Making use of noise in biological systems

Disorder and noise are inherent in biological systems. They are required to provide systems with the advantages required for proper functioning. Noise is a part of the flexibility and plasticity of biological systems. It provides systems with increased routes, improves information transfer, and assists in response triggers. This paper reviews recent studies on noise at the genome, cellular, and whole organ levels. We focus on the need to use noise in system engineering. We present some of the challenges faced in studying noise. Optimizing the efficiency of complex systems requires a degree of variability in their functions within certain limits. Constrained noise can be considered a method for improving system robustness by regulating noise levels in continuously dynamic settings. The digital pill-based artificial intelligence (AI)-based platform is the first to implement second-generation AI comprising variability-based signatures. This platform enhances the efficacy of the therapeutic regimens. Systems requiring variability and mechanisms regulating noise are mandatory for understanding biological functions.

Antibody Immobilization

In the ELISA format(s), the capture antibody is usually affixed to a solid phase, commonly referred to as the immunosorbent. How to tether the antibody most effectively will depend upon the physical properties of the support (plate well, latex bead, flow cell, etc.) as well as its chemical nature (hydrophobic, hydrophilic, the presence of reactive groups such as epoxide, etc.). Of course, it is ultimately the suitability of the antibody to withstand the linking process while preserving its antigen-binding efficiency that must be determined. In this chapter, the antibody immobilization processes and their consequences are described.

Bayesian analysis reveals the influence of maternal effect on pre-weaning body weights in Landlly piglets

The present study was undertaken to estimate the (co)variance components and genetic parameters of body weights recorded in Landlly piglets from birth to weaning at weekly intervals (w0 to w6). The data pertained to body weights of 2462 piglets, born to 91 sires and 159 dams across different generations during a 7-year period from 2014 to 2020. Five animal models (I-V), differentiated by inclusion or exclusion of maternal effects with or without covariance between maternal and direct genetic effects, were fitted on the data using the Bayesian algorithm. The analyses were implemented by Gibbs sampling in the BLUPF90 program and Markov chain Monte Carlo (MCMC) methodology was used to draw samples of posterior distribution pertaining to (co)variance components. Based on deviance information criteria (DIC), model V with inclusion of direct additive genetic, direct maternal genetic and permanent environmental effect of dam as random factors along with covariance between direct additive and maternal effects best fitted the data on pre-weaning traits (w0 to w5). Whereas, model I incorporating only the direct additive genetic effect best fitted the weaning weight (w6) data in Landlly piglets. The posterior mean estimates of direct heritability under the best models for W0 to W6 were 0.13, 0.19, 0.29, 0.13, 0.26, 0.32 and 0.46, respectively. Inclusion of the maternal component helped in better partitioning of variance for different body weights in Landlly piglets. The maternal heritability ranged from 0.06 to 0.14, while the litter heritability ranged from 0.11 to 0.15 for pre-weaning weights (W0 to W5) under the best-fit models. The influence of maternal environment was greater than maternal genetic effect from birth to 4th week of age. The results implied that variations in body weight of Landlly pigs were genetically controlled to moderate levels (especially w2 and w4) with contributions from direct additive and maternal genotype that can be exploited by designing efficient breeding programmes.

Average and Standard Deviation of the Error Function for Random Genetic Codes with Standard Stop Codons

The origin of the genetic code has been attributed in part to an accidental assignment of codons to amino acids. Although several lines of evidence indicate the subsequent expansion and improvement of the genetic code, the hypothesis of Francis Crick concerning a frozen accident occurring at the early stage of genetic code evolution is still widely accepted. Considering Crick's hypothesis, mathematical descriptions of hypothetical scenarios involving a huge number of possible coexisting random genetic codes could be very important to explain the origin and evolution of a selected genetic code. This work aims to contribute in this regard, that is, it provides a theoretical framework in which statistical parameters of error functions are calculated. Given a genetic code and an amino acid property, the functional code robustness is estimated by means of a known error function. In this work, using analytical calculations, general expressions for the average and standard deviation of the error function distributions of completely random codes with standard stop codons were obtained. As a possible biological application of these results, any set of amino acids and any pure or mixed amino acid properties can be used in the calculations, such that, in case of having to select a set of amino acids to create a genetic code, possible advantages of natural selection of the genetic codes could be discussed.

Sinus-like versus random vibration: Acute effects on elderly people with a high risk of falling

BACKGROUND

Whole-body vibration (WBV) could be an alternative training method for elderly with a high risk of falling.

RESEARCH QUESTION

What acute effects of sinus-like and random WBV intervention occur in this risk group and how do they differ?

METHODS

This prospective pilot study was performed on two days separated by a one-week wash-out phase. Twelve subjects (10 women and 2 men, age 77.7 ± 5.3; 162.3 ± 7.4 cm; 82.4 ± 15.2 kg; BMI 31.2 ± 5.1 kg/m²) undertook sinus-like WBV intervention. One week later random WBV were performed. This consisted of six intervals each lasting 60 s, with heart and respiratory rates monitored. Feasibility outcomes involved safety and compliance. The primary endpoint was postural control, measured by a static posturography before and after the first interval and complete intervention. Secondary outcomes measured before and after the intervention were a Timed-Up-and-Go-Test (TUGT) and an instrumental gait analysis.

RESULTS

Random WBV intervention showed positive acute effect on postural control (Standard deviation (SD) Ellipse area p = 0.007; SD of the Center of force (CoF) independent from direction p = 0.017; SD of the CoF in the antero-posterior direction p = 0.011). There were no significant acute effects on TUGT or gait analysis (comparison between sinus-like and random WBV: Single Task: ΔVelocity p = 0.373, ΔStep time p = 0.077, ΔStep length p = 0.369, ΔStride length p = 0.408, ΔDouble-support-time p = 0.492; Dual task: ΔVelocity p = 0.580, ΔStep-time p = 0.559, ΔStep length p = 0.626, ΔStride length p = 0.584, ΔDouble-support-time p = 0.550). During sinus-like WBV, heart rate increased significantly from rest 69.7 ± 20.9bpm to max.146.0 ± 24.9bpm (p = 0.025). Respiratory rate increased significantly from 10.0 ± 1.0 to max.32.0 ± 6.0 (p = 0.011) during random WBV. No undesirable side effects were observed.

SIGNIFICANCE

Findings demonstrate that random WBV improves acute functional ability of postural control, but not gait for elderly people with a high risk of falling. Intervention with WBV seems safe and well accepted by participants. Monitoring of heart and respiratory rate offers protection for subjects with heart disease.

Ovarian stimulation for fertility preservation in women with cancer: A systematic review and meta-analysis comparing random and conventional starts

OBJECTIVE

In female cancer patients anticipating chemotherapy or radiation, oocyte retrieval for fertility should be performed as efficiently as possible to avoid postponing cancer treatments. Our objective was to compare clinical outcomes among female cancer patients who underwent a conventional early follicular phase-start ovarian stimulation cycle and those who underwent a random-start ovarian stimulation cycle.

EVIDENCE REVIEW

A systematic review of the literature was performed in accordance with PRISMA guidelines. Medline, Embase.com, Scopus, Cochrane Library, and Clinicaltrials.gov databases were searched to identify all original research published in English through July 2020 on the topic of female cancer patients undergoing ovarian stimulation with a random or conventional start. Studies lacking a comparison group or including women who had already undergone chemotherapy at the time of ovarian stimulation were excluded. The primary author assessed all identified article titles and abstracts, and two independent reviewers assessed full-text articles and extracted data. A meta-analysis with a random-effects model was used to calculate weighted mean differences (WMDs) for outcomes of interest. The primary outcome was the number of mature (meiosis II) oocytes retrieved. Secondary outcomes included duration of stimulation, total dose of gonadotropins, total number of oocytes retrieved, fertilization rate, and number of embryos or zygotes cryopreserved.

RESULTS

A total of 446 articles were screened, and 9 full-text articles (all retrospective cohort or prospective observational) were included for review. Additionally, pooled primary retrospective data from two institutions were included. In total, data from 10 studies including 1653 women were reviewed. Five studies reported the number of embryos cryopreserved, and four reported fertilization rates. Random-start cycles were slightly longer (WMD 0.57 days, 95 % confidence interval [CI] 0.0-1.14 days) and used more total gonadotropins (WMD 248.8 international units, 95 % CI 57.24-440.40) than conventional-start cycles. However, there were no differences in number of mature oocytes retrieved (WMD 0.41 oocytes, 95 % CI -0.84-1.66), number of total oocytes retrieved (WMD 0.90 oocytes, 95 % CI -0.21-2.02), fertilization rates (WMD -0.12, 95 % CI -1.22-0.98), or number of embryos cryopreserved (WMD 0.12 embryos, 95 %CI -0.98-1.22) between random-start and conventional-start cycles. All outcomes except for the parameter "total oocytes retrieved" yielded an I² of over 50 %, indicating substantial heterogeneity between studies.

CONCLUSION(S)

Although random-start cycles may entail a longer duration of stimulation and use more total gonadotropins than conventional-start cycles, the absolute differences are small and likely do not significantly affect treatment costs. The similar numbers of mature oocytes retrieved, fertilization rates, and number of embryos cryopreserved in the two start-types suggest that they do not differ in any clinically important ways. Given that random-start cycles can be initiated quickly, they may help facilitate fertility preservation for cancer patients.

Industrial pipelines data generator

The construction of industrial projects involves fabricating and installing massive quantities of pipelines. The design data of pipelines is complex, usually unique for each project and not easily available to researchers and the public for confidentiality reasons. As a result, an industrial pipelines data generator able to realistically simulate pipelines structures will lessen the dependence on real-life data. This article describes an industrial pipelines data generator that was developed using topological and physical properties of pipelines from real industrial projects. This generator can simulate the properties (the type of component, length, diameter, running direction, and the connectivity relationships between components) of real industrial pipelines. Its application in construction engineering and management research, more specifically in the experimental analysis of an optimization algorithm, was described by the authors in previous work [1]. The data generator can be used to develop benchmark problem instances for optimization problems and for simulation studies of construction operations in industrial projects.

Role of N-Acetylcysteine in the Treatment of Acute Nonacetaminophen, Nonalcoholic and Nonviral Hepatitis: A Meta-analysis

Introduction

N-acetylcysteine (NAC) has been extensively investigated for the use in acetaminophen and alcoholic hepatitis and is indicated in acetaminophen overdose. Studies assessing the effect of NAC on other forms of acute hepatitis in adult patients are limited and therefore here we aimed at evaluating the effect of NAC on survival in nonacetaminophen, nonalcoholic and nonviral hepatitis in adults.

Methods

A comprehensive literature search up to September 2019 was completed for randomized controlled trials (RCTs) comparing NAC to placebo in the management of acute nonacetaminophen, nonalcoholic and nonviral hepatitis. Studies with insufficient data, non-RCT or nonprospective design, paediatric studies and studies with no comparator were excluded. Study selection, quality assessment and data extraction were independently performed by two co-authors. Primary outcome was survival. Secondary outcomes were an increase in infection rate. We used random model Mantel–Haenszel meta-analysis with Cochrane risk of bias to assess the quality of included studies. The recommendation was presented using the GRADE framework.

Results

Seven out of 42 retrieved studies were included. Study population included patients with post-liver transplant, postsurgical, hypoxia-induced, ischemic and other nonalcoholic hepatitis. There was no difference in overall survival between NAC and placebo (odds ratio [OR] 0.95 [0.55 to 1.62]) in seven studies including 1033 patients. Furthermore, there was no difference in the rate of infection between NAC and placebo (OR 0.87 [0.43 to 1.79]). Random model analysis was used to adjust the effect of statistically significant heterogeneity in both analyses (P = 0.02). Lack of blinding in one study was found as a possible source of heterogeneity.

Conclusions

NAC does not improve overall survival or the rate of infection in patients with acute nonacetaminophen, nonalcoholic and nonviral hepatitis as compared to placebo and should not be recommended in such setting which may even delay a transplant evaluation (level of evidence: 2a, GRADE of recommendation: B).

Random effects inducing heart pathological dynamics: An approach based on mathematical models

This work deals with an investigation of randomness effects on heart rhythm analysis. A mathematical model composed by three-coupled nonlinear oscillators coupled by time-delayed connections is employed for this aim. In this regard, heart rhythm is governed by delayed-differential equations. Nondeterministic aspects are incorporated considering random connections among oscillators. The main idea is to show that nonlinearities and randomness define together the great variety of possibilities in the heart dynamical system. In general, results corroborate that the model is able to capture the main behaviors of the cardiac system showing that pathological behaviors can evolve from normal rhythms due to random couplings. Experimental data corroborate this argues pointing that nonlinear dynamical analysis is useful for a proper physiological comprehension.

Random gene sets in predicting survival of patients with hepatocellular carcinoma

Despite multiple publications, molecular signatures predicting the course of hepatocellular carcinoma (HCC) have not yet been integrated into clinical routine decision-making. Given the diversity of published signatures, optimal number, best combinations, and benefit of functional associations of genes in prognostic signatures remain to be defined. We investigated a vast number of randomly chosen gene sets (varying between 1 and 10,000 genes) to encompass the full range of prognostic gene sets on 242 transcriptomic profiles of patients with HCC. Depending on the selected size, 4.7 to 23.5% of all random gene sets exhibit prognostic potential by separating patient subgroups with significantly diverse survival. This was further substantiated by investigating gene sets and signaling pathways also resulting in a comparable high number of significantly prognostic gene sets. However, combining multiple random gene sets using "swarm intelligence" resulted in a significantly improved predictability for approximately 63% of all patients. In these patients, approx. 70% of all random 50-gene containing gene sets resulted in equal and stable prediction of survival. For all other patients, a reliable prediction seems highly unlikely for any selected gene set. Using a machine learning and independent validation approach, we demonstrated a high reliability of random gene sets and swarm intelligence in HCC prognosis. Ultimately, these findings were validated in two independent patient cohorts and independent technical platforms (microarray, RNASeq). In conclusion, we demonstrate that using "swarm intelligence" of multiple gene sets for prognosis prediction may not only be superior but also more robust for predictive purposes. KEY MESSAGES: Molecular signatures predicting HCC have not yet been integrated into clinical routine Depending on the selected size, 4.7 to 23.5% of all random gene sets exhibit prognostic potential; independent of the technical platform (microarray, RNASeq) Using "swarm intelligence" resulted in a significantly improved predictability In these patients, approx. 70% of all random 50-gene containing gene sets resulted in equal and stable prediction of survival Overall, "swarm intelligence" is superior and more robust for predictive purposes in HCC.

Point-of-care ultrasound-guided cannulation versus standard cannulation in haemodialysis vascular access: protocol for a controlled random order crossover pilot and feasibility study

BACKGROUND

Point-of-care ultrasound (POCUS) has been used in various vascular access contexts; however, to date, it has not been widely adopted in haemodialysis clinics. People with end-stage kidney disease receiving haemodialysis require an arteriovenous fistula (AVF), arteriovenous graft (AVG), or central venous access device (CVAD) in order to access their blood for therapy/treatment. Cannulation issues, such as haematoma and extravasation, related to AVFs and AVGs are common. This pilot and feasibility study will assess the feasibility of a randomised controlled trial aimed at evaluating whether POCUS-guided cannulation results in more successful and accurate AVF needle placement than the standard practice of blind cannulation.

METHODS

A controlled, random order crossover design will be used to evaluate two clinical conditions: (1) POCUS-guided cannulation and (2) standard practice of blind cannulation, when used by haemodialysis nurses. The feasibility of conducting this type of trial for these two clinical conditions will be assessed through recruitment, retention, and attrition rates; perceptions of acceptability; implementation measures; and assessment of methods of data collection. Clinical outcomes to be assessed are overall cannulation success on first attempt, accuracy of needle tip placement, number of extravasations, procedural time, and patient and nurse perceptions. The setting is a 16-chair dialysis unit in regional Australia. Participants will include adult haemodialysis patients with an AVF in situ for greater than 2 months and haemodialysis-trained registered nurses working full- or part-time. Clinical outcomes will be analysed using generalised linear mixed models. Feasibility data will be reported using descriptive statistics. Qualitative audio data will be digitally recorded, transcribed verbatim, and analysed using thematic analysis.

DISCUSSION

Point-of-care ultrasound for cannulation has the potential to promote high-quality, safe nursing care and decrease cannulation damage for patients on haemodialysis. Due to the lack of evidence for patient benefit and its innovative and niche use in haemodialysis centres, POCUS is currently only specified in one international guideline. This study will inform sample size calculations for a future multi-site trial.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, (21/11/2017) ACTRN12617001569392.

A Prospective Randomized Comparison of a Covered Metallic Ureteral Stent and a Double-J Stent for Malignant Ureteral Obstruction

Objective

To compare the safety and efficacy between a covered metallic ureteral stent (CMS) and a double-J ureteral stent (DJS) for the treatment of a malignant ureteral obstruction (MUO).

Materials and Methods

Nineteen patients (seven men and 12 women; mean age, 53.4 years) were randomly assigned to the CMS (n = 10) or DJS (n = 9) group. The following were compared between the two groups: technical success, i.e., successful stent placement into desired locations; stent malfunction; stent patency, i.e., no obstruction and no additional intervention; complications; and patient survival.

Results

The technical success rate was 100% in all 10 and 12 ureteral units in the CMS and DJS groups, respectively. During the mean follow-up period of 253.9 days (range, 63–655 days), stent malfunction was observed in 40.0% (4/10) and 66.7% (8/12) in the CMS and DJS groups, respectively. In the per-ureteral analysis, the median patency time was 239.0 days and 80.0 days in the CMS and DJS groups, respectively. The CMS group yielded higher patency rates compared with the DJS group at three months (90% vs. 35%) and at six months (57% vs. 21%). The overall patency rates were significantly higher in the CMS group (p = 0.041). Complications included the migration of two metallic stents in one patient in the CMS group, which were removed in a retrograde manner. The two patient groups did not differ significantly regarding their overall survival rates (p = 0.286).

Conclusion

Covered metallic ureteral stent may be effective for MUO.

Cancer detection rate of prebiopsy MRI with subsequent systematic and targeted biopsy are superior to non-targeting systematic biopsy without MRI in biopsy naïve patients: a retrospective cohort study

Background

To determine whether prebiopsy multiparametric magnetic resonance imaging (mpMRI) with subsequent systematic plus targeted biopsies for suspicious lesions improve prostate cancer detection compared with standard non-targeting systematic biopsies without mpMRI in biopsy-naïve patients.

Methods

Patients who underwent their first prostate biopsy due to suspicion of prostate cancer were analyzed retrospectively to compare the biopsy outcomes between patients who received prebiopsy mpMRI (215 patients) and those who did not (281 patients). mpMRI was performed to determine pre-biopsy likelihood of the presence of prostate cancer using a three-point scale (1 = low level of suspicion, 2 = equivocal, and 3 = high level of suspicion). Systematic biopsies were performed in both groups. Targeted biopsies were added for a high level of suspicious lesions on mpMRI. All biopsies were performed by transperineal biopsy technique. After biopsy, Prostate Imaging Reporting and Data System ver. 2 (PIRADS-2) scoring was performed to describe the mpMRI findings and predictive value of PIRADS-2 was evaluated.

Results

The detection rate of total and clinically significant prostate cancer was significantly higher in patients who received prebiopsy mpMRI than in those who did not (55.3 and 46.0% vs. 42.0 and 35.2%, respectively; p = 0.004 and p = 0.016). The clinically insignificant prostate cancer detection rate was similar between the two groups (9.3% vs. 6.8%; p = 0.32). Of 86 patients who underwent systematic plus targeted biopsy in the MRI cohort and were diagnosed with prostate cancer, seven patients were detected by addition of targeted biopsy whereas 29 patients were missed by targeted biopsy but detected by systematic biopsy. There was a correlation between the PIRADS-2 and prostate cancer detection rate, and a receiver-operator curve analysis yielded an area under the curve of 0.801 (p <  0.0001).

Conclusions

Prebiopsy mpMRI with subsequent systematic plus targeted biopsies for suspicious lesions can yield a higher cancer detection rate than non-targeting systematic biopsies. PIRADS-2 scoring is useful for predicting the biopsy outcome.

Experts' memory superiority for domain-specific random material generalizes across fields of expertise: A meta-analysis

Experts’ remarkable ability to recall meaningful domain-specific material is a classic result in cognitive psychology. Influential explanations for this ability have focused on the acquisition of high-level structures (e.g., schemata) or experts’ capability to process information holistically. However, research on chess players suggests that experts maintain some reliable memory advantage over novices when random stimuli (e.g., shuffled chess positions) are presented. This skill effect cannot be explained by theories emphasizing high-level memory structures or holistic processing of stimuli, because random material does not contain large structures nor wholes. By contrast, theories hypothesizing the presence of small memory structures—such as chunks—predict this outcome, because some chunks still occur by chance in the stimuli, even after randomization. The current meta-analysis assessed the correlation between level of expertise and recall of random material in diverse domains. The overall correlation was moderate but statistically significant (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{r} = .41,p < .001 $$\end{document}r¯=.41,p<.001), and the effect was observed in nearly every study. This outcome suggests that experts partly base their superiority on a vaster amount of small memory structures, in addition to high-level structures or holistic processing.

Performance in a blocked versus randomized emotional Stroop task in an aged, early traumatized group with and without posttraumatic stress symptoms

BACKGROUND AND OBJECTIVES

Attentional biases (AB) for trauma-related stimuli have been examined in many studies assessing different trauma samples. In emotional Stroop tasks (EST), blocked and single-trial formats are used almost interchangeably in clinical research. There is reason to believe that different designs yield different results and assess different processes, which, however, has been hardly examined in studies. Furthermore, there is a dearth of information about AB in older trauma survivors with posttraumatic stress symptoms.

METHODS

Older adults with (n = 20) and without PTSD symptoms (n = 26) as well as non-traumatized controls (n = 21) completed an EST, in which words were presented both blocked and randomized.

RESULTS

Analyses revealed that individuals with PTSD symptoms showed AB for trauma- and depression-related words; however, mode of administration did not significantly influence reaction times.

LIMITATIONS

The emotional Stroop task cannot disentangle the underlying cognitive mechanism (i.e., facilitation, interference, avoidance).

CONCLUSIONS

PTSD symptoms in older trauma survivors are associated with AB. Overall, participants with PTSD symptoms did not show greater impairment of cognitive control in comparison to both control groups. Results also illustrate that methodological differences between task versions need to be considered more thoroughly.

Biochemical Refinement Before Genetics: Chance Utility

Given two primordial conditions that seem likely to be common, near-ideal reactions for evolutionary progress are realized. These requisites are sporadic availability of pooled reactants and evolutionarily useful products within a pool’s repertoire. These intrinsically optimizing circumstances function without genetics, and therefore can help evolve a first genetic system. This process is termed chance utility.

[Serendipities in medicine]

Coincidences accompany our lives. This paper shows to which extent serendipity plays a role in important discoveries and developments in medicine. These include, among others, Mendel's laws, the determination of the human chromosome number, the discovery of DNA by Watson and Crick, the PAP test, or the discovery of X-rays and radioactivity. But also and especially in pharmacology, there are many examples of serendipity. Some go closely with serendipities in the discovery of bacteriology.

Effects of the copper intrauterine device versus injectable progestin contraception on pregnancy rates and method discontinuation among women attending termination of pregnancy services in South Africa: a pragmatic randomized controlled trial

BACKGROUND

The copper intrauterine device (IUD) is under-utilised in South Africa, where injectable progestin contraception (IPC) dominates contraception usage. There is a lack of robust comparative data on these contraceptive options to inform policy, programs, clinical counseling, and women's choices.

METHODS

Within the context of a South African program to increase women's access to the IUD, we conducted a pragmatic, open-label, parallel-arm, randomised controlled trial of the IUD versus IPC at two South African hospitals. The target sample size was 7,000 women and the randomisation ratio was 1:1. The random sequence was computer-generated and group allocation was concealed in sealed, opaque, consecutively-numbered envelopes. Counselled, consenting women attending termination of pregnancy services were randomly assigned to IUD or IPC immediately post-termination. Condoms were promoted for the prevention of sexually-transmitted infections. The primary outcome was pregnancy; secondary outcomes were discontinuation, side-effects, and HIV acquisition and disease progression. Pregnancy and discontinuation outcomes are reported here.

RESULTS

The trial closed early with 2,493 participants randomised (IUD = 1,247, IPC = 1,246), due to international concerns regarding a possible association between IPC and HIV acquisition. Median follow-up was 20 months; 982 and 1000 participants were followed up in the IUD and IPC groups, respectively. Baseline group characteristics were comparable. Pregnancy occurred significantly less frequently among women allocated to the IUD than IPC: 56/971 (5.8%) versus 83/992 (8.4%), respectively; risk ratio (RR) 0.69, 95% confidence interval (CI) 0.50 to 0.96; P = 0.025. There were more protocol violations in the IUD group; however, discontinuation rates were similar between IUD and IPC groups (141/855 [16.5%] and 143/974 [14.7%], respectively). Women in the IUD group were more likely to discontinue contraceptive use due to abdominal pain or backache and non-specific symptoms, and those in the IPC group due to oligo- or amenorhoea and lack of sexual activity.

CONCLUSIONS

The IUD was significantly more effective in preventing pregnancy than IPC. Efforts to expand contraception options and improve access to the IUD in settings where it is under-utilised are worthwhile. This trial shows that randomising long-acting, reversible contraceptives is feasible.

TRIAL REGISTRATION

Pan African Clinical Trials Registry number PACTR201409000880157 (04-09-2014).

Combined immunotherapy with dendritic cells and cytokine-induced killer cells for malignant tumors: a systematic review and meta-analysis

PURPOSE

A new strategy of adoptive and passive immunotherapy involves combining dendritic cells (DCs) with a subset of natural killer T lymphocytes termed cytokine-induced killer (CIK) cells. The objective of this systematic review and meta-analysis was to evaluate the safety and efficacy of DC-CIK therapy vs. placebo, no intervention, conventional treatments, or other complementary and alternative medicines for malignant tumors.

METHOD

We searched PubMed, Medline, Embase, Cochrane, Wangfang, Weipu, CNKI databases and reference lists of articles. We selected randomized controlled trials of DC-CIK therapy vs. placebo, no intervention, conventional treatments, or other complementary and alternative medicines in patients with all types and stages of malignant tumor. Primary outcome measures were overall survival and treatment response. Secondary outcome measures were health-related quality of life (HRQoL) assessment, progression free survival (PFS), and adverse events.

RESULTS

Six trials met our inclusion criteria. There was evidence that chemotherapy+DC-CIK increased the 2-year (RR 2.88, 95% CI 1.38 to 5.99, P=0.005) and 3-year (RR 11.67, 95% CI 2.28 to 59.69, P=0.003) survival rates and progression free survival (RR 0.64, 95% CI 0.34 to 0.94, P<0.0001) in patients with non-small cell lung cancer compared to those treated with chemotherapy alone. DC-CIK therapy appears to be well-tolerated by cancer patients and to improve post-treatment patient health related quality of life.

CONCLUSION

DC-CIK immunotherapy is a safe and effective treatment for patients with malignant tumors. Further clinical trials to provide supportive evidence for the routine use of DC-CIK therapy in clinical practice are warranted.

Highly accelerated aortic 4D flow MR imaging with variable-density random undersampling

PURPOSE

To investigate an effective time-resolved variable-density random undersampling scheme combined with an efficient parallel image reconstruction method for highly accelerated aortic 4D flow MR imaging with high reconstruction accuracy.

MATERIALS AND METHODS

Variable-density Poisson-disk sampling (vPDS) was applied in both the phase-slice encoding plane and the temporal domain to accelerate the time-resolved 3D Cartesian acquisition of flow imaging. In order to generate an improved initial solution for the iterative self-consistent parallel imaging method (SPIRiT), a sample-selective view sharing reconstruction for time-resolved random undersampling (STIRRUP) was introduced. The performance of different undersampling and image reconstruction schemes were evaluated by retrospectively applying those to fully sampled data sets obtained from three healthy subjects and a flow phantom.

RESULTS

Undersampling pattern based on the combination of time-resolved vPDS, the temporal sharing scheme STIRRUP, and parallel imaging SPIRiT, were able to achieve 6-fold accelerated 4D flow MRI with high accuracy using a small number of coils (N=5). The normalized root mean square error between aorta flow waveforms obtained with the acceleration method and the fully sampled data in three healthy subjects was 0.04±0.02, and the difference in peak-systolic mean velocity was -0.29±2.56cm/s.

CONCLUSION

Qualitative and quantitative evaluation of our preliminary results demonstrate that time-resolved variable-density random sampling is efficient for highly accelerating 4D flow imaging while maintaining image reconstruction accuracy.

Electrophysiological analysis of the affective congruence between pattern regularity and word valence

Reflection symmetry is an important property of human designs and biological organisms, and it is often judged to be beautiful. Previous reaction-time based studies have shown a congruency effect, where reflection symmetry facilitates processing of positive words, and random patterns facilitate negative words. But what is the neural basis of affective responses to symmetry? In Experiment 1 we recorded ERPs from posterior electrode clusters while participants viewed reflection or random patterns with either a positive or negative word superimposed. In the Discriminate Regularity task, participants categorized the patterns (reflection or random). In the Discriminate Word task, they categorized the words as positive or negative. In Experiment 2, participants classified words and patterns on each trial. We found a difference between ERP waves from congruent (reflection with positive word, random with negative word) and incongruent trials (reflection with negative, random with positive). This congruency effect began around 200 ms, and persisted up to 1,000 ms post stimulus, and was only present in the Discriminate Word task. We suggest that when evaluating words, participants automatically evaluate the background pattern as well, and this alters early visual processing.

The comparative analysis of species occurrence patterns on archipelagos

We present a technique based on recent developments in contingency table analysis to analyze species occurrence patterns on archipelagos. This technique, through a "logistic" transformation, fits a sigmoidal-shaped surface on the species presence-absence matrix using only three parameters. This technique does not follow from any a priori or theoretical motivation, but is simply a descriptive statistical procedure. It accounts for roughly half the variation of the empirical contingency matrices for 14 different island systems. The taxa studied included plants, birds, herps and mammals. The matrix technique for a set of species in an archipelago provides three biologically relevant summary statistics. The first statistic indicates the overall colonizing success of the species in the archipelago. The second statistic describes the orderedness of the matrix (species occurrences). The third indicates the distribution of colonizing success between species. The technique is useful in computing the range of these statistics across taxa and over archipelagos.