Tag: statistics

Pediatr Transplant. 2022 Mar 13:e14251. doi: 10.1111/petr.14251. Online ahead of print.

ABSTRACT

BACKGROUND: Our knowledge of de novo anti-HLA donor-specific antibodies (dnDSA) in liver transplantation continues to be defined. We hypothesized that differences of HLA-DR/DQ mismatches can improve precision in alloimmune risk categorization and be applied to tailor immunosuppression.

METHODS: A retrospective chart review of 244 pediatric patients consecutively transplanted at our center between 2003 and 2019 was performed to identify patients tested for dnDSA. Records were queried for: demographics, pre-transplant diagnosis, biopsy-proven T-cell-mediated rejection (TCMR), radiology proven biliary complications, tacrolimus trough levels, dnDSA characteristics, and HLA typing. The eplet mismatch analyses were performed using HLAMatchmaker^™ 3.1. All statistical analyses were conducted using R software version 3.40.

RESULTS: There were 99 dnDSA-negative patients and 73 dnDSA-positive patients (n = 70 against class II and n = 3 against class I and II). ROC analysis identified optimal cutoff of eplet mismatch load for dnDSA and defined risk groups for an alloimmune outcome. Kaplan-Meier curves and log-rank tests showed high eplet mismatch load was associated with shorter dnDSA-free survival (log-rank p = .001). Multivariable Cox regression models showed that tacrolimus coefficient of variation and tacrolimus mean levels were significantly associated with dnDSA-free survival (p < .001 and p = .036). Fisher’s exact test showed that dnDSA was associated with an increased likelihood of TCMR (OR 14.94; 95% CI 3.65 – 61.19; p < .001). Patients without TCMR were more likely to have dnDSA to HLA-DQ7 and less likely to have dnDSA to HLA-DQ2 (p = .03, p = .080).

CONCLUSIONS: Mismatched epitope load predicts dnDSA-free survival in pediatric liver transplant, while dnDSA specificity may determine alloimmune outcome.

PMID:35279919 | DOI:10.1111/petr.14251

Vet Radiol Ultrasound. 2022 Mar 13. doi: 10.1111/vru.13079. Online ahead of print.

ABSTRACT

Monitoring the treatment outcome of canine cystic endometrial hyperplasia-pyometra complex (CEH-P) is essential to identify nonresponding patients who might require a rapid intervention to avoid life-threatening conditions. Uterine artery Doppler characterization may contribute to monitoring medically treated CEH-P, but published studies are currently lacking. Therefore, the aim of this longitudinal prospective observational study was to evaluate uterine artery resistance changes in the medical treatment of female dogs with CEH-P. Twelve diestrous female dogs suffering from CEH-P were treated with a combined protocol of cabergoline, cloprostenol, and antibiotics. The animals were clinically and ultrasonographically evaluated before the beginning of treatment (day 0) and on days 3, 7, 14, 21, and 28. The widest transverse diameter and luminal diameter of uterine horns were measured, as well as the peak systolic velocity (PSV) and end diastolic velocity (EDV) of uterine arteries. The resistance index (RI), pulsatility index (PI), and notch deep index (NDI) were calculated. On day 3, nine of 12 animals showed clinical improvement. In all these female dogs, the widest transverse sectional diameter (P < 0.01), luminal diameter (P < 0.01), PSV (P < 0.01), and EDV (P < 0.01) progressively decreased, while RI (P < 0.01), PI (P < 0.01), and NDI (P < 0.01) increased up to day 21. In nonresponding dogs (3/12), Doppler parameters remained unchanged. Although comparisons of PSV, EDV, and NDI were significantly different, these results should be cautiously interpreted due to the low statistical power. female dogs that responded to this treatment showed an increase in uterine artery resistance, along with clinical and ultrasonographic improvement.

PMID:35279908 | DOI:10.1111/vru.13079

J Bone Miner Res. 2022 Mar 12. doi: 10.1002/jbmr.4543. Online ahead of print.

ABSTRACT

Bone metabolism in men is in part determined by sex steroid exposure. This is especially clear during puberty and senescence but it remains to be established whether declines in sex steroid levels during young and middle adulthood associate with changes in bone mass and size. This study investigated changes in bone mineral content (BMC), areal and volumetric bone density (aBMD; vBMD) and bone size in relation to sex steroid levels in 999 young adult men (age 24-46 years) of whom 676 were re-evaluated after a mean period of 12 years. Sex hormone binding globulin (SHBG) levels were measured using immuno-assay, testosterone (T) and estradiol (E2) using LC-MS/MS, free fractions calculated (cFT; cFE2). Areal bone parameters and BMC were measured at the hip and lumbar spine using DXA. Radial and tibial vBMD and bone size were determined using pQCT. Linear mixed models were used for statistical analyses. With aging, we observed decreases in almost all bone mass and density indices whereas changes in bone geometry resulted in larger bones with thinner cortices. These changes in bone mass and size appeared related to sex steroid levels. Specifically, decreases in cFT (but not total T) levels were associated with larger decreases in lumbar spine BMC and especially with geometric changes in cortical bone at the tibia. Similarly, decreases in total E2 and cFE2 were associated with larger decreases in bone mass (all sites) and also with some geometric changes. Also increases in SHBG were independently associated with aging-related changes in bone mass and size in these men. In summary, even small changes in T, E2 and SHBG levels during young and middle adulthood in healthy men are associated with changes in bone mass and size. This article is protected by copyright. All rights reserved.

PMID:35279881 | DOI:10.1002/jbmr.4543

Bioessays. 2022 Mar 13:e2100170. doi: 10.1002/bies.202100170. Online ahead of print.

ABSTRACT

Complex-trait genetics has advanced dramatically through methods to estimate the heritability tagged by SNPs, both genome-wide and in genomic regions of interest such as those defined by functional annotations. The models underlying many of these analyses are inadequate, and consequently many SNP-heritability results published to date are inaccurate. Here, we review the modelling issues, both for analyses based on individual genotype data and association test statistics, highlighting the role of a low-dimensional model for the heritability of each SNP. We use state-of-art models to present updated results about how heritability is distributed with respect to functional annotations in the human genome, and how it varies with allele frequency, which can reflect purifying selection. Our results give finer detail to the picture that has emerged in recent years of complex trait heritability widely dispersed across the genome. Confounding due to population structure remains a problem that summary statistic analyses cannot reliably overcome.

PMID:35279859 | DOI:10.1002/bies.202100170

Perspect Psychiatr Care. 2022 Mar 13. doi: 10.1111/ppc.13064. Online ahead of print.

ABSTRACT

PURPOSE: The present study was conducted in a cross-sectional and descriptive design to examine the relations between alexithymia levels and social media addictions of nursing students.

METHOD: The study population consisted of nursing department students, and the sampling consisted of 202 students who had social media accounts and who volunteered to participate in the study. The study data were collected online between November 01, 2020 and November 08, 2020 with the questionnaire, Social Media Addiction Scale-Adult Form, and Toronto Alexithymia Scale. The data were evaluated with the Student’s t, one-way analysis of variance, Kruskal-Wallis, Mann-Whitney U, and correlation analysis.

RESULTS: It was found that 75.2% of the students were female, 57.9% were in the 18-20 age group, 60.3% of them spent 2-3 h a day on social media; social media addiction mean score was 64.81 ± 5.80 alexithymia mean score was 71.27 ± 8.62, and 46.03% were completely alexithymic. It was also found that there was a statistically positive and significant relation between the social media addiction and alexithymia scores of the students (p < 0.05).

CONCLUSION AND RECOMMENDATIONS: It was determined that the mean alexithymia and social media addiction scores of the students were high, and they affected each other. In this respect, it is recommended that students be given training on limiting the use of social media.

PRACTICE IMPLICATIONS: Social media addiction average score was found to be high in nursing department students. The alexithymia score averages of the nursing department students were found to be high. It was determined that the COVID pandemic nursing department students increased the time they use social media.

PMID:35279855 | DOI:10.1111/ppc.13064

Eur J Dent. 2022 Mar 13. doi: 10.1055/s-0042-1743148. Online ahead of print.

ABSTRACT

OBJECTIVE: Polylactic acid (PLA) is one of the most widely used materials in three-dimensional (3D) printing technology due to its multiple advantages such as biocompatibility and biodegradable. However, there is still a lack of study on 3D printing PLA for use as a denture base material. The goal of this study was to compare 3D printing PLA to traditional poly(methyl methacrylate) (PMMA) as a denture basis.

MATERIALS AND METHODS: The PMMA (M) and PLA (L) specimens were fabricated by compression molding, and fuse deposition modeling technique, respectively. Each specimen group was divided into three different temperature groups of 25°C (25), 37°C (37), and 55°C (55). The glass transition temperature (T_g) of raw materials and specimen was investigated using differential scanning calorimetry. The heat deflection temperature (HDT) of each material was also observed.

STATISTICAL ANALYSIS: The data of flexural strength and flexural modulus were analyzed with two-way analysis of variance, and Tukey honestly significant difference. The T_g and HDT data, on the other hand, were descriptively analyzed.

RESULTS: The results showed that PLA had lower flexural strength than PMMA in all temperature conditions, while the PMMA 25°C (M25) and PMMA 37°C (M37) obtained the highest mean values. PLA 25°C (L25) and PLA 37°C (L37) had significant higher flexural modulus than the other groups. However, the flexural properties of L55 could not be observed, which may be explained by T_g and HDT of PLA.

CONCLUSION: PLA only meets the flexural modulus requirement, although it was greater than flexural modulus of PMMA. On the other hand, PMMA can meet both good flexural strength and modulus requirement. However, increase in temperature could reduce flexural strength and flexural modulus of PMMA and PLA.

PMID:35279819 | DOI:10.1055/s-0042-1743148

Eur J Dent. 2022 Mar 13. doi: 10.1055/s-0041-1741376. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of the study was to analyze the occurrence of stress on teeth with abfraction lesions restored with six different restorative materials, and by introducing the tensile strength parameters to calculate the safety factor of the material under the load (ratio between the strength of the material and the maximum stress).

MATERIALS AND METHODS: Three-dimensional models of the mandibular premolar are created from a microcomputed tomography images. An abfraction lesion is modeled on the tooth. The stress of the dental tissues and six restorative materials under functional and nonfunctional occlusal loading of 200 (N) are analyzed by finite element method.

STATISTICAL ANALYSIS: CTAn program 1.10 and ANSYS Workbench (version 14.0) were used for analysis. Results are presented in von Mises stress.

RESULTS: Oblique loads caused ≈ four times higher stress in restorative materials than the axial ones. It is noticeable that high values of von Mises stress are measured at the bottom of the sharp lesion, even up to 240 MPa, that are significantly reduced after the restoration. The highest stresses at the restorative material are present at the lower (gingival) margin of the restoration. The highest stresses under both types of loads are measured in nanohybrid composite (Tetric EvoCeram, Ivoclar Vivadent). The lowest values of the stress are measured in the flowable composite (Tetric Flow, Ivoclar Vivadent), but at the same time, the highest value of the stress is measured in the surrounding dental tissues on the tooth restored with the flowable composite. The microhybrid composite (Herculite XR, Kerr), with the highest safety factor, is the material that best withstands the stresses it is exposed to. The obtained safety factor did not exceed the critical limit, except for the glass ionomer cement, with the safety factor lower than 1.

CONCLUSION: The type of tooth loading has the greatest influence on the intensity of stress. The value of the obtained stresses in the restorative material and dental tissues differ due to the different mechanical properties of the materials. Restoration of noncarious lesions significantly reduces extremely high stress values at their bottom.

PMID:35279820 | DOI:10.1055/s-0041-1741376

Eur J Dent. 2022 Mar 13. doi: 10.1055/s-0042-1743150. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of this study was to determine the technical quality of root canal fillings and the presence of iatrogenic errors in the cases treated by undergraduate dental students using radiographic images.

MATERIALS AND METHODS: This study included 480 root-filled teeth, which were evaluated using intraoral periapical radiographic images. The technical quality of obturation was assessed by observing the length, density, and taperness of the root filling. Ledges, apical transportation, fractured instruments, zipping, and root perforation were recorded as iatrogenic errors. Teeth were classified as acceptable if the technical parameters were adequate and there were no iatrogenic errors.

STATISTICAL ANALYSIS: Data were statistically analyzed using Pearson’s chi-squared test.

RESULTS: The quality of root filling was acceptable in 183 of the 480 teeth. The rate of acceptable quality was higher for the teeth treated by 4th-year students (41.9%) than for those treated by 5th-year students (27.4%; p = 0.004). Length and taperness were adequate in more of the patients treated by the 4th-year students (p<0.05). There was a significant difference in the incidence of ledge formation and apical transportation in relation to the student’s level (p<0.05).

CONCLUSIONS: The technical quality of root fillings performed without iatrogenic errors by undergraduate dental students was declared acceptable in 38.1% of the assessed teeth. There was a noticeable difference in the quality of root canal treatment between the 4th- and 5th-year students.

CLINICAL RELEVANCE: The findings demonstrate that periodic assessment of the technical quality of root filling performed by undergraduate dental students provides feedback on curriculum standards.

PMID:35279818 | DOI:10.1055/s-0042-1743150

Adv Ther. 2022 Mar 12. doi: 10.1007/s12325-022-02099-0. Online ahead of print.

ABSTRACT

INTRODUCTION: Given the relatively short life expectancy of patients with hepatocellular carcinoma (HCC), quality of life (QOL) plays a significant role in treatment selection. This analysis aimed to compare time to deterioration (TTD) in QOL with transarterial radioembolization (TARE) and atezolizumab-bevacizumab, as well as sorafenib, in advanced and unresectable HCC.

METHODS: Patient-level data from SARAH (TARE using SIR-Spheres^® Y-90 resin microspheres [SIR-Spheres] versus sorafenib) and aggregate data from IMbrave150 (atezolizumab-bevacizumab versus sorafenib) randomized controlled trials were used to conduct an anchored matching-adjusted indirect comparison (MAIC). Patients with a Child-Pugh score B in SARAH were excluded to align with exclusion criteria in IMbrave150. To identify potential effect modifiers for adjustment, the literature was searched and multivariate Cox proportional hazards models were implemented using SARAH data. Patients from SARAH were then weighted to balance with baseline characteristics from IMbrave150. Median TTD in QOL and hazard ratios (HRs) were calculated.

RESULTS: Four potential effect modifiers were identified and used for adjustment: cause of disease (viral/non-viral), macrovascular invasion, Eastern Cooperative Oncology Group performance score, and alpha-fetoprotein level. The MAIC included 217 patients from SARAH (TARE = 94; sorafenib = 123). Median TTD in QOL was 11.23 and 8.64 months for atezolizumab-bevacizumab and TARE, respectively (HR = 1.06; 95% confidence interval [CI] 0.75-1.50; p = 0.725). A sensitivity analysis was conducted adjusting for cause of disease defined as hepatitis B/hepatitis C/non-viral: median TTD in QOL was higher for TARE compared with atezolizumab-bevacizumab (19.88 vs 11.23 months; HR = 0.66; 95% CI 0.36-1.19; p = 0.163). Sorafenib resulted in the shortest TTD in QOL, with statistically significant differences in both base case and sensitivity analyses.

CONCLUSION: TARE using SIR-Spheres may achieve similar TTD in QOL compared with atezolizumab-bevacizumab, as the analyses found no statistically significant differences between these two interventions. Both TARE using SIR-Spheres and atezolizumab-bevacizumab seem to be more efficacious than sorafenib in maintaining QOL.

PMID:35279814 | DOI:10.1007/s12325-022-02099-0

Eur J Dent. 2022 Mar 13. doi: 10.1055/s-0041-1741377. Online ahead of print.

ABSTRACT

OBJECTIVES: Esthetics have become a primary influencing factor for patient satisfaction, thus dental restorations shade selection is critical, as it should closely resemble a healthy tooth. During various dental procedures, teeth are subjected to dehydration. The commonly used shade guides are being replaced with electronic color measurement devices for more precise measurements. The aim of this study was to evaluate the effect of dehydration time on tooth color measurement using a spectrophotometer.

MATERIALS AND METHODS: Study sample is represented by 20 extracted caries-free maxillary central incisors, which were obtained from several private clinics in Riyadh, Saudi Arabia, and soaked in normal saline for 24 hours. The VITA Easyshade Advance 4.0 spectrophotometer was used to measure the color at different areas of the tooth (cervical, middle, and incisal thirds) at three time intervals (baseline, after 1 hour of dehydration, and after 2 hours of dehydration).

STATISTICAL ANALYSIS: All color coordinates across the different areas of each tooth at the incisal, middle, and cervical thirds descriptive statistics of mean (standard deviation) values were calculated and were compared at the different time intervals at baseline, after 1 hour of dehydration, and after 2 hours of dehydration. Finally, the color change value ∆E was calculated using the formula ∆E*_ab = √ (L₂∗ – L₁∗)² + (a₂∗ – a₁∗)² + (b₂∗ – b₁∗)².

RESULTS: The color difference ∆E showed statistically significant changes at different time intervals: at baseline, after 1 hour of dehydration, and after 2 hours of dehydration (p < 0.001). Hue had statistically significant changes between 1 hour and 2 hours of dehydration (p = 0.002). Chroma value also showed statistically significant changes (p < 0.001) in all time intervals.

CONCLUSION: By using VITA Easyshade Advance 4.0 spectrophotometer, it was indicated that the tooth color measurements were significantly affected by dehydration time, and tooth shade appeared lighter due to changes in the refractive indices as air replaces the interprism spaces within the enamel. Tooth color measurements for shade selection should be taken as soon as possible to limit dehydration effect and ensure a more accurate shade selection for an enhanced esthetic result.

PMID:35279817 | DOI:10.1055/s-0041-1741377