Novel transcriptional regulator OxtR1 regulates potential ferrodoxin in response to oxygen stress in Treponema denticola.

OBJECTIVE: Treponema denticola has been strongly implicated in the pathogenesis of chronic periodontitis. Previously, we reported that the potential transcriptional regulator TDE_0259 (oxtR1) is upregulated in the bacteriocin ABC transporter gene-deficient mutant. OxtR1 may regulate genes to adapt to environmental conditions during colonization; however, the exact role of the gene in T. denticola has not been reported. Therefore, we investigated its function using an oxtR1-deficient mutant. METHODS: The growth rates of the wild-type and oxtR1 mutant were monitored under anaerobic conditions; their antibacterial agent susceptibility and gene expression were assessed using a liquid dilution assay and DNA microarray, respectively. An electrophoretic mobility shift assay was performed to investigate the binding of OxtR1 to promoter regions. RESULTS: The growth rate of the bacterium was accelerated by the inactivation of oxtR1, and the mutant exhibited an increased minimum inhibitory concentration against ofloxacin. We observed a relative increase in the expression of genes associated with potential ferrodoxin (TDE_0260), flavodoxin, ABC transporters, heat-shock proteins, DNA helicase, iron compounds, and lipoproteins in the mutant. OxtR1 expression increased upon oxygen exposure, and oxtR1 complementation suppressed the expression of potential ferrodoxin. Our findings also suggested that OxtR1 binds to a potential promoter region of the TDE_0259-260 operon. Moreover, the mutant showed a marginal yet significantly faster growth rate than the wild-type strain under H2O2 exposure. CONCLUSION: The oxygen-sensing regulator OxtR1 plays a role in regulating the expression of a potential ferrodoxin, which may contribute to the response of T. denticola to oxygen-induced stress.

Diagnostic performance of fluoroscopic video analysis for pulmonary embolism: a prospective observational study.

PURPOSE: Dynamic chest radiography using X-ray fluoroscopic video analysis has shown potential for the diagnosis of pulmonary embolism (PE), but its diagnostic performance remains uncertain. We aimed to evaluate the diagnostic performance of fluoroscopic video analysis for diagnosing PE. METHODS: A prospective single-center observational study was conducted between October 2020 and January 2022. Fifty consecutive adult patients, comprising definitive PE, pulmonary hypertension (PH), or suspected PH, were enrolled. The study population was classified into 23 PE and 27 non-PE cases by contrast-enhanced computed tomography, lung scintigraphy, right heart catheterization, and pulmonary angiography. Cineradiographic images of 10-second breath-holds were obtained and analyzed using a fluoroscopic video analysis workstation to generate pulmonary circulation images. Two blinded cardiologists qualitatively assessed the presence or absence of perfusion defects on the pulmonary circulation images. The diagnosis obtained from the fluoroscopic analysis was compared with the definitive diagnosis. The primary outcomes included sensitivity, specificity, positive and negative predictive values, and overall accuracy for diagnosing PE. RESULTS: Perfusion defects were observed in 21 of 23 PE patients and 13 of 27 non-PE patients. The diagnostic performance of fluoroscopic video analysis for diagnosing PE showed a sensitivity of 91%, specificity of 52%, positive predictive value of 62%, negative predictive value of 88%, and overall accuracy of 70%. CONCLUSIONS: The high sensitivity of the fluoroscopic video analysis suggests its potential usefulness in ruling out PE without the need for contrast media or radionuclide; however, its specificity and overall accuracy remain limited.

Risk Factors for Anemia Exacerbation Requiring Red Blood Cell Transfusion During Edoxaban Thromboprophylaxis After Orthopedic Surgery.

Background An increased risk of anemia during edoxaban thromboprophylaxis in orthopedic surgery has been reported. However, the risk factors for the exacerbation of anemia requiring transfusion with irradiated red blood cell concentrates during postoperative edoxaban thromboprophylaxis remain unknown. Therefore, this study investigated the factors that increase the possibility of transfusion during edoxaban thromboprophylaxis after orthopedic surgery by reanalyzing clinical data from a previous collection. Methods A total of 221 patients who underwent total hip or knee arthroplasty at a single center between July 2011 and June 2012 were included in this study. Among these, 167 patients who received 30 mg of postoperative edoxaban thromboprophylaxis were retrospectively analyzed to identify critical factors for transfusion during edoxaban thromboprophylaxis after orthopedic surgery. Results Lower preoperative hemoglobin levels and higher intraoperative blood loss per body weight were significantly associated with an increase in the frequency of transfusion during postoperative edoxaban thromboprophylaxis. These factors were also potentially related to increased coagulation parameters during edoxaban thromboprophylaxis. Conclusion Our study shows that lower preoperative hemoglobin levels and higher intraoperative blood loss are associated with increased coagulation parameters with edoxaban thromboprophylaxis after orthopedic surgery and may lead to worsening of anemia, thereby requiring blood transfusion.

Influence of remaining coronal tooth morphology with resin abutment and fiber post on static and dynamic fracture resistances.

This study aimed to clarify the fracture resistance of resin abutments built on endodontically treated roots with the remaining coronal teeth via static and cyclic loading tests. Endodontically treated bovine roots, which had a remaining coronal tooth covered with an occupied area for a quarter and half of the circumference at the tensile side or covered the circumference at both the tensile and compressive sides, were fabricated to build up to the resin abutment. Fracture resistance was evaluated via static and cyclic loading tests by applying a load of 30° to the tooth axis. Half of the circumference of the remaining coronal tooth showed a significantly higher static fracture load and survival rate. The remaining coronal tooth on the compressive side improved the dynamic fracture resistance associated with severe fractures. The occupied area and location of the remaining coronal tooth affected the static and dynamic fracture resistances.

Ideal insertion point and projection of the infra-acetabular screw in acetabular fracture surgery.

BACKGROUND: In acetabular fracture surgery, an infra-acetabular screw (IAS) is inserted from the anterior to the posterior column through the infra-acetabular corridor to stabilize both columns. Although the IAS is useful for increasing fixation strength, proper placement requires proficiency and often results in extraosseous screw penetration. The complex anatomy of the infra-acetabular corridor and difficult intraoperative detection of the ideal insertion point and angle make proper placement of the IAS challenging. This study aimed to detect the ideal insertion point and angle of the IAS based on anatomical landmarks that can be directly identified intraoperatively. METHODS: We retrospectively reviewed the pelvic CT of 50 adults who underwent serial slice CT imaging. The pelvic inlet plane (PIP), which contains the anterior border of both the sacroiliac joint and posterior superior edge of the pubic symphysis, was used as the reference plane for the pelvic coordinate system to simulate the ideal insertion of IAS. The distance from the posterior superior edge of the pubic symphysis to the ideal insertion point of the IAS (IAS distance) and the angle and length of the IAS that could be inserted from the ideal insertion point were measured. RESULTS: The mean IAS distance was 61.0 ± 5.7 mm (57.6 ± 4.3 mm in men and 64.4 ± 4.9 mm in women). The mean angle between ideal IAS and yz-plane on the outlet view (α-angle) was 8.4 ± 6.6 ° (6.4 ± 5.6° in men and 10.5 ± 7.0° in women). The mean angle between ideal IAS and y-axis on the yz-plane (ß-angle) was 86.5 ± 10.6 ° (86.0 ± 10.3° in men and 87.0 ± 10.9° in women). The length of IAS was 97.1 ± 4.7 mm in men and 89.2 ± 3.6 mm in women. CONCLUSION: The IAS ideal insertion point detected as a distance from the pubic symphysis may aid in the proper insertion of the IAS during surgery. The insertion angle was parallel or tilted 10 ° laterally to the longitudinal axis in the pelvic outlet plane and almost perpendicular to the PIP in the sagittal plane when inserted from the ideal insertion point.

Design of closed loop for reproduction of gas-dominated hydrate flow.

The study presents a novel setup for measuring the flow regime of hydrate particles in a gas-dominated flow, which is of interest for applications such as natural gas transportation. A closed-flow loop, driven by a novel internal fan, enables continuous observation of hydrate particle behavior in a gas flow. The experimental setup allows the production and insertion of HFC134a gas hydrate particles with diameters of 10-50 µm into the gas flow loop via a bypass loop. The performance curve of the internal fan is validated, and its suitability for achieving the required flow speed (5 m/s) is demonstrated. Through an observation window using camera systems, the flow regime of glass beads is successfully visualized and analyzed. To validate the experimental data, a coupled computational fluid dynamics-discrete element method model is used to simulate the particle flow density distribution. The study findings demonstrate the effectiveness of the experimental setup in characterizing the flow regime of hydrate particles in a gas-dominated flow.

Management of pulmonary hemodynamics prior to delivery in a pregnant woman with development of decompensated pulmonary arterial hypertension.

Prompt termination of pregnancy in patients with decompensated pulmonary arterial hypertension (PAH) is imperative for improvement of maternal hemodynamics, but such termination may also result in maternal death due to further deterioration of PAH immediately after delivery. However, there have been limited reports on whether implementation of PAH therapy with continuation of pregnancy improves the maternal outcome, especially in treatment-naïve patients with PAH. A 24-year-old woman was admitted to our hospital with a chief complaint of dyspnea (WHO functional class IV) at 22 weeks and 3 days of gestation. She was diagnosed with PAH accompanied by right heart failure and low cardiac output. Intensive treatment was initiated with inotropic agents, oxygen therapy, and PAH therapy, resulting in improvement of her hemodynamics. A caesarean section was performed at 23 weeks and 3 days. Although her pulmonary arterial pressure transiently increased with oxygenation deteriorating immediately after delivery, worsening PAH improved without mechanical circulatory support. She continued receiving pulmonary vasodilators without relapse of pulmonary hypertension for three years. The improvement of pulmonary hemodynamics prior to delivery with PAH therapy led to a favorable outcome after delivery. Learning objective: Pulmonary hemodynamics in pregnant patients with pulmonary arterial hypertension (PAH) can deteriorate with the continuation of pregnancy, while termination can also cause PAH surge immediately after delivery. In treatment-naïve patients with PAH, who are most likely to benefit from PAH therapy, implementation of PAH therapy with continuation, even with a decompensated status, may improve the hemodynamics prior to delivery, resulting in a favorable outcome after delivery.

Fragility and long-term clinical outcomes in patients with venous thromboembolism receiving direct oral anticoagulants: From the COMMAND VTE REGISTRY-2.

INTRODUCTION: There is limited data on the safety of direct oral anticoagulants (DOACs) in fragile patients with venous thromboembolism (VTE). MATERIALS AND METHODS: We used the COMMAND VTE Registry-2 enrolling patients with acute symptomatic VTE. The study population consisted of 3928 patients receiving DOACs, who were divided into fragile (2136 patients) and non-fragile groups (1792 patients). Fragility was defined as patients of age ≥ 75 years, creatinine clearance level ≤ 50 ml/min, and/or body weight ≤ 50 kg. RESULTS: The fragile group significantly more often received reduced doses of DOACs compared to the non-fragile group (51 % and 19 %, P < 0.001). The cumulative 5-year incidence of major bleeding was numerically higher in the fragile group than the non-fragile group (15.0 % and 11.1 %, P = 0.052), even with no significant excess risk after adjusting for confounders (HR 1.03, 95%CI 0.81-1.31, P = 0.78). The cumulative 5-year incidence of clinically relevant bleeding was significantly higher in the fragile group than the non-fragile group (28.6 % and 19.6 %, P < 0.001), even after adjusting for confounders (HR 1.28, 95%CI 1.08-1.53, P = 0.005). There was no significant difference in cumulative 5-year incidence of recurrent VTE between the groups (9.6 % and 8.9 %, P = 0.68), which was consistent after adjusting for confounders (HR 1.13, 95%CI 0.84-1.51, P = 0.41). CONCLUSIONS: Among VTE patients receiving DOACs, fragile patients were associated with a numerically higher rate of major bleeding and a significantly increased risk of clinically relevant bleeding, but not an increased risk of recurrent VTE.