Utjecaj brzine doze pulsnoga zračenja na nastanak mikronukleusa u limfocitima periferne ljudske krvi

The micronucleus assay in human peripheral blood lymphocytes is a sensitive indicator of radiation damage and could serve as a biological dosimeter in evaluating suspected overexposure to ionising radiation. Micronucleus (MN) frequency as a measure of chromosomal damage has also extensively been employed to quantify the effects of radiation dose rate on biological systems. Here we studied the effects of 8 MeV pulsed electron beam emitted by Microtron electron accelerator on MN induction at dose rates between 35 Gy min-1 and 352.5 Gy min-1. These dose rates were achieved by varying the pulse repetition rate (PRR). Fricke dosimeter was employed to measure the absorbed dose at different PRR and to ensure uniform dose distribution of the electron beam. To study the dose rate effect, blood samples were irradiated to an absorbed dose of (4.7±0.2) Gy at different rates and cytogenetic damage was quantifi ed using the micronucleus assay. The obtained MN frequency showed no dose rate dependence within the studied dose rate range. Our earlier dose effect study using 8 MeV electrons revealed that the response of MN was linear-quadratic. Therefore, in the event of an accident, dose estimation can be made using linear-quadratic dose response parameters, without adding dose rate as a correction factor.Mikronukleus-test pokazao se osjetljivim pokazateljem oštećenja u limfocitima periferne ljudske krvi te se primjenjuje kao biološki dozimetar posumnja li se na prekomjerno izlaganje ionizirajućem zračenju. Mikronukleusi kao mjera oštećenja kromosoma često se rabe za procjenu učinaka zračenja u biološkim sustavima. Ovdje je istraženo djelovanje pulsnoga elektronskoga snopa od 8 MeV, dobivenog s pomoću elektronskoga akceleratora marke Microtron, na nastanak mikronukleusa u rasponu brzina doza od 35 Gy min-1 do 352.5 Gy min-1. Brzine doza mijenjale su se mijenjajući brzinu ponavljanja pulsa (tzv. pulse repetition rate, krat. PRR). Za mjerenje apsorbirane doze pri različitim PRR-ovima rabio se Frickeov dozimetar. Dozimetrijska su mjerenja također poslužila za ujednačavanje doze elektronskoga snopa. Za istraživanje utjecaja brzine doze, uzorci krvi ozračeni tako da apsorbiraju dozu od (4.7±0.2) Gy pri različitim brzinama doze, a zatim se s pomoću mikronukleus-testa utvrdilo citogenetsko oštećenje. Pokus s pulsnim snopovima energije 8 MeV upućuje na neovisnost broja mikronukleusa o brzinama doze u rasponu ispitanome u ovom istraživanju. Naše ranije istraživanje utjecaja doze pulsnoga elektronskoga zračenja energije 8 MeV upozorilo je na linearni do kvadratni odgovor izmjerenih parametara. Stoga se akcidentalna doza može procijeniti s pomoću linearnih do kvadratnih parametara odgovora na dozu, bez potrebe za korekcijom s pomoću brzine doze

Village Baseline Study: Site Analysis Report for Vaishali, Mukundpur Village, India

The baseline effort consists of three components – a household survey, village study and organisational survey. The household baseline survey, a quantitative questionnaire on basic indicators of welfare, information sources, livelihood/agriculture/natural resource management strategies, needs and uses of climate and agricultural-related information and current risk management, mitigation and adaptation practices, was implemented by CCAFS partners in 35 sites (245 villages) with nearly 5,000 households in 12 countries to date. CCAFS partners are implementing village baseline studies (VBS) and organisational surveys in one out of the seven villages within each CCAFS site where the household survey was implemented. The plan is to revisit these villages in roughly 5 years, and again in 10 years, to monitor what changes have occurred since the baseline was carried out. The goal is not to attribute these changes to the program, but to be able to assess what kinds of changes have occurred and whether these changes are helping villages adapt to, and mitigate, climate change. The focus of this site analysis report is the VBS. To date, seventeen VBS were conducted. The VBS aims to provide baseline information at the village level about some basic indicators of natural resource utilisation, organisational landscapes, information networks for weather and agricultural information, as well as mitigation baseline information, which can be compared across sites and monitored over time

Village Baseline Study: Site Analysis Report for Rupandehi, Madhuri Village, Nepal

This is the report of the village baseline study of Madhuri Village in the CCAFS benchmark site of Rupandehi, Nepal conducted from June 5-9, 2011 to complement an earlier household baseline survey done in the same village. Madhuri is located in the fertile area of the Indo-Gangetic Plain in Nepal yet faces challenges due to increasing populations, encroachment on forests, decreasing soil fertility, limited agriculture and animal productivity, lack of opportunities, and variable climatic conditions. Its circumstances present manageable opportunities to prevent an increase in food insecurity and further degradation natural resources. Madhuri has yet to incur any food or environmental crises

Village Baseline Study: Site Analysis Report for Khulna - Morrelganj, Bangladesh

The Gabgachhia village is located in the coastal region of Bangladesh’s Khulna district. The population is rising and living with high levels of poverty and food insecurity. Local resources that are not critically strained from climate change and poor resource management are few, beyond mosques, roads and schools. The community has seen dramatic changes in resources, as early as 1990, which they attribute to increased population pressures and climate change impacts. Forests have been depleted, rivers are full of silt and lacking life, farmlands have low productivity due to rising salinity, flooding and inappropriate varieties, drinking water is insufficient to meet human, crop and animal needs, and infrastructure is weak and unable to withstand the environmen

Village Baseline Study: Site Analysis Report for Haryana - Karnal, India

This is the report of the village baseline study of Pakhana in the CCAFS benchmark site of Karnal, India conducted from March 15-17, 2013 to complement an earlier household baseline survey done in the same village. Pakhana is located in the fertile flat land of the Indo-Gangetic plains and has good access to roads, markets, electricity and communication. The community has not experienced a food crisis and 90% of the population enjoys year-round food security. Pakhana benefited from the Green Revolution and has adopted improved varieties and the use of chemical fertilizers and pesticides. However, Pakhana now faces challenges resulting from population growth, deforestation, reduced and variable rainfall, declining soil fertility and organic matter, monocropping, over application of chemical inputs, and depletion of the water table. As a result, access to water resources is more difficult, profits have decreased and production is constrained. Without adjustments, Pakhana’s food security, livelihoods and natural resources will be further strained and threatened

Novel corona virus disease (COVID-19) in pregnancy: What clinical recommendations to follow?

Pregnancy is a state of partial immune suppression which makes pregnant women more vulnerable to viral infections, and the morbidity is higher even with seasonal influenza. Therefore, the COVID‐19 epidemic may have serious consequences for pregnant women. Although the vast majority of cases of COVID‐19 are currently in China, the risk of outward transmission appears to be significantly raising global concern. Human to human transmission of the virus is proven to occur,1, 2 perhaps even from asymptomatic patients,3, 4 and the mortality is substantial, especially among frail, elderly patients with comorbidities.5 Although there have been some criticisms surrounding suppression of early warnings, and slow initial response followed by heavy‐handed quarantine measures, as well as concerns expressed about the capacity to cope with the large number of patients, and shortage of protective equipment and in‐hospital infections leading to deaths among a substantial number of healthcare professionals,6, 7 China's effort to contain the disease and slow down its spread in China and world‐wide has been commendable. A large number of cases requiring hospitalization and intensive care is a serious burden even for affluent countries with well‐developed healthcare systems. However, the Chinese government, its health professionals, and the public, have set a new standard for handling the epidemic, and they have certainly contributed to reducing the potential risk of outbreak in neighboring countries with weaker healthcare systems. Furthermore, Chinese researchers and health professionals have generously shared their data, knowledge, experience and expertise that has helped to develop diagnostic tools, clinical management algorithms, set up clinical trials, and accelerate vaccine development. Clinical course and outcome of a substantial number of COVID‐19 patients have been reported, and recommendations regarding the care of such patients have been issued by several national health authorities across the world. However, the practices seem to vary considerably

Fetal heart rate variability with hypoxemia in an instrumented sheep model

Abstract Objective We examined the effect of hypoxemia on fetal heart rate variability using the instrumented fetal sheep model. Methods In this prospective study, 19 pregnant sheep were instrumented under general anesthesia at a mean gestational age of 127 days. After a 5-day recovery, hypoxaemia was induced by attaching the mother to a re-breathing circuit. Hypoxemia was further extended till 120 minutes, following which it was reversed till matenal and fetal pO2 returned back to baseline. The heart rate recordings at baseline, hypoxemia of 30 and 120 minutes, and recovery were analysed to calculate short term variation (STV) in 16 epochs of 3.75sec each, every minute. Phase rectified signal averaging (window length L= 10, time T= 2 and Scale S=T) was used to calculate acceleration capacity (AC) and deceleration capacity (DC). Results At baseline, mean (SD) fetal pO2 was 2.90±0.38 kPa. Acute hypoxaemia was associated with a significant reduction in mean pO2 at 30 (1.60±0.37 kPa) and 120 (1.50±0.16 kPa) minutes. Mean (SD) fetal pO2 at recovery was 2.80±0.32 kPa. The median STV, AC and DC were 1.307 msec (IQR: 0.515 to 2.508), 1.295 (IQR: 0.990 to 2.685) BPM and 1.197 (IQR: 0.850 to 1.836) BPM respectively, at baseline. With 30-minute hypoxaemia, the values were 1.323 (IQR 0.753 to 2.744) msecs, 1.696 (IQR: 1.310 to 3.013) BPM & 1.584 (IQR 1.217 to 4.132) BPM. With 120-minute hypoxaemia, the values were 1.760 (IQR: 0.928 ? 4.656) msecs, 3.098 (IQR: 1.530 ? 5.163) BPM & 3.054 (IQR: 1.508 ? 4.522) BPM. At recovery they changed to 0.962 (IQR: 0.703 ? 1.154) msecs, 1.228 (IQR: 1.071 ? 2.234) BPM & 1.086 (IQR: 0.873 ? 1.568) BPM respectively. Hypoxemia for 30 and 120 minutes were associated with a significant increase in the DC compared to baseline (p = 0.014 & 0.017 respectively). The changes in STV and AC were not significant. Conclusion Acute hypoxaemia is associated with a significant increase in the deceleration capacity of the fetal heart rate. This article is protected by copyright. All rights reserved.Peer reviewe

Static and functional hemodynamic profiles of women with abnormal uterine artery doppler at 22-24 weeks of gestation

Published version. Source at http://doi.org/10.1371/journal.pone.0157916. License CC BY 4.0.Objective To compare cardiac function, systemic hemodynamics and preload reserve of women with increased (cases) and normal (controls) uterine artery (UtA) pulsatility index (PI) at 22–24 weeks of gestation. Materials and Methods A prospective cross-sectional study of 620 pregnant women. UtA blood flow velocities were measured using Doppler ultrasonography, and PI was calculated. Mean UtA PI ≥ 1.16 (90th percentile) was considered abnormal. Maternal hemodynamics was investigated at baseline and during passive leg raising (PLR) using impedance cardiography (ICG). Preload reserve was defined as percent increase in stroke volume (SV) 90 seconds after passive leg raising compared to baseline. Results Mean UtA PI was 1.49 among cases (n = 63) and 0.76 among controls (n = 557) (p < 0.0001). Eighteen (28.6%) cases and 53 (9.5%) controls developed pregnancy complications (p <0.0001). The mean arterial pressure and systemic vascular resistance were 83 mmHg and 1098.89±293.87 dyne s/cm5 among cases and 79 mmHg and 1023.95±213.83 dyne s/cm5 among controls (p = 0.007 and p = 0.012, respectively). Heart rate, SV and cardiac output were not different between the groups. Both cases and controls responded with a small (4–5%) increase in SV in response to PLR, but the cardiac output remained unchanged. The preload reserve was not significantly different between two groups. Conclusion Pregnant women with abnormal UtA PI had higher blood pressure and systemic vascular resistance, but similar functional hemodynamic profile at 22–24 weeks compared to controls. Further studies are needed to clarify whether functional hemodynamic assessment using ICG can be useful in predicting pregnancy complications

Sex-specific reference ranges of cerebroplacental and umbilicocerebral ratios: A longitudinal study

This is the peer reviewed version of the following article: Acharya, G., Ebbing, C., Karlsen, H., Kiserud, T. & Rasmussen, S. (2019). Sex-specific reference ranges of cerebroplacental and umbilicocerebral ratios: A longitudinal study. Ultrasound in Obstetrics and Gynecology, 2019, which has been published in final form at https://doi.org/10.1002/uog.21870. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Objectives - The ratio of middle cerebral artery (MCA) pulsatility index (PI) to umbilical artery (UA) PI, i.e. cerebro‐placental ratio (CPR), has been suggested as a measure of fetal “brain sparing” phenomenon reflecting redistribution of fetal cardiac output as a response to placental insufficiency. Observational studies have shown that low CPR values predict increased risk of adverse perinatal outcomes although evidence from randomized clinical trials is lacking. The inverse ratio, i.e. umbilico‐cerebral ratio (UCR), is preferred by some as it increases with increasing degree of fetal compromise. Monitoring fetal wellbeing requires serial assessment, and for this purpose, appropriate reference values should be based on data from longitudinal studies. However, longitudinal reference ranges for the UCR have not been established. Furthermore, the sex of the fetus influences its growth velocity, cord properties, in utero circadian rhythm, behavioral states and placental function, but whether gestational age‐dependent changes in CPR or UCR differ between male and female fetuses has not been studied. Thus, our objective was to investigate sex‐specific, gestational age‐associated serial changes in CPR and UCR during the second half of pregnancy and establish longitudinal reference ranges. Methods - This was a dual‐center prospective longitudinal study of singleton low risk pregnancies. Doppler blood flow velocity waveforms were obtained serially from the UA and MCA during 19‐41 weeks of gestation, and PIs were determined. CPR and UCR were calculated as the ratios, MCA PI/ UA PI and UA PI/ MCA PI, respectively. The course and outcome of pregnancies was recorded. Sex of the fetus was determined after delivery. Reference intervals were constructed using multilevel modelling and gestational age‐specific Z‐scores of male and female fetuses were compared. Results - Of a total of 299 pregnancies enrolled, 284 women and their fetuses (148 male and 136 female) were included in the final analysis, and 979 paired measurements of UA and MCA PIs were used to construct sex‐specific longitudinal reference intervals. Both CPR and UCR had U‐shaped curves of development during pregnancy, but with opposite directions. There was a small but significant (P=0.007) difference in z‐scores of CPR and UCR between male and female fetuses throughout the second half of pregnancy. Conclusions - We have established longitudinal reference ranges for CPR and UCR suitable for serial monitoring with possibilities to refine the assessment by fetal sex‐specific ranges and the conditioning by a previous measurement. The clinical significance of such refinements needs further evaluation