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Acharya G. Bridging the gap between evidence-based knowledge and clinical practice by avoiding sex-biased research and rediscovering the value of traditions in promoting health. Acta Obstet Gynecol Scand 2015; 94:795-6. [PMID: 26171824 DOI: 10.1111/aogs.12690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Acharya G. Global state of women's health: should we be content? Acta Obstet Gynecol Scand 2015; 94:913-4. [DOI: 10.1111/aogs.12715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sitras V, Fenton C, Acharya G. Gene expression profile in cardiovascular disease and preeclampsia: a meta-analysis of the transcriptome based on raw data from human studies deposited in Gene Expression Omnibus. Placenta 2014; 36:170-8. [PMID: 25555499 DOI: 10.1016/j.placenta.2014.11.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 11/18/2014] [Accepted: 11/24/2014] [Indexed: 02/01/2023]
Abstract
INTRODUCTION Cardiovascular disease (CVD) and preeclampsia (PE) share common clinical features. We aimed to identify common transcriptomic signatures involved in CVD and PE in humans. METHODS Meta-analysis of individual raw microarray data deposited in GEO, obtained from blood samples of patients with CVD versus controls and placental samples from women with PE versus healthy women with uncomplicated pregnancies. Annotation of cases versus control samples was taken directly from the microarray documentation. Genes that showed a significant differential expression in the majority of experiments were selected for subsequent analysis. Hypergeometric gene list analysis was performed using Bioconductor GOstats package. Bioinformatic analysis was performed in PANTHER. RESULTS Seven studies in CVD and 5 studies in PE were eligible for meta-analysis. A total of 181 genes were found to be differentially expressed in microarray studies investigating gene expression in blood samples obtained from patients with CVD compared to controls and 925 genes were differentially expressed between preeclamptic and healthy placentas. Among these differentially expressed genes, 22 were common between CVD and PE. DISCUSSION Bioinformatic analysis of these genes revealed oxidative stress, p-53 pathway feedback, inflammation mediated by chemokines and cytokines, interleukin signaling, B-cell activation, PDGF signaling, Wnt signaling, integrin signaling and Alzheimer disease pathways to be involved in the pathophysiology of both CVD and PE. Metabolism, development, response to stimulus, immune response and cell communication were the associated biologic processes in both conditions. Gene set enrichment analysis showed the following overlapping pathways between CVD and PE: TGF-β-signaling, apoptosis, graft-versus-host disease, allograft rejection, chemokine signaling, steroid hormone synthesis, type I and II diabetes mellitus, VEGF signaling, pathways in cancer, GNRH signaling, Huntingtons disease and Notch signaling. CONCLUSION CVD and PE share same common traits in their gene expression profile indicating common pathways in their pathophysiology.
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Adhikari N, Shah PK, Acharya G, Vaidya KM. Bacteriological profile and associated risk factors of neonatal sepsis in Paropakar Maternity and Women's Hospital Thapathali, Kathmandu. NEPAL MEDICAL COLLEGE JOURNAL : NMCJ 2014; 16:161-164. [PMID: 26930737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Neonatal Sepsis is one of the most common reasons for admission to neonatal units in developing countries. It is also a major cause of mortality in both developed and developing countries. Identification of the common bacteria and risk factors causing such infections and their susceptibility patterns will provide necessary information for timely intervention. This study was carried out to determine the bacteriological profile and associated risk factors of neonatal sepsis in Paropakar Maternity and Women's hospital. A cross-sectional prospective study was conducted among neonates suspected of neonatal sepsis. Blood culture was performed and organisms were identified and antibiotic susceptibility was carried out with standard microbiological methods. Data were analysed by using SPSS. Ver. 16 software. The positive yield of blood culture was 21%. The most common isolates were Staphylococcus epidermidis, E. coli, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas spp. In Antibiotic susceptibility pattern Gentamycin showed the highest sensitivity to all types of isolated organisms. Vancomycin sensitivity was highest for Gram positive organism and Ciprofloxacin was most effective for Gram negative organisms isolated. Ampicillin and Amoxycillin were the least effective drug. Multiple drug resistance was observed in 77.15% of isolates. Prematurity, low birth weight and maternal pyrexia before delivery were found to be strongly associated with neonatal sepsis. Gram positive organisms were more prevalent than gram negative organisms.
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MESH Headings
- Anti-Bacterial Agents/therapeutic use
- Cross-Sectional Studies
- Drug Resistance, Multiple, Bacterial
- Female
- Fever/complications
- Hospitals, Maternity
- Humans
- Infant, Low Birth Weight
- Infant, Newborn
- Infant, Newborn, Diseases/drug therapy
- Infant, Newborn, Diseases/microbiology
- Infant, Premature
- Male
- Nepal
- Pregnancy
- Pregnancy Complications
- Prospective Studies
- Risk Factors
- Sepsis/drug therapy
- Sepsis/microbiology
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Acharya G, Arora KK, Kumar D. Nasogastric tube coiled around endotracheal tube. J Anaesthesiol Clin Pharmacol 2014; 30:584-6. [PMID: 25425802 PMCID: PMC4234813 DOI: 10.4103/0970-9185.142891] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Øian P, Acharya G. Simulation training needs to be adequate to improve clinical outcomes. BJOG 2014; 121:1719. [DOI: 10.1111/1471-0528.12770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Flo K, Widnes C, Vårtun Å, Acharya G. Blood flow to the scarred gravid uterus at 22-24 weeks of gestation. BJOG 2013; 121:210-5. [DOI: 10.1111/1471-0528.12441] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2013] [Indexed: 11/30/2022]
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Acharya G, Goldbeck-Wood S. Commentary on 'Unsafe abortion after legalization in Nepal: a cross-sectional study of women presenting to hospitals'. BJOG 2013; 120:1083-1084. [PMID: 24000407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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Acharya G. Measurement of atrioventricular annular plane displacement has been revived: will it prove to be useful in assessing fetal cardiac function? ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 42:125-129. [PMID: 23775904 DOI: 10.1002/uog.12542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 06/05/2013] [Accepted: 06/11/2013] [Indexed: 06/02/2023]
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Bhide A, Acharya G, Bilardo CM, Brezinka C, Cafici D, Hernandez-Andrade E, Kalache K, Kingdom J, Kiserud T, Lee W, Lees C, Leung KY, Malinger G, Mari G, Prefumo F, Sepulveda W, Trudinger B. ISUOG practice guidelines: use of Doppler ultrasonography in obstetrics. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 41:233-239. [PMID: 23371348 DOI: 10.1002/uog.12371] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Rohilla M, Chopra S, Aggrawal N, Suri V, Rajvanshi A, Acharya G. Diagnostic dilemma of adnexal mass in a postmenopausal woman. J OBSTET GYNAECOL 2012; 32:315-6. [DOI: 10.3109/01443615.2011.645919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Sitras V, Fenton C, Paulssen R, Vårtun Å, Acharya G. Differences in gene expression between first and third trimester human placenta: a microarray study. PLoS One 2012; 7:e33294. [PMID: 22442682 PMCID: PMC3307733 DOI: 10.1371/journal.pone.0033294] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 02/13/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The human placenta is a rapidly developing organ that undergoes structural and functional changes throughout the pregnancy. Our objectives were to investigate the differences in global gene expression profile, the expression of imprinted genes and the effect of smoking in first and third trimester normal human placentas. MATERIALS AND METHODS Placental samples were collected from 21 women with uncomplicated pregnancies delivered at term and 16 healthy women undergoing termination of pregnancy at 9-12 weeks gestation. Placental gene expression profile was evaluated by Human Genome Survey Microarray v.2.0 (Applied Biosystems) and real-time polymerase chain reaction. RESULTS Almost 25% of the genes spotted on the array (n = 7519) were differentially expressed between first and third trimester placentas. Genes regulating biological processes involved in cell proliferation, cell differentiation and angiogenesis were up-regulated in the first trimester; whereas cell surface receptor mediated signal transduction, G-protein mediated signalling, ion transport, neuronal activities and chemosensory perception were up-regulated in the third trimester. Pathway analysis showed that brain and placenta might share common developmental routes. Principal component analysis based on the expression of 17 imprinted genes showed a clear separation of first and third trimester placentas, indicating that epigenetic modifications occur throughout pregnancy. In smokers, a set of genes encoding oxidoreductases were differentially expressed in both trimesters. CONCLUSIONS Differences in global gene expression profile between first and third trimester human placenta reflect temporal changes in placental structure and function. Epigenetic rearrangements in the human placenta seem to occur across gestation, indicating the importance of environmental influence in the developing feto-placental unit.
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Acharya G, Albrecht C, Benton SJ, Cotechini T, Dechend R, Dilworth MR, Duttaroy AK, Grotmol T, Heazell AE, Jansson T, Johnstone ED, Jones HN, Jones RL, Lager S, Laine K, Nagirnaja L, Nystad M, Powell T, Redman C, Sadovsky Y, Sibley C, Troisi R, Wadsack C, Westwood M, Lash GE. IFPA Meeting 2011 workshop report I: Placenta: Predicting future health; roles of lipids in the growth and development of feto-placental unit; placental nutrient sensing; placental research to solve clinical problems--a translational approach. Placenta 2011; 33 Suppl:S4-8. [PMID: 22154691 DOI: 10.1016/j.placenta.2011.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 10/14/2022]
Abstract
Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2011 there were twelve themed workshops, four of which are summarized in this report. These workshops related to both basic science and clinical research into placental growth and nutrient sensing and were divided into 1) placenta: predicting future health; 2) roles of lipids in the growth and development of feto-placental unit; 3) placental nutrient sensing; 4) placental research to solve clinical problems: a translational approach.
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Manning N, Acharya G, Impey L, Wilson N, Archer N. Fetal aortic valvuloplasty as a means to survival. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2011; 38:603-604. [PMID: 21547976 DOI: 10.1002/uog.9040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Flo K, Wilsgaard T, Acharya G. A new non-invasive method for measuring uterine vascular resistance and its relationship to uterine artery Doppler indices: a longitudinal study. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2011; 37:538-542. [PMID: 21154788 DOI: 10.1002/uog.8907] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/15/2010] [Indexed: 05/30/2023]
Abstract
OBJECTIVES To describe a new method for measuring uterine vascular resistance (R(uta) ), establish longitudinal reference ranges and explore the relationship between uterine artery (UtA) Doppler indices and R(uta) . METHODS This was a longitudinal study of 53 low-risk pregnancies. Doppler ultrasonography was used to measure UtA velocities, and the pulsatility index (PI), resistance index (RI) and systolic/diastolic velocity (S/D) ratio were calculated. R(uta) was calculated as a ratio between maternal mean arterial pressure and UtA time-averaged maximum velocity. RESULTS At 22 + 0 to 39 + 6 weeks of gestation, the mean R(uta) decreased from 1628 to 1180 dyne.s/cm(3) (P < 0.0001). UtA velocities increased (P < 0.0001), whereas the PI (0.79-0.56), RI (0.51-0.40) and S/D ratio (2.0-1.7) decreased (P < 0.0001). R(uta) and the UtA Doppler indices were positively associated (P = 0.003-0.001). CONCLUSION We describe a non-invasive method for measuring R(uta) and provide reference ranges for serial evaluation of UtA velocities, Doppler indices and R(uta) .
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Aljabri MB, Songstad NT, Lund T, Serrano MC, Andreasen TV, Al-Saad S, Lindal S, Sitras V, Acharya G, Ytrehus K. Pregnancy protects against antiangiogenic and fibrogenic effects of angiotensin II in rat hearts. Acta Physiol (Oxf) 2011; 201:445-56. [PMID: 21281454 DOI: 10.1111/j.1748-1716.2010.02234.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AIM To investigate the difference between physiological and pathological cardiac remodelling induced, respectively, by pregnancy and angiotensin (Ang) II, and to test the hypothesis that pregnancy protects against Ang II effects. METHODS Female Wistar rats, pregnant (n = 12) and non-pregnant (n = 12), were implanted with mini-pumps containing saline (sham) or 150 ng kg(-1) min(-1) Ang II. Ten days later echocardiography and blood pressure measurement were performed. Expression of 22 genes was assessed using RT-PCR. Microscopic sections of LV were prepared to determine collagen content (Sirius Red staining), vessel density (β-actin immunolabelling) and myocytes diameter (Toluidine Blue). RESULTS Heart weight (HW) was increased in Ang II treated groups compared with their controls. Furthermore, HW of Ang II treated pregnant rats (1.0 ± 0.03 g) was higher than that in non-pregnant sham (0.7 ± 0.02 g), pregnant (0.8 ± 0.01 g) and Ang II treated non-pregnant (0.8 ± 0.02 g) rats. Relative LV wall thickness showed similar pattern. Aortic pressure was significantly increased in Ang II groups. Collagen content was increased in Ang II (4.0 ± 0.5%) compared with sham (1.5 ± 0.1%) but reduced again when treated rats were pregnant (2.8 ± 0.4%). Vessel density was reduced by 47.8% after Ang II treatment in non-pregnant and by only 13.9% in pregnant rats. Gene expression analysis showed increased expression of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), anykrin repeat domain-containing protein 1 (Ankrd-1), protein kinase C-α and -δ and tumour suppressor gene TP53 (p53) in Ang II treated groups and upregulation of ANF, BNP and Ankrd-1 remained when pregnancy was combined with Ang II. Pregnancy reduced expression of: α-myosin heavy chain, tumour necrosis factor-α, p53, endothelial nitric oxide synthase and inducible nitric oxide synthase. CONCLUSION Pregnancy seems to counteract the detrimental effects of Ang II on fibrosis and angiogenesis in heart. In addition, pregnancy and Ang II lead to partly opposite changes in the expression of some genes important for heart function.
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Panda PK, Mohanty N, Dash SC, Acharya S, Acharya G, Nathsharma PK. A comparative clinical trial of Chincha kshara and Kadali kshara on Amlapitta. Ayu 2011; 32:494-9. [PMID: 22661843 PMCID: PMC3361924 DOI: 10.4103/0974-8520.96122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A clinical trial was carried out on 30 patients of Amlapitta aged between 20 to 35 years with complaints of Avipaka, hrit-kanthadaha, tikta-amlodgara, utklesa, udarasula, adhmana and aruchi, who were registered from OPD and IPD of Gopabandhu Ayurveda Mahavidyalaya, Puri. They were equally divided into three groups Chincha kshara, Kadali kshara and placebo (who were administered with fresh wheat powder) for 30 days in a dose of 500 mg thrice daily with water. Investigations was done in order to exclude upper gastrointestinal tract ulcer, carcinoma in stomach, cholecystitis, carcinoma gall bladder, and heart diseases. The clinical assessments were carried out on the 30th day by subjective and objective parameters and it was inferred that both Chincha kshara and Kadali kshara were effective and reduced the symptoms of amlapitta. Chincha kshara was found to be more effective than Kadali kshara. The study shows the effect of Chincha and Kadali kshara which led to cure in 4(40%) and 3(30%) patients respectively, and maximum improvement in 4(40%) and 5(50%) patients affected with amlapitta disease, respectively. No untoward effect was noticed due to administration of ksharas during the clinical trial period.
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Flo K, Wilsgaard T, Acharya G. Longitudinal reference ranges for umbilical vein blood flow at a free loop of the umbilical cord. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2010; 36:567-572. [PMID: 20586043 DOI: 10.1002/uog.7730] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To establish longitudinal reference ranges for the umbilical vein (UV) diameter, velocities and volume blood flow (Q(uv)) at a free loop of the umbilical cord and estimate the UV spatial velocity profile at this site. METHODS This was a prospective study of 53 low-risk pregnancies. The UV diameter and blood flow velocities were measured at 4-weekly intervals from 22 + 0 to 39 + 6 weeks of gestation (232 observations) using B-mode ultrasonography and pulsed-wave Doppler. Multilevel regression modeling was used to estimate the reference percentiles. RESULTS The mean UV diameter, velocities and Q(uv) increased with advancing gestation, whereas the Q(uv) normalized for estimated fetal weight decreased. The UV spatial velocity profile coefficient was 0.62. CONCLUSION We have established reference ranges for serial measurements of Q(uv) at a free loop of the umbilical cord during the second half of pregnancy. The spatial velocity profile of the UV is not completely parabolic at this site.
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Rozmus-Warcholinska W, Wloch A, Acharya G, Cnota W, Czuba B, Sodowski K, Skrzypulec V. Reference values for variables of fetal cardiocirculatory dynamics at 11-14 weeks of gestation. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2010; 35:540-547. [PMID: 20178107 DOI: 10.1002/uog.7595] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE Despite the increasing popularity of first-trimester fetal echocardiography, the evaluation of fetal heart function during this period remains challenging. The parameters of normal cardiac function at 11-14 weeks' gestation are not well defined and appropriate reference values have not yet been established. The purpose of this study was to evaluate the fetal cardiocirculatory dynamics during routine first-trimester screening and establish cross-sectional reference ranges for 11-14 weeks' gestation. METHODS Fetal echocardiography was performed on 202 women with singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation. Global cardiac function was evaluated using the heart : chest area ratio and Tei index of the left (LV) and right (RV) ventricles. The proportion of isovolumic contraction (ICT%) and ejection (ET%) times of the cardiac cycle, and the outflow velocities described the systolic function. Diastolic function was evaluated by the proportion of relaxation (IRT%) and filling (FT%) times, the ratio of the blood velocity through the atrioventricular valves during early filling (E) and atrial contraction (A) phases of the cardiac cycle, and ductus venosus pulsatility index for veins (DV-PIV). All participants had additional fetal echocardiography in the second trimester and neonatal clinical examination after birth to confirm normality. RESULTS The mean heart : chest area ratio (0.203 +/- 0.04) and the Tei indices of both ventricles did not vary significantly during weeks 11-14, but the mean Tei index of the LV (0.375 +/- 0.092) was significantly higher than that of the RV (0.332 +/- 0.079) (P = 0.001). The fetal heart rate (FHR) decreased with increasing crown-rump length (CRL) (P < 0.00001). The LV-ICT% did not vary significantly (P = 0.27), LV-IRT% (P = 0.03) and LV-ET% decreased (P = 0.01), whereas the LV-FT% increased (P = 0.02) with CRL. The RV-ET% (P = 0.84) and RV-FT% (P = 0.60) remained relatively stable. The LV-ET% was lower than the RV-ET% (P = 0.0001). The LV (P = 0.004) and RV (P < 0.00001) outflow velocities and E : A ratios of both ventricles (P < 0.0001) increased with advancing gestation. The E-velocity of the LV (P = 0.003) and RV (P = 0.002) increased significantly but the increase in A-velocity was not significant. The outflow velocity (P = 0.008) and E-velocity (P = 0.005) of the RV were higher than that of the LV but the A-velocities were similar (P = 0.066). The mean DV-PIV was 0.97 +/- 0.23 and did not change significantly (P = 0.95) during weeks 11-14. The FHR and DV-PIV did not correlate with the Tei index of either ventricle. CONCLUSION We have established reference ranges for the noninvasive evaluation of fetal cardiocirculatory dynamics at 11-14 weeks' gestation.
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Flo K, Wilsgaard T, Vårtun A, Acharya G. A longitudinal study of the relationship between maternal cardiac output measured by impedance cardiography and uterine artery blood flow in the second half of pregnancy. BJOG 2010; 117:837-44. [PMID: 20353457 DOI: 10.1111/j.1471-0528.2010.02548.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To study serial changes in maternal systemic and uterine artery haemodynamics and establish reference ranges for the second half of pregnancy. DESIGN Prospective longitudinal observational study. SETTING University hospital in Norway. POPULATION Low-risk pregnant women. METHODS Fifty-three low-risk pregnancies were evaluated at approximately 4-weekly intervals. Maternal systemic haemodynamics was assessed with impedance cardiography. Uterine artery blood velocity and diameter were measured using Doppler ultrasonography and uterine artery volume blood flow (Q(uta)) was calculated as the product of mean velocity and cross-sectional area of the uterine artery. The fraction of cardiac output (CO) distributed to the uterine circulation was calculated as: Q(uta)/CO x 100. MAIN OUTCOME MEASURES CO, Q(uta), uterine vascular resistance (R(uta)) and the fraction of CO distributed to the uterine circulation. RESULTS The CO increased (P = 0.0063) until 34 weeks and remained stable until term. Total Q(uta) increased from 299 to 673 ml/minute and R(uta) halved from 0.26 to 0.13 mmHg/ml/minute (P < 0.0001). The fraction of CO distributed to the uterine circulation increased from 5.6% to 11.7% (P < 0.0001). CONCLUSION During the second half of pregnancy, Q(uta) and the fraction of maternal CO distributed to the uterine circulation increase approximately two-fold, mainly as a result of decrease in R(uta).
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Flo K, Wilsgaard T, Acharya G. Agreement between umbilical vein volume blood flow measurements obtained at the intra-abdominal portion and free loop of the umbilical cord. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2009; 34:171-176. [PMID: 19606469 DOI: 10.1002/uog.6441] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE The umbilical vein (UV) is a single vessel and theoretically the volume of blood flowing through it should be equal whether it is measured at the intra-abdominal portion (IA) or a free loop of the umbilical cord (FL). However, the reported values vary considerably depending on the technique and site of measurement. Our objective was to investigate the correlation and agreement between UV volume blood flows (Q(uv)) measured at the IA and FL. METHODS Blood flow velocities and inner diameter of the UV were measured cross-sectionally at the IA and FL in 131 pregnant women at 22-24 weeks' gestation, and in 53 of them longitudinally at 4-weekly intervals until delivery. For each sampling site, the Q(uv) was calculated as: 0.5 x time-averaged maximum velocity x pi x (UV diameter/2)(2). RESULTS The mean Q(uv) measured at the IA (61.5 +/- 23.3 mL/min) and FL (60.7 +/- 17.6 mL/min) cross-sectionally in 131 fetuses at 22-24 weeks of gestation were similar, but the bivariate correlation between them was not strong (r = 0.38; P < 0.0001) and the intraclass correlation coefficient (ICC) was 0.37 (95% CI, 0.21-0.51). When the agreement between 131 pairs of Q(uv) measurements was tested with Bland-Altman analysis, the mean of the ratio IA-Q(uv)/FL-Q(uv) was found to be 1.05 (i.e. IA-Q(uv) exceeded FL-Q(uv) on average by 5%) with 95% limits of agreement of 0.31-1.78. In the longitudinal analysis of 232 pairs of Q(uv) measurements from 53 fetuses at 22-40 weeks, the mean Q(uv) obtained at the IA and FL were similar, i.e. 164 +/- 87 (range, 25-484) mL/min vs. 159 +/- 82 (range, 30-470) mL/min, and the correlation between them, assessed after grouping the observations in five different gestational age groups of 4-week intervals, was slightly better (r = 0.45-0.62; P < 0.0001). The ICC for the Q(uv) measurements obtained at the two sites ranged from 0.38 to 0.54. The mean of the ratio IA-Q(uv)/FL-Q(uv) was 1.07 (i.e. IA-Q(uv) exceeded FL-Q(uv) on average by 7%), with 95% limits of agreement of 0.39-1.75. CONCLUSION Average Q(uv) measured at the IA and FL was similar, but the agreement between individual pairs of measurements was not good enough to be able to use them interchangeably. Therefore, any clinical application of Q(uv) measurement would require standardization of the technique, strict adherence to methodology and use of appropriate reference ranges for it to be useful.
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Acharya G. Technical aspects of aortic isthmus Doppler velocimetry in human fetuses. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2009; 33:628-633. [PMID: 19479680 DOI: 10.1002/uog.6406] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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Vimpeli T, Huhtala H, Wilsgaard T, Acharya G. Fetal aortic isthmus blood flow and the fraction of cardiac output distributed to the upper body and brain at 11-20 weeks of gestation. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2009; 33:538-544. [PMID: 19350568 DOI: 10.1002/uog.6354] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To measure serial changes in fetal aortic isthmus (AI) blood flow and estimate the fraction of fetal cardiac output distributed to the upper body, including the brain, at 11-20 weeks of gestation. METHODS Using pulsed-wave Doppler and two-dimensional ultrasound, blood flow velocities and inner diameter of the AI, aortic valve (AV) and pulmonary valve (PV) were measured longitudinally in 143 fetuses and volume blood flows (Q) were calculated for each site using the formula: Q (mL/min) = pix (diameter/2)(2) x velocity time integral x heart rate x 60. The sum of Q(av) and Q(pv) constituted the combined cardiac output (CCO) and the fraction (%) of the upper body (including brain) blood flow was calculated as: (Q(av)-Q(ai))x100/CCO. RESULTS AI blood velocities as well as the vessel diameter increased with advancing gestation, resulting in a significant increase in Q(ai) from 1.9 to 40.5 mL/min during weeks 11 to 20. The AI peak systolic velocity increased from 29 to 63 cm/s, end-diastolic velocity from 1.2 to 5.2 cm/s, and the time-averaged maximum velocity from 11 to 22 cm/s, resulting in a fairly stable pulsatility index (PI) of 2.4-2.6 and resistance index (RI) of 0.91-0.94. On average, 75% of blood ejected by the left ventricle (which represented about 35% of the CCO) passed through the AI to the descending aorta. The fraction of CCO distributed to the upper body, including the brain, was estimated as approximately 13%. CONCLUSION We have established longitudinal reference ranges for fetal AI diameter, blood flow velocities, PI, RI and volume blood flow at 11-20 weeks of gestation. The human fetus appears to direct a relatively small fraction (13%) of its CCO to the upper body, including the brain, during this period of pregnancy.
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Dangelmayr G, Acharya G, Gleeson JT, Oprea I, Ladd J. Diagnosis of spatiotemporal chaos in wave envelopes of a nematic electroconvection pattern. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:046215. [PMID: 19518320 DOI: 10.1103/physreve.79.046215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 10/09/2008] [Indexed: 05/27/2023]
Abstract
In this paper we report and analyze complex spatiotemporal dynamics recorded in electroconvection in the nematic liquid crystal I52, driven by an ac voltage slightly above the onset value. The instability mechanism creating the pattern is an oscillatory (Hopf) instability, giving rise to two pairs of counterpropagating rolls traveling in oblique directions relative to the unperturbed director axis. If a system of nonlinear partial differential equations shows the same set of unstable modes, the pattern above the onset is represented in a weakly nonlinear analysis as a superposition of the traveling rolls in terms of wave envelopes varying slowly in space and time. Motivated by this procedure, we extract slowly varying envelopes from the space-time data of the pattern, using a four-wave demodulation based on Fourier analysis. In order to characterize the spatiotemporal dynamics, we apply a variety of diagnostic methods to the envelopes, including the calculation of mean intensities and correlation lengths, global and local Karhunen-Loève decompositions in Fourier space and physical space, the location of holes, the identification of coherent vertical structures, and estimates of Lyapunov exponents. The results of this analysis provide strong evidence that our pattern exhibits extensive spatiotemporal chaos. One of its main characteristics is the presence of coherent structures of low and high intensities extended in the vertical (parallel to the director) direction.
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