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Nevin Manimala Statistics

Corneal diamond burr debridement for superficial non-healing corneal ulcers in cats

Vet Ophthalmol. 2022 Sep 24. doi: 10.1111/vop.13026. Online ahead of print.

ABSTRACT

OBJECTIVE: To describe the clinical outcomes and efficacy of diamond burr debridement (DBD) treatment for corneal ulceration in cats.

PROCEDURE(S): Medical records of cats that received DBD at two private practices between 2015 and 2021 were retrospectively reviewed. DBD was performed using a battery-powered, handheld motorized burr and a bandage contact lens was placed in 18/21 eyes. Corneal ulceration was considered resolved if the cornea was fluorescein negative with a stable epithelial surface. Recurrence was defined as return of corneal ulceration. Descriptive statistics and a Fisher’s exact test were conducted on the study population.

RESULTS: Twenty-one eyes from 20 cats with superficial corneal ulcers refractory to medical treatment underwent DBD. Domestic and Burmese were the most commonly encountered breeds and the median age of affected cats was 8.83 years (range 0.5-20 years). Corneal ulceration was present for a median of 14 days prior to DBD. Healing was achieved in 81% of eyes; with four eyes failing to heal and requiring further intervention. Corneal sequestrum was reported in one case that failed to heal. Of the healed cases, three cases recurred (17.6%) at a mean of 116.3 days (range 79-135 days). Burmese were overrepresented (p < .001) in cases that failed to heal or recurred (6/7 eyes; 85.7%). The median postoperative follow-up time was 93 days (range 6-1613 days).

CONCLUSIONS: Diamond burr debridement is a safe, non-invasive treatment for corneal ulceration in cats but, compared with published results, it had a lower success rate than superficial lamellar keratectomy.

PMID:36152338 | DOI:10.1111/vop.13026

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Prospective, randomized controlled multicenter study of posterior lumbar facet arthroplasty for the treatment of spondylolisthesis

J Neurosurg Spine. 2022 Sep 23:1-11. doi: 10.3171/2022.7.SPINE22536. Online ahead of print.

ABSTRACT

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial.

METHODS: The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory.

RESULTS: A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4-5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°).

CONCLUSIONS: This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.

PMID:36152329 | DOI:10.3171/2022.7.SPINE22536

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Presence of a fundal fluid cap on preoperative magnetic resonance imaging may predict long-term facial nerve function after resection of vestibular schwannoma via the retrosigmoid approach

J Neurosurg. 2022 Sep 23:1-9. doi: 10.3171/2022.8.JNS221516. Online ahead of print.

ABSTRACT

OBJECTIVE: Preservation of neurological function is a priority when performing a resection of a vestibular schwannoma (VS). Few studies have examined the radiographic value of a fundal fluid cap-i.e., cerebrospinal fluid in the lateral end of a VS within the internal auditory canal-for prediction of postoperative neurological function. The aim of this study was to clarify whether the presence of a fundal fluid cap on preoperative magnetic resonance images has a clinical impact on facial nerve function after resection of VSs.

METHODS: The presence of a fundal fluid cap and its prognostic impact on long-term postoperative facial nerve function were analyzed.

RESULTS: A fundal fluid cap was present in 102 of 143 patients who underwent resection of sporadic VSs via the retrosigmoid approach. Facial nerve function was acceptable (House-Brackmann grade I-II) immediately after surgery in 82 (80.4%) patients with a fundal fluid cap and in 26 (63.4%) of those without this sign. The preservation rate of facial nerve function increased in a time-dependent manner after surgery in patients with a fundal fluid cap but plateaued by 3 months postoperatively in those without a fundal fluid cap; the difference was statistically significant at 12 months (96.1% vs 82.9%, p = 0.013) and 24 months (97.1% vs 82.9%, p = 0.006) after surgery. The presence of a fundal fluid cap had a significantly positive effect on long-term facial nerve function at 24 months after surgery when tumor size and intraoperative neuromonitoring response were taken into account (OR 5.55, 95% CI 1.12-27.5, p = 0.034).

CONCLUSIONS: Neuromonitoring-guided microsurgery for total resection of VSs is more likely to be successful in terms of preservation of facial nerve function if a fundal fluid cap is present. This preoperative radiographic sign could be helpful when counseling patients and deciding the treatment strategy.

PMID:36152320 | DOI:10.3171/2022.8.JNS221516

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Maximum SNP FST outperforms full-window statistics for detecting soft sweeps in local adaptation

Genome Biol Evol. 2022 Sep 24:evac143. doi: 10.1093/gbe/evac143. Online ahead of print.

ABSTRACT

Local adaptation can lead to elevated genetic differentiation at the targeted genetic variant and nearby sites. Selective sweeps come in different forms, and depending on the initial and final frequencies of a favored variant, very different patterns of genetic variation may be produced. If local selection favors an existing variant that had already recombined onto multiple genetic backgrounds, then the width of elevated genetic differentiation (high FST) may be too narrow to detect using a typical windowed genome scan, even if the targeted variant becomes highly differentiated. We therefore used a simulation approach to investigate the power of SNP-level FST (specifically, the maximum SNP FST value within a window, or FST_MaxSNP) to detect diverse scenarios of local adaptation, and compared it against whole-window FST and the Comparative Haplotype Identity statistic. We found that FST_MaxSNP had superior power to detect complete or mostly complete soft sweeps, but lesser power than full-window statistics to detect partial hard sweeps. Nonetheless, the power of FST_MaxSNP depended highly on sample size, and confident outliers depend on robust precautions and quality control. To investigate the relative enrichment of FST_MaxSNP outliers from real data, we applied the two FST statistics to a panel of Drosophila melanogaster populations. We found that FST_MaxSNP had a genome-wide enrichment of outliers compared to demographic expectations, and though it yielded a lesser enrichment than window FST, it detected mostly unique outlier genes and functional categories. Our results suggest that FST_MaxSNP is highly complementary to typical window-based approaches for detecting local adaptation, and merits inclusion in future genome scans and methodologies.

PMID:36152314 | DOI:10.1093/gbe/evac143

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IgE and IgG4 Epitope Mapping of Food Allergens with a Peptide Microarray Immunoassay

Methods Mol Biol. 2023;2578:219-236. doi: 10.1007/978-1-0716-2732-7_16.

ABSTRACT

Peptide microarrays are a powerful tool to identify linear epitopes of food allergens in a high-throughput manner. The main advantages of the microarray-based immunoassay are as follows: the possibility to assay thousands of targets simultaneously, the requirement of a low volume of serum, the more robust statistical analysis, and the possibility to test simultaneously several immunoglobulin subclasses. Among them, the last one has a special interest in the field of food allergy, because the development of tolerance to food allergens has been associated with a decrease in IgE and an increase in IgG4 levels against linear epitopes. However, the main limitation to the clinical use of microarray is the automated analysis of the data. Recent studies mapping the linear epitopes of food allergens with peptide microarray immunoassays have identified peptide biomarkers that can be used for early diagnosis of food allergies and to predict their severity or the self-development of tolerance. Using this approach, we have worked on epitope mapping of the two most important food allergens in the Spanish population, cow’s milk, and chicken eggs. The final aim of these studies is to define subsets of peptides that could be used as biomarkers to improve the diagnosis and prognosis of food allergies. This chapter describes the protocol to produce microarrays using a library of overlapping peptides corresponding to the primary sequences of food allergens and data acquisition and analysis of IgE and IgG4 binding epitopes.

PMID:36152291 | DOI:10.1007/978-1-0716-2732-7_16

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Vegetation detection using vegetation indices algorithm supported by statistical machine learning

Environ Monit Assess. 2022 Sep 24;194(11):826. doi: 10.1007/s10661-022-10425-w.

ABSTRACT

In precision agriculture (PA), the usage of image processing, artificial intelligence, data analysis, and internet of things provides an increase in efficiency, energy, and time saving. In image processing-based applications, vegetation detection, in other words, segmentation that allows monitoring of plant growth and health as well as identification of weeds has a great importance. Vegetation indices (VIs) are widely used algorithms for segmentation. Their advantages include low computational cost and easy implementation and handling compared to the other algorithms. Nevertheless, they require a manual threshold detection that customizes the process and prevents generalization. In this study, a novel automatic segmentation method, which does not require a manual threshold detection by combining VIs with a classification algorithm, is proposed. It deals with the segmentation process as a two class classification problem (vegetation and background). As the classification algorithm, Discriminative Common Vector Approach (DCVA) that has a high discrimination power is used. Each image pixel is represented with a 3 × 1 dimensional vector whose elements correspond to Excess Green (ExG), Green minus Blue (GB), and Color Index of Vegetation (CIVE); VI values are obtained. Then, on the sample space accepting this pixel vector as a sample, DCVA is applied and a discriminative common vector for each class which is unique and describes that class in the best way possible is obtained and it is used for classification. Proposed segmentation method’s performance is compared with Convolutional Neural Networks (CNN) and Random Forest (RF) algorithm. The proposed segmentation algorithm outperformed both CNN’s and RF’s performance.

PMID:36152226 | DOI:10.1007/s10661-022-10425-w

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Surgery for brain metastases: radiooncology scores predict survival-score index for radiosurgery, graded prognostic assessment, recursive partitioning analysis

Acta Neurochir (Wien). 2022 Sep 24. doi: 10.1007/s00701-022-05356-x. Online ahead of print.

ABSTRACT

BACKGROUND: Radiooncological scores are used to stratify patients for radiation therapy. We assessed their ability to predict overall survival (OS) in patients undergoing surgery for metastatic brain disease.

METHODS: We performed a post-hoc single-center analysis of 175 patients, prospectively enrolled in the MetastaSys study data. Score index of radiosurgery (SIR), graded prognostic assessment (GPA), and recursive partitioning analysis (RPA) were assessed. All scores consider age, systemic disease, and performance status prior to surgery. Furthermore, GPA and SIR include the number of intracranial lesions while SIR additionally requires metastatic lesion volume. Predictive values for case fatality at 1 year after surgery were compared among scoring systems.

RESULTS: All scores produced accurate reflections on OS after surgery (p ≤ 0.003). Median survival was 21-24 weeks in patients scored in the unfavorable cohorts, respectively. In cohorts with favorable scores, median survival ranged from 42 to 60 weeks. Favorable SIR was associated with a hazard ratio (HR) of 0.44 [0.29, 0.66] for death within 1 year. For GPA, the HR amounted to 0.44 [0.25, 0.75], while RPA had a HR of 0.30 [0.14, 0.63]. Overall test performance was highest for the SIR.

CONCLUSIONS: All scores proved useful in predicting OS. Considering our data, we recommend using the SIR for preoperative prognostic evaluation and counseling.

PMID:36152217 | DOI:10.1007/s00701-022-05356-x

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Is orbital wall fracture associated with SARS-CoV-2 ocular surface contamination in asymptomatic COVID-19 patients?

Int Ophthalmol. 2022 Sep 24. doi: 10.1007/s10792-022-02535-8. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess the relationship between orbital wall fractures connecting to paranasal sinuses (OWF-PNS) and SARS-CoV-2 ocular surface contamination (SARS-CoV-2-OSC) in asymptomatic COVID-19 patients.

METHODS: This was a prospective case-control study enrolling two asymptomatic COVID-19 patient cohorts with vs. without OWF-PNS in the case-control ratio of 1:4. All subjects were treated in a German level 1 trauma center during a one-year interval. The main predictor variable was the presence of OWF-PNS (case/control); cases with preoperative conjunctival positivity of SARS-CoV-2 were excluded to rule out the possibility of viral dissemination via the lacrimal gland and/or the nasolacrimal system. The main outcome variable was laboratory-confirmed SARS-CoV-2-OSC (yes/no). Descriptive and bivariate statistics were computed with a statistically significant P ≤ 0.05.

RESULTS: The samples comprised 11 cases and 44 controls (overall: 27.3% females; mean age, 52.7 ± 20.3 years [range, 19-85]). There was a significant association between OWF-PNS and SARS-CoV-2-OSC (P = 0.0001; odds ratio = 20.8; 95% confidence interval = 4.11-105.2; R-squared = 0.38; accuracy = 85.5%), regardless of orbital fracture location (orbital floor vs. medial wall versus both; P = 1.0).

CONCLUSIONS: Asymptomatic COVID-19 patients with OWF-PNS are associated with a considerable and almost 21-fold increase in the risk of SARS-CoV-2-OSC, in comparison with those without facial fracture. This could suggest that OWF-PNS is the viral source, requiring particular attention during manipulation of ocular/orbital tissue to prevent viral transmission.

PMID:36152172 | DOI:10.1007/s10792-022-02535-8

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Evaluation of the Use of Diluted Formic Acid in Sample Preparation for Elemental Determination in Crustacean Samples by MIP OES

Biol Trace Elem Res. 2022 Sep 24. doi: 10.1007/s12011-022-03409-x. Online ahead of print.

ABSTRACT

A simple procedure for determination of Al, Cr, K, Mg, Mn, and Zn using diluted organic acid in the preparation of shrimp (Macrobrachium amazonicum) and crab samples (Ucides cordatus) was proposed in this study. Determinations were performed using microwave-induced plasma optical emission spectrometer (MIP OES). The contents of elements were evaluated after solubilization of samples in 50% formic acid (v v-1) and subsequent heating in bath with stirring and heating at 90 °C. The accuracy of the proposed procedure was assessed using certified fish protein reference material (DORM-4) and the recovery percentages ranged from 91 to 117%. Microwave-assisted acid decomposition was used for a comparison of results with the procedure proposed using diluted formic acid, and the values obtained for all analytes were statistically equal at 95% confidence level. Cr levels were below the limit of detection. Potassium (7917-19,644 mg kg-1), Mg (1319-5376 mg kg-1), and Zn (43-307 mg kg-1) were the most abundant elements in the crustacean species studied can be considered good sources of these constituents for human diet. The proposed procedure using diluted formic acid was considered simple and suitable to determine Al, Cr, K, Mg, Mn, and Zn concentrations in crustaceans using MIP OES.

PMID:36152170 | DOI:10.1007/s12011-022-03409-x

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Data Processing and Analysis in Liquid Chromatography-Mass Spectrometry-Based Targeted Metabolomics

Methods Mol Biol. 2023;2571:241-255. doi: 10.1007/978-1-0716-2699-3_21.

ABSTRACT

Mass spectrometry (MS)-based metabolomics provides high-dimensional datasets; that is, the data include various metabolite features. Data analysis begins by converting the raw data obtained from the MS to produce a data matrix (metabolite × concentrations). This is followed by several steps, such as peak integration, alignment of multiple data, metabolite identification, and calculation of metabolite concentrations. Each step yields the analytical results and the accompanying information used for the quality assessment of the anterior steps. Thus, the measurement quality can be analyzed through data processing. Here, we introduce a typical data processing procedure and describe a method to utilize the intermediate data as quality control. Subsequently, commonly used data analysis methods for metabolomics data, such as statistical analyses, are also introduced.

PMID:36152165 | DOI:10.1007/978-1-0716-2699-3_21