Publications by authors named "Jakub Pietrzak"

6 Publications

  • Page 1 of 1

A review of randomized trials comparisons of epidural with parenteral forms of pain relief during labour and its impact on operative and cesarean delivery rate.

Ginekol Pol 2018 ;89(8):460-467

Department of Obstetric and Gynaecological Nursing, Medical University in Gdansk, Poland, Poland.

Objectives: The aim of this review was to summarise the available literature on different modalities of labour pain relief (epidural vs. parenteral) and to assess their impact on the rate of caesarean section deliveries and instrumental deliveries, and on the need to support the uterine contractile function.

Material And Methods: The PubMed, Web of Science and Cochrane databases were reviewed to identify articles describing the effect of labour pain relief on the course of labour. This review includes 16 studies with 7150 patients.

Results: The analysis of the obtained data revealed that epidural analgesia (EA) or combined epidural and spinal anaesthesia (CESA) provided significantly better labour pain relief when compared with parenteral opioids. Conduction anaesthesia was not associated with an increase in the caesarean section delivery rate. Some authors concluded that conduction anaesthesia was associated with the need for assisted delivery.

Conclusions: Epidural analgesia is a well-recognised method of labour pain relief. It is associated with the parturient's higher satisfaction when compared to parenteral opioids. EA does not directly increase the caesarean section delivery rate, yet it can lead to instrumental deliveries (vacuum-assisted, obstetrics forceps) and a need to pharmacologically support the uterine contractile function. Further studies are required to evaluate the effect of EA on the course of labour, and methods of minimising its adverse effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5603/GP.a2018.0079DOI Listing
April 2019

Hybrid framework for feasible modeling of an edge illumination X-ray phase-contrast imaging system at a human scale.

Phys Med 2017 Aug 17;40:1-10. Epub 2017 Jul 17.

Biomedical Physics Division, Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw, Poland.

Here, we present a hybrid approach for simulating an edge illumination X-ray phase-contrast imaging (EIXPCi) set-up using graphics processor units (GPU) with a high degree of accuracy. In this study, the applicability of pixel, mesh and non-uniform rational B-splines (NURBS) objects to carry out realistic maps of X-ray phase-contrast distribution at a human scale is accounted for by using numerical anthropomorphic phantoms and a very fast and robust simulation framework which integrates total interaction probabilities along selected X-ray paths. We exploit the mathematical and algorithmic properties of NURBS and describe how to represent human scale phantoms in an edge illumination X-ray phase-contrast model. The presented implementation allows the modeling of a variety of physical interactions of x-rays with different mathematically described objects and the recording of quantities, e.g. path integrals, interaction sites and deposited energies. Furthermore, our efficient, scalable and optimized hybrid Monte Carlo and ray-tracing projector can be used in iterative reconstruction algorithms on multi GPU heterogeneous systems. The preliminary results of our innovative approach show the fine performance of an edge illumination X-ray phase-contrast medical imaging system on various human-like soft tissues with noticeably reduced computation time. Our approach to the EIXPCi modeling confirms that building a true imaging system at a human scale should be possible and the simulations presented here aim at its future development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmp.2017.05.067DOI Listing
August 2017

Analytical reconstructions of intensity modulated x-ray phase-contrast imaging of human scale phantoms.

Biomed Opt Express 2015 Nov 5;6(11):4255-72. Epub 2015 Oct 5.

Biomedical Physics Department, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.

This paper presents analytical approach to modeling of a full planar and volumetric acquisition system with image reconstructions originated from partial illumination x-ray phase-contrast imaging at a human scale using graphics processor units. The model is based on x-ray tracing and wave optics methods to develop a numerical framework for predicting the performance of a preclinical phase-contrast imaging system of a human-scaled phantom. In this study, experimental images of simple numerical phantoms and high resolution anthropomorphic phantoms of head and thorax based on non-uniform rational b-spline shapes (NURBS) prove the correctness of the model. Presented results can be used to simulate the performance of partial illumination x-ray phase-contrast imaging system on various preclinical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.6.004255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4646535PMC
November 2015

NVIDIA OptiX ray-tracing engine as a new tool for modelling medical imaging systems.

Proc SPIE Int Soc Opt Eng 2015 Mar;9412

The Maria Skłodowska - Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland.

The most accurate technique to model the X- and gamma radiation path through a numerically defined object is the Monte Carlo simulation which follows single photons according to their interaction probabilities. A simplified and much faster approach, which just integrates total interaction probabilities along selected paths, is known as ray tracing. Both techniques are used in medical imaging for simulating real imaging systems and as projectors required in iterative tomographic reconstruction algorithms. These approaches are ready for massive parallel implementation e.g. on Graphics Processing Units (GPU), which can greatly accelerate the computation time at a relatively low cost. In this paper we describe the application of the NVIDIA OptiX ray-tracing engine, popular in professional graphics and rendering applications, as a new powerful tool for X- and gamma ray-tracing in medical imaging. It allows the implementation of a variety of physical interactions of rays with pixel-, mesh- or nurbs-based objects, and recording any required quantities, like path integrals, interaction sites, deposited energies, and others. Using the OptiX engine we have implemented a code for rapid Monte Carlo simulations of Single Photon Emission Computed Tomography (SPECT) imaging, as well as the ray-tracing projector, which can be used in reconstruction algorithms. The engine generates efficient, scalable and optimized GPU code, ready to run on multi GPU heterogeneous systems. We have compared the results our simulations with the GATE package. With the OptiX engine the computation time of a Monte Carlo simulation can be reduced from days to minutes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1117/12.2082349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6037296PMC
March 2015

Modulation of age- and cancer-associated DNA methylation change in the healthy colon by aspirin and lifestyle.

J Natl Cancer Inst 2014 Jul 28;106(7). Epub 2014 Jun 28.

Affiliations of authors: Department of Biomedicine, University of Basel, Basel, Switzerland (FN, SW, PU, PS, KT); Department of Epidemiology & Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland (MR); Department of Gastroenterology, Medical Center for Postgraduate Education, Maria Sklodowska-Curie Memorial Cancer Center, Warsaw, Poland (PG, JP, JR); FMH Gastroenterology and Internal Medicine, Langenthal, Switzerland (KT).

Background: Aberrant DNA methylation in gene promoters is associated with aging and cancer, but the circumstances determining methylation change are unknown. We investigated the impact of lifestyle modulators of colorectal cancer (CRC) risk on the stability of gene promoter methylation in the colonic mucosa.

Methods: We measured genome-wide promoter CpG methylation in normal colon biopsies (n = 1092) from a female screening cohort, investigated the interaction of lifestyle factors with age-dependent increase in methylation with log-linear multivariable regression, and related their modifying effect to hypermethylation in CRC. All statistical tests were two-sided.

Results: Of 20025 promoter-associated CpGs analyzed, 1713 showed statistically significant age-dependent methylation gains. Fewer CpGs acquired methylation in users of aspirin (≥ 2 years) and hormonal replacement therapy (HRT age ≥ 50 years) compared with nonusers (43 vs 1355; 1 vs1377, respectively), whereas more CpGs were affected in smokers (≥ 20 years) and individuals with a body mass index (BMI) of 25 kg/m(2) and greater compared with control groups (180 vs 39; 554 vs 144, respectively). Fifty percent of the CpGs showing age-dependent methylation were found hypermethylated in CRC (odds ratio [OR] = 20; 95% confidence interval [CI] = 18 to 23; P < 2 × 10(-16)). These loci gained methylation with a higher median rate compared with age-only methylated sites (P = 2 × 10(-76)) and were enriched for polycomb regions (OR = 3.67). Importantly, aspirin (P < .001) and HRT use (P < .001) reduced the methylation rate at these cancer-related genes, whereas smoking (P < .001) and high BMI (P = .004) increased it.

Conclusions: Lifestyle, including aspirin use, modulates age-associated DNA methylation change in the colonic epithelium and thereby impacts the evolution of cancer methylomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jnci/dju161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4112799PMC
July 2014

Fast and accurate rotator for rotation-based iterative reconstruction algorithms

IEEE Nucl Sci Symp Conf Rec (1997) 2013 Oct-Nov;2012:3295-3297. Epub 2013 Jul 8.

Maria Skłodowska - Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland

View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6031292PMC
http://dx.doi.org/10.1109/NSSMIC.2012.6551751DOI Listing
July 2013
-->