Tag: pubmed

Am J Epidemiol. 2021 Nov 9:kwab263. doi: 10.1093/aje/kwab263. Online ahead of print.

ABSTRACT

When an entire cohort of patients receives a treatment it is difficult to estimate the treatment effect in the treated because there are no directly comparable untreated patients. Attempts can be made to find a suitable control group, (e.g. historical controls), but underlying differences between the treated and untreated can result in bias. We show how negative control outcomes (NCO) combined with difference-in-differences analysis can be used to assess bias in treatment effect estimates and obtain unbiased estimates under certain assumptions. Causal diagrams and potential outcomes are used to explain the methods and assumptions. We apply the methods to UK Cystic Fibrosis (CF) Registry data to investigate the effect of ivacaftor, introduced in 2012 for a subset of the CF population with a particular genotype, on lung function and days receiving intravenous antibiotics (IV days). We consider two NCOs: outcomes measured in the pre-ivacaftor period and outcomes in individuals ineligible for ivacaftor due to their genotype. Ivacaftor was found to improve lung function in year one (~6.5 increase in FEV1%), was associated with reduced lung function decline (~0.5 decrease in annual FEV1% decline, though confidence intervals include 0), and reduced the rate of IV days (~60% over 3 years).

PMID:34753177 | DOI:10.1093/aje/kwab263

J Infus Nurs. 2021 Nov-Dec 01;44(6):339-345. doi: 10.1097/NAN.0000000000000443.

ABSTRACT

The aim of this single-blinded, randomized controlled study was to determine the effectiveness of vapocoolant spray in reducing pain related to venipuncture in young, healthy male blood donors. The participants were separated into 2 groups by randomization. The donors in the control group (n = 44) were not given any intervention during the blood collection process. Vapocoolant spray was applied to the donors in the vapocoolant spray group (n = 44). The pain score was 1.90 ± 1.47 for the vapocoolant spray group and 3.23 ± 2.21 for the control group, and the difference between the groups was found to be statistically significant (P = .02). The study result showed that the use of vapocoolant spray for pain management is an effective method of reducing pain related to venipuncture during the process of blood donation in young male donors.

PMID:34753153 | DOI:10.1097/NAN.0000000000000443

Cerebrovasc Dis. 2021 Nov 9:1-8. doi: 10.1159/000519553. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVE: Although the mechanism of stroke in cervical artery dissection (CAD) has been hypothesized to be embolization rather than hemodynamic compromise, there are a limited number of studies supporting this hypothesis. Detection of micro-embolic signals (MESs) using transcranial Doppler (TCD) helps in understanding the mechanism in these patients. A systematic review and meta-analysis were performed to estimate the prevalence of MES and its association with stroke outcomes in patients with acute stroke/TIA secondary to dissection.

METHODS: A comprehensive literature search was conducted for studies before January 26, 2021, in PubMed, Embase, Google Scholar, Cochrane Library, and ClinicalTrials.gov. Studies were identified that used TCD to detect MES in stroke/TIA patients secondary to CAD. Pooled prevalence was calculated. Entire statistical analysis was conducted in R version 3.6.2.

RESULTS: Eleven studies involving 112 patients (50 MES+, 62 MES-) were included in our meta-analysis. The pooled prevalence of MES among acute stroke/TIA patients secondary to dissection was 46.0% (95% CI 26.0-67.0%). The presence of MES was associated with an increased risk of early ischemic recurrence in patients with CAD. We could not estimate the functional outcome and mortality associated with the presence of MES due to the scarcity of data.

CONCLUSIONS: Our meta-analysis showed 46% prevalence of MES in the studies which looked at acute stroke/TIA secondary to CAD using TCD. This finding supports the assumption that embolism may be a major cause of stroke in patients with dissection although this could be determined only in a small population.

PMID:34753137 | DOI:10.1159/000519553

Biomed Phys Eng Express. 2021 Nov 9. doi: 10.1088/2057-1976/ac37ca. Online ahead of print.

ABSTRACT

Optical coherence tomography (OCT) is a well-established imaging technology for high-resolution, cross-sectional imaging of biological tissues. Imaging processing and light attenuation coefficient estimation allows to further improve the OCT diagnostic capability. In this paper we use a commercial OCT system, Telesto II-1325LR from Thorlabs, and demonstrate its ability to differentiate normal and tumor mammary mouse glands with the OCT attenuation coefficient. Using several OCT images of normal and tumor mammary mouse glands (n=26), a statistical analysis was performed. The attenuation coefficient was calculated in depth, considering a slope of 0.5 mm. The normal glands present a median attenuation coefficient of 0.403 mm^-1, comparatively to 0.561 mm^-1obtained for tumor mammary glands. This translates in an attenuation coefficient approximately 39 % higher for tumor mammary glands when compared to normal mammary glands. The OCT attenuation coefficient estimation eliminates the subjective analysis provided by direct visualization of the OCT images.

PMID:34753120 | DOI:10.1088/2057-1976/ac37ca

Obes Facts. 2021 Nov 9:1-13. doi: 10.1159/000519621. Online ahead of print.

ABSTRACT

INTRODUCTION: Ectopic fat deposition in the pancreas is involved in the pathogenesis of metabolic sequelae following an attack of pancreatitis. However, its relationship with the exocrine pancreas has never been explored in this setting. The aim was to investigate the associations between intra-pancreatic fat deposition (IPFD), pancreas size, and pancreatic enzymes.

METHODS: This cross-sectional study recruited individuals with a history of acute pancreatitis and healthy controls. All participants underwent 3T magnetic resonance imaging, from which IPFD, total pancreas volume (TPV), and pancreas diameters (across the head, body, and tail) were measured independently by 2 raters in a blinded fashion. Circulating levels of pancreatic amylase, pancreatic lipase, and chymotrypsin were measured in a fasted state. A series of linear regression analyses was conducted, accounting for possible confounders.

RESULTS: A total of 108 individuals with pancreatitis and 60 healthy controls were studied. There was a statistically significant difference in IPFD (p < 0.001), but not in TPV (p = 0.389), between the groups. In the post-pancreatitis group, IPFD was significantly inversely associated with pancreas tail diameter (β = -0.736, p = 0.036 in the most adjusted model). In the control group, IPFD was significantly inversely associated with TPV (β = -3.557, p = 0.026 in the most adjusted model). Levels of pancreatic amylase were significantly directly associated with pancreas tail diameter in the post-pancreatitis group (β = 3.891, p = 0.042 in the most adjusted model), whereas levels of pancreatic lipase were significantly inversely associated with TPV in the control group (β = -10.533, p = 0.024 in the most adjusted model).

CONCLUSION: Increased IPFD in individuals after an attack of pancreatitis is associated with reduced pancreas tail diameter, which is in turn associated with reduced circulating levels of pancreatic amylase. The relationship between IPFD and the exocrine pancreas warrants further investigations.

PMID:34753126 | DOI:10.1159/000519621

Comput Biol Med. 2021 Nov 3;139:105011. doi: 10.1016/j.compbiomed.2021.105011. Online ahead of print.

ABSTRACT

Analysing local texture and generating features are two key issues for automatic cancer detection in mammographic images. Recent researches have shown that deep neural networks provide a promising alternative to hand-driven features which suffer from curse of dimensionality and low accuracy rates. However, large and balanced training data are foremost requirements for deep learning-based models and these data are not always available publicly. In this work, we propose a fully-automated method for breast cancer diagnosis that performs training using small sets of data. Feature extraction from mammographic images is performed using a genetic-programming-based descriptor that exploits statistics on a local binary pattern-like local distribution defined in each pixel. The effectiveness of the suggested method is demonstrated on two challenging datasets, (1) the digital database for screening mammography and (2) the mammographic image analysis society digital mammogram database, for content-based image retrieval as well as for abnormality/malignancy classification. The experimental results show that the proposed method outperforms or achieves comparable results with deep learning-based methods even those with transfer learning and/or data-augmentation.

PMID:34753080 | DOI:10.1016/j.compbiomed.2021.105011

Water Res. 2021 Nov 1;207:117828. doi: 10.1016/j.watres.2021.117828. Online ahead of print.

ABSTRACT

Microplastic contamination in reservoirs is receiving increasing attention worldwide. However, a holistic understanding of the occurrence, drivers, and potential risks of microplastics in reservoirs is lacking. Building on a systematic review and meta-analysis of 30 existing publications, we construct a global microplastic dataset consisting of 440 collected samples from 43 reservoirs worldwide which we analyze through a framework of Data processing and Multivariate statistics (DM). The purpose is to provide comprehensive understanding of the drivers and mechanisms of microplastic pollution in reservoirs considering three different aspects: geographical distribution, driving forces, and ecological risks. We found that microplastic abundance varied greatly in reservoirs ranging over 2-6 orders of magnitude. Small-sized microplastics (< 1 mm) accounted for more than 60% of the total microplastics found in reservoirs worldwide. The most frequently detected colors, shapes, and polymer types were transparent, fibers, and polypropylene (polyester within aquatic organisms), respectively. Geographic location, seasonal variation and land-use type were main factors influencing microplastic abundance. Detection was also dependent on analytical methods, demonstrating the need for reliable and standardized methods. Interaction of these factors enhanced effects on microplastic distribution. Microplastics morphological characteristics and their main drivers differed between environmental media (water and sediment) and were more diverse in waters compared to sediments. Similarity in microplastic morphologies decreased with increasing geographic distance within the same media. In terms of risks, microplastic pollution and potential ecological risk levels are high in reservoirs and current policies to mitigate microplastic pollution are insufficient. Based on the DM framework, we identified temperate/subtropical reservoirs in Asia as potential high-risk areas and offer recommendations for analytical methods to detect microplastics in waters and sediments. This framework can be extended and applied to other multi-scale and multi-attribute contaminants, providing effective theoretical guidance for reservoir ecosystems pollution control and management.

PMID:34753090 | DOI:10.1016/j.watres.2021.117828

J Behav Ther Exp Psychiatry. 2021 Oct 26;74:101690. doi: 10.1016/j.jbtep.2021.101690. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVES: The tendency of people with schizophrenia to gather insufficient information before making decisions or jumping to conclusions has been repeatedly reported. However, criticism has also been expressed regarding the ecological validity of this finding. Here we present the results obtained by a group of people with schizophrenia and a control group in a non-probabilistic task that requires obtaining items of information before interpreting an ambiguous social situation.

METHODS: Patients with schizophrenia (n = 48) and controls (n = 44) aged 18-50 years participated in the study. All subjects completed the Beads Task and the modified Social Information Preference Task.

RESULTS: Patients with schizophrenia showed a statistically significant tendency to jump to conclusions, including in the proposed novel social task. Unlike other studies, we were unable to find a relationship between this bias and greater severity of psychotic symptoms.

LIMITATIONS: We did not include patients with high levels of psychotic symptoms or a clinical control group.

CONCLUSIONS: The tendency to jump to conclusions in schizophrenia could be present in everyday interpersonal situations.

PMID:34753052 | DOI:10.1016/j.jbtep.2021.101690

Knee. 2021 Nov 6;33:334-341. doi: 10.1016/j.knee.2021.10.017. Online ahead of print.

ABSTRACT

BACKGROUND: Anterior knee pain is an important complication after total knee arthroplasty (TKA). One possible contributor is the elevation of the joint line, known as pseudo-patella baja (PPB). Limited research has been conducted regarding this condition impacting TKA management. This study aims to evaluate the incidence, identify possible related factors and assess PPB clinical repercussions.

METHODS: A total of 813 consecutive TKAs were retrospectively reviewed. Patients were submitted to the same surgical procedure and information regarding TKA characteristics was collected. Lateral postoperative knee radiographs were analyzed using the modified Insall-Salvati Ratio and the Blackburne-Peel Index. A clinical evaluation was conducted on 112 knees where the Oxford Knee and Kujala Scores were applied. Range of motion was evaluated, and knee pain was assessed using the numeric pain rating scale, in addition to analgesic consumption.

RESULTS: A cohort of 612 knees was analyzed, of which 64 knees developed PPB (10.5% incidence). Statistically significant differences were found for advance components sizes (femoral P = 0.026 and tibial P < 0.001), polyethylene thickness (P < 0.001) and patients’ height (P = 0.022) with smaller implant sizes, greater insert thicknesses and lower height showing an association with PPB. The PPB group had a significantly lower median Kujala score (P = 0.011), higher frequency of flexion contracture and of anterior knee pain (P = 0.039).

CONCLUSION: PPB has a clinical relevance that should not be overlooked. Its prevention through the recreation of the natural position of the joint line and correct choice of implant sizes and polyethylene thickness is of major importance and should always be considered.

PMID:34753025 | DOI:10.1016/j.knee.2021.10.017

J Biomech. 2021 Oct 29;130:110847. doi: 10.1016/j.jbiomech.2021.110847. Online ahead of print.

ABSTRACT

Obtaining biomechanical properties of biological tissues for simulation purposes or graft developments is time and resource consuming. The number of samples required for biomechanical tests could be reduced if the load-deformation properties of a given tissue layer could be estimated from adjacent layers or if the biomechanical parameters were unaffected by age, bodyside, sex or post-mortem interval. This study investigates for the first time potential correlations of multiple super-imposed tissue layers using the temporal region of the human head as an area of broad interest in biomechanical modelling. Spearman correlations between biomechanical properties of the scalp, muscle fascia, muscle, bone and dura mater from up to 83 chemically unfixed cadavers were investigated. The association with age, sex and post-mortem interval was assessed. The results revealed sporadic correlations between the corresponding layers, such as the maximum force (r = 0.43) and ultimate tensile strength (r = 0.33) between scalp and muscle. Side- and age-dependence of the biomechanical properties were different between the tissue types. Strain at maximum force of fascia (r = -0.37) and elastic modulus of temporal muscle (r = 0.26) weakly correlated with post-mortem interval. Only strain at maximum force of scalp differed significantly between sexes. Uniaxial biomechanical properties of individual head tissue layers can thus not be estimated solely based on adjacent layers. Therefore, correlations between the tissues’ biomechanical properties, anthropometric data and post-mortem interval need to be established independently for each layer. Sex seems not to be a relevant influencing factor for the passive tissue mechanics of the here investigated temporal head tissue layers.

PMID:34753030 | DOI:10.1016/j.jbiomech.2021.110847