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Nevin Manimala Statistics

Development and Validation of a Model for Predicting Surgical Site Infection After Pelvic Organ Prolapse Surgery

Female Pelvic Med Reconstr Surg. 2022 Jun 29. doi: 10.1097/SPV.0000000000001222. Online ahead of print.

ABSTRACT

IMPORTANCE: Surgical site infection (SSI) is a common and costly complication. Targeted interventions in high-risk patients may lead to a reduction in SSI; at present, there is no method to consistently identify patients at increased risk of SSI.

OBJECTIVE: The aim of this study was to develop and validate a model for predicting risk of SSI after pelvic organ prolapse surgery.

STUDY DESIGN: Women undergoing surgery between 2011 and 2017 were identified using Current Procedural Terminology codes from the Centers for Medicare and Medicaid Services 5% Limited Data Set. Surgical site infection ≤90 days of surgery was the primary outcome, with 41 candidate predictors identified, including demographics, comorbidities, and perioperative variables. Generalized linear regression was used to fit a full specified model, including all predictors and a reduced penalized model approximating the full model. Model performance was measured using the c-statistic, Brier score, and calibration curves. Accuracy measures were internally validated using bootstrapping to correct for bias and overfitting. Decision curves were used to determine the net benefit of using the model.

RESULTS: Of 12,334 women, 4.7% experienced SSI. The approximated model included 10 predictors. Model accuracy was acceptable (bias-corrected c-statistic [95% confidence interval], 0.603 [0.578-0.624]; Brier score, 0.045). The model was moderately calibrated when predicting up to 5-6 times the average risk of SSI between 0 and 25-30%. There was a net benefit for clinical use when risk thresholds for intervention were between 3% and 12%.

CONCLUSIONS: This model provides estimates of probability of SSI within 90 days after pelvic organ prolapse surgery and demonstrates net benefit when considering prevention strategies to reduce SSI.

PMID:35830590 | DOI:10.1097/SPV.0000000000001222

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Nevin Manimala Statistics

No news from old drawings? Stomach anatomy in muroid rodents in relation to body size and ecology

J Morphol. 2022 Jul 13. doi: 10.1002/jmor.21496. Online ahead of print.

ABSTRACT

Muroid rodents mostly have a complex stomach: one part is lined with a cornified (non-glandular) epithelium, referred to as a ‘forestomach,’ whereas the rest is lined with glandular epithelium. Numerous functions for the forestomach have been proposed. We collated a catalog of anatomical depictions of the stomach of 174 muroid species from which the respective non-glandular and glandular areas could be digitally measured, yielding a ‘stomach ratio’ (non-glandular:glandular area) as a scale-independent variable. Stomach ratios ranged from 0.13 to 20.15, and the coefficient of intraspecific variation if more than one picture was available for a species averaged at 29.7% (± 21.5). We tested relationships of the ratio with body mass and various anatomical and ecological variables, including diet. There was a consistent phylogenetic signal, suggesting that closely related species share a similar anatomy. Apart from classifying stomachs into hemiglandular and discoglandular, no anatomical or ecological measure showed a consistent relationship to the stomach ratio. In particular, irrespective of statistical method or the source of dietary information, dietary proxies did not significantly correlate with the stomach ratio, except for a trend towards significance for invertivory (insectivory). Yet, even this relationship was not convincing: whereas highly insectivorous species had high but no low stomach ratios, herbivorous species had both low and high stomach ratios. Thus, the statistical effect is not due to a systematic increase in the relative forestomach size with invertivory. The most plausible hypotheses so far associate the muroid forestomach and its microbiome with a generic protective role against microbial or fungal toxins and diseases, without evident correlates of a peculiar need for this function under specific ecological conditions. Yet, this function remains to be confirmed. While providing a catalog of published depictions and hypotheses, this study highlights that the function of the muroid rodent forestomach remains enigmatic to date. This article is protected by copyright. All rights reserved.

PMID:35830587 | DOI:10.1002/jmor.21496

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Nevin Manimala Statistics

Effect of Collagenase A on Descemet Membrane Endothelial Keratoplasty Scroll Tightness

Cornea. 2022 Aug 1;41(8):1029-1034. doi: 10.1097/ICO.0000000000003030. Epub 2022 Mar 30.

ABSTRACT

PURPOSE: The scrolling properties of the Descemet membrane endothelial keratoplasty (DMEK) graft are essential for surgical success. Currently, there is limited knowledge on what dictates the tightness of the DMEK scroll. The purpose of this study was to determine the impact of temperature and protein digestion on DMEK graft scroll tightness.

METHODS: For the temperature experiment, a total of 28 eyes were used for this study. Scrolls in the cold group were kept at 4°C while scrolls in the hot group were kept at 37°C. Scroll width was recorded at the 5-, 15-, and 30-minute mark. For the protein digestion experiment, a total of 18 eyes were exposed to collagenase A (10 CDU/mL) in Optisol solution. Scroll width was recorded at the time points of 1, 3, 5, 10, and 20 minutes.

RESULTS: The results of the temperature experiment did not yield any statistically significant changes in the mean scroll width of the DMEK scrolls across both temperature ranges and observation times. For the protein digestion experiment, the mean scroll width grew from 1.85 mm to 2.13 mm from the beginning of the experiment until the final observation at 20 minutes. This is a 14.7% change over 20 minutes with a P value (<0.001), exemplifying a statistically significant change in scroll width.

CONCLUSIONS: Temperature did not have any significant effect over scroll tightness, but scroll tightness decreased with collagenase exposure.

PMID:35830580 | DOI:10.1097/ICO.0000000000003030

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Nevin Manimala Statistics

LONG-TERM OUTCOMES OF ROBOT-ASSISTED RADICAL THYMECTOMY FOR LARGE THYMOMAS: A PROPENSITY MATCHED ANALYSIS

Int J Med Robot. 2022 Jul 13:e2439. doi: 10.1002/rcs.2439. Online ahead of print.

ABSTRACT

BACKGROUND: The aim of this study was to evaluate the long-term results of robot-assisted (RATS) thymectomy in the treatment of large thymomas, defined as larger than 5 cm.

METHODS: We retrospectively reviewed 106 thymectomies from 2010 to 2020, creating two groups based on the surgical approach (open or RATS) and size. Kaplan-Meier and Cox-regression were used to estimate and identify risk factors of oncological outcomes. To perform a well-balanced analysis, a propensity score matched (PSM) analysis was conducted for large thymomas.

RESULTS: From 2015, we performed 54 RATS thymectomies: 53.7% (n=29) for small and 46.3% (n=25) for large thymomas. Conversions were similar and all patients had a complete resection. The overall (82% vs 92%, p=0.57) and disease-free survival were comparable between RATS and open (92.5% vs 93%, p=0.67), outcomes confirmed after PSM for large thymomas.

CONCLUSIONS: RATS thymectomy could be considered a valid option in selected patients with large thymomas.

PMID:35830541 | DOI:10.1002/rcs.2439

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Nevin Manimala Statistics

Long-term changes in serum gastrin levels during standard dose vonoprazan therapy

Scand J Gastroenterol. 2022 Jul 13:1-5. doi: 10.1080/00365521.2022.2097893. Online ahead of print.

ABSTRACT

BACKGROUND: Long-term acid suppression during vonoprazan therapy causes hypergastrinemia which may induce gastric mucosal changes such as fundic gland and hyperplastic polyps. The aim of this study is to clarify the long-term changes in serum gastrin levels and risk factors for hypergastrinemia.

METHODS: From July 2016 to April 2020, 48 patients receiving vonoprazan 10 mg once daily for more than one year were reviewed. Serum gastrin level was evaluated by radioimmunoassay in a fasting condition (reference range 37-172 pg/ml).

RESULTS: The baseline median gastrin level was 100 (range, 54-415) pg/ml. The gastrin level over 4 years was 700-1200 pg/ml, which plateaued at 1.5 years. Multivariate analysis revealed factors associated with gastrin levels 12 months after starting vonoprazan and identified severe gastric atrophy as a significant positive risk factor (p = .046). The gastrin level over 4 years in patients with severe gastric atrophy and no atrophy was approximately 900-1500 and 500-1000 pg/ml, respectively. Female gender was also identified as a positive factor, although it was not statistically significant (p = .087). The gastrin level over 4 years in females was approximately 900-1300 pg/ml, greater than in males (500-900 pg/ml).

CONCLUSION: A continued increase in gastrin levels was not found during long-term vonoprazan therapy. Severe gastric atrophy is a significant risk factor for hypergastrinemia.

PMID:35830502 | DOI:10.1080/00365521.2022.2097893

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Nevin Manimala Statistics

Risk Factors for Free Flap Outcomes: A Retrospective Study of 318 Free Flaps for Head and Neck Defect Reconstruction

Ear Nose Throat J. 2022 Jul 13:1455613221115143. doi: 10.1177/01455613221115143. Online ahead of print.

ABSTRACT

OBJECTIVES: This study was conducted to identify the risk factors for free flap outcomes in head and neck reconstruction.

METHODS: A retrospective review of 318 free flaps were used for head and neck reconstructions in 317 patients over seven years. The patient characteristics, surgical data, and flap outcomes were recorded. The impact of risk factors related on the outcomes of free flaps were analyzed using single and multivariate analysis.

RESULTS: For single factor analysis, 295 free flaps for the first reconstruction were included. Hypertension and the type of recipient vein are associated with venous thrombosis (P = .018, P = .047). Hypertension, type of free flap, recipient artery, and recipient vein were associated with the incidence of re-exploration (P = .009, P = .011, P = .017, P = .021). Hypertension had an obvious effect on the flap survival (P = .005). For multivariate analysis, hypertension (odds ratio = .166, 95% confidence interval: .043 – .636; P = .009) was a statistically significant risk factor for flap survival. For types of recipient artery and vein, selecting two venous anastomosis (one of IJVS and one of EJVS) had the minimum incidence of venous thrombosis (2.2%), and selecting facial artery, single vein (one of IJVS), and two veins (one of IJVS and one of EJVS) for anastomosis had lower incidence of re-exploration, which were 4.4%, 2.9%, and 6.0%, respectively (P < .05).

CONCLUSIONS: Risk factors as hypertension, type of free flap, recipient artery and vein should be paid more attention in the free flaps for head and neck reconstructions. We believe proper measures will lead to better results in head and neck reconstruction.

PMID:35830468 | DOI:10.1177/01455613221115143

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Nevin Manimala Statistics

Identifying genes targeted by disease-associated non-coding SNPs with a protein knowledge graph

PLoS One. 2022 Jul 13;17(7):e0271395. doi: 10.1371/journal.pone.0271395. eCollection 2022.

ABSTRACT

Genome-wide association studies (GWAS) have identified many single nucleotide polymorphisms (SNPs) that play important roles in the genetic heritability of traits and diseases. With most of these SNPs located on the non-coding part of the genome, it is currently assumed that these SNPs influence the expression of nearby genes on the genome. However, identifying which genes are targeted by these disease-associated SNPs remains challenging. In the past, protein knowledge graphs have often been used to identify genes that are associated with disease, also referred to as “disease genes”. Here, we explore whether protein knowledge graphs can be used to identify genes that are targeted by disease-associated non-coding SNPs by testing and comparing the performance of six existing methods for a protein knowledge graph, four of which were developed for disease gene identification. We compare our performance against two baselines: (1) an existing state-of-the-art method that is based on guilt-by-association, and (2) the leading assumption that SNPs target the nearest gene on the genome. We test these methods with four reference sets, three of which were obtained by different means. Furthermore, we combine methods to investigate whether their combination improves performance. We find that protein knowledge graphs that include predicate information perform comparable to the current state of the art, achieving an area under the receiver operating characteristic curve (AUC) of 79.6% on average across all four reference sets. Protein knowledge graphs that lack predicate information perform comparable to our other baseline (genetic distance) which achieved an AUC of 75.7% across all four reference sets. Combining multiple methods improved performance to 84.9% AUC. We conclude that methods for a protein knowledge graph can be used to identify which genes are targeted by disease-associated non-coding SNPs.

PMID:35830458 | DOI:10.1371/journal.pone.0271395

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Nevin Manimala Statistics

Hyperbolic odorant mixtures as a basis for more efficient signaling between flowering plants and bees

PLoS One. 2022 Jul 13;17(7):e0270358. doi: 10.1371/journal.pone.0270358. eCollection 2022.

ABSTRACT

Animals use odors in many natural contexts, for example, for finding mates or food, or signaling danger. Most analyses of natural odors search for either the most meaningful components of a natural odor mixture, or they use linear metrics to analyze the mixture compositions. However, we have recently shown that the physical space for complex mixtures is ‘hyperbolic’, meaning that there are certain combinations of variables that have a disproportionately large impact on perception and that these variables have specific interpretations in terms of metabolic processes taking place inside the flower and fruit that produce the odors. Here we show that the statistics of odorants and odorant mixtures produced by inflorescences (Brassica rapa) are also better described with a hyperbolic rather than a linear metric, and that combinations of odorants in the hyperbolic space are better predictors of the nectar and pollen resources sought by bee pollinators than the standard Euclidian combinations. We also show that honey bee and bumble bee antennae can detect most components of the B. rapa odor space that we tested, and the strength of responses correlates with positions of odorants in the hyperbolic space. In sum, a hyperbolic representation can be used to guide investigation of how information is represented at different levels of processing in the CNS.

PMID:35830455 | DOI:10.1371/journal.pone.0270358

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Nevin Manimala Statistics

Automated app-based augmented reality cognitive behavioral therapy for spider phobia: Study protocol for a randomized controlled trial

PLoS One. 2022 Jul 13;17(7):e0271175. doi: 10.1371/journal.pone.0271175. eCollection 2022.

ABSTRACT

BACKGROUND: Fear of spiders, or Arachnophobia, is one of the most common specific phobias. The gold standard treatment, in vivo exposure therapy, is effective, but comes with significant limitations, including restricted availability, high costs, and high refusal rates. Novel technologies, such as augmented reality, may help to overcome these limitations and make Exposure Therapy more accessible by using mobile devices.

OBJECTIVE: This study will use a Randomized Controlled Trial design to investigate whether ZeroPhobia: Arachnophobia, a 6-week Augmented Reality Exposure Therapy smartphone self-help application, can effectively reduce spider phobia symptoms. Additionally, we will examine user-friendliness of the application and the effect of usage intensity and presence on treatment outcome.

METHODS: This study is registered in the Netherlands Trial Registry under NL70238.029.19 (Trial NL9221). Ethical approval was received on October 11, 2019. One-hundred-twelve participants (age 18-64, score ≥ 59) on the Fear of Spiders Questionnaire [FSQ] will be recruited from the general Dutch population and randomly assigned to a treatment or waitlist control group. The ZeroPhobia application can be accessed on users’ smartphone. Baseline, post-test (i.e., at six weeks), 3- and 12-month follow-up assessments will be done, each including the Fear of Spiders Questionnaire as the main outcome measure as well as additional measures of anxiety, depression, user-friendliness, and presence as secondary measures and covariates.

RESULTS: The study was funded on September 25, 2018. Data collection started in September 2021 and the study is expected to run until September 2022.

CONCLUSIONS: Our study will improve our understanding of the efficacy and feasibility of providing Exposure Therapy for spider phobia using an Augmented Reality self-help application, with the intention of making mental health care more accessible.

PMID:35830423 | DOI:10.1371/journal.pone.0271175

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Nevin Manimala Statistics

Peripheral artery disease affects the function of the legs of claudicating patients in a diffuse manner irrespective of the segment of the arterial tree primarily involved

PLoS One. 2022 Jul 13;17(7):e0264598. doi: 10.1371/journal.pone.0264598. eCollection 2022.

ABSTRACT

Different levels of arterial occlusive disease (aortoiliac, femoropopliteal, multi-level disease) can produce claudication symptoms in different leg muscle groups (buttocks, thighs, calves) in patients with peripheral artery disease (PAD). We tested the hypothesis that different locations of occlusive disease uniquely affect the muscles of PAD legs and produce distinctive patterns in the way claudicating patients walk. Ninety-seven PAD patients and 35 healthy controls were recruited. PAD patients were categorized to aortoiliac, femoropopliteal and multi-level disease groups using computerized tomographic angiography. Subjects performed walking trials both pain-free and during claudication pain and joint kinematics, kinetics, and spatiotemporal parameters were calculated to evaluate the net contribution of the calf, thigh and buttock muscles. PAD patients with occlusive disease affecting different segments of the arterial tree (aortoiliac, femoropopliteal, multi-level disease) presented with symptoms affecting different muscle groups of the lower extremity (calves, thighs and buttocks alone or in combination). However, no significant biomechanical differences were found between PAD groups during the pain-free conditions with minimal differences between PAD groups in the claudicating state. All statistical differences in the pain-free condition occurred between healthy controls and one or more PAD groups. A discriminant analysis function was able to adequately predict if a subject was a control with over 70% accuracy, but the function was unable to differentiate between PAD groups. In-depth gait analyses of claudicating PAD patients indicate that different locations of arterial disease produce claudication symptoms that affect different muscle groups across the lower extremity but impact the function of the leg muscles in a diffuse manner generating similar walking impairments.

PMID:35830421 | DOI:10.1371/journal.pone.0264598