

RESUMO

Quality of life is a complex concept characterised by several dualities, it has many definitions depending on the field of research and an abundance of diverse objective and subjective measures. The latter often represents the extent of perceived (dis)satisfaction with various domains of life experienced by individuals or groups, and research is increasingly focusing on subjective measures of well-being to better understand personal drivers related to quality of life. A better understanding of these factors at a local level has potential to shed light on an often-overlooked aspect of the mental health landscape in Aotearoa New Zealand. Individual-level data on adults (15+ years) is sourced from the New Zealand Attitudes and Values Study 2018 (N = 47,949) and aggregate-level data from the Census 2018 (N = 3,775,854). Matching constraint variables include sex, age, ethnicity, highest qualification, and labour force status. Outcome variables include personal and national well-being scores from 0 to 10 (extremely dissatisfied-extremely satisfied). Spatial microsimulation is used to create a synthetic population based on the above data. Results show lower mean national well-being scores than personal well-being scores, with spatial variations that broadly reflect patterns of socioeconomic deprivation. Low mean values for both personal and national well-being scores are seen in rural areas of high socioeconomic deprivation, particularly those with large Maori populations. High mean values are associated with areas of low deprivation. Additionally, high national well-being scores are associated with areas of agricultural activity, particularly in the South Island. Consideration should be given to factors that influence responses in such topics however, including demographic profiles as well as economic and social conditions of individuals and their surrounding communities. This study demonstrates that spatial microsimulation can be used as a powerful tool to understand population well-being. It can help support future planning and resource allocation, aiding in achieving health equity.


Assuntos
Povo Maori , Saúde Mental , Qualidade de Vida , Determinantes Sociais da Saúde , Adolescente , Adulto , Humanos , Adulto Jovem , Simulação por Computador , Emprego , Etnicidade , Sistemas de Informação Geográfica , Nova Zelândia/epidemiologia
2.
Soc Sci Med ; 301: 114801, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35366459

RESUMO

BACKGROUND: The determinants of health behaviours and health outcomes are multifaceted and the surrounding environment is increasingly considered as an important influence. This pre-registered study investigated the associations between the geospatial environment people live within and their health behaviours as well as their mental and physical health outcomes. METHOD: We used the newly developed Healthy Location Index (HLI) to identify health-promoting and health-constraining environmental features where people live. We then used Time 10 (2018) data from the New Zealand Attitudes and Values Survey (NZAVS; N = 47,951), a national probability sample of New Zealand adults, to gauge mental health outcomes including depression, anxiety and psychological distress, physical health outcomes including BMI and type II diabetes, and health behaviours such as tobacco smoking and vaping. Linear and logistic multilevel mixed effect regression models with random intercepts of individuals nested within geographical areas (meshblocks) were employed. RESULTS: The presence of health-constraining environmental features were adversely associated with self-reported mental health outcomes of depression, anxiety and psychological distress, physical health outcomes of BMI and type II diabetes, and negative health behaviours of tobacco smoking and vaping. By contrast, health-promoting environmental features were uniquely associated only with physical health outcomes of BMI and type II diabetes. CONCLUSION: The current study advances research on environmental determinants of health behaviours by demonstrating that close proximity to health-constraining environmental features is related to a number of self-reported physical and mental health outcomes or behaviours. We provide some evidence to support the notion that preventive population-health interventions should be sought.


Assuntos
Diabetes Mellitus Tipo 2 , Angústia Psicológica , Adulto , Ansiedade/epidemiologia , Comportamentos Relacionados com a Saúde , Humanos , Autorrelato
3.
Am J Physiol Heart Circ Physiol ; 318(2): H252-H263, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31809211

RESUMO

Fetal growth restriction (FGR), where a fetus fails to reach its genetic growth potential, affects up to 8% of pregnancies and is a major risk factor for stillbirth and adulthood morbidity. There are currently no treatments for FGR, but candidate therapies include the phosphodiesterase-5 inhibitor sildenafil citrate (SC). Randomized clinical trials in women demonstrated no effect of SC on fetal growth in cases of severe early onset FGR; however, long-term health outcomes on the offspring are unknown. This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure, and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg/kg) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in wild-type (WT) female offspring (P < 0.05) and reduced glucose sensitivity in both WT (P < 0.01) and P0 (P < 0.05) female offspring compared with controls. Antenatal SC treatment increased systolic blood pressure in both male (WT vs. WT-SC: 117 ± 2 vs. 140 ± 3 mmHg, P < 0.0001; P0 vs. P0-SC: 113 ± 3 vs. 140 ± 4 mmHg, P < 0.0001; means ± SE) and female (WT vs. WT-SC: 121 ± 2 vs. 140 ± 2 mmHg, P < 0.0001; P0 vs. P0-SC: 117 ± 2 vs. 144 ± 4 mmHg, P < 0.0001) offspring at 8 and 13 wk of age. Increased systolic blood pressure was not attributed to altered mesenteric artery function. In utero exposure to SC may result in metabolic dysfunction and elevated blood pressure in later life.NEW & NOTEWORTHY Sildenafil citrate (SC) is currently used to treat fetal growth restriction (FGR). We demonstrate that SC is ineffective at treating FGR, and leads to a substantial increase systolic blood pressure and alterations in glucose homeostasis in offspring. We therefore urge caution and suggest that further studies are required to assess the safety and efficacy of SC in utero, in addition to the implications on long-term health.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Retardo do Crescimento Fetal/tratamento farmacológico , Fator de Crescimento Insulin-Like II/genética , Citrato de Sildenafila/uso terapêutico , Vasodilatadores/uso terapêutico , Animais , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal/genética , Teste de Tolerância a Glucose , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Circulação Esplâncnica/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacos
4.
J Vector Borne Dis ; 56(1): 41-45, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31070164

RESUMO

Since the declaration of the vision of malaria eradication in 2007, the overall burden of malaria has been reduced substantially in many countries in the endemic world. This progress has, however, recently slowed worldwide and even an increase of morbidity and mortality has been observed in some regions. That reality has led to reflection on the strategy for malaria elimination, noting that focusing only on low transmission sites has competed with the efforts in countries that still have foci with high malaria burdens. This opinion piece outlines the collaboration of the ICMR-National Institute of Malaria Research (ICMR-NIMR) and other partner Institutions in India with the WorldWide Antimalarial Resistance Network (WWARN), one part of a global effort to manage the spread of Plasmodium falciparum parasites associated with antimalarial resistance.


Assuntos
Erradicação de Doenças/organização & administração , Saúde Global , Malária/prevenção & controle , Animais , Antimaláricos/farmacologia , Erradicação de Doenças/métodos , Resistência a Medicamentos , Geografia , Humanos , Índia/epidemiologia , Colaboração Intersetorial , Malária/epidemiologia , Malária/transmissão , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Saúde Pública , Estações do Ano , Viagem
5.
Sci Rep ; 9(1): 6871, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053725

RESUMO

A diverse microbiota exists within the airways of individuals with non-cystic fibrosis bronchiectasis (nCFB). How the lung microbiome evolves over time, and whether changes within the microbiome correlate with future disease progression is not yet known. We assessed the microbial community structure of 133 serial sputa and subsequent disease course of 29 nCFB patients collected over a span of 4-16 years using 16S rRNA paired-end sequencing. Interestingly, no significant shifts in the microbial community of individuals were observed during extended follow-up suggesting the microbiome remains relatively stable over prolonged periods. Samples that were Pseudomonas aeruginosa culture positive displayed markedly different microbial community structures compared to those that were positive for Haemophilus influenzae. Importantly, patients with sputum of lower microbial community diversity were more likely to experience subsequent lung function decline as defined by annual change in ≥-1 FEV1% predicted. Shannon diversity values <1 were more prevalent in patients with FEV1 decline (P = 0.002). However, the relative abundance of particular core microbiota constituents did not associate with risk of decline. Here we present data confirming that the microbiome of nCFB individuals is generally stable, and that microbiome-based measurements may have a prognostic role as biomarkers for nCFB.


Assuntos
Brônquios/microbiologia , Bronquiectasia/microbiologia , Microbiota , Adulto , Idoso , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bronquiectasia/tratamento farmacológico , Feminino , Humanos , Estudos Longitudinais , Masculino , Microbiota/efeitos dos fármacos , Pessoa de Meia-Idade
6.
Br J Dermatol ; 178(1): 76-85, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28542914

RESUMO

Despite many years of clinical use of isotretinoin, a comprehensive review of evidence for isotretinoin therapy in patients with acne is lacking. We searched MEDLINE, Embase, Cochrane Central, relevant web pages and bibliographies for randomized controlled trials in acne evaluating isotretinoin vs. control (placebo or other therapy). Data were extracted and summarized descriptively. Eleven trials were identified (total 760 patients randomized), containing mostly men. Mean treatment ages ranged from 18 to 47·9 years and participants generally had moderate-to-severe acne. Across all trials, isotretinoin therapy reduced acne lesion counts by a clinically relevant amount, and always by a greater amount than control, which was either placebo (two studies), oral antibiotics (seven studies) or other control (two studies). Across trials with an overall low risk of bias, two of three demonstrated statistically significant differences between isotretinoin and control. The frequency of adverse events was twice as high with isotretinoin (751 events) than with control (388 events). More than half of all adverse events were dermatological and related to dryness. Adverse events from isotretinoin causing participant withdrawal from trials (12 patients) included Stevens-Johnson syndrome, cheilitis, xerosis, acne flare, photophobia, elevated liver enzymes, decreased appetite, headaches and depressed mood. This review suggests that isotretinoin is effective in reducing acne lesion counts, but adverse events are common. This study was registered with PROSPERO number CRD42015025080.


Assuntos
Acne Vulgar/tratamento farmacológico , Fármacos Dermatológicos/administração & dosagem , Isotretinoína/administração & dosagem , Administração Oral , Adolescente , Adulto , Antibacterianos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Toxidermias/etiologia , Oftalmopatias/induzido quimicamente , Feminino , Gastroenteropatias/induzido quimicamente , Humanos , Isotretinoína/efeitos adversos , Masculino , Transtornos Mentais/induzido quimicamente , Pessoa de Meia-Idade , Otorrinolaringopatias/induzido quimicamente , Resultado do Tratamento , Adulto Jovem
7.
Ethn Health ; 23(4): 353-366, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-27892696

RESUMO

OBJECTIVES: Maori, the indigenous peoples of Aotearoa (New Zealand), continue to exhibit the highest rate of smoking of any ethnic group in the nation. Clarifying the present day factors which perpetuate Maori smoking has become matter of some urgency. DESIGN: We investigate links between subjective elements of Maori identity, demographic factors and perceived discrimination with smoking status in a national probability sample of self-identified Maori (N = 667). RESULTS: Our results suggest that core aspects of Maori identity and cultural engagement were not significantly linked with smoking. However, the extent to which participants felt they were perceived as prototypically Maori (measured as Perceived Appearance) was reliably associated with smoking. The effect of Perceived Appearance held when adjusting for perceived experiences of discrimination and other standard demographic indicators. CONCLUSION: Our analysis indicates that simply feeling that one is more visibly Maori is associated with an increased likelihood of smoking. This may reflect how Maori negotiate the larger systemic forces of racism present in New Zealand society.


Assuntos
Havaiano Nativo ou Outro Ilhéu do Pacífico , Autoimagem , Fumar , Percepção Social , Adulto , Demografia , Etnicidade/psicologia , Reconhecimento Facial , Feminino , Humanos , Masculino , Havaiano Nativo ou Outro Ilhéu do Pacífico/etnologia , Havaiano Nativo ou Outro Ilhéu do Pacífico/psicologia , Nova Zelândia/epidemiologia , Racismo/prevenção & controle , Racismo/psicologia , Fumar/etnologia , Fumar/psicologia
8.
Int J Parasitol Drugs Drug Resist ; 7(2): 181-190, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28384505

RESUMO

INTRODUCTION: Recurrent P. vivax infections are associated with significant morbidity and mortality. Although radical cure can reduce recurrent infection, it is confounded by antimalarial resistance and the lack of safe and effective hypnozoitocidal treatment. This study documents the available literature of published clinical trials of P. vivax, providing an up to date, online, open access tool to view and download available information. METHODS: A systematic review was conducted according to PRISMA guidelines to identify prospective P. vivax therapeutic clinical trials with at least 28 days follow-up published between 1st January 1960 and 12th October 2016. Treatment arms and evidence of chloroquine resistance were mapped to trial sites. RESULTS: Since 1960, a total of 1152 antimalarial clinical trials with a minimum 28 days follow-up have been published, of which 230 (20.0%) enrolled patients with P. vivax and were included. Trials were conducted in 38 countries: 168 (73.0%) in the Asia-Pacific, 13 (5.7%) in Africa and 43 (18.7%) in the Americas. The proportion of antimalarial trials assessing P. vivax rose from 10.7% (12/112) in 1991-1995, to 24.9% (56/225) in 2011-2015. Overall, 188 (81.7%) P. vivax trials included a chloroquine treatment arm, either alone or in combination with primaquine, and 107 (46.5%) trials included a chloroquine treatment arm with early primaquine to assess radical cure. There has been a recent increase in treatment arms with artemisinin derivatives. Of the 131 sites in which chloroquine resistance could be quantified, resistance was present in 59 (45.0%) sites in 15 endemic countries. CONCLUSIONS: Over the last 20 years there has been a substantial increase in clinical research on the treatment of P. vivax, which has generated a greater awareness of the global extent of chloroquine resistance. The WWARN open access, online interactive map provides up to date information of areas where drug resistant P. vivax is emerging.


Assuntos
Antimaláricos/uso terapêutico , Ensaios Clínicos como Assunto , Bases de Dados Factuais , Malária Vivax/tratamento farmacológico , Sistemas On-Line , África , América , Ásia , Cloroquina/uso terapêutico , Resistência a Medicamentos , Humanos
9.
Placenta ; 42: 51-8, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27238714

RESUMO

OBJECTIVES: To test the hypothesis that third trimester placental biometry and volume can be measured by two-dimensional (2D) and three-dimensional (3D) ultrasound in utero, determining which method of measurement was most strongly correlated with true placental size ex vivo. METHODS: Singleton pregnancies underwent placental ultrasound within seven days of delivery (n = 87, 29(+3)-41(+5) weeks). Length and width (linear and curvilinear) and depth were estimated. Placental volume (PV) was estimated using 2D ellipse and shell techniques and 3D rotational (15° and 30° rotation angles) and multiplanar (5 and 10 mm slicing intervals) techniques. Measurements were compared to their true correlates following delivery. Intra- and inter-observer reliabilities of candidate placental size estimates were assessed by intraclass correlation coefficient (ICC). RESULTS: Curvilinear placental length (Rs = 0.24, p = 0.031), width (Rs = 0.27, p = 0.013) and depth (Rs = 0.31, p = 0.0056) correlated well with ex vivo measurements. All methods of PV estimation were related to ex vivo volume (Rs ≥ 0.32, p < 0.01) but not placental weight (p > 0.05); 30° rotational estimation demonstrated the strongest biological correlation (Rs = 0.40, p = 0.0004). Intra- and inter-observer placental size measurements intraclass correlation coefficients were suboptimal (0.59-0.70 and 0.10-0.58 respectively). DISCUSSION: We have demonstrated that it is possible to obtain information about the size of the third trimester placenta in utero using 2D and 3D ultrasound. However it is essential that the reliability (particularly interobserver reliability) of these estimates is improved prior to prospective studies to determine their predictive value.


Assuntos
Biometria/métodos , Imageamento Tridimensional/métodos , Placenta/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Adulto , Feminino , Humanos , Tamanho do Órgão/fisiologia , Gravidez , Terceiro Trimestre da Gravidez , Reprodutibilidade dos Testes , Adulto Jovem
10.
Biochim Biophys Acta ; 1858(7 Pt A): 1451-61, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27045077

RESUMO

Placental amino acid transfer is essential for fetal development and its impairment is associated with poor fetal growth. Amino acid transfer is mediated by a broad array of specific plasma membrane transporters with overlapping substrate specificity. However, it is not fully understood how these different transporters work together to mediate net flux across the placenta. Therefore the aim of this study was to develop a new computational model to describe how human placental amino acid transfer functions as an integrated system. Amino acid transfer from mother to fetus requires transport across the two plasma membranes of the placental syncytiotrophoblast, each of which contains a distinct complement of transporter proteins. A compartmental modelling approach was combined with a carrier based modelling framework to represent the kinetics of the individual accumulative, exchange and facilitative classes of transporters on each plasma membrane. The model successfully captured the principal features of transplacental transfer. Modelling results clearly demonstrate how modulating transporter activity and conditions such as phenylketonuria, can increase the transfer of certain groups of amino acids, but that this comes at the cost of decreasing the transfer of others, which has implications for developing clinical treatment options in the placenta and other transporting epithelia.


Assuntos
Aminoácidos/metabolismo , Feto/metabolismo , Troca Materno-Fetal/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Modelos Biológicos , Placenta/metabolismo , Transporte Biológico , Simulação por Computador , Feminino , Humanos , Cinética , Proteínas de Membrana Transportadoras/classificação , Gravidez , Artérias Umbilicais/metabolismo , Veias Umbilicais/metabolismo
11.
Reproduction ; 151(6): 657-71, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27002000

RESUMO

Syncytial nuclear aggregates (SNAs), clusters of nuclei in the syncytiotrophoblast of the human placenta, are increased as gestation advances and in pregnancy pathologies. The origins of increased SNAs are unclear; however, a better appreciation of the mechanism may give insight into placental ageing and factors underpinning dysfunction. We developed three models to investigate whether SNA formation results from a dynamic process of nuclear movement and to generate alternative hypotheses. SNA count and size were measured in placental explants cultured over 16 days and particles released into culture medium were quantified. Primary trophoblasts were cultured for 6 days. Explants and trophoblasts were cultured with and without cytoskeletal inhibitors. An in silico model was developed to examine the effects of modulating nuclear behaviour on clustering. In explants, neither median SNA number (108 SNA/mm(2) villous area) nor size (283 µm(2)) changed over time. Subcellular particles from conditioned culture medium showed a wide range of sizes that overlapped with those of SNAs. Nuclei in primary trophoblasts did not change position relative to other nuclei; apparent movement was associated with positional changes of the syncytial cell membrane. In both models, SNAs and nuclear clusters were stable despite pharmacological disruption of cytoskeletal activity. In silico, increased nuclear movement, adhesiveness and sites of cytotrophoblast fusion were related to nuclear clustering. The prominence of SNAs in pregnancy disorders may not result from an active process involving cytoskeleton-mediated rearrangement of syncytial nuclei. Further insights into the mechanism(s) of SNA formation will aid understanding of their increased presence in pregnancy pathologies.


Assuntos
Membrana Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Citoesqueleto/ultraestrutura , Placenta/ultraestrutura , Trofoblastos/ultraestrutura , Feminino , Imunofluorescência , Humanos , Gravidez , Imagem com Lapso de Tempo
12.
Am J Physiol Regul Integr Comp Physiol ; 310(9): R828-36, 2016 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-26676251

RESUMO

Membrane transporters are considered essential for placental amino acid transfer, but the contribution of other factors, such as blood flow and metabolism, is poorly defined. In this study we combine experimental and modeling approaches to understand the determinants of [(14)C]phenylalanine transfer across the isolated perfused human placenta. Transfer of [(14)C]phenylalanine across the isolated perfused human placenta was determined at different maternal and fetal flow rates. Maternal flow rate was set at 10, 14, and 18 ml/min for 1 h each. At each maternal flow rate, fetal flow rates were set at 3, 6, and 9 ml/min for 20 min each. Appearance of [(14)C]phenylalanine was measured in the maternal and fetal venous exudates. Computational modeling of phenylalanine transfer was undertaken to allow comparison of the experimental data with predicted phenylalanine uptake and transfer under different initial assumptions. Placental uptake (mol/min) of [(14)C]phenylalanine increased with maternal, but not fetal, flow. Delivery (mol/min) of [(14)C]phenylalanine to the fetal circulation was not associated with fetal or maternal flow. The absence of a relationship between placental phenylalanine uptake and net flux of phenylalanine to the fetal circulation suggests that factors other than flow or transporter-mediated uptake are important determinants of phenylalanine transfer. These observations could be explained by tight regulation of free amino acid levels within the placenta or properties of the facilitated transporters mediating phenylalanine transport. We suggest that amino acid metabolism, primarily incorporation into protein, is controlling free amino acid levels and, thus, placental transfer.


Assuntos
Modelos Biológicos , Fenilalanina/metabolismo , Placenta/fisiologia , Transporte Biológico , Radioisótopos de Carbono , Creatinina/metabolismo , Feminino , Humanos , Troca Materno-Fetal , Perfusão , Fenilalanina/química , Gravidez
13.
Placenta ; 48 Suppl 1: S3-S6, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26693894

RESUMO

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops covered areas of placental regulation and nutrient handling: 1) placental epigenetics; 2) placental mitochondrial function; 3) placental transport systems.


Assuntos
Epigênese Genética , Mitocôndrias/metabolismo , Placenta/metabolismo , Placentação/fisiologia , Animais , Transporte Biológico/fisiologia , Feminino , Humanos , Gravidez
14.
Placenta ; 36 Suppl 1: S20-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25582276

RESUMO

In high-income countries, placental failure is implicated in up to 65% of cases of stillbirth. Placental failure describes the situation where the placenta cannot meet the fetus' needs and may be the end-result of a variety of underlying pathological processes evident in the placental disc, membranes and umbilical cord. These include lesions with genetic, environmental, infectious, inflammatory, mechanical, metabolic, traumatic or vascular origin. Investigation of placental tissue from stillbirths and from pregnancies at an increased risk of stillbirth has demonstrated changes in macroscopic and microscopic structure which are themselves related to abnormal placental function. A better understanding and identification of placental failure may improve the management of pregnancy complications and of pregnancies after stillbirth (which have a 5-fold increased risk of stillbirth). The majority of current antenatal tests focus on the fetus and its response to the intrauterine environment; few of these investigations reduce stillbirths in low-risk pregnancies. However, some currently used investigations reflect placental development, structure and vascular function, while other investigations employed in clinical research settings such as the evaluation of placental structure and shape have a good predictive value for adverse fetal outcome. In addition, recent studies suggest that biomarkers of placental inflammation and deteriorating placental function can be detected in maternal blood suggesting that holistic evaluation of placental structure and function is possible. We anticipate that development of reliable tests of placental structure and function, coupled to assessment of fetal wellbeing offer a new opportunity to identify pregnancies at risk of stillbirth and to direct novel therapeutic strategies to prevent it.


Assuntos
Morte Fetal/prevenção & controle , Doenças Placentárias/diagnóstico , Diagnóstico Pré-Natal , Animais , Feminino , Humanos , Recém-Nascido , Nascido Vivo , Doenças Placentárias/terapia , Gravidez , Diagnóstico Pré-Natal/métodos , Diagnóstico Pré-Natal/tendências , Natimorto/epidemiologia
15.
J Theor Biol ; 365: 352-64, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25451528

RESUMO

Placental amino acid transport is required for fetal development and impaired transport has been associated with poor fetal growth. It is well known that placental amino acid transport is mediated by a broad array of specific membrane transporters with overlapping substrate specificity. However, it is not fully understood how these transporters function, both individually and as an integrated system. We propose that mathematical modelling could help in further elucidating the underlying mechanisms of how these transporters mediate placental amino acid transport. The aim of this work is to model the sodium independent transport of serine, which has been assumed to follow an obligatory exchange mechanism. However, previous amino acid uptake experiments in human placental microvillous plasma membrane vesicles have persistently produced results that are seemingly incompatible with such a mechanism; i.e. transport has been observed under zero-trans conditions, in the absence of internal substrates inside the vesicles to drive exchange. This observation raises two alternative hypotheses; (i) either exchange is not fully obligatory, or (ii) exchange is indeed obligatory, but an unforeseen initial concentration of amino acid substrate is present within the vesicle which could drive exchange. To investigate these possibilities, a mathematical model for tracer uptake was developed based on carrier mediated transport, which can represent either facilitated diffusion or obligatory exchange (also referred to as uniport and antiport mechanisms, respectively). In vitro measurements of serine uptake by placental microvillous membrane vesicles were carried out and the model applied to interpret the results based on the measured apparent Michaelis-Menten parameters Km and Vmax. In addition, based on model predictions, a new time series experiment was implemented to distinguish the hypothesised transporter mechanisms. Analysis of the results indicated the presence of a facilitated transport component, while based on the model no evidence for substantial levels of endogenous amino acids within the vesicle was found.


Assuntos
Aminoácidos/metabolismo , Difusão Facilitada , Troca Materno-Fetal , Modelos Biológicos , Placenta/metabolismo , Vesículas Transportadoras/metabolismo , Feminino , Humanos , Cinética , Membranas/metabolismo , Gravidez , Serina/metabolismo , Fatores de Tempo
16.
Int J Obes (Lond) ; 39(4): 557-64, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25547282

RESUMO

BACKGROUND/OBJECTIVES: Maternal obesity increases the risk of poor pregnancy outcome including stillbirth, pre-eclampsia, fetal growth restriction and fetal overgrowth. These pregnancy complications are associated with dysfunctional syncytiotrophoblast, the transporting epithelium of the human placenta. Taurine, a ß-amino acid with antioxidant and cytoprotective properties, has a role in syncytiotrophoblast development and function and is required for fetal growth and organ development. Taurine is conditionally essential in pregnancy and fetal tissues depend on uptake of taurine from maternal blood. We tested the hypothesis that taurine uptake into placental syncytiotrophoblast by the taurine transporter protein (TauT) is lower in obese women (body mass index (BMI)⩾30 kg m(-)(2)) than in women of ideal weight (BMI 18.5-24.9 kg m(-)(2)) and explored potential regulatory factors. SUBJECTS/METHODS: Placentas were collected from term (37-42-week gestation), uncomplicated, singleton pregnancies from women with BMI 19-49 kg m(-)(2). TauT activity was measured as the Na(+)-dependent uptake of (3)H-taurine into placental villous fragments. TauT expression in membrane-enriched placental samples was investigated by western blot. In vitro studies using placental villous explants examined whether leptin or IL-6, adipokines/cytokines that are elevated in maternal obesity, regulates TauT activity. RESULTS: Placental TauT activity was significantly lower in obese women (BMI⩾30) than women of ideal weight (P<0.03) and inversely related to maternal BMI (19-49 kg m(-)(2); P<0.05; n=61). There was no difference in TauT expression between placentas of ideal weight and obese class III (BMI⩾40) subjects. Long-term exposure (48 h) of placental villous explants to leptin or IL-6 did not affect TauT activity. CONCLUSIONS: Placental TauT activity at term is negatively related to maternal BMI. We propose that the reduction in placental TauT activity in maternal obesity could lower syncytiotrophoblast taurine concentration, compromise placental development and function, and reduce the driving force for taurine efflux to the fetus, thereby increasing the risk of poor pregnancy outcome.


Assuntos
Retardo do Crescimento Fetal/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Obesidade/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Complicações na Gravidez/metabolismo , Taurina/metabolismo , Adulto , Western Blotting , Índice de Massa Corporal , Proteínas de Transporte/biossíntese , Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Células Cultivadas , Vilosidades Coriônicas/metabolismo , Feminino , Retardo do Crescimento Fetal/etiologia , Humanos , Recém-Nascido , Obesidade/complicações , Placenta/fisiopatologia , Pré-Eclâmpsia/etiologia , Gravidez , Natimorto
17.
BJOG ; 121(13): 1588-94, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24816043

RESUMO

OBJECTIVE: Magnetic resonance imaging allows the noninvasive observation of PO2 changes between air breathing and oxygen breathing through quantification of the magnetic longitudinal relaxation time T1. Changes in PO2 are proportional to changes in the longitudinal relaxation rate ΔR1 (where ΔR1=1/T1oxygen-1/T1air). Knowledge of this response could inform clinical interventions using maternal oxygen administration antenatally to treat fetal growth restriction. We present in vivo measurements of the response of the fetal-placental unit to maternal hyperoxia. DESIGN: Prospective cohort. SETTING: Large tertiary maternity hospital. SAMPLE: Nine women undergoing low-risk pregnancy (21-33 weeks of gestation) and five nonpregnant adults. METHODS: During imaging the air supply to mothers was changed from medical air (21% oxygen) to medical oxygen (100% oxygen) and T1 was monitored over time in both the placenta and fetal brain using a periodically repeated magnetic resonance imaging sequence. To demonstrate that the method could detect a brain response, brain responses from five normal adult volunteers were measured using a similar imaging protocol. MAIN OUTCOME MEASURE: Changes in T1 following oxygen challenge. RESULTS: No significant ΔR1 (P=0.42, paired t-test) was observed in fetal brains. A significant placental ΔR1 (P=0.0002, paired t-test) of 0.02±0.01/s (mean±SD) was simultaneously observed in the same participants. In the brains of the nonpregnant adults, a significant ΔR1 (P=0.01, paired t-test) of 0.005±0.002/s was observed. CONCLUSION: Short-term maternal oxygen administration does not improve fetal brain oxygenation, in contrast to the response observed in the adult brain.


Assuntos
Encéfalo/metabolismo , Feto/metabolismo , Hiperóxia/metabolismo , Oxigênio/metabolismo , Placenta/metabolismo , Adulto , Estudos de Coortes , Feminino , Humanos , Imageamento por Ressonância Magnética , Oxigenoterapia , Pressão Parcial , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Adulto Jovem
18.
Placenta ; 34(12): 1251-4, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24172869

RESUMO

Syncytial nuclear aggregates (SNAs) are increased in pregnancy complications and include 'true' syncytial knots and inter-villous bridges. Apparent nuclear overlay caused by sectioning artefacts are frequently counted from single sections. Haematoxylin and eosin stained serial sections were assessed for frequency of SNA subtypes in placentas from normal, preeclamptic and fetal growth restricted (FGR) pregnancies. There were more sectioning artefacts and syncytial knots and fewer bridges in samples from preeclampsia compared to controls. There were no significant differences between FGR and control samples. This suggests the villous tree in preeclampsia has less inherent structural support and trophoblast cell dynamics are different.


Assuntos
Artefatos , Núcleo Celular/patologia , Vilosidades Coriônicas/patologia , Microtomia , Pré-Eclâmpsia/patologia , Trofoblastos/patologia , Adulto , Forma do Núcleo Celular , Cesárea , Feminino , Retardo do Crescimento Fetal/patologia , Humanos , Placentação , Gravidez , Adulto Jovem
19.
Clin Microbiol Infect ; 19(10): 908-16, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24033691

RESUMO

Following a decade-long scale up of malaria control through vector control interventions, the introduction of rapid diagnostic tests and highly efficacious Artemisinin-based Combination Therapy (ACT) along with other measures, global malaria incidence declined significantly. The recent development of artemisinin resistance on the Cambodia-Thailand border, however, is of great concern. This review encompasses the background of artemisinin resistance in Plasmodium falciparum, its situation, especially in the Greater Mekong Sub-region (GMS), and the responses taken to overcome this resistance. The difficulties in defining resistance are presented, particularly the necessity of measuring the clinical response to artemisinins using the slow parasite-clearance phenotype. Efforts to understand the molecular basis of artemisinin resistance and the search for molecular markers are reviewed. The markers, once identified, can be applied as an efficient tool for resistance surveillance. Despite the limitation of current surveillance methods, it is important to continue vigilance for artemisinin resistance. The therapeutic efficacy "in vivo study" network for monitoring antimalarial resistance in the GMS has been strengthened. GMS countries are working together in response to artemisinin resistance and aim to eliminate all P. falciparum parasites. These efforts are crucial since a resurgence of malaria due to drug and/or insecticide resistance, program cuts, lack of political support and donor fatigue could set back malaria control success in the sub-region and threaten malaria control and elimination if resistance spreads to other regions.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Sudeste Asiático , Resistência a Medicamentos , Quimioterapia Combinada , Humanos , Malária Falciparum/tratamento farmacológico , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade
20.
J Thromb Haemost ; 11(6): 1078-84, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23565981

RESUMO

BACKGROUND: HMG-CoA reductase inhibitors (statins) reduce the risk of venous thromboembolism (VTE) in healthy people. Statins reduce levels of inflammation biomarkers; however, the mechanism for the reduction in VTE risk is unknown. AIM: In a large cohort of healthy people, we studied associations of statin use with plasma hemostatic factors related to VTE risk. METHODS: Cross-sectional analyses were performed in the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study of 6814 healthy men and women aged 45-84 years, free of clinical cardiovascular disease at baseline; 1001 were using statins at baseline. Twenty-three warfarin users were excluded. Age, race and sex-adjusted mean hemostatic factor levels were compared between statin users and non-users, and multivariable linear regression models were used to assess associations of statin use with hemostatic factors, adjusted for age, race/ethnicity, education, income, aspirin use, hormone replacement therapy (in women), and major cardiovascular risk factors. RESULTS: Participants using statins had lower adjusted levels of D-dimer (- 9%), C-reactive protein (- 21%) and factor VIII (- 3%) than non-users (P < 0.05). Homocysteine and von Willebrand factor levels were non-significantly lower with statin use. Higher fibrinogen (2%) and plasminogen activator inhibitor-1 (22%) levels were observed among statin users than among non-users (P < 0.05). Further adjustment for LDL and triglyceride levels did not attenuate the observed differences in these factors with statin use. CONCLUSIONS: Findings of lower D-dimer, FVIII and C-reactive protein levels with statin use suggest hypotheses for mechanisms whereby statins might lower VTE risk. A prospective study or clinical trial linking these biochemical differences to VTE outcomes in statin users and non-users is warranted.


Assuntos
Aterosclerose/sangue , Doenças Cardiovasculares/sangue , Hemostasia/fisiologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Tromboembolia Venosa/sangue , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/diagnóstico , Aterosclerose/etnologia , Biomarcadores/metabolismo , Coagulação Sanguínea , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etnologia , Estudos de Coortes , Fator VIII/metabolismo , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinólise , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Trombina/metabolismo , Tromboembolia Venosa/prevenção & controle
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