Endoscopic Treatment of Malignant Hilar Biliary Obstruction.

Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we reviewed the currently used access methods for biliary stent placement (percutaneous transhepatic biliary drainage, endoscopic biliary drainage, endosonography guided biliary drainage), the available stent types (plastic stent, self-expanding metallic stent, full cover self-expanding metallic stent, radioactive self-expanding metallic stent), major approaches (unilateral, bilateral) and deployment methods (stent-in-stent, stent-by-stent). Finally, this review gives an outlook on perspectives of development in stenting and other palliative methods in MHBO.

Women's Knowledge about Pharmacological and Non-Pharmacological Methods of Pain Relief in Labor.

This study aimed to assess knowledge about non-pharmacological pain-relief methods in labor among women who have given birth at least once. This cross-sectional study was conducted using an online survey among 466 adult women. The minimum sample size was estimated based on the number of labor admissions in the year before the study in Poland. The survey included questions about respondents' sociodemographics and knowledge of pain-relief methods. The knowledge score was calculated using the sum of correct answers. Non-parametric Spearman's correlation, Kruskal-Wallis and Wilcoxon variance tests were used. Antenatal classes (313/68.9%) and the Internet (248/54.6%) were the most common sources of knowledge. The most popular pharmacological pain-relief methods included epidural anesthesia (386/85.0%) and nitrous oxide (301/66.3%). Massage and breathing techniques were the most commonly known non-pharmacological methods (405/89.2% and 400/88.1%, respectively). The knowledge score about non-pharmacological methods was significantly higher as compared to the pharmacological methods score (rc = 0.85; p < 0.001). Respondents' age correlated with knowledge about non-pharmacological methods (rs = -0.10,p = 0.026) but did not correlate with knowledge about pharmacological methods. Educational level correlated with knowledge about pharmacological (rs = -0.13,p = 0.007) and non-pharmacological (rs = 0.14, p = 0.003) methods concerning pain relief in labor. No correlation was found between respondents' knowledge and gravidity, number of vaginal or cesarean deliveries, and hospital referral levels for previous deliveries. Our findings support the need to implement educational programs to increase evidence-based knowledge about pain-relief methods during labor in women.

Dosimetric verification of cancer patient's treatment plan using an anthropomorphic, 3D-printed phantom.

The main aim of this research is to formulate a method of creating an accurate, personalised anthropomorphic phantom, retaining efficient production at a low cost. The project accomplishment consisted of selecting appropriate materials, designing and printing the phantom, which was afterwards used in radiotherapy plan verification based on dosimetric measurements. Finally, data collected with radiotherapy film was analysed with the use of the gamma index. Obtained results show that a phantom created with the proposed method provides an alternative for the water phantom in terms of practical application in the verification of a cancer patient's treatment plan.

A Cross-Sectional Survey of Labor Pain Control and Women's Satisfaction.

Introduction: Pain experienced during labor is a symptom of contractile activity and is a physiological feature of the uterus that occurs at the appropriate stages of labor. For the majority of women, labor pain is the most severe pain they will ever experience, and therefore should be relieved. OBJECTIVE: (1) To evaluate labor pain intensity before and after using non-pharmacological and pharmacological interventions; (2) to assess women's satisfaction of labor pain management. METHODS: A multicenter cross-sectional survey study was performed on 500 women who gave birth in different reference level hospitals (i.e., I, II, III). Pain intensity was assessed according the Numeric Rating Scale (range 0-10), whereas women's satisfaction was measured with a 5 point Likert scale. RESULTS: The use of both non-pharmacological (median 6.7 (5; 8) vs. 4.5 (3.3; 5.5)) and pharmacological methods (median 8 (7; 9) vs. 5 (3; 6)) resulted in a significant reduction in pain (p < 0.01). Water immersion and epidural anesthesia proved to be the most effective non-pharmacological and pharmacological methods, respectively. In hospitals of reference I, analgesic management was based primarily on the use of non-pharmacological techniques, less often mixed, i.e., non-pharmacological and pharmacological techniques (27.5%). On the other hand, in hospitals with higher referentiality, mixed methods were used more often (level II-65.8%; level III-81.2%). Pain intensity was significantly higher (p < 0.0001) in hospitals with reference level I (median 5 (4; 6)) than in the hospitals with reference level II (median 4.2 (3; 5)) or level III (median 4.2 (3.3; 5.4)). Epidural anesthesia was most often performed (60%) in the hospital of reference II. Women's satisfaction (median 4 (3; 5)), inter alia, was associated with the effectiveness of applied methods. CONCLUSIONS: The study findings suggest that women giving birth in hospitals of higher referentiality have better control of labor pain due to access to pharmacological methods. Epidural anesthesia remains the gold standard for relieving labor pain. The choice of a specific method is determined by the degree of hospital and associated with the pain referentiality.

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.

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.

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

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.

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

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.

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

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.

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

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.