Changes in the corrected carotid flow time can predict spinal anesthesia-induced hypotension in patients undergoing cesarean delivery: an observational study.

PURPOSE: Spinal anesthesia is a standard technique for cesarean delivery; however, it possesses a risk of hypotension. We hypothesised that the changes in the corrected flow time induced by the Trendelenburg position could predict the incidence of hypotension after spinal anesthesia for cesarean delivery. METHODS: Patients undergoing elective cesarean delivery under spinal anesthesia were enrolled. Before anesthesia induction, corrected flow time was measured in the supine and Trendelenburg positions (FTc-1 and FTc-2, respectively). Additionally, a percent change in corrected flow time induced by the Trendelenburg position was defined as ΔFTc. The primary endpoint was to investigate the ability of ΔFTc to predict the incidence of spinal anesthesia-induced hypotension until delivery. The receiver operating characteristics curves to assess the ability of FTc-1, FTc-2, and ΔFTc to predict the incidence of hypotension were generated. RESULTS: Finally, 40 patients were included, and of those, 26 (65%) developed spinal anesthesia-induced hypotension. The areas under the curve for FTc-1, FTc-2, and ΔFTc were 0.591 (95% CI: 0.424 to 0.743) (P = 0.380), 0.742 (95% CI: 0.579 to 0.867) (P = 0.004), and 0.882 (95% CI: 0.740 to 0.962) (P < 0.001) respectively, indicating ΔFTc as the best predictor among these three parameters. The best threshold for ΔFTc was 6.4% (sensitivity: 80.8% (95% CI: 53.8 to 96.2), specificity: 85.7% (95% CI: 42.9 to 100.0)). CONCLUSIONS: This study demonstrated that changes in the corrected carotid flow time induced by the Trendelenburg position could serve as a good predictor of spinal anesthesia-induced hypotension for cesarean delivery.

Chirally and chemically reversible Strecker reaction.

In the pursuit of a credible mechanism for the abiotic synthesis of α-amino acids, solid-state asymmetric Strecker/retro-Strecker reactions have been demonstrated. Asymmetric addition of cyanide to enantiomorphic crystals of achiral imines proceeded to produce enantioenriched aminonitriles. Moreover, dehydrocyanation of enantioenriched aminonitriles gave chiral crystals of achiral imines stereoselectively. We found, for the first time to the best of our knowledge, a stereoinversion of the synthetic intermediates imine and aminonitrile in the sequence of reactions including HCN addition and elimination. Thus, the reversible Strecker reaction is expected to be a focus of research on the origin of chirality.

Virtual Noncontrast Images Derived From Contrast-Enhanced Dual-Layer Spectral Abdominal Computed Tomography: A Pilot Study Between Pediatric and Adult Scans.

OBJECTIVE: We aimed to compare the accuracy of virtual noncontrast (VNC) images obtained from contrast-enhanced dual-layer spectral computed tomography (DLSCT) scans of the abdomen between pediatric and adult patients. METHODS: We retrospectively studied 10 pediatric and 40 adult patients who underwent unenhanced and contrast-enhanced DLSCT for nontraumatic acute abdomen or a follow-up of tumor or aneurysm. On true noncontrast (TNC) and VNC images, we placed a region-of-interest on 7 abdominal structures. The mean attenuation difference between VNC and TNC images was compared between these structures and between pediatric and adult scans. Data were analyzed by using the Wilcoxon signed-rank test, 1-way analysis of variance, Scheffe's test and independent t test. A P value less than 0.05 was considered statistically significant. RESULTS: In mean attenuation difference between VNC and TNC images, there was a significant interstructure difference in adult scans (P < 0.05), but not in pediatric scans. Mean attenuation difference between VNC and TNC images of the kidney was significantly higher on adult than pediatric scans (P = 0.0046). CONCLUSIONS: The VNC images obtained from contrast-enhanced DLSCT data may be more accurate on pediatric than adult scans. Patient age can be a factor influencing the accuracy of the VNC images.

Effects of baicalin on the proliferation and expression of OPG and RANKL in human cementoblast-lineage cells.

BACKGROUND/PURPOSE: Baicalin, a natural bioactive flavonoid extracted from Scutellaria baicalensis Georgi, mediates bone metabolism, and recent studies have revealed that it has cell signaling properties. However, its biological functions in cementoblasts still remain unclear. This study therefore aimed to investigate the effects of baicalin on bone resorption markers, including osteoprotegerin (OPG) and receptor activator of nuclear factor-κß ligand (RANKL), in human cementoblast-lineage cells, as well as their proliferation ability. MATERIALS AND METHODS: Human cementoblast cell line (HCEM) cells were cultured and treated with 0, 0.01, 0.1, or 1 µM of baicalin. The proliferative capacity of cultured HCEM cells was analyzed using bromodeoxyuridine immunoassay and cell counting. The baicalin effect on OPG and RANKL expression was determined using quantitative polymerase chain reaction (qPCR) and western blotting. Furthermore, OPG expression was measured in 1 µM baicalin-treated HCEM cells in the presence or absence of the Wnt signaling pathway inhibitor, Dickkopf (Dkk)-1, using qPCR and western blotting. RESULTS: The addition of 0.01, 0.1, and 1 µM of baicalin did not significantly change the proliferative capacity of cultured HCEM cells. Compared with the non-supplemented group, baicalin increased and suppressed OPG and RANKL gene and protein expression, respectively, in a concentration-dependent manner. OPG mRNA and protein expression levels were increased by 1 µM baicalin, which was suppressed by Dkk-1 addition. CONCLUSION: Baicalin enhanced OPG expression in HCEM cells through the Wnt/beta-catenin signaling pathway, which could contribute to periodontal tissue regeneration.

Detection of acute rib fractures on CT images with convolutional neural networks: effect of location and type of fracture and reader's experience.

PURPOSE: The evaluation of all ribs on thin-slice CT images is time consuming and it can be difficult to accurately assess the location and type of rib fracture in an emergency. The aim of our study was to develop and validate a convolutional neural network (CNN) algorithm for the detection of acute rib fractures on thoracic CT images and to investigate the effect of the CNN algorithm on radiologists' performance. METHODS: The dataset for development of a CNN consisted of 539 thoracic CT scans with 4906 acute rib fractures. A three-dimensional faster region-based CNN was trained and evaluated by using tenfold cross-validation. For an observer performance study to investigate the effect of CNN outputs on radiologists' performance, 30 thoracic CT scans (28 scans with 90 acute rib fractures and 2 without rib fractures) which were not included in the development dataset were used. Observer performance study involved eight radiologists who evaluated CT images first without and second with CNN outputs. The diagnostic performance was assessed by using figure of merit (FOM) values obtained from the jackknife free-response receiver operating characteristic (JAFROC) analysis. RESULTS: When radiologists used the CNN output for detection of rib fractures, the mean FOM value significantly increased for all readers (0.759 to 0.819, P = 0.0004) and for displaced (0.925 to 0.995, P = 0.0028) and non-displaced fractures (0.678 to 0.732, P = 0.0116). At all rib levels except for the 1st and 12th ribs, the radiologists' true-positive fraction of the detection became significantly increased by using the CNN outputs. CONCLUSION: The CNN specialized for the detection of acute rib fractures on CT images can improve the radiologists' diagnostic performance regardless of the type of fractures and reader's experience. Further studies are needed to clarify the usefulness of the CNN for the detection of acute rib fractures on CT images in actual clinical practice.

Protective effects of remote ischemic preconditioning against spinal cord ischemia-reperfusion injury in rats.

OBJECTIVES: We aimed to investigate the protective effect of remote ischemic preconditioning against spinal cord ischemia and find a clue to its mechanism by measuring glutamate concentrations in the spinal ventral horn. METHODS: Male Sprague-Dawley rats were divided into 5 groups (n = 6 in each group) as follows: sham; SCI (only spinal cord ischemia); RIPC/SCI (perform remote ischemic preconditioning before spinal cord ischemia); MK-801/RIPC/SCI (administer MK-801, N-methyl-D-aspartate receptor antagonist, before remote ischemic preconditioning); and MK-801/SCI (administer MK-801 without remote ischemic preconditioning). Remote ischemic preconditioning was achieved by brief limb ischemia 80 minutes before spinal cord ischemia. MK-801 (1 mg/kg, intravenous) was administered 60 minutes before remote ischemic preconditioning. The glutamate concentration in the ventral horn was measured by microdialysis for 130 minutes after spinal cord ischemia. Immunofluorescence was also performed to evaluate the expression of N-methyl-D-aspartate receptor 2B subunit in the ventral horn 130 minutes after spinal cord ischemia. RESULTS: The glutamate concentrations in the spinal cord ischemia group were significantly higher than in the sham group at all time points (P < .01). Remote ischemic preconditioning attenuated the spinal cord ischemia-induced glutamate increase. When MK-801 was preadministered before remote ischemic preconditioning, glutamate concentration was increased after spinal cord ischemia (P < .01). Immunofluorescence showed that remote ischemic preconditioning prevented the increase in the expression of N-methyl-D-aspartate receptor 2B subunit on the surface of motor neurons (P = .047). CONCLUSIONS: Our results showed that remote ischemic preconditioning prevented spinal cord ischemia-induced extracellular glutamate increase in ventral horn and suppressed N-methyl-D-aspartate receptor 2B subunit expression.

Protective effects of hydrogen gas against spinal cord ischemia-reperfusion injury.

OBJECTIVE: This experimental study aimed to assess the efficacy of hydrogen gas inhalation against spinal cord ischemia-reperfusion injury and reveal its mechanism by measuring glutamate concentration in the ventral horn using an in vivo microdialysis method. METHODS: Male Sprague-Dawley rats were divided into the following 6 groups: sham, only spinal ischemia, 3% hydrogen gas (spinal ischemia + 3% hydrogen gas), 2% hydrogen gas (spinal ischemia + 2% hydrogen gas), 1% hydrogen gas (spinal ischemia + 1% hydrogen gas), and hydrogen gas dihydrokainate (spinal ischemia + dihydrokainate [selective inhibitor of glutamate transporter-1] + 3% hydrogen gas). Hydrogen gas inhalation was initiated 10 minutes before the ischemia. For the hydrogen gas dihydrokainate group, glutamate transporter-1 inhibitor was administered 20 minutes before the ischemia. Immunofluorescence was performed to assess the expression of glutamate transporter-1 in the ventral horn. RESULTS: The increase in extracellular glutamate induced by spinal ischemia was significantly suppressed by 3% hydrogen gas inhalation (P < .05). This effect was produced in increasing order: 1%, 2%, and 3%. Conversely, the preadministration of glutamate transporter-1 inhibitor diminished the suppression of spinal ischemia-induced glutamate increase observed during the inhalation of 3% hydrogen gas. Immunofluorescence indicated the expression of glutamate transporter-1 in the spinal ischemia group was significantly decreased compared with the sham group, which was attenuated by 3% hydrogen gas inhalation (P < .05). CONCLUSIONS: Our study demonstrated hydrogen gas inhalation exhibits a protective and concentration-dependent effect against spinal ischemic injury, and glutamate transporter-1 has an important role in the protective effects against spinal cord injury.

Changes in corrected carotid flow time induced by recruitment maneuver predict fluid responsiveness in patients undergoing general anesthesia.

Non-invasive methods to assess patients' fluid responsiveness during lung-protective ventilation are needed. We hypothesized changes in the corrected carotid flow time induced by the recruitment maneuver predict fluid responsiveness under general anesthesia. Thirty patients undergoing general anesthesia in the supine position were prospectively enrolled. The study protocol was conducted when the patient was hemodynamically stable during surgery. Flow time was measured on Doppler images of the common carotid artery. Carotid flow time, heart rate, stroke volume, stroke volume variation, and pulse pressure variation were recorded before and after a recruitment maneuver at a continuous airway pressure of 30 cmH2O for 30 s, and before and after volume expansion with 250 mL for 10 min. Patients were defined as fluid responders if the increase in stroke volume was > 10% after volume expansion. Twenty patients (67%) were fluid responders. All Doppler images for carotid flow time were obtained within 30 s. Changes in the corrected flow time accurately predicted fluid responsiveness (area under the curve: 0.82, 95% confidence interval [CI] 0.64-0.94, p = 0.002). The optimal threshold for changes in the corrected flow time was - 11.7% with a sensitivity of 95.0% (95% CI 75.1-99.9%) and a specificity of 80.0% (95% CI 44.4-97.5%). The gray-zone of changes in the corrected flow time was from - 25.1 to - 12.2% and included 12 patients (40%). Changes in the corrected carotid flow time were a useful, technically easy-to-perform, and non-invasive method to predict fluid responsiveness without a need for hemodynamic monitoring or arterial cannulation.

Suppression of Bone Necrosis around Tooth Extraction Socket in a MRONJ-like Mouse Model by E-rhBMP-2 Containing Artificial Bone Graft Administration.

Medication-related osteonecrosis of the jaw (MRONJ) is related to impaired bone healing conditions in the maxillomandibular bone region as a complication of bisphosphonate intake. Although there are several hypotheses for the onset of MRONJ symptoms, one of the possible causes is the inhibition of bone turnover and blood supply leading to bone necrosis. The optimal treatment strategy for MRONJ has not been established either. BMP-2, a member of the TGF-ß superfamily, is well known for regulating bone remodeling and homeostasis prenatally and postnatally. Therefore, the objectives of this study were to evaluate whether cyclophosphamide/zoledronate (CY/ZA) induces necrosis of the bone surrounding the tooth extraction socket, and to examine the therapeutic potential of BMP-2 in combination with the hard osteoinductive biomaterial, ß-tricalcium phosphate (ß-TCP), in the prevention and treatment of alveolar bone loss around the tooth extraction socket in MRONJ-like mice models. First, CY/ZA was intraperitoneally administered for three weeks, and alveolar bone necrosis was evaluated before and after tooth extraction. Next, the effect of BMP-2/ß-TCP was investigated in both MRONJ-like prevention and treatment models. In the prevention model, CY/ZA was continuously administered for four weeks after BMP-2/ß-TCP transplantation. In the treatment model, CY/ZA administration was suspended after transplantation of BMP-2/ß-TCP. The results showed that CY/ZA induced a significant decrease in the number of empty lacunae, a sign of bone necrosis, in the alveolar bone around the tooth extraction socket after tooth extraction. Histological analysis showed a significant decrease in the necrotic alveolar bone around tooth extraction sockets in the BMP-2/ß-TCP transplantation group compared to the non-transplanted control group in both MRONJ-like prevention and treatment models. However, bone mineral density, determined by micro-CT analysis, was significantly higher in the BMP-2/ß-TCP transplanted group than in the control group in the prevention model only. These results clarified that alveolar bone necrosis around tooth extraction sockets can be induced after surgical intervention under CY/ZA administration. In addition, transplantation of BMP-2/ß-TCP reduced the necrotic alveolar bone around the tooth extraction socket. Therefore, a combination of BMP-2/ß-TCP could be an alternative approach for both prevention and treatment of MRONJ-like symptoms.

Usefulness of Virtual Monochromatic Images and Iodine Maps Derived from Dual-Energy Computed Tomography for Diagnosing Deep Neck Abscesses.

OBJECTIVE: We aimed to determine whether dual-energy computed tomography (CT) is useful for evaluating deep neck abscesses. METHODS: This study included 22 consecutive patients who were clinically suspected of having a deep neck abscess and underwent dual-energy CT. Conventional 120-kVp images, 70- and 40-keV virtual monochromatic images (VMIs), and iodine maps were inspected to calculate the contrast ratio of the abscess rim (AR) to the abscess center (AC) or to the adjacent muscle (M). The diagnostic certainty of abscesses was assessed on these images. RESULTS: Twenty (91%) of 22 patients had a definitive diagnosis. The contrast ratio for AR/AC and AR/M was significantly higher on 40-keV VMIs and iodine maps than on 120-kVp images and 70-keV VMIs (P < 0.05). On both 40-keV VMIs and iodine maps, the diagnostic certainty of abscess improved in 3 (15%) cases compared with 120-kVp images and 70-keV VMIs. CONCLUSIONS: Dual-energy CT-based 40-keV VMIs and iodine maps are useful for evaluating deep neck abscesses and may improve diagnostic certainty.

When citizen science is public relations.

Amid rising interest in participatory research, some industries have recently begun to practice public relations citizen science (PRCS). Unlike citizen science and crowdsourcing projects that generate raw materials for product development, PRCS benefits capitalist firms primarily by improving their public image and deflecting accusations of causing harm. Three cases illustrate how PRCS works: (1) a growing assortment of citizen science projects associated with Antarctic tourism, (2) an initiative to document biodiversity, linked to Canada's oil and gas industry, and (3) a study sponsored by Biology Fortified, a nonprofit organization that works to communicate positive information about agricultural biotechnology. Scientists and research organizations may have legitimate reasons for entering into these partnerships, but PRCS can benefit industries in problematic ways. First, by supporting environmental science, PRCS can attach a 'sustainable' image to a polluting industry, without changing its core practices. Second, PRCS can accumulate data and steer volunteers' observations in ways that undermine claims about the harms caused by the industry's practices or products. Finally, in some cases, PRCS organizers hope to induce people to view an industry more 'rationally' than those who make 'emotional' or 'ideological' claims about its harms.

Effects of Polymorphisms in the Serotonin Transporter Promoter-Linked Polymorphic Region on Postthoracotomy Pain Severity.

PURPOSE: Serotonin (5-HT) is highly associated with pain modulation. The human 5-HT transporter (5-HTT) gene (SLC6A4) features several polymorphisms in its promoter region (5-HTTLPR) that affect the 5-HTT expression. The S allele of 5-HTTLPR induces low 5-HT tone, and it may influence the modulation of chronic pain. Meanwhile, pain occurs in 40-50% of patients after thoracic surgery, and its mechanism remains under investigation. This study assessed the role of 5-HTTLPR polymorphisms in postthoracotomy pain severity. PATIENTS AND METHODS: A total of 178 patients undergoing pneumonectomy were enrolled. The genotypes of 5-HTTLPR were divided into two groups: S/S group and S/L or L/L group. Linear mixed-effects models were used to assess the association between 5-HTTLPR genotypes and the numerical rating scale (NRS) score change over time. RESULTS: Among the participants, data were obtained for 162 patients. The genotype distribution was as follows: S/S, 67.3%; S/L or L/L, 32.7%. No significant difference in patient characteristics was found between the genotype groups. There was no significant interaction between the 5-HTTLPR genotypes and the NRS score change over time (p = 0.842). CONCLUSION: Polymorphisms in 5-HTTLPR were not associated with postthoracotomy pain severity.

Hemodynamic Changes via the Lung Recruitment Maneuver Can Predict Fluid Responsiveness in Stroke Volume and Arterial Pressure During One-Lung Ventilation.

BACKGROUND: We aimed to evaluate the ability of lung recruitment maneuver-induced hemodynamic changes to predict fluid responsiveness in patients undergoing lung-protective ventilation during one-lung ventilation (OLV). METHODS: Thirty patients undergoing thoracic surgery with OLV (tidal volume: 6 mL/kg of ideal body weight and positive end-expiratory pressure: 5 cm H2O) were enrolled. The study protocol began 30 minutes after starting OLV. Simultaneous recordings were performed for hemodynamic variables of heart rate, mean arterial pressure (MAP), stroke volume (SV), pulse pressure variation (PPV), and stroke volume variation (SVV) were recorded at 4 time points: before recruitment maneuver (continuous airway pressure: 30 cm H2O for 30 seconds), at the end of recruitment maneuver, and before and after volume loading (250 mL over 10 minutes). Patients were recognized as fluid responders if the increase in SV or MAP was >10%. Receiver operating characteristic curves for percent decrease in SV and MAP by recruitment maneuver (ΔSVRM and ΔMAPRM, respectively) were generated to evaluate the ability to discriminate fluid responders from nonresponders. The gray-zone approach was applied for ΔSVRM and ΔMAPRM. RESULTS: Of 30 patients, there were 17 SV-responders (57%) and 12 blood pressure (BP)-responders (40%). Area under the curve (AUC) for ΔSVRM to discriminate SV-responders from nonresponders was 0.84 (95% confidence interval [CI], 0.67-0.95; P < .001). The best threshold for ΔSVRM to discriminate the SV-responders was -23.7% (95% CI, -41.2 to -17.8; sensitivity, 76.5% [95% CI, 50.1-93.2]; specificity, 84.6% [95% CI, 54.6-98.1]). For BP-responders, AUC for ΔMAPRM was 0.80 (95% CI, 0.61-0.92, P < .001). The best threshold for ΔMAPRM was -17.3% (95% CI, -23.9 to -5.1; sensitivity, 75.0% [95% CI, 42.8-94.5]; specificity, 77.8% [95% CI, 52.4-93.6]). With the gray-zone approach, the inconclusive range of ΔSVRM for SV-responders was -40.1% to -13.8% including 13 (43%) patients, and that of ΔMAPRM was -23.9% to -5.1%, which included 16 (53%) patients. CONCLUSIONS: ΔSVRM and ΔMAPRM could predict hemodynamic responses after volume expansion during OLV.

Effect of Systemic Vascular Resistance on the Reliability of Noninvasive Hemodynamic Monitoring in Cardiac Surgery.

OBJECTIVE: To assess the effect of systemic vascular resistance (SVR) on the reliability of the ClearSight system (Edwards Lifesciences, Irvine, CA) for measuring blood pressure (BP) and cardiac output (CO). DESIGN: Observational study. SETTING: University hospital. PARTICIPANTS: Twenty-five patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BP, measured using ClearSight and an arterial line, and CO, measured using ClearSight and a pulmonary artery catheter, were recorded before (T1) and two minutes after phenylephrine or ephedrine administration. Bland-Altman analysis was used to compare BP and CO measurements at T1. A polar plot was used to assess trending abilities. Patients were divided into the following three groups according to the SVR index (SVRI) at T1: low (<1,200 dyne s/cm5/m2), normal (1,200-25,00 dyne s/cm5/m2), and high (>2,500 dyne s/cm5/m2). The bias in BP and CO was -4.8 ± 8.9 mmHg and 0.10 ± 0.81 L/min, respectively, which was correlated significantly with SVRI (p < 0.05). The percentage error in CO was 40.6%, which was lower in the normal SVRI group (33.3%) than the low and high groups (46.3% and 47.7%, respectively). The angular concordance rate was 96.3% and 95.4% for BP and 87.0% and 92.5% for CO after phenylephrine and ephedrine administration, respectively. There was a low tracking ability for CO changes after phenylephrine administration in the low-SVRI group (angular concordance rate 33.3%). CONCLUSION: The ClearSight system showed an acceptable accuracy in measuring BP and tracking BP changes in various SVR states; however, the accuracy of CO measurement and its trending ability in various SVR states was poor.

Baicalin inhibits root resorption during tooth movement in a rodent model.

OBJECTIVE: Baicalin mediates bone metabolism and has shown protective activity against periodontal tissue damage in a rat model of periodontitis. Therefore, we hypothesized that baicalin may inhibit the root resorption that occurs during orthodontic tooth movement and examined its effect on the histological changes in periodontal tissue that occur during tooth movement. METHODS: First molars of rats were subjected to traction using excessive orthodontic force to produce a root resorption model. Rats in the baicalin group received baicalin for 3 weeks during tooth movement, and the amount of first molar movement on day 21 after the initiation of traction was measured by three-dimensional micro-computed tomography analysis. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin-eosin and tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemical staining for the receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG). The severity of root resorption was also determined by histological analysis. RESULTS: There was no significant intergroup difference in tooth movement during the experimental exaggerated tooth movement. In comparison with the control group, the baicalin-treated group showed increased OPG expression, suppressed RANKL expression, and significantly fewer TRAP-positive cells in the first molars. The root resorption area was significantly smaller in the baicalin group. CONCLUSIONS: Treatment with baicalin prevented root resorption without preventing tooth movement. Baicalin may be useful for the management of root resorption during orthodontic treatment.

Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts.

Introduction: In recent years, laser irradiation in the near-infrared ray (NIR) area has been reported to promote bone healing. There are also reports that laser irradiation accelerates orthodontic tooth movement. In this study, we investigated the effect of NIR laser irradiation and mechanical stimulation on osteoblasts. Methods: We seeded osteoblast-like cells and laser irradiation was performed 24 hours after cell seeding. In addition, a control group not receiving anything, a group receiving only Nd: YAG (neodymium-doped yttrium aluminum garnet) laser irradiation, a group receiving only centrifugal loading, and a group receiving both Nd: YAG laser irradiation and centrifugal force loading were set, and after 24 hours and after 48 hours, cells were collected and quantitative real-time polymerase chain reaction (PCR) was performed. Results: 24 hours after laser irradiation, the gene expression of alkaline phosphatase (ALP), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) was significantly higher in the 2.0 W group than in the control group. In addition, the RANKL/OPG ratio was higher in the 2.0 W group than in the control group. Also, in the group using laser irradiation and centrifugal loading in combination, 24 hours after laser irradiation, ALP and OPG showed significantly higher values than those in the centrifugal load only group. Furthermore, the RANKL/OPG ratio also showed high values. Conclusion: These results suggest that osteoblast-like cells activate genes related to bone metabolism by combining mechanical stimulation and laser irradiation. This helps to elucidate the influence of laser irradiation during tooth movement.

Impact of deep breathing on predictability of stroke volume variation in spontaneous breathing patients.

BACKGROUND: This study investigated the ability of stroke volume variation (SVV) during deep breathing to discriminate fluid responders among spontaneously breathing patients. METHODS: Thirty patients undergoing general anaesthesia were enrolled and assessed before anaesthetic induction. Haemodynamic variables, including stroke volume (SV) and SVV, were measured using the ClearSight system during normal breathing. After these measurements, each patient was required to maintain deep breathing (6 breaths min-1 ) and haemodynamic variables were recorded. Then, the table was adjusted to the Trendelenburg position (15°) for 2 minutes, and haemodynamic variables were measured. Receiver operating characteristic curves were created for SVV during normal and deep breathing, and the difference in SVV between normal and deep breathing (ΔSVV) to discriminate fluid responders (SV increase >10% after changing position). The correlation between SV increase and ΔSVV was examined using Pearson's correlation coefficient. The grey zone approach was used to assess the inconclusive range of the haemodynamic variables. RESULTS: Receiver operating characteristic curve analysis indicated that ΔSVV showed good reliability in predicting fluid responsiveness (AUC: 0.850; 95% CI: 0.672-0.953; threshold: 4%, sensitivity: 75.0%, specificity: 88.9%], while SVV during normal breathing did not (AUC: 0.579; 95% CI: 0.386-0.756)]. Although SVV during deep breathing exhibited acceptable predictability (AUC: 0.778; 95% CI: 0.589-0.908), the sensitivity was not good (58.3%). With the grey zone approach, the inconclusive range of ΔSVV was small with the range of 1.4%-4.2% (23% of patients). CONCLUSION: Deep breathing could improve the reliability of dynamic indices in spontaneously breathing patients. TRIAL REGISTRATION: UMIN-CTR, identifer: UMIN000027970. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000032040.

Comparison of the venous-arterial CO2 to arterial-venous O2 content difference ratio with the venous-arterial CO2 gradient for the predictability of adverse outcomes after cardiac surgery.

This study aimed to compare the prognostic performance of the ratio of mixed and central venous-arterial CO2 tension difference to arterial-venous O2 content difference (Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2, respectively) with that of the mixed and central venous-to-arterial carbon dioxide gradient (Pv-aCO2 and Pcv-aCO2, respectively) for adverse events after cardiac surgery. One hundred and ten patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled. After catheter insertion, three blood samples were withdrawn simultaneously through arterial pressure, central venous, and pulmonary artery catheters, before and at the end of the operation, and preoperative and postoperative values were determined. The primary end-point was set as the incidence of postoperative major organ morbidity and mortality (MOMM). Receiver operating characteristic (ROC) curve and multivariate logistic regression analyses were performed to evaluate the prognostic reliability of Pv-aCO2, Pcv-aCO2, Pv-aCO2/Ca-vO2, and Pcv-aCO2/Ca-cvO2 for MOMM. MOMM events occurred in 25 patients (22.7%). ROC curve analysis revealed that both postoperative Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2 were significant predictors of MOMM. However, postoperative Pv-aCO2 was the best predictor of MOMM (area under the curve [AUC]: 0.804; 95% confidence interval [CI] 0.688-0.921), at a 5.1-mmHg cut-off, sensitivity was 76.0%, and specificity was 74.1%. Multivariate analysis revealed that postoperative Pv-aCO2 was an independent predictor of MOMM (odds ratio [OR]: 1.42, 95% CI 1.01-2.00, p = 0.046) and prolonged ICU stay (OR: 1.45, 95% CI 1.05-2.01, p = 0.024). Pv-aCO2 at the end of cardiac surgery was a better predictor of postoperative complications than Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2.

A case of esophageal perforation after intraoperative transesophageal echocardiography in a patient with a giant left atrium: unexpectedly large distortion of the esophagus revealed on retrospectively constructed three-dimensional imaging.

BACKGROUND: Esophageal perforation is a rare but serious complication of transesophageal echocardiography (TEE). An enlarged left atrium (LA), which is commonly associated with mitral stenosis (MS), is an under-recognized risk factor for esophageal perforation after intraoperative TEE. CASE PRESENTATION: We describe a case of TEE-induced esophageal perforation after cardiac surgery in a 79-year-old woman with a giant LA due to MS. Esophageal perforation was detected on postoperative day 6. After surgical repair, the patient gradually recovered with prolonged conservative treatment. Retrospectively constructed three-dimensional chest computed tomography images revealed an unusually distorted esophagus that was possibly vulnerable to injury. CONCLUSION: A giant LA can markedly distort the esophagus. It should be recognized as a risk factor for TEE-induced esophageal perforation.