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1.
Ultrasound Obstet Gynecol ; 62(5): 660-667, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37289938

RESUMO

OBJECTIVES: To assess whether coexisting fetal growth restriction (FGR) influences pregnancy latency among women with preterm pre-eclampsia undergoing expectant management. Secondary outcomes assessed were indication for delivery, mode of delivery and rate of serious adverse maternal and perinatal outcomes. METHODS: We conducted a secondary analysis of the Pre-eclampsia Intervention (PIE) and the Pre-eclampsia Intervention 2 (PI2) trial data. These randomized controlled trials evaluated whether esomeprazole and metformin could prolong gestation of women diagnosed with pre-eclampsia between 26 and 32 weeks of gestation undergoing expectant management. Delivery indications were deteriorating maternal or fetal status, or reaching 34 weeks' gestation. FGR (defined by Delphi consensus) at the time of pre-eclampsia diagnosis was examined as a predictor of outcome. Only placebo data from PI2 were included, as the trial showed that metformin use was associated with prolonged gestation. All outcome data were collected prospectively from diagnosis of pre-eclampsia to 6 weeks after the expected due date. RESULTS: Of the 202 women included, 92 (45.5%) had FGR at the time of pre-eclampsia diagnosis. Median pregnancy latency was 6.8 days in the FGR group and 15.3 days in the control group (difference 8.5 days; adjusted 0.49-fold change (95% CI, 0.33-0.74); P < 0.001). FGR pregnancies were less likely to reach 34 weeks' gestation (12.0% vs 30.9%; adjusted relative risk (aRR), 0.44 (95% CI, 0.23-0.83)) and more likely to be delivered for suspected fetal compromise (64.1% vs 36.4%; aRR, 1.84 (95% CI, 1.36-2.47)). More women with FGR underwent a prelabor emergency Cesarean section (66.3% vs 43.6%; aRR, 1.56 (95% CI, 1.20-2.03)) and were less likely to have a successful induction of labor (4.3% vs 14.5%; aRR, 0.32 (95% CI, 0.10-1.00)), compared to those without FGR. The rate of maternal complications did not differ significantly between the two groups. FGR was associated with a higher rate of infant death (14.1% vs 4.5%; aRR, 3.26 (95% CI, 1.08-9.81)) and need for intubation and mechanical ventilation (15.2% vs 5.5%; aRR, 2.97 (95% CI, 1.11-7.90)). CONCLUSION: FGR is commonly present in women with early preterm pre-eclampsia and outcome is poorer. FGR is associated with shorter pregnancy latency, more emergency Cesarean deliveries, fewer successful inductions and increased rates of neonatal morbidity and mortality. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Metformina , Pré-Eclâmpsia , Recém-Nascido , Lactente , Gravidez , Feminino , Humanos , Resultado da Gravidez , Cesárea/efeitos adversos , Pré-Eclâmpsia/diagnóstico , Retardo do Crescimento Fetal/etiologia , Conduta Expectante , Metformina/uso terapêutico
2.
Ultrasound Obstet Gynecol ; 52(2): 196-204, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-28557250

RESUMO

OBJECTIVES: Pre-eclampsia (PE) is associated with both postpartum endothelial dysfunction and asymptomatic structural heart alterations consistent with heart failure Stage B (HF-B). In this study, we assessed the relationship between endothelial function, measured by flow-mediated dilation (FMD), and HF-B in women with a history of PE. METHODS: This was an observational study in which 67 formerly pre-eclamptic women (≥ 4 years postpartum) and 37 healthy parous controls were assessed ultrasonographically for cardiac function and geometry, as well as for endothelial function by means of brachial artery FMD. HF-B was diagnosed as left ventricular hypertrophy (left ventricular mass index (LVMi) > 95 g/m2 ), concentric remodeling (relative wall thickness > 0.42 and LVMi ≤ 95 g/m2 ), mild systolic dysfunction (left ventricular ejection fraction > 40% and < 55%) or asymptomatic valvular disease. Cardiovascular and metabolic syndrome variables were compared between women with history of PE and controls, as well as between those in the formerly pre-eclamptic group who had HF Stage A, HF-B or no HF. Logistic regression analysis was performed to assess the associations of FMD with PE, metabolic syndrome risk factors and obstetric parameters. RESULTS: The prevalence of HF-B amongst formerly pre-eclamptic women was three-fold higher than that observed for controls (25% vs 8%, P < 0.05), while FMD was lower in formerly pre-eclamptic women compared with controls (6.12% vs 8.22%, P < 0.01); history of PE remained associated independently with lower FMD after adjusting for metabolic syndrome risk factors and obstetric parameters (ß, -1.88; 95% CI, -3.59 to -0.18). However, HF-B did not relate to low FMD in formerly pre-eclamptic women. CONCLUSIONS: Years after pregnancy, formerly pre- eclamptic women have lower FMD and have HF-B more often compared with healthy parous controls. Nonetheless, HF-B was not related to reduced FMD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Artéria Braquial/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Período Pós-Parto/fisiologia , Pré-Eclâmpsia/fisiopatologia , Função Ventricular Esquerda/fisiologia , Adulto , Artéria Braquial/diagnóstico por imagem , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/etiologia , Humanos , Avaliação de Resultados da Assistência ao Paciente , Gravidez , Prevalência , Fluxo Sanguíneo Regional/fisiologia
3.
Ultrasound Obstet Gynecol ; 50(6): 683-696, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28078751

RESUMO

OBJECTIVE: The aim of this systematic review and meta-analysis was to describe comprehensively the pattern of cardiac remodeling during normotensive human singleton pregnancy and to compare it with that of pregnancy complicated by hypertension. METHODS: We performed a meta-analysis of the current literature on cardiac remodeling during normotensive and complicated pregnancies. Literature was retrieved from PubMed (NCBI) and EMBASE (Ovid) databases. Included studies needed to report a reference measurement (matched non-pregnant control group, prepregnancy or postpartum) and measurements made during predetermined gestational-age intervals. Mean differences between reference and pregnancy data were calculated using the random-effects model described by DerSimonian and Laird. RESULTS: Forty-eight studies were included in the meta-analysis, with publication dates ranging from 1977 to 2016. During normotensive pregnancy, most geometric indices started to increase in the second trimester. Left ventricular mass (LVM) increased by 28.36 (95% CI, 19.73-37.00) g (24%), and relative wall thickness (RWT) increased by 0.03 (95% CI, 0.02-0.05) (10%) compared with those in the reference group. During hypertensive pregnancy, LVM and RWT increased more than during normotensive pregnancy (92 (95% CI, 75.46-108.54) g (95%) and 0.14 (95% CI, 0.09-0.19) (56%), respectively). CONCLUSIONS: During normotensive pregnancy, most cardiac geometric indices change from the second trimester onwards. Both LVM and RWT increase, by 20% and 10%, respectively, consistent with concentric rather than eccentric remodeling. Cardiac adaptation in hypertensive pregnancy deviates from that in healthy pregnancy by a greater change in LVM (95% increase from reference) and RWT (56% increase from reference). Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Hipertensão Induzida pela Gravidez/fisiopatologia , Resistência Vascular/fisiologia , Remodelação Ventricular/fisiologia , Adaptação Fisiológica , Ecocardiografia , Feminino , Humanos , Mães , Gravidez
4.
Compr Psychiatry ; 57: 125-31, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25481236

RESUMO

BACKGROUND: Although a number of studies have found significant associations between maternal psychological distress, anxiety and changes in fetoplacental blood flow, findings remain inconsistent. A recent pilot study by our group highlighted some of these inconsistencies. In the current study, we expanded this pilot analysis to include psychological distress, anxiety and a range of antenatal variables, with the aim of identifying predictors of fetoplacental blood flow. METHODS: Healthy pregnant women (n=148) underwent Doppler flow studies on uterine, umbilical and fetal arteries; as well as assessments of distress, anxiety and other antenatal variables (e.g. perceived social support, resilience, nicotine and alcohol use) in each trimester. RESULTS: Stepwise regression analyses found that state anxiety was associated with lower mid-cerebral artery pulsatility index at trimester 3. LIMITATIONS: Subjects were recruited from selected midwife obstetric units in the same health district, so the generalizability of our results may be limited. While most subjects received Doppler assessment at trimesters 2 and 3, only approximately half of our sample was assessed at trimester 1. CONCLUSION: The finding that anxiety is associated with increased blood flow to the fetal brain during trimester 3 of pregnancy, coincide with previous work. The findings emphasize a growing appreciation of the potential importance of psychological well-being during pregnancy for infant development. However, as associations were small and variable, further research using multivariate models to determine the precise mechanisms underlying these associations would be warranted.


Assuntos
Circulação Placentária/fisiologia , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Ansiedade/fisiopatologia , Circulação Cerebrovascular , Feminino , Humanos , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Projetos Piloto , Placenta/diagnóstico por imagem , Gravidez , Segundo Trimestre da Gravidez , Escalas de Graduação Psiquiátrica , Resiliência Psicológica , Fumar/efeitos adversos , Apoio Social , Estresse Psicológico/fisiopatologia , Ultrassonografia Doppler , Ultrassonografia Pré-Natal , Adulto Jovem
5.
Ultrasound Obstet Gynecol ; 42(2): 235-7, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23303616

RESUMO

Congenital rubella infection has been associated with a number of abnormalities including cardiac, central nervous system and placental complications. We present a case with multiple fetal abnormalities detected on prenatal ultrasound, and confirmed postnatally, that included a single umbilical artery, severe tricuspid regurgitation, micrognathia and agenesis of the inferior cerebellar vermis. Postnatal echocardiography additionally revealed unobstructed total anomalous pulmonary venous drainage (TAPVD) into the coronary sinus. Placental examination showed signs of placentitis, and polymerase chain reaction on neonatal serum was positive for rubella. Following a multidisciplinary team review, it was decided to provide only supportive care, and the infant died at 6 months of age owing to a respiratory tract infection. To our knowledge, TAPVD and agenesis of the inferior cerebellar vermis have not been reported previously in association with congenital rubella infection. This case illustrates how congenital infection may present in atypical ways and stresses the importance of considering congenital infection in the differential diagnosis of fetal anomalies when multiple features are present.


Assuntos
Doenças Cerebelares/virologia , Anormalidades do Olho/virologia , Doenças Renais Císticas/virologia , Complicações Infecciosas na Gravidez , Veias Pulmonares/anormalidades , Retina/anormalidades , Rubéola (Sarampo Alemão)/congênito , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/virologia , Adolescente , Doenças Cerebelares/diagnóstico por imagem , Cerebelo/anormalidades , Anormalidades do Olho/diagnóstico por imagem , Evolução Fatal , Feminino , Humanos , Recém-Nascido , Doenças Renais Císticas/diagnóstico por imagem , Masculino , Gravidez , Veias Pulmonares/diagnóstico por imagem , Retina/diagnóstico por imagem , Retina/virologia , Ultrassonografia Pré-Natal
6.
S Afr Med J ; 113(11): 27-34, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38525638

RESUMO

BACKGROUND: Screening for trisomy 21 provides pregnant women with accurate risk information. Different algorithms are used to screen for trisomy 21 in South Africa (SA). The Fetal Medicine Foundation (FMF) provides software to screen for trisomy 21 in the first trimester by ultrasound or a combination of ultrasound and biochemistry (combined screening), and requires regular and stringent quality control. With αlpha software, first trimester combined screening and screening with biochemistry alone in the first or second trimester are possible. The αlpha screening requires quality control of biochemical tests, but not of ultrasound measurements. Ideally, a screening test should have a high detection and a low screen positive rate. Despite the availability of these screening programmes, only a minority of infants with trisomy 21 are detected prenatally, raising questions about the effectiveness of screening. OBJECTIVES: To determine the screen positive and detection rates of prenatal screening for trisomy 21 in the SA private healthcare system. METHODS: Data from the three largest laboratories collected between 2010 and 2015 were linked with genetic tests to assess screen positive and detection rates. Biochemical screening alone with αlpha software (first or second trimester) and combined screening using either FMF or αlpha software were compared. RESULTS: One-third of an estimated 675 000 pregnancies in private practice in the 6-year study period underwent screening. There were 687 cases of trisomy 21 in 225 021 pregnancies, with only 239 (35%) diagnosed prenatally. The screen positive rates were 11.8% for first trimester biochemistry, 7.6% for second trimester biochemistry, 7.3% for first trimester FMF software ultrasound alone, 3.7% for combined first trimester screening with FMF software, and 3.5% for combined first trimester screening with αlpha software. The detection rates for a 5% false positive rate were 63% for first trimester biochemistry, 69% for second trimester biochemistry, 95% for combined first trimester screening with FMF software and 80% for combined first trimester screening with αlpha software. Detection and confirmation rates were highest with FMF software. CONCLUSION: Screening with FMF software has a similar screen positive rate and better detection rate than screening with αlpha software. The low prenatal detection rate of trisomy 21 is mainly due to a low prevalence of screening. More research is needed in the SA setting to explore why screening and confirmatory testing after high-risk results are not performed in many pregnancies.


Assuntos
Síndrome de Down , Gravidez , Humanos , Feminino , Síndrome de Down/diagnóstico , Síndrome de Down/epidemiologia , Perinatologia , Ultrassonografia Pré-Natal/métodos , África do Sul , Diagnóstico Pré-Natal , Algoritmos , Software
7.
Eur J Vasc Endovasc Surg ; 43(1): 88-94, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22070856

RESUMO

OBJECTIVES: Preoperative mapping of arterial and venous anatomy helps to prevent postoperative complications after vascular access creation. The use of gadolinium in contrast-enhanced (CE) magnetic resonance angiography (MRA) has been linked to nephrogenic systemic fibrosis in patients with end-stage renal disease (ESRD). The purpose of this study was to evaluate non-contrast-enhanced (NCE) MRA for assessment of upper extremity and central vasculature and to compare it with CE-MRA. METHODS: NCE and CE-MRA images were acquired in 10 healthy volunteers and 15 patients with ESRD. In each data set, two observers analysed 11 arterial and 16 venous segments with regard to image quality (0-4), presence of artefacts (0-2) and vessel-to-background ratio. RESULTS: More arterial segments were depicted using CE-MRA compared to NCE-MRA (99% vs. 96%, p = 0.001) with mean image quality of 3.80 vs. 2.68, (p < 0.001) and mean vessel-to-background ratio of 6.47 vs. 4.14 (p < 0.001). Ninety-one percent of the venous segments were portrayed using NCE-MRA vs. 80% using CE-MRA (p < 0.001). Mean image quality and vessel-to-background ratio were 2.41 vs. 2.21 (p = 0.140) and 5.13 vs. 3.88 (p < 0.001), respectively. CONCLUSIONS: Although arterial image quality and vessel-to-background ratios were lower, NCE-MRA is considered a feasible alternative to CE-MRA in patients with ESRD who need imaging of the upper extremity and central vasculature prior to dialysis access creation.


Assuntos
Derivação Arteriovenosa Cirúrgica , Meios de Contraste , Falência Renal Crônica/terapia , Angiografia por Ressonância Magnética , Diálise Renal , Extremidade Superior/irrigação sanguínea , Adulto , Idoso , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Artefatos , Estudos de Casos e Controles , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Valor Preditivo dos Testes , Cuidados Pré-Operatórios , Adulto Jovem
8.
S Afr Med J ; 109(9): 698-703, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31635597

RESUMO

BACKGROUND: Neural tube defects (NTDs) are an important category of birth defect, but surveillance remains inadequate in South Africa. OBJECTIVES: To assess the identification of NTDs at a tertiary hospital using a range of prenatal, perinatal and postnatal data sources, and to estimate the impact of prenatal diagnosis and birth prevalence for the referral area. METHODS: Cases of anencephaly, encephalocele and spina bifida (SB) in a 6-year period were retrospectively identified from 5 data sources covering prenatal, perinatal and postnatal care. These were cross-correlated to avoid duplicate entries and to determine the contribution of different data sources. Details of prenatal diagnosis and termination of pregnancy (TOP) were obtained for 10 years, and birth prevalence over 2 years. RESULTS: During a 6-year period 195 NTDs were identified at a Western Cape Province tertiary hospital. These included 59 (30%) cases of anencephaly, 28 (14%) of encephalocele and 108 (55%) of SB. The majority of NTDs (71%) were detected prenatally, although SB was less commonly diagnosed prenatally than cranial defects (56% v. 88%; p<0.001). Of SB cases ascertained pre- or postnatally, 57% of patients were born alive and 50% discharged alive, but 72% of survivors had not been diagnosed prenatally. Women receiving prenatal diagnosis of any type of NTD before 24 weeks' gestation were nearly always offered TOP, and the majority accepted termination after non-directive counselling. For SB, later prenatal diagnosis was associated with much lower termination rates because the option was less often offered (51% v. 100%; p<0.001), and perhaps less often accepted (57% v. 78%; p=0.06). The estimated NTD birth prevalence for the referral area was 0.76 - 0.80 per 1 000 live births, but perhaps up to 1.18 per 1 000 when considering under-referral of lethal cranial lesions from rural areas. CONCLUSIONS: A substantial number of NTDs can be ascertained from a tertiary hospital environment if multiple data sources are used, even though adding data from the Perinatal Problem Identification Program for outlying health facilities increases detection of lethal defects. Hospital-based surveillance can be considered, especially for SB. Prenatal diagnosis was fairly common and pregnancy termination was often offered and accepted if detected before 24 weeks' gestation. A regional prenatal ultrasound programme, predominantly based in primary care but with ready access to a tertiary centre, can be quite effective, although limited or delayed access to prenatal diagnosis must be addressed.


Assuntos
Anencefalia/epidemiologia , Encefalocele/epidemiologia , Defeitos do Tubo Neural/epidemiologia , Disrafismo Espinal/epidemiologia , Aborto Induzido/estatística & dados numéricos , Anencefalia/diagnóstico , Encefalocele/diagnóstico , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Defeitos do Tubo Neural/diagnóstico , Vigilância da População , Gravidez , Diagnóstico Pré-Natal/estatística & dados numéricos , Prevalência , Estudos Retrospectivos , África do Sul/epidemiologia , Disrafismo Espinal/diagnóstico , Centros de Atenção Terciária
9.
Artigo em Inglês | MEDLINE | ID: mdl-31106259

RESUMO

OBJECTIVE: To examine the effects of cigarette, marihuana and methamphetamine smoking and consumption of alcohol during pregnancy on maternal serum alpha-fetoprotein (MSAFP) levels at 20-24 weeks. STUDY DESIGN: In the Safe Passage Study (SPS) more than 12,000 pregnant women were prospectively followed up during pregnancy and until the infant was one year old to examine the effects of exposure to alcohol during pregnancy on stillbirth and sudden infant death syndrome. The present study is a cross-sectional secondary analysis of MSAFP analyses done at 20-24 weeks gestation in 1,679 SPS participants, recruited at the Bishop Lavis Community Health Centre, Cape Town, South Arica. RESULTS: Low or moderate alcohol consumption with or without smoking, nor methamphetamine or marihuana use affected mean MSAFP levels. High MSAFP levels were associated with high alcohol consumption, young age, low body mass index (BMI) (<18 kg/m2) or small mid upper arm circumference (MUAC) (<230mm). High MSAFP levels were associated with stillbirth, preterm birth, abruption and a birth weight z-score of less than -1. CONCLUSION: The study confirms the association between high MSAFP levels and adverse pregnancy outcomes but, although exposure to smoking or drinking is associated with adverse pregnancy outcomes including stillbirth, MSAFP levels were not affected by any of these exposures except for continued high consumption of alcohol. The observed association between higher MSAFP levels and maternal nutritional status (as demonstrated by the lower MUAC and BMI) could explain some of the correlations of poor socioeconomic conditions with higher stillbirth rates effect.

10.
Toxicol In Vitro ; 49: 90-98, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28941583

RESUMO

Assessment of ocular irritation is a regulatory requirement in safety evaluation of industrial and consumer products. Although a number of in vitro ocular irritation assays exist, none are capable of fully categorizing chemicals as stand-alone assays. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project was developed to assess the reliability of eight in vitro test methods and computational models as well as establishing an optimal tiered-testing strategy. For three computational models (Toxtree, and Case Ultra EYE_DRAIZE and EYE_IRR) performance parameters were calculated. Coverage ranged from 15 to 58%. Coverage was 2 to 3.4 times higher for liquids than for solids. The lowest number of false positives (5%) was reached with EYE_IRR; this model however also gave a high number of false negatives (46%). The lowest number of false negatives (25%) was seen with Toxtree; for liquids Toxtree predicted the lowest number of false negatives (11%), for solids EYE_DRAIZE did (17%). It can be concluded that the training sets should be enlarged with high quality data. The tested models are not yet sufficiently powerful for stand-alone evaluations, but that they can surely become of value in an integrated weight-of-evidence approach in hazard assessment.


Assuntos
Olho/efeitos dos fármacos , Irritantes/classificação , Irritantes/toxicidade , Modelos Biológicos , Animais , Simulação por Computador , Relação Quantitativa Estrutura-Atividade , Coelhos , Testes de Toxicidade
11.
Mol Cell Biol ; 8(8): 3051-7, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2850478

RESUMO

Addition of glucose to Saccharomyces cerevisiae cells grown on a nonfermentable carbon source triggers a cyclic AMP (cAMP) signal, which induces a protein phosphorylation cascade. In a yeast strain lacking functional RAS1 and RAS2 genes and containing a bcy mutation to suppress the lethality of RAS deficiency, the cAMP signal was absent. Addition of dinitrophenol, which stimulates in vivo cAMP synthesis by lowering intracellular pH, also did not enhance the cAMP level. A bcy control strain, with functional RAS genes present, showed cAMP responses similar to those of a wild-type strain. In disruption mutants containing either a functional RAS1 gene or a functional RAS2 gene, the cAMP signal was not significantly different from the one in wild-type cells, indicating that RAS function cannot be a limiting factor for cAMP synthesis during induction of the signal. Compared with wild-type cells, the cAMP signal decreased in intensity with increasing temperature in a ras2 disruption mutant. When the mutant RAS2Val-19, which carries the equivalent of the human H-rasVal-12 oncogene, was grown under conditions in which RAS1 expression is repressed, the cAMP signal was absent. The oncogene product is known to be deficient in GTPase activity. However, the amino acid change at position 19 (or 12 in the corresponding human oncogene product) might also have other effects, such as abolishing receptor interaction. Such an additional effect probably provides a better explanation for the lack of signal transmission than the impaired GTPase activity. When the RAS2Val-19 mutant was grown under conditions in which RAS1 is expressed, the cAMP signal was present but significantly delayed compared with the signal in wild-type cells. This indicates that oncogenic RAS proteins inhibit normal functioning of wild-type RAS proteins in vivo and also that in spite of the presence of the RAS2(Val-19) oncogene, adenyl cyclase is not maximally stimulated in vivo. Expression of only the RAS(Val-19) gene product also prevented most of the stimulation of cAMP synthesis by dinitrophenol, indicating that lowered intracellular pH does not act directly on adenyl cyclase but on a step earlier in the activation pathway of the enzyme. The results obtained with the control bcy strain, the RAS2(Val-19) strain under conditions in which RAS1 is expressed, and with dinitrophenol show that the inability of the oncogene product to mediate the cAMP signal is not due to feedback inhibition by the high protein kinase activity in strains containing the RAS2(Val-19) oncogene. Hence, the present results show that the RAS protein in S. cerevisiae are involved in the transmission of the glucose-induced cAMP signal and that the oncogenic RAS protein is unable to act as a signal transducer. The RAS protein in S. cerevisiae apparently act similarly to the Gs proteins of mammalian adenyl cyclase, but instead of being involved in hormone signal transmission, they function in a nutrient-induced signal transmission pathway.


Assuntos
AMP Cíclico/fisiologia , Genes Fúngicos , Genes ras , Variação Genética , Glucose/farmacologia , Saccharomyces cerevisiae/genética , Dinitrofenóis/farmacologia , Genes Letais , Mutação , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia
12.
J Perinatol ; 27(6): 335-42, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17443202

RESUMO

OBJECTIVE: Assess the prognostic value of ultrasound and Doppler parameters in severe preterm pre-eclampsia. STUDY DESIGN: Prospective cohort study in Cape Town, South Africa, involving 113 women with severe pre-eclampsia between 24 and 34 weeks of gestation and managed expectantly when suitable. Serial ultrasound and multivessel Doppler assessments were performed 2 to 3 times weekly. Observations included fetal weight estimation, growth pattern, amniotic fluid volume, appearance of the heart and bowel, pulsatility index of the uterine, umbilical and middle cerebral arteries and ductus venosus. Perinatal outcome (death or neurological compromise, n=12) and major morbidity (n=62) were related to findings at recruitment and on the last assessment preceding delivery. RESULTS: In univariate analysis, fetal growth asymmetry and waveform analysis of all three fetal vessels significantly correlated with both end points. The initial fetal weight estimation with a cutoff weight of 1080 g had the highest sensitivity (83.3%) and negative predictive value (97.5%) for poor outcome (P<0.001) while the final ductus venosus pulsatility index had the highest specificity (92%) and positive predictive value (33%). The combination of a raised placentocerebral ratio and ductus venosus pulsatility index close to delivery had the highest (57.1%) positive predictive value. Logistic regression showed the best overall predictive model for poor outcome to be a combination of initial fetal weight estimation and final ductus venosus pulsatility index (overall accuracy 94.6%, RR 20.20 (7.36, 55.41)). The initial fetal weight estimation with a cutoff weight of 1283 g provided the best correct prediction of major morbidity (83.2% overall accuracy, sensitivity 79.0%, specificity 88.2%, positive and negative predictive values of 89.1 and 77.6% respectively). This was better than using the gestational age at recruitment or delivery, birth weight or any of the Doppler results. The prediction of morbidity was not improved by the addition of any other variable in logistic regression analysis. CONCLUSION: For the short-term outcome measures assessed in this study, the estimated fetal weight at the time of diagnosis is the most important prognostic factor in severe pre-eclampsia with some additional value of ductus venosus assessment.


Assuntos
Pré-Eclâmpsia/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adolescente , Adulto , Estudos de Coortes , Feminino , Peso Fetal , Idade Gestacional , Humanos , Pré-Eclâmpsia/patologia , Valor Preditivo dos Testes , Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Índice de Gravidade de Doença , Ultrassonografia Doppler
13.
Fertil Steril ; 59(6): 1245-50, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8495773

RESUMO

OBJECTIVE: To limit the high number of multiple pregnancies in an IVF program. SETTING: In Vitro Fertilization Laboratory, Fertility Department, Public Hospital. INTERVENTIONS: The number of embryos transferred was limited to two instead of three. RESULTS: Limiting the number of embryos transferred to only two did not influence the take home baby rate but eliminated triplet and quadruplet gestations. Moreover, the number of patients with good quality supernumerary embryos available for cryopreservation increased. CONCLUSIONS: To reduce the high frequency of multiple gestations in an IVF program, the number of embryos replaced should be limited to a maximum of two.


Assuntos
Fertilização in vitro , Gravidez Múltipla , Criopreservação , Parto Obstétrico , Implantação do Embrião , Transferência Embrionária/métodos , Embrião de Mamíferos , Feminino , Humanos , Gravidez
14.
J Androl ; 15 Suppl: 10S-13S, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7721668

RESUMO

The fertilizing capacity of human testicular spermatozoa and the positive outcome of an in vitro fertilization program open a wide range of opportunities for men suffering from obstructive and inoperable azoospermia. In six cases, subzonal sperm injection or intracytoplasmic sperm injection techniques were applied to inject testicular spermatozoa into human oocytes. The fertilization rate after testicular sperm injection reached 45%. Normal cleavage was observed and replacement of 10 embryos in 6 patients resulted in one chemical and one ongoing pregnancy.


Assuntos
Fertilização in vitro , Espermatozoides , Testículo/citologia , Separação Celular , Transferência Embrionária , Feminino , Humanos , Masculino , Oligospermia/fisiopatologia , Gravidez
15.
Int J Gynaecol Obstet ; 84(1): 23-31, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14698826

RESUMO

OBJECTIVES: To investigate the impact of an ultrasound dating service on obstetric services. METHODS: A prospective trial with 3009 unselected women presenting for antenatal care at two Midwife Obstetric Units in a socioeconomically deprived urban area, South Africa. In the study unit, student ultrasonographers provided a basic ultrasound service. In the control unit, obstetric ultrasound was only available for specific indications. The main outcome measures were number of antenatal visits and referrals for fetal surveillance. RESULTS: The two cohorts were comparable except for the number of primigravidas but stratified analysis according to parity did not affect the results. Ultrasonography did not alter pregnancy outcome but reduced the number of perceived preterm labors/ruptured membranes (12.0 vs. 16.7%, P<0.003), post-term deliveries (8.1 vs. 10.8%, P<0.04) and referrals for fetal surveillance [15.9 vs. 29.6%, P<0.000, RR 0.79 (0.71-0.88)]. CONCLUSIONS: This community-based basic ultrasound service significantly reduced referrals to a regional center for fetal surveillance and delivery.


Assuntos
Atenção à Saúde , Cuidado Pré-Natal/métodos , Ultrassonografia Pré-Natal , Adulto , Distribuição de Qui-Quadrado , Estudos de Coortes , Análise Custo-Benefício , Atenção à Saúde/economia , Feminino , Humanos , Áreas de Pobreza , Gravidez , Cuidado Pré-Natal/economia , Estudos Prospectivos , Encaminhamento e Consulta/economia , Encaminhamento e Consulta/estatística & dados numéricos , África do Sul/epidemiologia , Ultrassonografia Pré-Natal/economia , Ultrassonografia Pré-Natal/métodos , Ultrassonografia Pré-Natal/estatística & dados numéricos , Saúde da População Urbana , População Urbana
16.
Bull Soc Belge Ophtalmol ; (293): 7-15, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15510718

RESUMO

The treatment of choice for epiretinal membranes (ERM) causing marked retinal distortion and substantial visual impairment remains vitreoretinal surgery. The purpose of this study was to evaluate the results of surgery performed in our department and to investigate the prognostic value of different factors such as preoperative best-corrected visual acuity (BCVA), pre-existing cystoid macular edema (CME), intra-operative peeling of the internal limiting membrane (ILM), age and duration of symptoms. Eighty-eight consecutive eyes of 88 patients were operated on for ERM from July 1998 to June 2000. Both idiopathic and secondary cases were included. In all cases the ERM was successfully removed from the fovea. Mean BCVA after surgery increased from Snellen 0.2 (hand motion (HM) - 0.6) to Snellen 0.5 (HM - 1.0) (p<0.0001). Our results confirm the efficacy of surgical removal of the ERM in improving the visual acuity. Although not statistically significant, mean postoperative BCVA was slightly better in the group without pre-existing CME (p>0.05) and in the group where peeling of the ILM was performed (p>0.05). The data suggest that early surgery is likely to decrease the risk of developing irreversible macular damage (p<0.05). Because accelerated nuclear sclerosis with visual impairment is a common phenomenon after vitrectomy, one might consider performing a phaco-emulsification at the same time, especially in the elderly.


Assuntos
Membrana Epirretiniana/cirurgia , Acuidade Visual , Vitrectomia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Catarata/etiologia , Catarata/terapia , Membrana Epirretiniana/complicações , Feminino , Seguimentos , Humanos , Edema Macular/etiologia , Edema Macular/prevenção & controle , Masculino , Pessoa de Meia-Idade , Facoemulsificação , Prognóstico , Vitrectomia/efeitos adversos
17.
Food Chem Toxicol ; 50(7): 2575-83, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22554646

RESUMO

Phthalates are organic lipophilic compounds that are principally used as plasticiser to increase the flexibility of plastic polymers. Other applications are a.o. the use of phthalates in printing inks and lacquers. Human exposure to phthalates mainly occurs via food ingestion and can induce adverse health effects. In this study, the presence of eight phthalate compounds--dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-n-octyl phthalate (DnOP)--was investigated in 400 food products, divided over eleven groups, and packages sold on the Belgian market. For this purpose, suitable extraction techniques were developed and validated for four different matrices, namely high-fat foods, low-fat food products, aqueous-based beverages and packaging materials. The instrumental analysis was performed by means of gas chromatography-low resolution-mass spectrometry with electron impact ionisation (GC-EI-MS). A wide variety of phthalate concentrations was observed in the different groups. DEHP was found in the highest concentration in almost every group. Moreover, DEHP was the most abundant phthalate compound, followed by DiBP, DnBP and BBP. This survey is part of the PHTAL project, which is the first project that discusses phthalate contamination on the Belgian food market.


Assuntos
Embalagem de Alimentos , Ácidos Ftálicos/análise , Bélgica
18.
S Afr Med J ; 101(1): 45-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21626982

RESUMO

OBJECTIVE: The prenatal screening programme for Down syndrome (DS) in the South African public health sector remains primarily based on advanced maternal age (AMA). We assessed the changes over time and effectiveness of this screening programme within a Cape Town health district. METHODS: Retrospective analysis of the Groote Schuur Hospital Cytogenetic Laboratory and Pregnancy Counselling Clinic databases and audit of maternal delivery records at a primary health care facility. RESULTS: The number of amniocenteses performed for AMA in consecutive 5-year periods reduced progressively from 786 in 1981 - 1985 to 360 in 2001 - 2005. Comparing prenatal with neonatal diagnoses of DS, the absolute number and the proportion diagnosed prenatally have remained relatively constant over time. The Pregnancy Counselling Database showed that, of 507 women receiving genetic counselling for AMA in 2008 - 2009, 158 (3.1.1%) accepted amniocentesis--uptake has reduced considerably since the early 1990s. The audit of women delivering at a primary care facility found that only 10 (16.4%) of 61 AMA women reached genetic counselling in tertiary care: reasons included late initiation of antenatal care and low referral rates from primary care. CONCLUSION: Prenatal screening and diagnosis for DS based on AMA is working ineffectively in the Cape Town health district assessed, and this appears to be representative of a broader trend in South Africa. Inclusion of fetal ultrasound in the process of prenatal screening for DS should be explored as a way forward.


Assuntos
Síndrome de Down/diagnóstico , Idade Materna , Diagnóstico Pré-Natal , Feminino , Aconselhamento Genético , Humanos , Gravidez , Estudos Retrospectivos
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