Two-Way Relationship Between Helicobacter Pylori Infection and Periodontitis: Results from A Systematic Review and Meta-Analysis

Aim: Helicobacter pylori (H. pylori) infection and periodontitis have considerable worldwide prevalence once they both present systemic alterations with a possible association between them. Therefore, we have performed this meta-analysis to assess the possible association between H. pylori infection and periodontitis. Material and Methods: A systematic search in the literature was performed for studies published before December 2, 2019 in diverse scientific and educational databases. The data was extracted by two investigators and the statistical analysis was performed by Review Manager statistical program with heterogeneity and Odds Ratio (OR) with 95% of Confidence Intervals (CI) calculations as well as a sensitive analysis to assess the accuracy of the results. The value of P<0.05 was considered as significant. In addition, we performed the analysis of the quality of included studies as well as the evaluation for risk of bias. Results: In overall analysis, H. pylori infection was associated with the risk of periodontitis development (OR = 1.72, CI: 1.47, 2.02, P<0.00001) and the periodontitis was considered as a risk factor for H. pylori infection (OR = 3.21, CI: 2.31, 4.47, P<0.00001). Moreover, the evaluation of dental plaque from patients with periodontitis reveled increased risk of H. pylori infection (OR = 3.46, CI: 2.39, 5.01, P<0.00001). Conclusions: This current systematic review and meta-analysis composed by 12 studies in 7,059 participants showed that H. pylori infection increased significantly the risk of the development of periodontitis and the periodontitis may be a risk for this bacterial infection.

Volumetric changes of the primary esophageal tumor during radiation therapy.

134 Background: Management of esophageal cancer with radiotherapy requires weeks of daily treatments. The objective of this study is to identify edematous/obstructive changes in the esophageal tumor occurring during therapy and quantifying its change relative to the original tumor volume. Methods: A total of 66 patients were reviewed on a retrospective IRB-approved protocol between July 2012 – July 2016. The gross tumor volume (GTV) targeted with radiation (GTVsim) was constructed on a CT-simulation image. Cone beam CT images (CBCTs) were taken daily during treatment. GTVs (GTVCT#) were contoured on the CBCT on treatment days 1, 6, 11, 16, 21, and 25. Volumes for the GTVsim and each GTVCT# per patient were calculated. A conformality index (CI) was determined by visual confirmation of overlap and calculation of GTVCT#/GTVsim. The standard deviation (SD) was calculated. A theoretical max volume (GTVCTMAX) was determined per patient based on the upper range of 2SD from the average GTVCT# value. A theoretical PTV created from a 1cm (PTV1) and 0.5cm (PTV0.5) expansions were also calculated with associated CIs for PTVCTMAX/PTV1 and PTVCTMAX/PTV0.5. Results: Twenty-one patients had a total of 94 CBCT volumes. The median age was 67 years (53-83), sixteen patients were male, 5 female. T-stage was 1/2 in 5 patients and 3/4 in 15 patients. Chemotherapy was administered concurrently in 17 patients. Median duration of radiotherapy was 35 days (2-50). Results were analyzed by absolute volume comparison and CI calculations as noted in table 1.The median CI for PTVCTMAX/PTV1 was 0.40 (0.15-0.84) and PTVCTMAX/PTV0.5was 0.65 (0.34-0.89). Conclusions: Review of the weekly CBCTs demonstrated a larger tumor volume in the first day of therapy relative to the subsequent weeks, and even relative to the volume at the time of simulation. However, in projecting potential changes in maximum size of the individual tumors, 100% remained within standard PTV volumes constructed with a 1cm and 0.5cm expansions. [Table: see text]

Generalization of Brillouin theorem for the non-relativistic electronic Schrödinger equation in relation to coupling strength parameter, and its consequences in single determinant basis sets for configuration interactions

<p> The Brillouin theorem has been generalized for the extended non-relativistic electronic Hamiltonian (H_Ñ+ H_ne+ aH_ee) in relation to coupling strength parameter (a), as well as for the configuration interactions (CI) formalism in this respect. For a computation support, we have made a particular modification of the SCF part in the Gaussian package: essentially a single line was changed in an SCF algorithm, wherein the operator r_ij^-1 was overwritten as r_ij^-1 ® ar_ij^-1, and “a” was used as input. The case a=0 generates an orto-normalized set of Slater determinants which can be used as a basis set for CI calculations for the interesting physical case a=1, removing the known restriction by Brillouin theorem with this trick. The latter opens a door from the theoretically interesting subject of this work toward practice. </p>

Generalization of Brillouin theorem for the non-relativistic electronic Schrödinger equation in relation to coupling strength parameter, and its consequences in single determinant basis sets for configuration interactions

<p> The Brillouin theorem has been generalized for the extended non-relativistic electronic Hamiltonian (H_Ñ+ H_ne+ aH_ee) in relation to coupling strength parameter (a), as well as for the configuration interactions (CI) formalism in this respect. For a computation support, we have made a particular modification of the SCF part in the Gaussian package: essentially a single line was changed in an SCF algorithm, wherein the operator r_ij^-1 was overwritten as r_ij^-1 ® ar_ij^-1, and “a” was used as input. The case a=0 generates an orto-normalized set of Slater determinants which can be used as a basis set for CI calculations for the interesting physical case a=1, removing the known restriction by Brillouin theorem with this trick. The latter opens a door from the theoretically interesting subject of this work toward practice. </p>