The impact of perioperative ketamine or esketamine on the subjective quality of recovery after surgery: a meta-analysis of randomised controlled trials

BACKGROUND

This meta-analysis aimed to evaluate the impact of ketamine/esketamine on postoperative subjective quality of recovery (QoR).

METHODS

MEDLINE, Embase, Cochrane library, and Google Scholar were searched for randomised controlled trials (RCTs) that examined the impacts of perioperative ketamine/esketamine use and postoperative QoR. The primary outcome was subjective QoR (QoR-9, QoR-15, QoR-40) on postoperative day (POD) 1-3, whereas the secondary outcomes included pain severity, anxiety scores, depression scores, risk of adverse events (i.e. nausea, vomiting, dizziness, drowsiness), and length of stay.

RESULTS

The analysis included 18 RCTs (1554 participants; ketamine: seven trials, esketamine: 11 trials), of which 15 were conducted in China. Ketamine/esketamine improved the QoR scores on PODs 1 and 2 compared with the control (standardised mean difference [SMD]: 0.63, P<0.0001 for POD 1; SMD: 0.56, P=0.04 for POD 2), without beneficial effect on POD 3. Subgroup analyses revealed significant differences in QoR scores on POD 1 by regimen (SMD: esketamine 1.14, ketamine 0.01) and country (SMD: China 0.82, other countries -0.21). The emotional domain of QoR was improved from PODs 1 to 3, whereas the other domains were only improved on POD 1. Lower postoperative anxiety (SMD: -0.48, P=0.003) and depression (SMD: -0.72, P=0.001) scores were also observed with ketamine/esketamine use. Furthermore, pain severity was reduced on PODs 1 and 2, with no difference in the risk of adverse events or length of stay.

CONCLUSIONS

This meta-analysis demonstrated that ketamine/esketamine use in the perioperative period is associated with improved early subjective QoR, pain severity, and psychological symptoms without an increase in the likelihood of adverse events.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023477580).

Impact of the geriatric nutritional risk index on long-term outcomes in patients undergoing hemodialysis: a meta-analysis of observational studies

Background

This meta-analysis aimed to synthesize current evidence on the association between the Geriatric Nutritional Risk Index (GNRI) and long-term outcomes in patients undergoing hemodialysis.

Methods

Electronic databases were systematically searched for relevant studies that investigated the association between GNRI and long-term outcomes in hemodialysis patients until November 2023. The primary outcome was the association between the GNRI (i.e., low versus high) and overall mortality risk, while the secondary outcome was the relationship between the GNRI and cardiovascular mortality risk.

Results

Thirty cohort studies involving 55,864 patients were included. A low GNRI was found to be significantly associated with increased overall mortality (hazard ratio [HR]: 2.42, 95% confidence interval [CIs]: 2.10-2.79, p < 0.00001, I2 = 65%). Each unit increase in GNRI corresponded to a 5% reduction in mortality risk (HR: 0.95, 95% CI: 0.93-0.96, p < 0.00001, I2 = 79%). The association remained consistent across Asian (HR = 2.45, 95% CI: 2.08-2.88, p < 0.00001, I2 = 70%) and non-Asian subgroups (HR = 2.3, 95% CI: 1.72-3.06, p < 0.00001, I2 = 23%). Meta-regression analysis of patient age (coefficient: -0.002; p = 0.896), male proportion (coefficient: 0.002; p = 0.875), percentage of diabetes mellitus (coefficient: -0.003; p = 0.605), and follow-up duration (coefficient: -0.003; p = 0.431) revealed that these moderator variables did not significantly influence the association between GNRI and overall mortality risk. Cardiovascular mortality risk also increased with low GNRI (HR, 1.93; 95%CI: 1.51-2.45, p < 0.00001; I2 = 2%). Similarly, an inverse association was observed between the GNRI values and cardiovascular mortality risk (HR, 0.94; 95% CI: 0.91-0.97; p < 0.0001; I2 = 65%) (per unit increase).

Conclusion

The GNRI is a simple nutritional screening tool that can be used to effectively stratify patients undergoing hemodialysis globally. Further studies are warranted to determine whether nutrition optimization based on the GNRI improves long-term outcomes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, CRD42023483729.

Virtual Dental Articulation Using Computed Tomography Data and Motion Tracking

Dental articulation holds crucial and fundamental importance in the design of dental restorations and analysis of prosthetic or orthodontic occlusions. However, common traditional and digital articulators are difficult and cumbersome in use to effectively translate the dental cast model to the articulator workspace when using traditional facebows. In this study, we have developed a personalized virtual dental articulator that directly utilizes computed tomography (CT) data to mathematically model the complex jaw movement, providing a more efficient and accurate way of analyzing and designing dental restorations. By utilizing CT data, Frankfurt's horizontal plane was established for the mathematical modeling of virtual articulation, eliminating tedious facebow transfers. After capturing the patients' CT images and tracking their jaw movements prior to dental treatment, the jaw-tracking information was incorporated into the articulation mathematical model. The validation and analysis of the personalized articulation approach were conducted by comparing the jaw movement between simulation data (virtual articulator) and real measurement data. As a result, the proposed virtual articulator achieves two important functions. Firstly, it replaces the traditional facebow transfer process by transferring the digital dental model to the virtual articulator through the anatomical relationship derived from the cranial CT data. Secondly, the jaw movement trajectory provided by optical tracking was incorporated into the mathematical articulation model to create a personalized virtual articulation with a small Fréchet distance of 1.7 mm. This virtual articulator provides a valuable tool that enables dentists to obtain diagnostic information about the temporomandibular joint (TMJ) and configure personalized settings of occlusal analysis for patients.

Lidocaine induces epithelial‑mesenchymal transition and aggravates cancer behaviors in non‑small cell lung cancer A549 cells

The effects of clinically relevant concentrations of lidocaine on epithelial-mesenchymal transition (EMT) and associated lung cancer behaviors have rarely been investigated. The aim of the present study was to assess the impact of lidocaine on EMT and its related phenomena, including chemoresistance. Lung cancer cell lines (A549 and LLC.LG) were incubated with various concentrations of lidocaine, 5-fluorouracil (5-FU) or both to test their effects on cell viability. Subsequently, the effects of lidocaine on various cell behaviors were assessed in vitro and in vivo using Transwell migration, colony-formation and anoikis-resistant cell aggregation assays, and human tumor cell metastasis in a chorioallantoic membrane (CAM) model quantitated by PCR analysis. Prototypical EMT markers and their molecular switch were analyzed using western blotting. In addition, a conditioned metastasis pathway was generated through Ingenuity Pathway Analysis. Based on these measured proteins (slug, vimentin and E-cadherin), the molecules involved and the alteration of genes associated with metastasis were predicted. Of note, clinically relevant concentrations of lidocaine did not affect lung cancer cell viability or alter the effects of 5-FU on cell survival; however, at this dose range, lidocaine attenuated the 5-FU-induced inhibitory effect on cell migration and promoted EMT. The expression levels of vimentin and Slug were upregulated, whereas the expression of E-cadherin was downregulated. EMT-associated anoikis resistance was also induced by lidocaine administration. In addition, portions of the lower CAM with a dense distribution of blood vessels exhibited markedly increased Alu expression 24 h following the inoculation of lidocaine-treated A549 cells on the upper CAM. Thus, at clinically relevant concentrations, lidocaine has the potential to aggravate cancer behaviors in non-small cell lung cancer cells. The phenomena accompanying lidocaine-aggravated migration and metastasis included altered prototypical EMT markers, anoikis-resistant cell aggregation and attenuation of the 5-FU-induced inhibitory effect on cell migration.

Association of a low vitamin D status with risk of post-stroke depression: A meta-analysis and systematic review

Background

Although post-stroke depression (PSD) affects one-third of patients following an acute stroke, pooled evidence addressing the correlation between a low vitamin D status and the risk of PSD remains inconclusive.

Methods

Comprehensive database search of Medline, EMBASE, Cochrane library, and Google Scholar was performed from inception to December 2022. The primary outcome was the association of PSD risk with a low vitamin D status, while the secondary outcomes included the relationship between PSD and other risk factors.

Results

Analysis of seven observational studies published between 2014 and 2022 with 1,580 patients showed pooled incidences of vitamin D deficiency (defined as 25[OH] D levels < 50 nmol/L) and PSD of 60.1 and 26.1%, respectively. Patients with PSD had a lower circulating vitamin D concentration compared to those without [mean difference (MD) =-13.94 nmol/L, 95% CI: -21.83 to -6.05, p = 0.0005, I ² = 91%, six studies, 1,414 patients]. Meta-analysis also demonstrated a correlation between a low vitamin D level and an increased PSD risk [odd ratio (OR) = 3.25, 95% CI: 1.57-6.69, p = 0.001, I ² = 78.7%, 1,108 patients], the heterogeneity of which was found to be associated with the incidence of vitamin D deficiency but not female proportion on meta-regression. Besides, female gender (OR = 1.78, 95% CI: 1.3-2.44, p = 0.003, I ² = 31%, five studies, 1,220 patients), hyperlipidemia (OR = 1.55, 95% CI: 1.01-2.36, p = 0.04, I ² = 0%, four studies, 976 patients), and high National Institutes of Health Stroke Scale (NIHSS) scores (MD = 1.45, 95% CI: 0.58-2.32, p = 0.001, I ² = 82%, five studies, 1,220 patients) were potential risk factors for PSD. For the primary outcome, the certainty of evidence was very low. Regarding secondary outcomes, the certainty of evidence was low for BMI, female gender, hypertension, diabetes, and stroke history, and very low for age, level of education, hyperlipidemia, cardiovascular disease, and NIHSS scores.

Conclusion

The results suggested an association of a low circulating vitamin D level with an increased risk of PSD. Besides, female gender, hyperlipidemia, high NIHSS score were related to an increased risk or occurrence of PSD. The current study may imply the necessity of routine circulating vitamin D screening in this population.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022381580.

Usefulness of Analgesia Nociception Index for guiding intraoperative opioid administration: a systematic review and meta-analysis

INTRODUCTION

This study primarily aimed at investigating the efficacy of Analgesia Nociception Index (ANI) for guiding intraoperative opioid administration in patients receiving surgery under general anesthesia.

EVIDENCE ACQUISITION

The Medline, Embase, Google scholar, and the Cochrane Library databases were searched from inception to April 2022 for randomized controlled trials. The primary outcome was intraoperative opioid administration, while the secondary outcomes included postoperative opioid consumption, pain score, emergency time, risk of nausea/vomiting (PONV), and Postanesthesia Care Unit (PACU) stay.

EVIDENCE SYNTHESIS

Six studies including 399 participants (published from 2015 to 2022) focused on non-cardiac surgery, including spine surgery (two trials), breast surgery (two trials), gynecologic surgery (one trial), and laparoscopic cholecystectomy (one trial) were included. Meta-analysis revealed no difference in intraoperative opioid administration with the use of ANI-guided analgesia compared to the control group that used conventional clinical measurements (e.g., heart rate) to guide opioid use [standardized mean difference (SMD)=-0.17, 95% CI: -0.56 to 0.22, P=0.39, I²=72%, six trials, 399 participants]. Gender-based subgroup analysis showed effectiveness of ANI for reducing opioid administration in female patients (SMD=-0.53, P=0.02). There were no differences in postoperative recovery characteristics including pain score [Mean difference (MD): -0.03, P=0.79], opioid consumption (SMD: -0.34, P=0.08), emergence time (MD=1.12, P=0.47), length of stay in the PACU (MD: -0.56, P=0.83), and risk of PONV [risk ratio(RR): 0.75, P=0.46] between the two groups.

CONCLUSIONS

Analgesia nociception index-guided analgesia was unable to reduce intraoperative opioid administration compared to monitoring using conventional clinical parameters. Further studies are required to support our findings.

Efficacy of greater occipital nerve block for pain relief in patients with postdural puncture headache: A meta-analysis

BACKGROUND

This study aimed at assessing the therapeutic effectiveness of greater occipital nerve block (GONB) against postdural puncture headache (PDPH).

METHODS

Studies investigating analgesic effects of GONB against PDPH in adults were retrieved from the MEDLINE, EMBASE, Google scholar, and Cochrane central databases from their inception dates to May, 2021. Pain score at postprocedural 24 hours was the primary endpoint, while secondary endpoints were pain score at postprocedural 1 hour and 12 hours as well as the risk of intervention failure.

RESULTS

Of the 7 studies (randomized controlled trials [RCTs], n = 4; non-RCTs, n = 3) that recruited 275 patients, 2 investigated female patients undergoing cesarean section and the other 5 were conducted in both obstetric and nonobstetric settings. Pooled results showed a lower mean pain score at 24 hours (i.e., primary outcome) (mean difference [MD] = -2.66, 95%: CI: -3.98 to -1.33, P < .001; I2 = 97%, 6 studies), 1 hour (MD = -4.23, 95% confidence interval [CI]: -5.08 to -3.37, P < .00001; I2 = 86%, 5 studies), and 6 hours (MD = -2.78, 95% CI: -4.99 to -0.57, P = .01; I2 = 98%, 4 studies) in patients with GONB compared to those without. Trial sequential analysis supported the robustness of evidence at postprocedural 24 hours. The use of GONB also decreased the risk of intervention failure (relative ratio [RR] = 0.4, 95% CI: 0.19 to 0.82, P = .01; I2 = 96%, 6 studies, 277 patients).

CONCLUSION

Our results suggested a therapeutic effect of greater occipital nerve block against postdural puncture headache up to postprocedural 24 hours. Further large-scale studies are warranted to evaluate its therapeutic benefit beyond the acute stage.

Intercostal Nerve Block Using an Innovative Intraneedle Ultrasound Transducer: A Proof-of-Concept study

Intercostal nerve block is a widely used and effective approach to providing regional anesthesia in the thoracic region for pain relief. However, during ultrasound-guided intercostal nerve block, inaccurate identification of the anatomic structures or suboptimal positioning of the needle tip may result in complications and blockade failure. In this study, we designed an intraneedle ultrasound (INUS) system and validated its efficacy in identifying anatomic structures relevant to thoracic region anesthesia. The 20-MHz INUS transducer comprised a single lead magnesium niobate-lead titanate crystal, and gain was set to 20 dB. It fit into a regular 18G needle and emitted radiofrequency-mode ultrasound signals at 1 mm from the needle tip. One hundred intercostal punctures were performed in 10 piglets. Intercostal spaces were identified by surface ultrasound or palpation and located by inserting and advancing the INUS transducer needle until the appropriate anatomy was identified. Blockade success was defined by ideal saline and dye spreading and confirmed by dissection. The pleura had a distinctive ultrasound signal, and successful detection of the intercostal muscles, endothoracic fascia and double-layered parietal and visceral pleura was achieved in all 100 puncture attempts. INUS allows real-time identification of intercostal structures and facilitates successful intercostal nerve blocks.

The Use of Propofol versus Dexmedetomidine for Patients Receiving Drug-Induced Sleep Endoscopy: A Meta-Analysis of Randomized Controlled Trials

The sedation outcomes associated with dexmedetomidine compared with those of propofol during drug-induced sleep endoscopy (DISE) remains unclear. Electronic databases (i.e., the Cochrane controlled trials register, Embase, Medline, and Scopus) were searched from inception to 25 December 2020 for randomized controlled trials (RCTs) that evaluated the sedation outcomes with dexmedetomidine or propofol in adult patients diagnosed with obstructive sleep apnea (OSA) receiving DISE. The primary outcome was the difference in minimum oxygen saturation (mSaO2). Five RCTs (270 participants) published between 2015 and 2020 were included for analysis. Compared with dexmedetomidine, propofol was associated with lower levels of mSaO2 (mean difference (MD) = -7.24, 95% confidence interval (CI) -12.04 to -2.44; 230 participants) and satisfaction among endoscopic performers (standardized MD = -2.43, 95% CI -3.61 to -1.26; 128 participants) as well as a higher risk of hypoxemia (relative ratios = 1.82, 95% CI 1.2 to 2.76; 82 participants). However, propofol provided a shorter time to fall asleep and a lower risk of failed sedation compared with dexmedetomidine. No significant difference was found in other outcomes. Compared with propofol, dexmedetomidine exhibited fewer adverse effects on respiratory function and provided a higher level of satisfaction among endoscopic performers but was associated with an elevated risk of failed sedation.

Fire safety study on high-flow nasal oxygen in shared-airway surgeries with diathermy and laser: simulation based on a physical model

High-flow nasal oxygen (HFNO) has been used in "tubeless" shared-airway surgeries but whether HFNO increased the fire hazard is yet to be examined. We used a physical model for simulation to explore fire safety through a series of ignition trials. An HFNO device was attached to a 3D-printed nose with nostrils connected to a degutted raw chicken. The HFNO device was set at twenty combinations of different oxygen concentration and gas flow rate. An electrocautery and diode laser were applied separately to a fat cube in the cavity of the chicken. Ten 30 s trials of continuous energy source application were conducted. An additional trial of continuous energy application was conducted if no ignition was observed for all the ten trials. A total of eight short flashes were observed in one hundred electrocautery tests; however, no continuous fire was observed among them. There were thirty-six events of ignition in one hundred trials with laser, twelve of which turned into violent self-sustained fires. The factors found to be related to a significantly increased chance of ignition included laser application, lower gas flow, and higher FiO₂. The native tissue and smoke can ignite and turn into violent self-sustained fires under HFNO and continuous laser strikes, even in the absence of combustible materials. The results suggest that airway surgeries must be performed safely with HFNO if only a short intermittent laser is used in low FiO₂.

Modeling of digital dental articulator and its accuracy verification using optical measurement

BACKGROUND AND OBJECTIVES

Temporomandibular joint has been considered one of the most complex joints in human body. Dental articulation hinged upon temporomandibular joint is essential and fundamentally important for dental restoration design and prosthetic/orthodontic occlusion analysis. As digital dentistry rapidly grows, a complete digital work flow requires the use of a digital articulator for occlusion analysis. However, commercial CAD/CAM systems do not provide any method to verify the modeling accuracy of a digital articulator. There is also a lack of detail and generalized mathematical modeling of the digital articulator for simulating the jaw movement.

METHODS

This paper presents the development of a digital articulator by mathematically modeling a general dental articulator which simulates the relative jaw motion between the maxilla and mandible. As the digital articulator moves, the digital upper teeth move relatively to the digital lower teeth, thus simulating the occlusal path with teeth collision detection function. To verify the accuracy of our modeled digital articulator, an improved optical tracking method is proposed to measure the pose of a mechanical articulator with 6 degrees of freedom and compare that with the digital articulator.

RESULTS

The digital articulator system proposed in this paper achieves the following functions: 1. Digitalize the dental articulator with verified precision. Combined with dental design software, restorations can be designed with more efficiency and accuracy. 2. Provide an improved optical tracking method which can compare the movement error between the mechanical articulator and digital articulator. Thus the accuracy of the digital articulation can be verified. The result shows the error of our system is controlled under sub-millimeter which provides sufficient accuracy for the design of restoration under static and dynamic occlusion conditions.

CONCLUSIONS

We develop a general digital articulator which can simulate jaw movement between opposing teeth and an improved optical tracking method to verify the accuracy of the digital articulator. The modeling and accuracy verification of the digital articulator shows that there is a systematic and reliable way to replace traditional mechanical articulator and can close the gap for digital restoration fabrication.

Myasthenic crisis and late deep vein thrombosis following thymectomy in a patient with myasthenia gravis: A case report

INTRODUCTION

Surgical stress and pain are potential provoking factors for postoperative myasthenic crisis (POMC). We report the occurrence of early POMC and late deep vein thrombosis (DVT) in a man with myasthenia gravis (MG) undergoing thymectomy, addressing possible link between reversal of opioid overdose with naloxone and the triggering of POMC.

PATIENT CONCERNS

A 71-year-old man with impaired renal function (ie, estimated glomerular filtration rate [egfr]: 49.1 mL/min/1.73 m) with diagnosis of MG made 2 months ago was scheduled for thymectomy. After uncomplicated surgery, he experienced opioid overdose that was treated with naloxone. Hyperlactatemia then developed with a concomitant episode of hypertension. Three hours after reversal, he suffered from myasthenic crisis presenting with respiratory failure and difficult weaning from mechanical ventilation.

DIAGNOSIS

Stress-induced hyperlactatemia and subsequent myasthenic crisis INTERVENTIONS:: Pyridostigmine and immunosuppressive therapy with prednisolone were initiated. Hyperlactatemia subsided on postoperative day (POD) 5. Tracheal extubation was performed successfully on POD 6.

OUTCOMES

During the course of hospitalization, his eGFR (ie, 88.9 mL/min/1.73 m) was found to improve postoperatively. After discharge from hospital, he developed DVT in the left femoral and popliteal veins on POD 24 when he was readmitted for immediate treatment with low-molecular-weight heparin. He was discharged without sequelae on POD 31. There was no recurrence of myasthenic crisis or DVT at 3-month follow-up.

CONCLUSIONS

Following naloxone administration, hyperlactatemia may be an indicator of pain-related stress response, which is a potential provoking factor for myasthenic crisis. Additionally, patients with MG may have an increased risk of DVT possibly attributable to immune-mediated inflammation. These findings highlight the importance of perioperative avoidance of provoking factors including monitoring of stress-induced elevations in serum lactate concentration, close postoperative surveying for myasthenic crisis, and early recognition of possible thromboembolic complications in this patient population.

Optimized Spiral Metal-Gallium-Nitride Nanowire Cavity for Ultra-High Circular Dichroism Ultraviolet Lasing at Room Temperature

Circularly polarized laser sources with small footprints and high efficiencies can possess advanced functionalities in optical communication and biophotonic integrated systems. However, the conventional lasers with additional circular-polarization converters are bulky and hardly compatible with nanophotonic circuits, and most active chiral plasmonic nanostructures nowadays exhibit broadband emission and low circular dichroism. In this work, with spirals of gallium nitride (GaN) nanowires (NWRs) covered by a metal layer, we demonstrated an ultrasmall semiconductor laser capable of emitting circularly-polarized photons. The left- and right-hand spiral metal nanowire cavities with varied periods were designed at ultraviolet wavelengths to achieve the high quality factor circular dichroism metastructures. The dissymmetry factors characterizing the degrees of circular polarizations of the left- and right-hand chiral lasers were 1.4 and −1.6 (±2 if perfectly circular polarized), respectively. The results show that the chiral cavities with only 5 spiral periods can achieve lasing signals with the high degrees of circular polarizations.

Comparison of proficiency in an anesthesiology course across distinct medical student cohorts: psychometric approaches to test equating

BACKGROUND

Examinations are necessary for assessment of student proficiency in medical education, but comparison of achievement across different cohorts in different tests is challenging. We applied psychometric test equating methods to compare student proficiency in two different examinations for a clinical anesthesiology course.

METHODS

Each examination contained 50 multiple choice items and nine common items were identified from the two examinations (administered in 2011 and 2012). The common item design was used for test equating. Two psychometric test-equating approaches, chained linear equating and item response theory, were used to compare student proficiency in anesthesiology across distinct medical student cohorts. Raw scores from the 2012 test were linearly transformed to the 2011 scale using the chained method, and then Rasch analysis was applied to calibrate examinee ability and item difficulty in the two examinations on a common scale.

RESULTS

Both the linear equating method and Rasch analysis indicated that students in the 2011 examination performed better than those who took the 2012 examination (both p < 0.001). Rasch analysis revealed that the range of student ability was between -0.53 and 4.16, while the difficulty of all items ranged from -5.25 to 6.32. No significant difference in mean item difficulty was noted among the common items and other items in the two examinations.

CONCLUSION

Although both the chained linear equating method and Rasch analysis can be readily applied to practical test-equating issues in medical education, Rasch analysis exhibited more versatility in test parameter estimation and item bank development for clinical curriculums.

Successful removal of a potentially lethal left atrial thrombus detected by transesophageal echocardiography following the removal of a left ventricular assist device inflow cannula

The left ventricular assist device (LVAD) is a battery-operated, mechanical pump-type device that helps in maintaining the pumping ability of a failing heart. Thromboembolism poses a significant risk during and after LVAD implantation. It occurs in up to 35% of patients with adverse sequelae. We present the case of a 75-year-old man who underwent coronary artery bypass graft surgery and LVAD implantation for acute myocardial ischemia and severe left ventricular dysfunction. However, subsequent transthoracic echocardiographic examination revealed an LVAD thrombus, and LVAD removal was suggested following the failure of thrombolytic therapy. After the LVAD cannula was removed, transesophageal echocardiography (TEE) revealed a residual thrombus in the left atrium. Thrombectomy was successfully performed by opening the left atrium with cardiopulmonary bypass. We believe that TEE monitoring aided the implantation and removal of the LVAD device. In this case, we found that TEE not only helped in monitoring the ventricular function but also in detecting other problems such as the residual thrombus. We strongly recommend TEE monitoring during the entire LVAD-removal procedure, particularly for patients who need to undergo LVAD removal because of thrombosis formation.

The influence of lagoon on neighboring rivers by water and sediment quality

Canonical discriminant analysis (CDA) was applied in order to distinguish the water-quality and the sediment-quality parameters from neighboring rivers, and to recognize similarities of water and sediment properties between a lagoon and neighboring rivers. Two set of constructed discriminant functions showed a marked contribution to most of the discriminant variables. In water, the significant parameters - the total nitrogen, algae, dissolved oxygen and total phosphate - were combined as the nutrient effect factor. The recognition capacities of the two discriminant functions were 95.6 and 4.4%, respectively; the Kaoping River showed the most similarities with the water quality in Dapeng Bay; in sediment, the significant parameters porosity, Cd, Cr, Al, and Pb were combined as the heavy metal effect factor. The recognition capacities were 82.6 and 17.4%, respectively, but the sediment properties in these three rivers had no significant similarity with the Dapeng Bay.

Mechanical regulation of matrix reorganization and phenotype of smooth muscle cells and mesenchymal stem cells in 3D matrix

In an effort to develop small-diameter tissue-engineered vascular grafts (< 6 mm), collagen and fibrin gels seeded with human aortic smooth muscle cells (HASMCs) were constructed in a three-dimensional tubular environment and subjected to mechanical stimulation to investigate changes in cellular response and matrix remodeling. After testing various collagen and fibrin concentrations, experiments indicated 2:1 mg/mL of collagen:fibrin constructs with embedded HASMCs contracted as well as the pure fibrin, at 54% their original length after 3 days, indicating enhanced cellular activity and matrix remodeling . Vascular constructs were cultured for three days before undergoing pulsatile 10% cyclic strain at 1 Hz for three days. RT-PCR showed that cyclic strain increased the gene expression of SMC markers alpha-actin and SM22, indicating that mechanical stimulation induces SMCs to a more contractile phenotype. Histology showed a more compacted collagen fiber structure for mechanically stimulated constructs compared to the looser collagen network in static constructs. The effects of 3D mechanical strain were also tested on mesenchymal stem cells (MSCs), which can be a possible source for SMCs. Cyclic strain increased alpha-actin and SM22 gene expression in MSCs, suggesting the differentiation of MSCs into a SMC phenotype.

Water quality assessment and apportionment source of pollution from neighbouring rivers in the Tapeng Lagoon (Taiwan) using multivariate analysis: a case study

Factor analysis was conducted to explain the characteristics and variation in the quality of water during the disassembly of oyster frames and fishery boxes. The result shows that the most important latent factors in the Tapeng Lagoon are the ocean factor, the primary productivity factor, and the fishery pollution factor. Canonical discriminant analysis is applied to identify the source of pollution in neighbouring rivers outside the Tapeng Lagoon. The two constructed discriminant functions (CDFs) showed a marked contribution to all the discriminant variables, and that total nitrogen, algae, dissolved oxygen, and total phosphate combined in the nutrient effect factor. The recognition capacities in these two CDFs were 95.6% and 4.4%, respectively. The water quality in the Kaoping river most strongly affected the water quality in the Tapeng Lagoon. Disassembling the oyster frames and fishery boxes improved the water quality markedly. However, environmental topographic conditions indicate that strengthening stream pollution prevention and constructing another entrance to the ocean are the best approaches for improving the quality of water in the Tapeng Lagoon by reducing eutrophication. These approaches and results yield useful information concerning habitat recovery and water resource management.