Literature Review of Handheld Articulating Instruments in Minimally Invasive Surgery.

Background: Minimally invasive surgery (MIS) using handheld articulating instruments (HAIs) has emerged as an innovative approach, offering enhanced dexterity and accessibility compared with conventional straight tools. There has been a significant surge in market interest surrounding HAIs. However, the question about the potential benefits of these devices for surgeons and patients in clinical applications remains unclear. Methods: We thoroughly searched relevant literature about the HAIs with clinical applications. This article reviews the feasibility, safety, outcomes, ergonomics, and learning curve associated with utilizing HAIs, including notable commercial products FlexDex, ArtiSential, and HandX. This study also investigates the comparisons of the use of HAIs with traditional laparoscopy and the da Vinci robotic system in terms of surgical outcomes and operational efficiency. Results: Early clinical studies demonstrate the applicability of HAIs across gastrointestinal, urologic, cardiothoracic, and general surgery, with promising results and few complications reported. Comparisons with conventional laparoscopy reveal no significant differences in surgical outcomes. However, HAIs present a more prolonged learning curve than robotic surgery for novice users. Combining three-dimensional visualization techniques facilitate performance. Further research with larger sample sizes is warranted to establish definitive superiority in surgical efficiency and characterize optimal training methodology. Conclusions: Overall, the maneuverability and lower cost of HAIs present new possibilities in MIS, potentially expanding accessibility for smaller health care organizations and benefiting more patients.

In Situ Metal-Oxygen-Hydrogen Modified B-Tio2 @Co2 P-X S-Scheme Heterojunction Effectively Enhanced Charge Separation for Photo-assisted Uranium Reduction.

Photo-assisted uranium reduction from uranium mine wastewater is expected to overcome the competition between impurity ions and U(VI) in the traditional process. Here, B-TiO2 @Co2 P-X S-scheme heterojunction with metal-oxygen-hydrogen (M-O-H) is developed insitu modification for photo-assisted U(VI) (hexavalent uranium) reduction. Relying on the DFT calculation and Hard-Soft-Acid-Base (HSAB) theory, the introduction of metal-oxygen-hydrogen (M-O-H, hard base) metallic bonds in the B-TiO2 @Co2 P-X is found to enhance the hydrophilicity and the capture capability for uranyl ion (hard acid). Accordingly, B-TiO2 @Co2 P-500 hybrid nanosheets exhibit excellent U(VI) reduction ability (>98%) in the presence of competing ions. By self-consistent energy band calculations and in-situ KPFM spectral analysis, the formation of the internal electric field between B-TiO2 and Co2 P at the heterojunction is proven, offering a strong driving force and atomic transportation highway for accelerating the S-scheme charge carriers directed migration and promoting the photocatalytic reduction of uranium. This work provides a valuable route to explore the functionally modified photocatalyst with high-efficiency photoelectron separation for U(VI) reduction.

Failure analysis of local settlement induced Q345R bottom plate cracking of crude oil storage tank.

A 5000m3 single deck floating roof crude oil storage tank was found to have a cracked Q345R bottom plate during an open tank inspection. To analyze the cause of the failure, a series of experiments were carried out. The results showed that the chemical composition of the failed crude oil storage tank bottom plate material Q345R had a slight excess of S, V, and Ti which causes the material to form a bainite structure, resulting in a hard and brittle material with poor toughness. Q345R is susceptive to H2S stress corrosion cracking according to SCC test. Based on the working condition investigation, the cracked plate was subjected to the local settlement and H2S contained corrosive medium. With the stress concentration induced by local settlement, the bottom plate cracked. In order to avoid such incidents, Q345R material should be avoided in H2S containing environment, and online monitoring should be carried out regularly to assess the overall condition of the tanks.

Therapeutic Potential of Triptolide in Treating Bone-Related Disorders.

Triptolide, a diterpene triepoxide, is a pharmacologically active compound isolated from a Chinese medicinal herb Tripterygium wilfordii Hook F (TwHF). Triptolide has attracted considerable attention in recent times due to its multiple biological and pharmaceutical activities, with an emphasis on therapeutic importance in the treatment of diverse disorders. With essential medicinal implications, TwHF's extracts have been used as anti-inflammatory, antiproliferative, antioxidative, and immunosuppressive agents for centuries, with continuous and relevant modifications to date to enhance its utility in several diseases and pathophysiology. Here, in this review, we accentuate the studies, highlighting the effects of triptolide on treating bone-related disorders, both inflammatory and cancerous, particularly osteosarcoma, and their manifestations. Based on this review, future avenues could be estimated for potential research strategies, molecular mechanisms, and outcomes that might contribute toward reinforcing new dimensions in the clinical application of triptolide in treating bone-related disorders.

A Brief Talk on the Design of Biopharmaceutical Separation and Purification Technology Course.

Biological separation and purification technology is the basic technology of modern biotechnology, which is widely used in the pharmaceutical industry, especially the biopharmaceutical industry. In recent years, the biopharmaceutical industry has had a lot of room for development in the development of science and technology in South Korea, and the research on biopharmaceutical equipment and pharmaceutical technology has also achieved good research results. This article proposes a brief discussion on the design of biopharmaceutical separation and purification technology courses. In this study, by analyzing the synthesis potential of the secondary metabolites of the strain, using the α-glucosidase inhibition rate as an inspection indicator, the fermentation medium of the strain was optimized, and batch fermentation was carried out, and then, the metabolites were separated and purified, and the following conclusion was obtained: the α-glucosidase inhibition rate of the crude extract of the strain in the optimized fermentation medium is 35% higher than that of the initial medium.

Bronchial Artery Chemoembolization for Hemoptysis in Advanced Primary Lung Cancer.

BACKGROUND: To evaluate the safety and effectiveness of bronchial arterial infusion chemoembolization (BAICE) for lung cancer with hemoptysis. PATIENTS AND METHODS: Retrospectively analyze clinical data of patients undergoing BAICE for the treatment of lung cancer with hemoptysis, evaluate the clinical efficacy of this approach, observe postoperative adverse reactions, and analyze hemoptysis-free survival (HFS) and overall survival (OS). RESULTS: All 187 patients underwent BAICE with technical success rate of 100%, clinical success rate of 86.6%, clinical failure rate of 13.4%. After BAICE, the tumor curative effect was evaluated as complete remission in 56 cases, partial remission in 82 cases, stable disease in 26 cases, and progressive disease in 6 cases. The objective response rate was 73.8%, and the disease control rate was 87.7%. Median HFS of the 154 clinically successful cases was 10.5 months (95% confidence interval [CI]: 8.11-11.89). The degree of hemoptysis (massive hemoptysis hazard ratio [HR] = 5.9, 95% CI: 3.43-10.16, P = .00) and cavitary lung mass (HR = 2.39, 95% CI: 1.44-3.99, P = .001), were significantly related to a reduction in HFS after BAICE. The 6-month and 12-month survival rates were 66.5% and 45.6%, respectively. The median OS of clinically successful cases was 13.0 months (95% CI: 11.22-14.77). The median OS of 16 clinically failed cases was 2.0 months (95% CI: 0.41-2.45) (P < .001). All adverse events were grade 1. CONCLUSION: BAICE for advanced lung cancer with hemoptysis is safe, effective, and tolerable.

Exposing structural variations in SARS-CoV-2 evolution.

The mutation of SARS-CoV-2 influences viral function as residue replacements affect both physiochemical properties and folding conformations. Although a large amount of data on SARS-CoV-2 is available, the investigation of how viral functions change in response to mutations is hampered by a lack of effective structural analysis. Here, we exploit the advances of protein structure fingerprint technology to study the folding conformational changes induced by mutations. With integration of both protein sequences and folding conformations, the structures are aligned for SARS-CoV to SARS-CoV-2, including Alpha variant (lineage B.1.1.7) and Delta variant (lineage B.1.617.2). The results showed that the virus evolution with change in mutational positions and physicochemical properties increased the affinity between spike protein and ACE2, which plays a critical role in coronavirus entry into human cells. Additionally, these structural variations impact vaccine effectiveness and drug function over the course of SARS-CoV-2 evolution. The analysis of structural variations revealed how the coronavirus has gradually evolved in both structure and function and how the SARS-CoV-2 variants have contributed to more severe acute disease worldwide.

Sports Training Teaching Device Based on Big Data and Cloud Computing.

With the advent of the era of big data (BD), people have higher requirements for information, knowledge, and technology. Taking the Internet as the carrier, the use of cloud computing technology for distance education has become a trend. Our country's physical training teaching has also begun to change from traditional mode to modern mode. In order to improve the overall quality of our country's national sports, this paper studies the teaching device of sports training based on BD and cloud computing. This article mainly uses the questionnaire survey method, the experimental analysis method, the data analysis method, and the data statistics method to have an in-depth understanding of the research theme and uses swimming as an example to design the sports training device. 52% of people think that water in the ears and itching during swimming are more serious problems. After further understanding, an experimental design was carried out. Experimental studies have shown that the combination of BD and cloud computing can effectively solve the problems existing in the traditional teaching model, so as to achieve the goal of efficient and rapid development.

Exposing Structural Variations in SARS-CoV-2 Evolution.

The mutation of SARS-CoV-2 influences viral function as residue replacements affect both physiochemical properties and folding conformations. Although a large amount of data on SARS-CoV-2 is available, the investigation of how viral functions change in response to mutations is hampered by a lack of effective structural analysis. Here, we exploit advances in protein structure fingerprint technology to study the folding conformational changes induced by mutations. With the integration of both protein sequences and folding conformations and alignments of SARS-CoV to SARS-CoV-2, the UK variant and India variant, we found that structural variations in the spike protein at the binding interface interacting with ACE2 play a critical role in coronavirus entry into human cells. Additionally, the structural variations impact vaccine effectiveness and drug function over the course of SARS-CoV-2 evolution. The analysis of structural variations revealed how the coronavirus has gradually evolved in both structure and function and how the SARS-CoV-2 variants have contributed to more severe acute disease worldwide.

SH2B1 protects cardiomyocytes from ischemia/reperfusion injury via the activation of the PI3K/AKT pathway.

BACKGROUND: Apoptosis, reactive oxidative stress (ROS) and inflammation act as the pivotal pathogenesis of myocardial ischemia/reperfusion (I/R) injury (MIRI). Our prior study and other investigation have demonstrated the participations of src homology 2 (SH2) B adaptor protein 1 (SH2B1) in ischemic injury and cardiac hypertrophy; whereas, the involvements of SH2B1 in MIRI and underlying mechanisms are completely unknown. METHOD: In present study, MIRI model in vivo was induced by 30 min of ligation of LAD coronary artery and 24 h of reperfusion, and primary cultured cardiomyocytes were challenged with 2 h of hypoxia followed by 4 h of reoxygenation (H/R) to mimic MIRI in vitro. Adenovirus encoding for SH2B1 or GFP were pre-transfected into myocardium prior to MIRI both in vivo and in vitro. The myocardial damage, cardiac function, apoptosis, ROS and inflammation were evaluated systematically. Immunofluorescence staining and western blotting were alternatively performed to detect protein expression. RESULTS: The results exhibited that H/R or I/R significantly reduced SH2B1 in cardiomyocytes, followed by impaired cell survival and function, which were strongly reversed after the adenovirus-mediated SH2B1 up-regulation. Meanwhile, I/R- and H/R-elevated inflammation, apoptosis and ROS were also alleviated by SH2B1 up-regulation. A mechanistic study suggested that the protective contributions of SH2B1 on H/R-suffered cardiomyocytes were based on the activation of the PI3K/AKT pathway. The abolishment of the PI3K/AKT via a pharmacological inhibitor (LY294002) repressed anti-H/R capabilities of SH2B1. CONCLUSION: Therefore, SH2B1 prevents cardiomyocytes from inflammation, apoptosis and ROS in MIRI partially through the PI3K/AKT-dependent avenues. It may provide a novel therapeutic target for the treatment of MIRI.

Clinical validation of urine-based Xpert® MTB/RIF assay for the diagnosis of urogenital tuberculosis: A systematic review and meta-analysis.

OBJECTIVES: Effective methods for diagnosing urogenital tuberculosis (UGTB) are important for its clinical management. Therefore, we undertook a systematic review to assess the performance of the urine-based Xpert MTB/RIF assay for UGTB. METHODS: PubMed, Embase, Web of Science, the Cochrane library, and Scopus were systematically searched up to July 30, 2019. A hierarchical summary receiver operating characteristic (HSROC) was applied to calculate the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and odds ratio (OR) for the diagnostic accuracy of the Xpert test. RESULTS: Our search identified 858 unique articles from which 69 studies were selected for full-text revision, with 12 studies meeting the inclusion criteria. Eleven studies comprising 1202 samples compared Xpert with mycobacterial culture, while 924 samples from eight studies compared it with a composite reference standard (CRS). The values for pooled sensitivity, specificity, PLR, NLR, and OR were 0.89, 0.95, 20.1, 0.18, and 159.53, respectively, when compared with the mycobacterial culture. Likewise, when compared with a CRS, the respective pooled sensitivity, specificity, PLR, NLR, and OR values were 0.55, 0.99, 40.67, 0.43, and 166.17, thereby suggesting a high level of accuracy for diagnosing UGTB. A meta-regression and sub-group analysis of TB-burden countries, study design, decontamination, concentration, and reference standard could not explain the heterogeneity (p > 0.05) in the diagnostic efficiency. CONCLUSIONS: Our results suggested that Xpert is a promising diagnostic tool for the diagnosis of UGTB via urine specimen.

Inhibition of miR-9 decreases osteosarcoma cell proliferation.

Osteosarcoma (OS) is the most common primary bone tumor that affects adolescents and young adults. Disruption of microRNA (miRNA) regulation is well established in the pathophysiology of different cancers, including OS. Increased expression of miR-9 in OS positively correlates with the tumor size, clinical stage, and distant metastasis. In the present study, we used two different OS cell lines, MG-63 and Saos-2, as in vitro models. miR-9 inhibitor and miR-9 mimics were used to study the function of miR-9 in these two cell lines. We determined the effect of miR-9 inhibition on cell proliferation, cell cycle, apoptosis, and the protein expression of different genes. Our results demonstrated that miR-9 inhibition in the human OS cell lines suppresses their metastatic potential, as determined by decreased cell proliferation and cell cycle arrest, decreased invasion, and increased apoptosis. The Western blot analysis showed that E-cadherin, matrix metalloproteinase 13, forkhead box O3, Bcl-2-like protein 11, and ß-catenin are involved in miR-9 signaling. Moreover, miR-9 mimics rescued the effects caused by the inhibition of miR-9 in the OS cell lines. Our findings suggest that miR-9 is important for mediating OS cell migration, invasion, metastasis, and apoptosis. Inhibition of miR-9 could be further explored as a therapeutic target to treat OS.

Perioperative changes of inflammation-based biomarker for predicting the prognosis in colorectal cancer patients: a retrospective analysis.

INTRODUCTION: Perioperative inflammatory markers, including the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), are associated with oncological prognosis. However, their changes in colorectal cancer surgery for predicting the prognosis are rarely investigated. AIM: To compare perioperative changes to evaluate the prognostic significance of patients' survival. MATERIAL AND METHODS: Retrospective clinical data and baseline laboratory parameters of 183 colorectal cancer (CRC) patients who underwent curative surgery were collected between January 2007 and January 2013. The clinicopathological characteristics were compared. Statistical analysis was used to identify the predictive changes of perioperative NLR and PLR associated with survival prognosis. RESULTS: ROC analysis indicated that perioperative NLR/PLR showed higher predictive accuracy for prognosis, and the optimal cut-off values of pre-NLR, post-NLR, pre-PLR, and post-PLR were 2.94, 4.32, 184.29, and 212.37, respectively. Kaplan-Meier analysis suggested that the four groups stratified by perioperative changes had significantly different recurrence-free survival and overall survival (p < 0.05). Univariate and multivariable analysis revealed that patients with higher cancer stage, lymph node metastasis, and perioperative change of NLR/PLR (HH, LH) had significant association with poor prognosis of RFS and OS (all p < 0.05). CONCLUSIONS: Perioperative NLR and PLR might be good predictors for prognosis in CRC patients who have undergone curative surgery, which could guide the customised therapeutic strategy. Furthermore, their assessment could contribute to accurately predicting oncologic outcomes and provide an in-depth understanding of the patients, which could guide the operational strategy.

Prevalence of pulmonary tuberculosis in western China in 2010-11: a population-based, cross-sectional survey.

BACKGROUND: Progress in tuberculosis control in China has been the slowest in western areas, which have the highest prevalence. We assessed the prevalence of pulmonary tuberculosis in the Xinjiang province, China, 10 years after introduction of a control programme based on directly observed treatment, short course. METHODS: In this population-based, cross-sectional survey, we used a multistage stratified random cluster sample design to estimate the prevalence of smear-positive and bacteriologically confirmed (either smear positive or culture positive, or both) pulmonary tuberculosis among adults (aged ≥15 years) in Xinjiang who had been resident in their household for the last 6 months. The screening strategy and diagnosis followed WHO guidelines. We estimated prevalence by combining inverse probability weighting and multiple imputation of missing data. We compared our prevalence survey estimates with the ones from the 2010 China national pulmonary tuberculosis survey and the ones from a provincial pulmonary survey done in Xinjiang in 2000. The new smear-positive pulmonary tuberculosis notification rate in 2011 in Xinjiang was obtained to allow the calculation of patient diagnosis rate (PDR). FINDINGS: Between Sept 1, 2010, and July 31, 2011, 31 081 individuals were eligible, of whom 29 835 (96·0%) participated in the survey. We identified 50 (0·2%) smear-positive and 101 (0·3%) bacteriologically confirmed pulmonary tuberculosis cases. The weighted prevalence of smear-positive pulmonary tuberculosis was 170 (95% CI 103-233) per 100 000 people and of bacteriologically confirmed pulmonary tuberculosis was 430 (249-611) per 100 000 people. Compared with 2000 Xinjiang survey estimates, the prevalence of smear-positive pulmonary tuberculosis has decreased by 26·4% (from 231 [95% CI 148-314] per 100 000 people), whereas the prevalence of bacteriologically confirmed pulmonary tuberculosis has increased by 17·8% (from 365 [237-493] per 100 000 people). In each age group and sex, the pulmonary tuberculosis prevalence was higher in the 2010-11 Xinjiang survey than in the 2010 national survey. The PDR in 2011 was 0·34 (95% CI 0·25-0·44). INTERPRETATION: Despite progress in other parts of China, the prevalence of pulmonary tuberculosis in Xinjiang remains high. The very low PDR suggests poor access to diagnosis and care. Further studies are needed to understand the barriers to diagnosis and care of this population, and efforts are urgently needed to enhance tuberculosis screening in this area. FUNDING: Xinjiang Uyghur Autonomous Region Health Bureau.

The effect of the 5-HT7 serotonin receptor agonist, LP44, on micturition in rats with chronic spinal cord injury.

AIMS: To better understand the effects of the selective 5-HT7 receptor agonist 4-[2-(Methylthio)phenyl]-N-(1,2,3,4-tetrahydro-1-naphthalenyl)-1-piperazinehexanamide hydrochloride (LP44) on micturition in spinal cord injury (SCI) rats. METHODS: Female Sprague-Dawley rats weighing 200-275 g were used. SCI was produced in 8 of the 16 rats by transection at the T10 level; cystometric study occurred 8-12 weeks post-transection. Intravesical pressure was monitored in urethane-anesthetized animals via a transvesical catheter. The selective 5-HT7 antagonist (R)-3-[2-[2-(4-Methylpiperidin-1-yl)ethyl]pyrrolidine-1-sulfonyl] phenol hydrochloride (SB-269970) was administered after each LP44 dose-response curve (all drugs were administered intravenously, i.v). RESULTS: Compared to controls, SCI rats had a higher bladder capacity and residual volume, and a lower voiding efficiency. In SCI rats, LP44 (0.003-0.3 mg/kg, i.v) induced significant dose-dependent increases in micturition volume, significant dose-dependent decreases in residual volume, resulting in significant increases in voiding efficiency. CMG measurements showed a dose-dependent increase of the high-frequency oscillation (HFO) activity, including the number of small oscillation per voiding. This was correlated with the improved voiding efficiency. SB-269970 (0.1 mg/kg, i.v) partially or completely reversed all LP44-induced changes. CONCLUSIONS: HFOs seems to be correlated with external urethral sphincter (EUS) bursting activity during voiding. Both the bladder voiding efficiency and the periodic EUS activity were decreased in SCI rats. 5-HT7 receptor agonist can enhance HFO activity, thereby improving voiding efficiency. Whether or not these results may have implications for the future treatment of voiding dysfunction in SCI patients remains to be studied.

Brief communication: comparison the diagnostic performance of four HBsAg ELISA kits.

BACKGROUND: Comparison of diagnostic efficiency of four ELISA kits for determining HBsAg. METHODS: Collecting 348 serum samples from clinical laboratory of Renmin Hospital of Wuhan University without specific gender and age requirements, determining HBsAg by the four ELISA kits, simultaneously. Confirmatory test was carried out when the initial results are positive. RESULTS: 329 out of 348 samples results were consistent (94.5%), 152 out of 329 were positive, and 177 out of 329 were negative, and all the positive results can be confirmed; 19 samples were not consistent (5.5%), and only 1 sample was confirmed by the confirmatory test. After calculation, the diagnostic efficiencies of the four ELISA kits (Beijing Wantai, Xiamen Xinchuang, Zhuhai Lizhu, and Shanghai Kehua) were 98.6%, 98.0%, 99.7%, and 97.4%, respectively, the sensitivities were 100%, 99.4%, 99.4%, and 100%, respectively, the specificities were 97.5%, 96.9%, 100%, and 95.4%, respectively, the false positive rates were 2.5%, 3.1%, 0, and 4.6%, respectively, and the false negative rates were 0, 0.6%, 0.6%, and 0, respectively. All the initial absorbencies of the false positive samples were less than 1.0. CONCLUSION: The diagnostic efficiency of Lizhu is the highest, while Kehua is the lowest. False positive or false negative results would take place in any of the kits, an HBsAg confirmatory test is essential for initially positive samples, especially with absorbance <1.0, because it can exclude most false positives.

The effects of craniocerebral and extracranial trauma on the changes in serum testosterone and estradiol in the early stage and their clinical significance.

BACKGROUND: This study aimed to examine the correlation between the alterations in serum sex hormones testosterone (T) and estradiol (E2) in the early stages after craniocerebral and extracranial injuries, to assess the Injury Severity Score (ISS) and Glasgow Coma Scale (GCS) score in patients with multiple injuries, and to investigate the significance of the posttrauma changes in ISS and GCS as well as their ratio. METHODS: The serum levels of T and E(2) in 95 patients with multiple injuries in the early stages after trauma (within 24 hours) were determined by radioimmune double-antibody method. All the patients were classified by ISS, and among them, those complicated with craniocerebral injury were classified by GCS. The serum sex hormone levels and their ratio in the patients with trauma were compared with those in the control group consisting of 15 healthy persons. RESULTS: In patients with multiple injuries, in the early stage after injury, the serum T level decreased in proportion with the severity of the trauma, whereas the E2 level increased. There was a significant difference in T, E(2), and the ratio of E(2) and T in the severely traumatic group (ISS > 25) as compared with the other groups (p < 0.01). Among the groups complicated with craniocerebral injury that were classified by GCS, there were significant differences in the groups of 5 ≥ GCS ≥ 3 and 8 ≥ GCS > 5, compared with the control group (p < 0.01). CONCLUSION: The alterations in the serum sex hormones T and E2 levels and their ratio is correlated with the severity of trauma and craniocerebral injury and, thus probably, could serve as an indicator for the evaluation of the trauma severity and possibly in prognosis. LEVEL OF EVIDENCE: Prognostic study, level III.

Electrophysiologic characteristics of the Crista terminalis and implications on atrial tachycardia in rabbits.

The objective of this study was to evaluate the electrophysiologic characteristics of Crista terminalis (CT) and their implication in the pathogenesis of atrial tachycardia in rabbits. For this purpose, 27 New Zealand rabbits were used. Using standard glass microelectrode technique, cellular action potentials (APs) of CT and pectinate muscle (PM) were recorded in normal Tyrode's perfusion and Tyrode's perfusion with 4 µM isoproterenol. Longitudinal conduction velocity (V(L)) and transverse conduction velocity (V(T)) of CT were measured. As our data show, CT tissue had a trend of spontaneous phase IV depolarization. Conduction anisotropy (V(L)/V(T)) of CT was 4.53 ± 0.91. The duration of the AP of CT was longer than that of PM cells. APD(20) and APD(90) for CT were 28.1 ± 3.5 and 145.3 ± 7.1 ms; and for PM cells were 21.8 ± 4.1 and 125.3 ± 6.3 ms, respectively (all P values < 0.01). The early and delayed action depolarizations were recorded after isoproterenol perfusion. A fast paroxysmal irregular rhythm was recorded which could be arrested by 0.1 mmol/l Isoptin. It was, therefore, concluded that the latent autorhythmicity, trigger activity, and conduction properties of CT might provide the electrophysiologic basis for the occurrence and sustenance of atrial arrhythmia.

Digitalis does not improve left atrial mechanical dysfunction after successful electrical cardioversion of chronic atrial fibrillation.

This study was designed to investigate whether administration of digitalis could improve mechanical function of left atrial appendage (LAA) and left atrium prospectively in patients with atrial stunning. Fifty-four consecutive patients in whom atrial stunning was observed immediately after cardioversion of chronic atrial fibrillation (AF) were randomized into digitalis or control group for 1 week following cardioversion. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed prior to, immediately following, 1 day after and 1 week after cardioversion to measure transmitral flow velocity and LAA flow velocity. Electrical cardioversion of AF elicited significantly slower left atrial appendage peak emptying velocity (LAA-PEV) and peak filling velocity (LAA-PFV) immediately following cardioversion in both groups. 1 day post cardioversion, there were no significant differences in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or left atrial appendage ejection fraction (LAA-EF) between digitalis and control groups. 1 week post cardioversion, no significant differences were found in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or LAA-EF between the two groups. The occurrence rates of spontaneous echo contrast were not significantly different between digitalis and control groups one day and one week post cardioversion. In conclusion, digitalis did not improve left atrial and appendage mechanical dysfunction following cardioversion of chronic AF. Digitalis did not prevent the development of spontaneous echo contrast in left atrial chamber and appendage. This may be due to the fact that digitalis aggravates intracellular calcium overload induced by chronic AF and has a negative effect on ventricular rate.

Surface modification of a biodegradable composite by UV laser ablation: in vitro biological performance.

Melt blends of chitosan and biodegradable aliphatic polyester have been physically and biologically studied, presenting great potential for biomedical applications. Structurally, poly(butylene succinate)-chitosan (PBS/Cht) composite scaffolds are covered by a thin PBS layer, preventing the desired interaction of cells/tissues with the chitosan particules. In the present work, a selective and controlled ablation of this skin layer was induced by UV laser processing. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) data demonstrated an increment of chitosan components and others resulting from the laser ablation process. The biological activity (i.e. cell viability and proliferation) on the inner regions of the composite scaffolds is not significantly different from those of the external layer, despite the observed differences in surface roughness (determined by interferometric optical profilometry) and wettability (water contact angle). However, the morphology of human osteoblastic cells was found to be considerably different in the case of laser-processed samples, since the cells tend to aggregate in multilayer columnar structures, preferring the PBS surface and avoiding the chitosan-rich areas. Thus, UV laser ablation can be considered a model technique for the physical surface modification of biomaterials without detrimental effects on cellular activity.