Tag: pubmed

Ann Appl Stat. 2020 Mar;14(1):433-451. doi: 10.1214/19-aoas1312. Epub 2020 Apr 16.

ABSTRACT

Principal component analysis (PCA) is a popular method for dimension reduction in unsupervised multivariate analysis. However, existing ad hoc uses of PCA in both multivariate regression (multiple outcomes) and multiple regression (multiple predictors) lack theoretical justification. The differences in the statistical properties of PCAs in these two regression settings are not well understood. In this paper we provide theoretical results on the power of PCA in genetic association testings in both multiple phenotype and SNP-set settings. The multiple phenotype setting refers to the case when one is interested in studying the association between a single SNP and multiple phenotypes as outcomes. The SNP-set setting refers to the case when one is interested in studying the association between multiple SNPs in a SNP set and a single phenotype as the outcome. We demonstrate analytically that the properties of the PC-based analysis in these two regression settings are substantially different. We show that the lower order PCs, that is, PCs with large eigenvalues, are generally preferred and lead to a higher power in the SNP-set setting, while the higher-order PCs, that is, PCs with small eigenvalues, are generally preferred in the multiple phenotype setting. We also investigate the power of three other popular statistical methods, the Wald test, the variance component test and the minimum p-value test, in both multiple phenotype and SNP-set settings. We use theoretical power, simulation studies, and two real data analyses to validate our findings.

PMID:37398898 | PMC:PMC10313330 | DOI:10.1214/19-aoas1312

J Conserv Dent. 2023 May-Jun;26(3):338-343. doi: 10.4103/jcd.jcd_67_23. Epub 2023 May 16.

ABSTRACT

INTRODUCTION: The study evaluated the influence of coronal restoration after pulpotomy on the strength of electrical stimulus reaching the radicular pulp using an electric pulp test (EPT).

MATERIALS AND METHODS: The pulp tissue from ten freshly extracted mandibular premolar teeth was removed and replaced with an electroconductive gel. The cathode probe of Powerlab was inserted into the pulp space and the anode probe was attached to the EPT handpiece. The EPT probe coated with electro-conducting material was positioned in the middle third of the buccal crown surface. The EPT stimulus reaching the pulp space of an intact tooth at 40 numerical readings was recorded. The tooth was removed from model and endodontic access was made. The 2-mm thick mineral trioxide aggregate was placed at the cementoenamel junction followed by composite resin restoration. The experimental setup was re-established and postpulpotomy EPT stimulus data were recorded. The data collected were compared using the Wilcoxon signed-rank test.

RESULTS: There was a statistically significant difference (P = 0.038) between observed between the strength of EPT stimulus reaching the pulp space in prepulpotomy (mean 91.18 ± 101.02 V and median 25.79 V) and postpulpotomy (mean 58.49 ± 77.13 V and median 13.75 V) tooth samples.

CONCLUSION: The placement of the restoration and pulp capping agent after pulpotomy dampens the strength of EPT stimulus reaching the pulp canal space.

PMID:37398868 | PMC:PMC10309130 | DOI:10.4103/jcd.jcd_67_23

J Conserv Dent. 2023 May-Jun;26(3):265-270. doi: 10.4103/jcd.jcd_22_23. Epub 2023 May 16.

ABSTRACT

AIM: Using confocal laser scanning microscopy (CLSM), the current study assessed the impact of nonthermal atmospheric plasma (NTAP) on the dentinal tubule penetration of bioceramic and epoxy resin-based root canal sealers (CLSM).

MATERIALS AND METHODS: Forty human mandibular premolar teeth with a single root that had just undergone extraction were chosen and biomechanical preparation of root canals was done with ProTaper Gold rotary Nickel-titanium instruments. Samples were divided into four groups (n = 10). Group 1: Bioceramic sealer (BioRoot RCS); Group 2: Epoxy resin-based sealer (AH Plus) without application of NTAP; Group 3: Bioceramic sealer (BioRoot RCS); and Group 4: Epoxy resin-based sealer (AH Plus) with the application of NTAP for 30 s. In Groups 3 and 4, all of the samples underwent obturation with the appropriate sealers following NTAP application. For determination of the sealer’s dentinal tubule penetration values, slices with a thickness of 2 mm were taken from the middle third of sample’s root and examined using CLSM. The acquired data were statistically analyzed with one-way analysis of variance and the Post hoc Tukey’s test. The cutoff for statistical significance was P < 0.05.

RESULTS: In comparison to other groups, the maximum sealer penetration values into dentinal tubules were significantly higher in Group 3 for Bioceramic sealer with NTAP application and Group 4 for Epoxy resin-based sealer with NTAP application.

CONCLUSION: NTAP application increased the dentinal tubule penetration of bioceramic and epoxy resin-based sealers in comparison to groups without NTAP application.

PMID:37398866 | PMC:PMC10309127 | DOI:10.4103/jcd.jcd_22_23

J Conserv Dent. 2023 May-Jun;26(3):288-291. doi: 10.4103/jcd.jcd_62_23. Epub 2023 May 16.

ABSTRACT

AIM: The aim of this study was to assess and compare the quantity of apically debris which was extruded apically by TruNatomy (TN), ProTaper Next (PTN), HyFlex electric discharge machining (EDM), and HyFlex controlled memory (CM), following root canal preparation.

MATERIALS AND METHODS: Sixty extracted single-canal mandibular premolars were used. The root canal preparation was done with TN, HyFlex EDM, PTN, or HyFlex CM files. The preweight debris, which was extruded apically, was collected in the Eppendorf tube and later on incubated at 670°C for 3 days and weighed again to record the extruded debris.

RESULTS: The result showed that there was a significant reduction in debris extrusion by TN system, followed by PTN system, HyFlex EDM, and maximum extrusion in HyFlex CM (P < 0.05). Between the PTN and TN groups as well as between the HyFlex EDM and HyFlex CM groups, statistically significant difference was not observed (P > 0.05).

CONCLUSION: Apical debris extrusion is the inherent nature of the all file systems. Nevertheless, the TN file system produced substantially minimum debris extrusion among other systems compared in the study.

PMID:37398865 | PMC:PMC10309133 | DOI:10.4103/jcd.jcd_62_23

J Conserv Dent. 2023 May-Jun;26(3):326-333. doi: 10.4103/jcd.jcd_98_23. Epub 2023 May 16.

ABSTRACT

CONTEXT: The purpose of this study was to evaluate and compare the centering ability and canal transportation of TruNatomy, OneCurve, and Jizai file systems to assess their performance in oval-shaped canals using cone-beam computed tomography imaging.

MATERIALS AND METHODS: Forty-two fully formed single-rooted mandibular premolars were selected with a buccolingual canal size 2-2.5 times the mesiodistal size at 5 mm from the apex, with 0°-10° canal curvature with a 5-6 mm radius, at 5 mm from the apex. The teeth were divided into three groups (n = 14) and prepared with TruNatomy, OneCurve, and Jizai files based on the manufacturer’s instructions. Cone-beam computed tomographic images were taken before and after instrumentation. The canal transportation and centering ability was calculated at 3, 6, and 9 mm from the apex in both mesiodistal and buccolingual directions.

STATISTICAL ANALYSIS: Intergroup comparison was done using Kolmogorov-Smirnov test. Intragroup comparison was done using Freidman test. A comparison of categorical variables was done using the Chi-square test.

RESULTS: The results obtained did not present any statistically significant difference between the three groups, with TruNatomy and OneCurve showing relatively lesser canal transportation and better centering ratio when compared to the Jizai file system.

CONCLUSIONS: It can, therefore, be concluded that all three systems used in the study are capable of safely preparing root canals with minimal errors.

PMID:37398864 | PMC:PMC10309135 | DOI:10.4103/jcd.jcd_98_23

Eur J Gastroenterol Hepatol. 2023 Aug 1;35(8):865-873. doi: 10.1097/MEG.0000000000002581. Epub 2023 Jun 6.

ABSTRACT

OBJECTIVE: To investigate the association between body composition and prognosis in patients with advanced hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

METHODS: This cohort study analysed 119 patients who received atezolizumab plus bevacizumab for unresectable hepatocellular carcinoma. We investigated the association between body composition and progression-free survival and overall survival. Body composition was quantified by the visceral fat index, subcutaneous fat index, and skeletal muscle index. A high or low index score was defined as that above or below the median of these indices.

RESULTS: Poor prognosis was observed in the low visceral fat index and low subcutaneous fat index groups. The mean progression-free survival in the low visceral fat index and low subcutaneous fat index groups vs. the other groups were 194 and 270 days, respectively [95% confidence interval (CI), 153-236 and 230-311 days, respectively; P = 0.015], while the mean overall survival was 349 vs. 422 days, respectively (95% CI, 302-396 and 387-458 days, respectively; P = 0.027). In the multivariate analysis, both a low subcutaneous fat index and low visceral fat index were statistically associated with lower progression-free and overall survival rates [hazard ratio (HR) 1.721; 95% CI, 1.101-2.688; P = 0.017; and HR 2.214; 95% CI, 1.207-4.184; P = 0.011, respectively].

CONCLUSION: Low visceral fat index and subcutaneous fat index scores were independent predictors of poor prognosis in patients with unresectable hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

PMID:37395239 | DOI:10.1097/MEG.0000000000002581

Eur J Gastroenterol Hepatol. 2023 Aug 1;35(8):836-842. doi: 10.1097/MEG.0000000000002579. Epub 2023 Jun 6.

ABSTRACT

BACKGROUND AND AIMS: In endoscopic ultrasound (EUS)-fine-needle biopsy (FNB) of solid pancreatic mass lesions, the number of times the needle moves back and forth within the lesion might affect the collection of the sample and the subsequent diagnostic accuracy. Thus, this study was designed to compare the diagnostic adequacy between different numbers of back-and-forth movements in EUS-FNB.

METHODS: Fifty-five patients with solid pancreatic masses underwent EUS-FNB sampling with the needle (22-gauge) moved 20 times (MTT) and 40 times (MFT) randomly and sequentially for a total of four alternating passes. We compared the acquisition rate of appropriate and adequate specimens for histologic assessment and diagnostic accuracy.

RESULTS: Finally, 55 patients (35 men and 20 women) were included in the study. We found that 56.4% (31/55) and 60% (33/55) of the specimens obtained using MTT and MFT, respectively, could be adequately diagnosed histologically (P = 0.815, McNemar test). The diagnostic accuracy of MTT and MFT was 72.7% (40/55) and 80% (44/55), respectively (P = 0.289, McNemar test). The overall diagnostic accuracy was 89.1%.

CONCLUSION: There was no significant statistical difference between the histopathological diagnostic samples obtained in MTT and those obtained in MFT. Therefore, a large number of back-and-forth movements of the needle should be avoided during EUS-FNB, which can help reduce the operation time and may reduce the risk of intraoperative and postoperative complications (Clinical trial registration number: ChiCTR2000031106).

PMID:37395235 | DOI:10.1097/MEG.0000000000002579

Eur J Gastroenterol Hepatol. 2023 Aug 1;35(8):829-835. doi: 10.1097/MEG.0000000000002587. Epub 2023 Jun 6.

ABSTRACT

OBJECTIVES: The development of fundic gland polyps (FGPs) is the most common side effect of long-term proton pump inhibitor (PPI) use; however, the effect of drug use characteristics and their impact on the risk of other gastric polyp development remain unclear. We aimed to identify the influence of PPI administration, as well as its duration and dose, in the development of gastric polyps.

METHODS: A prospective cohort study was conducted on consecutive patients who underwent gastroscopy between September 2017 and August 2019. Detailed characteristics of gastric polyps, Helicobacter pylori infection, and PPI use were analyzed.

RESULTS: Among the 2723 patients included, gastric polyps (75% FGPs, 22% hyperplastic) were detected in 16.4%, and 60% were prescribed PPI. The risk of FGPs and hyperplastic polyps according to the duration of PPI use were as follows: 2-5 years [odds ratio (95% confidence interval); 2.86 (2.00-4.11) and 2.82 (1.69-4.78)]; 6-9 years [7.42 (5.03-11.01) and 2.32 (1.05-4.78)]; ≥10 years [14.94 (10.36-21.80) and 3.52 (1.67-7.03)]. Multivariate analysis confirmed that the risk of FGPs was 17.16 (11.35-26.23) for ≥10 years of PPI use. Portal hypertension-related conditions were associated with hyperplastic polyps [4.99 (2.71-9.20)].

CONCLUSION: Duration of and indications for PPI use are the most predictive factors for the development of gastric polyps. Prolonged PPI use increases the risk of polyp development and the number of patients with polyps, which may burden endoscopic practice. Highly selected patients may require particular care despite minimal risk of dysplasia and bleeding generally.

PMID:37395234 | DOI:10.1097/MEG.0000000000002587

Eur J Gastroenterol Hepatol. 2023 Aug 1;35(8):822-828. doi: 10.1097/MEG.0000000000002577. Epub 2023 Jun 6.

ABSTRACT

BACKGROUND AND AIMS: Endoscopic polypectomy can prevent colorectal cancer. Adequate surgical field visualization is crucial to complete resection. To prevent visual field loss caused by intestinal peristalsis, we investigated the efficacy and safety of topical lidocaine spraying during the endoscopic sigmoid polypectomy (ESP).

METHODS: Retrospective analysis was performed on 100 ESP patients admitted from July 2021 to October 2021, among which 50 patients received lidocaine (case group) and other 50 patients received normal saline (control group). Lidocaine or saline was sprayed on the colonic mucosa within 5 cm above and below the polyps before polypectomy. The en-bloc resection rate (EBRR) and complete resection rate (CRR) were primarily evaluated. Secondary outcomes included EBRR for polyps located in the 5-11 o’clock position, sigmoid colon peristalsis frequency, degree of exposure to the surgical field, operative times, and adverse events.

RESULTS: There were no significant differences in the basic demographic characteristics between the two groups. EBRR and CRR in the case group were 72.9% and 95.8%, and in the control group were 53.3% and 91.1%, respectively. The EBRR of sigmoid polyps located at the 5-11 o’clock positions was significantly higher in the case group (82.8%) than in the control group (56.7%) (P = 0.03). Sigmoid colonic peristalsis was significantly inhibited after lidocaine spraying (P < 0.01). There was no statistical difference in the operative times and adverse event rates between the two groups.

CONCLUSION: Topical spraying lidocaine around polyps can safely and effectively reduce intestinal peristalsis, thus improving the EBRR of sigmoid polypectomy.

PMID:37395233 | DOI:10.1097/MEG.0000000000002577

Eur J Gastroenterol Hepatol. 2023 Jun 16. doi: 10.1097/MEG.0000000000002591. Online ahead of print.

ABSTRACT

BACKGROUND: This study aimed to investigate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of patients with pyrrolidine alkaloids-induced hepatic sinusoidal obstruction syndrome (PA-HSOS).

METHODS: Patients diagnosed with PA-HSOS and treated in Ningbo No.2 Hospital between November 2017 and October 2022 were enlisted in this retrospective cohort study.

RESULTS: This cohort comprised a total of 22 patients with PA-HSOS, of which 12 patients received TIPS treatment and 10 patients experienced conservative treatment. The median follow-up duration was 10.5 months. Baseline characteristics existed with no significant difference between the two groups. No operation failures or any TIPS-associated intraoperative complications were observed after TIPS. In the TIPS group, the portal venous pressure was substantially decreased from 25.3 ± 6.3 mmHg to 14.4 ± 3.5 mmHg after TIPS (P = 0.002). Compared with preoperative, the ascites after TIPS were significantly subsided (P = 0.001) and there existed a considerable decrease in Child-Pugh score. At the end of follow-up, 5 patients died, involving 1 in the TIPS group and 4 in the conservative treatment group. The median survival time was 13 (3-28) months in the TIPS group and 6.5 (1-49) months in the conservative treatment group, respectively. The survival analysis demonstrated that the total survival time of TIPS group was longer than that of the conservative treatment group, no statistical significance was observed (P = 0.08).

CONCLUSION: TIPS may be a secure and effective therapeutic strategy for PA-HSOS patients who do not respond to conservative treatment.

PMID:37395216 | DOI:10.1097/MEG.0000000000002591