Tag: statistics

Int J Ophthalmol. 2023 Aug 18;16(8):1280-1286. doi: 10.18240/ijo.2023.08.14. eCollection 2023.

ABSTRACT

AIM: To evaluate the effectiveness, safety, predictability, precision and changes of higher-order aberrations (HOAs) on corneal front surface of selective corneal wavefront aberration-guided femtosecond laser-assisted in situ keratomileusis (CW-FS-LASIK) in patients with high myopia 1-year postoperatively.

METHODS: Totally 74 eyes of 37 patients with high myopia or myopic astigmatism in both the eyes who underwent the CW-FS-LASIK procedure in Xi’an Gaoxin Hospital from January 2021 to June 2021 were included. The changes of uncorrected distance visual acuity (UDVA), best corrected visual acuity (BCVA), spherical equivalent refraction (SER), astigmatism, HOAs and Strehl ratio (SR) on the anterior surface of the cornea after 1y of the surgery were analyzed.

RESULTS: At postoperative 1y, the UDVA (logMAR) of 74 eyes (100%) reached 0 or better, including 0 in 8 eyes (10.81%), -0.1 in 45 eyes (60.81%), and -0.2 in 21 eyes (28.38%). The effectiveness index was 1.29±0.134. There was no decrease in postoperative BCVA compared with preoperative BCVA in all patients. Postoperative BCVA was the same in 44 eyes (59.46%) as preoperative BCVA, increased by 1 line in 23 eyes (31.08%) and increased by 2 lines in 7 eyes (9.46%) compared with preoperative BCVA. The safety index was 1.11±0.159. The estimated corrected SER before surgery was (-7.76±1.21) D, and the actual corrected SER was (-7.83±1.25) D (Y=0.9811X+0.2156, R²=0.9084). There was a high correlation between the estimated corrected SER and the actual corrected SER. The postoperative SER in 74 eyes (100%) was within ±0.75 D. The postoperative astigmatism of all was within -0.75 D to 0. Root mean square (RMS) HOAs of spherical aberration and SR within 5 mm of the corneal front surface were all increased compared with those before operation (P<0.01). The total coma, horizontal coma and vertical coma were all decreased compared with those before operation (P<0.01). There was no statistically significant difference in horizontal trefoil and vertical trefoil compared with preoperative ones (P>0.05).

CONCLUSION: Selective CW-FS-LASIK for correction of high myopia is effective, safe, predictive, and accurate. For patients with preoperative RMS HOAs over 0.25 defocus equivalent, postoperative coma aberration can be significantly reduced, and SR value can be increased, thus corneal imaging quality can be improved.

PMID:37602337 | PMC:PMC10398522 | DOI:10.18240/ijo.2023.08.14

Int J Ophthalmol. 2023 Aug 18;16(8):1268-1273. doi: 10.18240/ijo.2023.08.12. eCollection 2023.

ABSTRACT

AIM: To investigate thickness characteristics and vascular plexuses in retinas with reticular pseudodrusen (RPD) as an early detection strategy for age-related macular degeneration (AMD).

METHODS: This retrospective study included 24 subjects (33 eyes) with RPD and 25 heathy control subjects (34 eyes). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) of the retinal posterior poles were investigated with optical coherence tomography angiography (OCTA). Retinal thicknesses and vessel densities were analyzed statistically.

RESULTS: The general retinal thicknesses of RPD eyes were significantly decreased (95%CI -14.080, -0.655; P=0.032). The vessel densities of DCP in RPD eyes were significantly increased in the global (95%CI 1.067, 7.312; P=0.027), parafoveal (95%CI 0.417, 5.241; P=0.022), and perifoveal (95%CI 0.181, 6.842; P=0.039) quadrants. However, the vessel densities of the SCP were rarely increased in the eyes with RPD.

CONCLUSION: The thinning of retinas in the RPD group suggests a reduction in the number of cells. Additionally, the increased vessel density of the DCP in retinas with RPD indicates a greater demand for blood supply, possibly due to the hypoxia induced RPD compensation caused by RPD in the outer retina. This study highlights the pathological risks associated with RPD and emphasizes the importance of early intervention to retard the progression of AMD.

PMID:37602336 | PMC:PMC10398519 | DOI:10.18240/ijo.2023.08.12

Int J Ophthalmol. 2023 Aug 18;16(8):1350-1355. doi: 10.18240/ijo.2023.08.22. eCollection 2023.

ABSTRACT

AIM: To assess metrics of diffusion tensor imagining (DTI) in evaluating microstructural abnormalities of horizontal extraocular muscles (EOM) in esotropia.

METHODS: Six adult concomitant esotropia patients, 5 unilateral abducent paralysis patients and 2 healthy volunteers were enrolled. Conventional magnetic resonance imaging (MRI) and DTI were performed on all subjects using 3T MR scanner. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of medial and lateral rectus muscles were measured and compared between patients group and control group.

RESULTS: Medial rectus MD and RD within the adducted eye of concomitant patients was significantly greater than that in unilateral abducent paralysis patients (0.259×10^-2 mm²/s vs 0.207×10^-2 mm²/s, P=0.014; 0.182×10^-2 mm²/s vs 0.152×10^-2 mm²/s, P=0.017). Both strabismus patients showed a significantly decreased MD and AD than that obtained in normal controls for lateral rectus muscles (P<0.05). Medial rectus MD of the adducted eye in concomitant strabismus patients was significantly decreased than that in healthy controls (0.259×10^-2 mm²/s vs 0.266×10^-2 mm²/s, P=0.010). Lateral rectus AD of the adducted eye in concomitant strabismus patients was significantly decreased as compared with that in healthy controls (0.515×10^-2 mm²/s vs 0.593×10^-2 mm²/s, P=0.013). No statistically significant differences were present between the adducted and fixating eyes in concomitant strabismus patients.

CONCLUSION: DTI represents a feasible technique to assess tissue characteristics of EOM. The effects of eye position changes on DTI parameters are subtle. Decreased MD and RD could be evidence for remodeling of the medial rectus muscle contracture. Lower medial and lateral recuts MD of concomitant esotropia patients indicates a thinner fibrous structure of the EOM. Lower MD and AD should be general character of esotropia.

PMID:37602335 | PMC:PMC10398516 | DOI:10.18240/ijo.2023.08.22

Int J Ophthalmol. 2023 Aug 18;16(8):1224-1230. doi: 10.18240/ijo.2023.08.06. eCollection 2023.

ABSTRACT

AIM: To observe the imaging features of color Doppler ultrasound (CDU) and computed tomography (CT) or computed tomography dacryocystography (CT-DCG) in different types of lacrimal sac space-occupying lesions (SOLs).

METHODS: This retrospective case series study included 21 patients with lacrimal sac SOLs who underwent lacrimal sac surgery between January 2018 and March 2022. The imaging features of CDU and CT or CT-DCG in these patients were extracted from the examination cloud system. The images were observed and analyzed.

RESULTS: The detection rate of lacrimal SOLs between CDU (21/21, 100%) and CT or CT-DCG (20/21, 95.2%) had no statistically significant difference (P=1.0). CDU could detect the blood flow signals in all SOLs except mucocele and mucopeptide concretion. Among them, polyps had characteristic imaging changes on CDU and CT-DCG. The mucoceles and mucopeptide concretions had characteristic imaging changes on CDU, which could provide more information for differential diagnosis.

CONCLUSION: The morphology and internal blood flow signals of lacrimal sac SOLs can be observed using CDU. CT or CT-DCG has advantages in observing structural damage around the lacrimal sac mass. Therefore, CDU may be used as a routine examination to exclude lacrimal sac SOLs before dacryocystorhinostomy in the absence of preoperative CT or CT-DCG.

PMID:37602333 | PMC:PMC10398530 | DOI:10.18240/ijo.2023.08.06

Front Mol Biosci. 2023 Aug 3;10:1222133. doi: 10.3389/fmolb.2023.1222133. eCollection 2023.

ABSTRACT

Introduction: Acute aortic dissection (AAD) often leads to the development of acute lung injury (ALI). However, the early detection and diagnosis of AAD in patients with ALI pose significant challenges. The objective of this study is to investigate distinct metabolic alterations in the plasma samples of AAD patients with ALI, AAD patients without ALI, and healthy individuals. Method: Between September 2019 and September 2022, we retrospectively collected data from 228 AAD patients who were diagnosed with ALI through post-surgery chest X-ray and PaO₂/FiO₂ assessments. Univariate analysis was employed to identify pre-surgery risk factors for ALI. Additionally, we conducted high-throughput target metabolic analysis on 90 plasma samples, comprising 30 samples from AAD patients with ALI, 30 from patients with AAD only, and 30 from healthy controls. After LC-MS spectral processing and metabolite quantification, the recursive feature elimination with cross-validation (RFECV) analysis based on the random forest was used to select the optimal metabolites as a diagnostic panel for the detection of AAD patients with ALI. The support vector machines (SVM) machine learning model was further applied to validate the diagnostic accuracy of the established biomarker panel. Results: In the univariate analysis, preoperative β-HB and TNF-α exhibited a significant association with lung injury (OR = 0.906, 95% CI 0.852-0.965, p = 0.002; OR = 1.007, 95% CI 1.003-1.011, p < 0.0001). The multiple-reaction monitoring analysis of 417 common metabolites identified significant changes in 145 metabolites (fold change >1.2 or <0.833, p < 0.05) across the three groups. Multivariate statistical analysis revealed notable differences between AAD patients and healthy controls. When compared with the non-ALI group, AAD patients with ALI displayed remarkable upregulation in 19 metabolites and downregulation in 4 metabolites. Particularly, combining citric acid and glucuronic acid as a biomarker panel improved the classification performance for distinguishing between the ALI and non-ALI groups. Discussion: Differentially expressed metabolites in the ALI group were primarily involved in amino acids biosynthesis, carbohydrate metabolism (TCA cycle), arginine and proline metabolism, and glucagon signaling pathway. These findings demonstrate a great potential of the targeted metabolomic approach for screening, routine surveillance, and diagnosis of pulmonary injury in patients with AAD.

PMID:37602331 | PMC:PMC10434778 | DOI:10.3389/fmolb.2023.1222133

Front Mol Biosci. 2023 Aug 4;10:1230282. doi: 10.3389/fmolb.2023.1230282. eCollection 2023.

ABSTRACT

This mini review focuses on the opportunities provided by current and emerging separation techniques for mass spectrometry metabolomics. The purpose of separation technologies in metabolomics is primarily to reduce complexity of the heterogeneous systems studied, and to provide concentration enrichment by increasing sensitivity towards the quantification of low abundance metabolites. For this reason, a wide variety of separation systems, from column chemistries to solvent compositions and multidimensional separations, have been applied in the field. Multidimensional separations are a common method in both proteomics applications and gas chromatography mass spectrometry, allowing orthogonal separations to further reduce analytical complexity and expand peak capacity. These applications contribute to exponential increases in run times concomitant with first dimension fractionation followed by second dimension separations. Multidimensional liquid chromatography to increase peak capacity in metabolomics, when compared to the potential of running additional samples or replicates and increasing statistical confidence, mean that uptake of these methods has been minimal. In contrast, in the last 15 years there have been significant advances in the resolution and sensitivity of ion mobility spectrometry, to the point where high-resolution separation of analytes based on their collision cross section approaches chromatographic separation, with minimal loss in sensitivity. Additionally, ion mobility separations can be performed on a chromatographic timescale with little reduction in instrument duty cycle. In this review, we compare ion mobility separation to liquid chromatographic separation, highlight the history of the use of ion mobility separations in metabolomics, outline the current state-of-the-art in the field, and discuss the future outlook of the technology. “Where there is one, you’re bound to divide it. Right in two”, James Maynard Keenan.

PMID:37602325 | PMC:PMC10436490 | DOI:10.3389/fmolb.2023.1230282

Front Mol Biosci. 2023 Aug 2;10:1184249. doi: 10.3389/fmolb.2023.1184249. eCollection 2023.

ABSTRACT

A model-based method is used to extract a short-lived state in the rotation kinetics of the F₁-ATPase of a bacterial species, Paracoccus denitrificans (PdF1). Imaged as a single molecule, PdF1 takes large 120^ø steps during it rotation. The apparent lack of further substeps in the trajectories not only renders the rotation of PdF1 unlike that of other F-ATPases, but also hinders the establishment of its mechano-chemical kinetic scheme. We addressed these challenges using the angular velocity extracted from the single-molecule trajectories and compare it with its theoretically calculated counterpart. The theory-experiment comparison indicate the presence of a 20μs lifetime state, 40^o after ATP binding. We identify a kinetic cycle in which this state is a three-nucleotide occupancy state prior to ADP release from another site. A similar state was also reported in our earlier study of the Thermophilic bacillus F₁-ATPase (lifetime $\sim 10\mu$s), suggesting thereby a common mechanism for removing a nucleotide release bottleneck in the rotary mechanism.

PMID:37602322 | PMC:PMC10433373 | DOI:10.3389/fmolb.2023.1184249

SAGE Open Med. 2023 Aug 18;11:20503121231187735. doi: 10.1177/20503121231187735. eCollection 2023.

ABSTRACT

BACKGROUND: Postabortion contraception is the initiation and use of postabortion contraceptive methods immediately after an abortion. It is a critical approach for preventing unwanted pregnancy, alleviating its complications, and avoiding repeated abortions by promoting immediate postabortion contraceptives provision.

OBJECTIVE: To assess the level of postabortion contraceptives uptake and its associated factors among clients visiting abortion care services in public hospitals in West Shewa Zone, Oromia regional state, Ethiopia.

METHODS AND MATERIALS: An institutional-based cross-sectional study was conducted in public hospitals in the West Shewa Zone from 1 March 2021 to 30 May 2021, among 227 proportionally allocated clients based on the proportion of the client served in the previous 3 months of the study period. Data were collected through face-to-face interviews using semi-structured and pretested questionnaire from women who received the abortion services. Bivariable and multivariable logistic regression were used to assess the association of independent variables with postabortion contraceptive uptake. Findings with p-value of 0.05 at 95% confidence interval were considered as statistically significant.

RESULTS: The overall postabortion contraception uptake among abortion service clients in public hospitals was 164 (74%) while about 42% of them used long-term contraceptive methods. Postabortion contraceptive uptake was significantly associated with media exposure to postabortion family planning information (adjusted odds ratio: 3.4 (95% confidence interval: 1.03-11.27)) and counseling on postabortion family planning (adjusted odds ratio: 20.48 (95% confidence interval: 5.02-83.64)).

CONCLUSION: Level of postabortion contraceptive method uptake in West Shewa was low as compared to the national target. Greater attention should be given on providing postabortion contraceptive counseling to increase the postabortion contraceptive uptake.

PMID:37602273 | PMC:PMC10437695 | DOI:10.1177/20503121231187735

SAGE Open Med. 2023 Aug 17;11:20503121231190963. doi: 10.1177/20503121231190963. eCollection 2023.

ABSTRACT

Background: A 2019 study by Prucnal and colleagues found that the majority of patients treated with unfractionated heparin for pulmonary embolism did not maintain therapeutic activated partial thromboplastin time levels during the first 48 h of therapy. Objective: The purpose of this study was to evaluate the ability of an institution’s unfractionated heparin dosing protocol to achieve and maintain therapeutic anti-Xa levels within the first 48 h of therapy in patients with venous thromboembolism. Methods: This retrospective study included 205 patients from May 2016 through September 2020. Patients were divided into two cohorts: bolus plus infusion (N = 89) and infusion only (N = 116). The primary objective was to determine the number of patients who achieved at least one therapeutic level. Results: Overall, 200 patients (97.6%) had at least one therapeutic level with no statistically significant difference between cohorts (p = 0.65). No more than 60% of patients achieved a therapeutic level at any of the 6-h intervals throughout the timeframe. The median time to the first therapeutic level in the overall group was 12.8 h with no statistically significant difference between the bolus plus infusion and infusion-only cohorts (13.3 h versus 12.7 h, respectively, p = 0.48). Conclusions: Most patients were able to achieve at least one therapeutic level within the first 48 h, but fewer were able to maintain therapeutic levels. Further studies are warranted to determine whether alternative dosing strategies would yield consistent achievement of therapeutic levels and affect patient-oriented outcomes.

PMID:37602272 | PMC:PMC10438427 | DOI:10.1177/20503121231190963

Surv Methodol. 2021 Jun;47(1):215-222. Epub 2021 Jun 24.

ABSTRACT

Predictive mean matching is a commonly used imputation procedure for addressing the problem of item nonrespone in surveys. The customary approach relies upon the specification of a single outcome regression model. In this note, we propose a novel predictive mean matching procedure that allows the user to specify multiple outcome regression models. The resulting estimator is multiply robust in the sense that it remains consistent if one of the specified outcome regression models is correctly specified. The results from a simulation study suggest that the proposed method performs well in terms of bias and efficiency.

PMID:37602271 | PMC:PMC10438827