Highly exfoliated functionalized MoS2 with sodium alginate-polydopamine conjugates for electrochemical sensing of cardio-selective ß-blocker by voltammetric methods.

Molybdenum disulfide (MoS2) surface functionalization was performed with a catechol-containing polymer sodium alginate (SA) and dopamine (DA) through simultaneous MoS2 exfoliation and self-polymerization of DA. The MoS2/SA-PDA nanocomposite was characterized using spectroscopic, microscopic, and electroanalytical techniques to evaluate its electrocatalytic performance. The electrocatalytic behavior of the MoS2/SA-PDA nanocomposite modified electrode for the detection of acebutolol (ACE), a cardio-selective ß-blocker drug was explored  through cyclic voltammetric and differential pulse voltammetric techniques. The influence of scan rate, concentration, and pH value on the oxidation peak current of ACE was investigated  to optimize the deducting condition. The electrochemical activity of the MoS2/SA-PDA nanocomposite electrode was attributed to the existence of reactive functional groups being contributed from SA, PDA, and MoS2 exhibiting a synergic effect. The MoS2/SA-PDA nanocomposite modified electrode exhibits admirable electrocatalytic activity with a wide linear response range (0.009 to 520 µM), low detection limit (5 nM), and high sensitivity (0.354 µA µM-1 cm-2) also in the presence of similar (potentially interfering) compounds. The fabricated MoS2/SA-PDA nanocomposite modified electrode can be useful for the detection of ACE in pharmaceutical analysis.

Tanshinone IIA Inhibits High Glucose-Induced Collagen Synthesis via Nuclear Factor Erythroid 2-Related Factor 2 in Cardiac Fibroblasts.

BACKGROUND/AIMS: Diabetes is associated with increased incidence of myocardial dysfunction, which is partly characterized by interstitial and perivascular fibrosis. Cardiac fibroblasts have been identified as an important participant in the development of cardiac fibrosis. Exposure of cultured cardiac fibroblasts to high glucose resulted in increased collagen synthesis. Tanshinone IIA can alleviate the ventricular fibrosis that develops in a number of different experimental conditions. However, whether tanshinone IIA can prevent high glucose-induced collagen synthesis in cardiac fibroblasts remains unknown. The aim of this study was to evaluate the effects of tanshinone IIA on high glucose-induced collagen synthesis in cardiac fibroblasts. METHODS: Rat cardiac fibroblasts were cultured in high glucose (25 mM) media in the absence or presence of tanshinone IIA and the changes in collagen synthesis, transforming growth factor-ß1 (TGF-ß1) production and related signaling molecules were assessed by 3H-proline incorporation, quantitative polymerase chain reaction, enzyme linked immunosorbent assay, and Western blotting. RESULTS: The results indicate cardiac fibroblasts exposed to high glucose condition show increased cell proliferation and collagen synthesis and these effects were abolished by tanshinone IIA treatment. Furthermore, the inhibitory effect of tanshinone IIA on high glucose induced cell proliferation and collagen synthesis may be associated with its activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the inhibition of TGF-ß1 production and Smad2/3 phosphorylation. CONCLUSION: In summary, our results highlights the critical role tanshinone IIA plays as an antioxidant in attenuating high glucose-mediated collagen synthesis through inhibiting TGF-ß1/Smad signaling in cardiac fibroblasts which provide a mechanistic basis for the clinical application of tanshinone IIA in the treating diabetic-related cardiac fibrosis.

Management of Venous Thromboembolisms: Part I. The Consensus for Deep Vein Thrombosis.

UNLABELLED: Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the existing literature, knowledge about the epidemiology of DVT is primarily based on investigations among Caucasian populations. There has been little information available about the epidemiology of DVT in Taiwan, and it is generally believed that DVT is less common in Asian patients than in Caucasian patients. However, DVT is a multifactorial disease that represents the interaction between genetic and environmental factors, and the majority of patients with incident DVT have either inherited thrombophilia or acquired risk factors. Furthermore, DVT is often overlooked. Although symptomatic DVT commonly presents with lower extremity pain, swelling and tenderness, diagnosing DVT is a clinical challenge for physicians. Such a diagnosis of DVT requires a timely systematic assessment, including the use of the Wells score and a D-dimer test to exclude low-risk patients, and imaging modalities to confirm DVT. Compression ultrasound with high sensitivity and specificity is the front-line imaging modality in the diagnostic process for patients with suspected DVT in addition to conventional invasive contrast venography. Most patients require anticoagulation therapy, which typically consists of parenteral heparin bridged to a vitamin K antagonist, with variable duration. The development of non-vitamin K oral anticoagulants has revolutionized the landscape of venous thromboembolism treatment, with 4 agents available,including rivaroxaban, dabigatran, apixaban, and edoxaban. Presently, all 4 drugs have finished their large phase III clinical trial programs and come to the clinical uses in North America and Europe. It is encouraging to note that the published data to date regarding Asian patients indicates that such new therapies are safe and efficacious. Ultimately, our efforts to improve outcomes in patients with DVT rely on the awareness in the scientific and medical community regarding the importance of DVT. KEY WORDS: Combination therapy; Hypertension; α1-blocker.

The Effect and Underlying Mechanism of Ethanol on Intracellular H(+) -Equivalent Membrane Transporters in Human Aorta Smooth Muscle Cells.

BACKGROUND: The presence of intracellular pH (pHi ) regulators, including Na(+) -H(+) exchanger (NHE), Na(+) -HCO3- co-transporter (NBC), Cl(-) /OH(-) exchanger (CHE), and Cl(-) /HCO3- exchanger (AE), have been confirmed in many mammalian cells. Alcohol consumption is associated with increased risk of cardiovascular disorder. The aims of the study were to identify the possible transmembrane pHi regulators and to explore the effects of ethanol (EtOH) (10 to 300 mM) on the resting pHi and pHi regulators in human aorta smooth muscle cells (HASMCs). METHODS: HASMCs were obtained from patients undergoing heart transplant. The pHi was measured by microspectrofluorimetry with the pH-sensitive dye, BCECF-AM. RESULTS: The following results are obtained. (i) In cultured HASMCs, the resting pHi was 7.19 ± 0.04 and 7.13 ± 0.02 for HEPES- and CO2 /HCO3--buffered solution, respectively. (ii) Two different Na(+) -dependent acid-equivalent extruders, including NHE and Na(+) -coupled HCO3- transporter, functionally coexisted. (iii) Two different Cl(-) -dependent acid loaders (CHE and AE) were functionally identified. (iv) EtOH induced a biphasic, concentration-dependent change in resting pHi (+0.25 pH unit at 100 mM but only +0.05 pH unit at 300 mM) in bicarbonate-buffered solution, while caused a concentration-dependent decrease in resting pHi (-0.06 pH unit at 300 mM) in HEPES-buffered solution. (v) The effect of EtOH on NHE activity was also biphasic: increase of 40% at lower concentration of 10 mM, followed by decrease of 30% at higher concentration of 300 mM. (vi) The increase in Na(+) -coupled HCO3- transporter activity by EtOH was concentration dependent. (vii) The effect of EtOH on CHE and AE activities was both biphasic: increase of ~25% at 30 mM, followed by decrease of 10 to 25% at 100 mM, and finally increase of 15 to 20% at 300 mM. CONCLUSIONS: This study demonstrated that 2 acid extruders and 2 acid loaders coexisted functionally in HASMCs and that EtOH induced a biphasic, concentration-dependent change in resting pHi by altering the activity of the 2 acid extruders, NHE and Na(+) -coupled HCO3- transporter, and the 2 acid loaders, CHE and AE.

Effects of Indomethacin on Intracellular pH and Na⁺/H⁺ Exchanger in the Human Monocytes.

The ability to maintain optimal intracellular pH (pH(i)) is an essential requirement for all cells. Na⁺-H⁺ exchanger (NHE), a ubiquitously expressed transmembrane protein, has been found widely as a major acid extruder in many different cell types, including human monocytes. We therefore investigated the mechanism of the active pH(i) recovery from intracellular acidosis (induced by NH4Cl prepulse) using intracellular 2',7'-bis (2-carboxethyl)-5(6)-carboxyl-fluorescein (BCECF) fluorescence in cultured human monocytes. Indomethacin is a potent, nonselective inhibitor of cyclooxygenases. Due to its toxicity, the clinical use of indomethacin as an analgesic-antipyretic agent is limited. However, it has recently been found that indomethacin can effectively treat many inflammatory/immune disorders. In this study, we further investigated the effect of indomethacin on the pHi and explored the underlying mechanism. In HEPES (nominally HCO3⁻-free) Tyrode solution, a pH(i) recovery from induced intracellular acidosis could be blocked completely by 30 µM HOE 694, a specific NHE1 inhibitor, or by removing [Na⁺]0. Therefore, in the present study, we provided functional evidence, physiologically and pharmacologically, that the HCO3⁻-independent acid extruder was mostly likely the NHE1 which was involved in acid extrusion in the human monocytes. Moreover, indomethacin (1 µM-1 mM) decreased pH(i) levels in a concentration-dependent manner and significantly suppressed the activity of the NHE1, suggesting that indomethacin-induced intracellular acidosis is caused both by the inhibition of NHE1 activity and the non-specified NHE1-independent acidifying mechanism. In conclusion, our present study demonstrates that NHE1 exists functionally in human monocytes, and the indomethacin-induced pHi decreasing is summation effects on NHE1-dependent and -independent mechanism.

Assessment of the Risk Factors and Outcomes for Postoperative Atrial Fibrillation Patients Undergoing Isolated Coronary Artery Bypass Grafting.

BACKGROUND: Atrial fibrillation is the most common complication of cardiac surgery and is associated with significant morbidity and mortality. Recognizing patients at high risk for developing postoperative atrial fibrillation (POAF) may help identify those who could benefit from strategies to prevent POAF. This study was conducted to delineate outcomes and to assess risk factors for POAF among Taiwanese patients undergoing coronary artery bypass grafting (CABG). METHODS: From January 2009 until February 2012, this prospective study included 266 consecutive patients admitted to our hospital with coronary artery disease. All patients underwent isolated CABG. Patients with preoperative permanent atrial fibrillation and concomitant surgery were excluded. Multiple risk factors associated with the incidence of POAF were collected and evaluated. RESULTS: POAF occurred in 126 of 226 patients (47.37%). Univariate analysis revealed that significant risk factors for the condition were age, gender, diabetes, dyslipidemia, smoking, impaired renal function, impaired cardiac function, and increased serum electrolytes. Multivariate analysis showed dyslipidemia [hazard ratio (HR): 0.418; 95% confidence interval (Cl): 0.190-0.915, p = 0.029], impaired renal function as indicated by an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) (HR: 3.174; 95% CI: 1.432-7.037, p = 0.004), and serum sodium (HR: 1.112; 95% Cl: 1.047-1.182, p = 0.001) prior to cardiopulmonary bypass as significant. Moreover, POAF was associated with lower 30-day, 1- and 3-year cumulative survival rates and higher early postoperative complications. CONCLUSIONS: Patients with isolated CABG who were administered ß-blockers, angiotensin converting enzyme inhibitor/angiotensin receptor blockers treatment, and lipid therapy before CABG were associated with reduced POAF, while those with impaired renal function and higher serum sodium before CABG predisposed POAF in a Taiwanese population. KEY WORDS: Atrial fibrillation (AF); Coronary artery bypass grafting (CABG); Coronary artery disease (CAD); Postoperative atrial fibrillation (POAF).

Prolonged Use of Levitronix Left Ventricular Assist Device as a Bridge to Heart Transplantation.

UNLABELLED: A 61-year-old male presented to our emergency room with chest tightness, dyspnea, and cold sweat. He underwent a 12-lead EKG which showed ST-elevation from leads V1-V4 and T wave inversion in leads II, III, and aVF. His troponin-I level was elevated to 70.3 ng/ml. He went into cardiogenic shock when he was in the catheter room. After advanced cardiac life support was administered for 30 min, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation was set up using 21-french arterial and 21-french venous cannula through the right femoral artery and right femoral vein by the puncture method for hemodynamic support. Subsequently, a coronary artery bypass graft (CABG) for acute myocardial infarction was performed. However, the patient was unable to be weaned from the VA-ECMO. Four days later, a CentriMag (Levitronix LLC, Waltham, MA, USA) left ventricular assist device (LVAD) was applied to avoid ECMO-related complications such as severe hemolysis, ischemic, deteriorated liver and renal function. The patient subsequently underwent a successful orthotopic heart transplant after 87 days on the CentriMag LVAD. The patient was extubated on the next postoperative day and was discharged 2 weeks later. KEY WORDS: Acute myocardial infarction; Extracorporeal membrane oxygenation; Heart transplantation; Ventricular assist device.

Functional characterization of intracellular pH regulators responsible for acid extrusion in human radial artery smooth muscle cells.

Intracellular pH (pHi) is a critical factor influencing many important cellular functions. Acid extrusion carriers such as an Na⁺/H⁺ exchanger (NHE) Na⁺/HCO3⁻ cotransporter (NBC) and monocarboxylate transporters (MCT) can be activated when cells are in an acidic condition (pHi < 7.1). Human radial artery smooth muscle cells (HRASMC) is an important conduit in coronary artery bypass graft surgery. However, such far, the pHi regulators have not been characterized in HRASMCs. We therefore investigated the mechanism of pHi recovery from intracellular acidosis and alkalosis, induced by NH4Cl-prepulse and Na-acetate-prepulse, respectively, using intracellular 2',7'-bis(2-carboxethyl)-5(6)- carboxy-fluorescein (BCECF)-fluorescence in HRASMCs. Cultured HRASMCs were derived from the segments of human radial artery that were obtained from patients undergoing bypass grafting. The resting pHi is 7.22 ± 0.03 and 7.17 ± 0.02 for HEPES- (nominally HCO3⁻-free) and CO2/HCO3⁻- buffered solution, respectively. In HEPES-buffered solution, a pHi recovery from induced intracellular acidosis could be blocked completely by 30 µM HOE 694 (3-methylsulfonyl-4-piperidinobenzoyl, guanidine hydrochloride) a specific NHE inhibitor, or by removing [Na⁺]0. In 3% CO2/HCO3⁻-buffered solution, HOE 694 slowed the pHi recovery from the induced intracellular acidosis only, while adding together with DIDS (a specific NBC inhibitor) or removal of [Na⁺]0 entirely inhibited the acid extrusion. Moreover, α-cyano-4-hydroxycinnamate (CHC; a specific blocker of MCT) blocked the lactate-induced pHi changes. In conclusion, we demonstrate, for the first time, that 3 different pHi regulators responsible for acid extruding, i.e. NHE and NBC, and MCT, are functionally co-existed in cultured HRASMCs.

Ligation of Macroscopically Detectable Arteriovenous Fistulas in Stewart-Bluefarb Syndrome.

UNLABELLED: We herein describe the case of a 21-year-old woman with Stewart-Bluefarb syndrome presenting with recurrent ulcers on the right foot and multiple congenital arteriovenous malformations. The painful recurrent ulcers and brownish macules at the dorsum of the right foot had appeared at 13 years of age, and the size of the right foot gradually became larger than the left. She underwent conservative treatment and polyvinyl alcohol embolization but the ulcer was recurrent. Two macroscopic detectable feeding arteries to arteriovenous fistulas were ligated under Doppler sonography. At her 6 month follow-up, the chronic ulcer had begun to heal and pain had been alleviated. KEY WORDS: Acroangiodermatitis; Arteriovenous malformation; Recurrent foot ulcer; Stewart-Bluefarb syndrome.

Experience of heart transplantation from hemodynamically unstable brain-dead donors with extracorporeal support.

The shortage of organ donors remains a major problem for transplantation worldwide. Potential donors after brain death may become hemodynamically unstable, despite maximal medical management, which ultimately leads to failure of organ procurement. We reviewed the medical records of five brain-dead potential donors who presented with hemodynamic instability despite maximal medical management that were supported by extracorporeal circulation membrane oxygenation (ECMO). The outcomes of heart recipients were reviewed. The five donors under extracorporeal support finished a declaration of brain death without cardiac arrest. Donor organs, including three hearts, nine kidneys, and four livers, were harvested from the five donors under ECMO support. All three heart recipients recovered uneventfully after one yr of follow-up. Our experience indicates that potential donors may experience central-failure-related hemodynamic instability after brain death, despite maximal medical support, which leads to a fatal result. Beyond medical management, prompt and early extracorporeal support for salvaging brain-dead potential donors from cardiac death seems to be a practical strategy to increase the donor pool and preserve donor organs.

Left atrial appendage aneurysm with paroxysmal atrial fibrillation.

Aneurysm of the left atrial appendage is extremely rare, and afflicted patients most commonly present with atrial tachyarrhythmia or thromboembolism. For these patients, resection of the aneurysm is the recommended and preferred therapy. We present the case of a 57-year-old woman who was found incidentally to have a large aneurysm of the left atrial appendage presenting as atrial fibrillation. After surgical intervention with resection of the aneurysm and a Cox maze III procedure, the patient recovered and was discharged in sinus rhythm.

Functional characterization of transmembrane intracellular pH regulators and mechanism of alcohol-induced intracellular acidosis in human umbilical cord blood stem cell-like cells.

Changing intracellular pH (pHi) exerts considerable influence on many cellular functions. Different pHi regulators, such as the Na-H exchanger (NHE), Na/(Equation is included in full-text article.)symporter, and Cl/OH exchanger (CHE), have been identified in mature mammalian cells. The aims of the present study were to investigate the physiological mechanisms of pHi recovery and to further explore the effects of alcohol on the pHi in human umbilical cord blood CD34 stem cell-like cells (HUCB-CD34STs). HUCB-CD34STs were loaded with the pH-sensitive dye, 2',7'-bis(2-carboxethyl)-5(6)-carboxyfluorescein, to examine pHi. In isolated HUCB-CD34STs, we found that (1) the resting pHi is 7.03 ± 0.02; (2) 2 Na-dependent acid extruders and a Cl-dependent acid loading carrier exist and are functional; (3) alcohol functions in a concentration-dependent manner to reduce pHi and increase NHE activity, but it does not affect CHE activity; and (4) fomepizole, a specific alcohol dehydrogenase inhibitor, does not change the intracellular acidosis and NHE activity-induced by alcohol, whereas 3-amino-1, 2,4-trizole, a specific catalase inhibitor, entirely abolishes these effects. In conclusion, we demonstrate that 2 acid extruders and 1 acid loader (most likely NHE, NBC, and CHE, respectively) functionally existed in HUCB-CD34STs. Additionally, the intracellular acidosis is mainly caused by catalase-mediated alcohol metabolites, which provoke the activity of NHE.

Coronary artery fistula detected by 64-slice multidetector computed tomography: case report.

Coronary artery fistula (CAF), a rare anomaly of a coronary artery, is defined as an anomalous communication between a coronary artery and a cardiac chamber or vessels. Coronary angiography remains the main modality for diagnosing CAF. We present a case of fistulous communication between the left anterior descending coronary artery and the main pulmonary artery. The exact anatomy of the fistula was demonstrated by 64-slice multidetector computed tomography (MDCT). Surgical ligation on a beating heart was carried out. Intraoperative Doppler flow detection was used to evaluate the shunt of the CAF. We prefer MDCT as a new diagnostic modality to provide the detailed anatomy of a CAF.

A novel polyurethane-based root canal-obturation material and urethane acrylate-based root canal sealer--part I: synthesis and evaluation of mechanical and thermal properties.

Resilon (RealSeal; SybronEndo, Orange, CA) has been developed as an alternative to gutta percha, but its advantages over gutta percha remain controversial. In this study, we developed a novel zinc oxide/thermoplastic polyurethane (ZnO/TPU) composite root canal-filling material and a visible-light curable urethane-acrylate/tripropylene glycol diacrylate (UA/TPGDA) root canal sealer. The mechanical and thermal properties of the ZnO/TPU composite were compared with those of gutta percha and Resilon. Results showed that the tensile strength and elastic modulus of the ZnO/TPU composite were markedly higher than those of gutta percha and Resilon. The melting points of all three materials were similar; however, the enthalpy change and specific heat of ZnO/TPU (9.4 J/g, 0.7 J/g degrees C) were close to those of gutta percha (10.9 J/g, 0.7 J/g degrees C) but lower than those of Resilon (28.9 J/g, 1.3 J/g degrees C). The results indicate that ZnO/TPU composite exhibits better mechanical strength than Resilon, and its combination with UA/TPGDA sealer has excellent potential to be used as a root canal-filling material.

Effects of age and degree of hearing loss on the agreement and correlation between sound field audiometric thresholds and tone burst auditory brainstem response thresholds in infants and young children.

BACKGROUND/PURPOSE: Early hearing rehabilitation programs eventually require measurement of the hearing threshold cutoff values over the whole range of speech frequencies. With tone burst auditory brainstem responses, excellent agreement and correlation between evoked-potential and behavioral thresholds have been demonstrated by previous studies. This study investigated the effects of different ages and degrees of hearing loss on the agreement and correlation in a large series of infants and young children in Taiwan. METHODS: Medical records were reviewed from a large series of 1281 infants and young children aged from 3 months to 3 years who had undergone diagnostic audiometry, including sound field audiometry and tone burst auditory brainstem response measurements. The effects of age and hearing loss on the agreement and correlation between two measured thresholds were studied. RESULTS: Significant correlations (p < 0.001) were seen between the two measured thresholds across groups of different ages and different degrees of hearing loss greater than 20 dB HL. However, the degree of correlation deteriorated at lower degrees of hearing loss. Correlations for hearing thresholds less than 20 dB HL were not significant at 1000, 2000 and 4000 Hz. CONCLUSION: The evoked-potentials test, properly obtained and interpreted with respect to the effects of age and degree of hearing loss, may provide a very informative hearing threshold reference to help in behavioral audiometric evaluation in infants and young children with hearing loss.

Thresholds of tone burst auditory brainstem responses for infants and young children with normal hearing in Taiwan.

BACKGROUND/PURPOSE: With respect to follow-up from newborn hearing screening, click evoked auditory brainstem response provides relatively accurate estimates of auditory thresholds at a broad frequency range between 1,000 Hz and 4,000 Hz. Further on the frequency-specific hearing evaluation, recent studies conclude that tone burst auditory brainstem response estimates the behavioral thresholds reasonably well. This study reports the preliminary data of tone burst auditory brainstem response measurements of infants and young children with normal hearing in Taiwan. METHODS: Ninety-four infants and young children aged from 3 months to 3 years of age were recruited as they were eventually determined to have normal hearing after a series of tests. They underwent tone burst auditory brainstem response measurements at four selected frequencies. Statistical methods were applied to study the relationship among recorded variables. RESULTS: The results indicated that the averaged tone burst auditory brainstem response thresholds of infants and young children with normal hearing in Taiwan are typically 10-20 dB nHL at 500, 1,000, 2,000, and 4,000 Hz, which is similar to the reported tone burst auditory brainstem response thresholds in adults with normal hearing. There was no statistically significant difference for the thresholds with regard to gender, laterality, and age distribution in this study. CONCLUSION: Based on the published research and our study, we suggest setting the normal criterion levels for infants and young children in Taiwan of the tone burst auditory brainstem response to air-conducted tones as 30 dB nHL for 500 and 1,000 Hz, and 25 dB nHL for 2,000 and 4,000 Hz.

Auditory cortical evoked potentials in tinnitus patients with normal audiological presentation.

BACKGROUND/PURPOSE: It is widely assumed that damage to the peripheral hearing system is an essential prerequisite for the occurrence of tinnitus. However, previous studies have failed to target tinnitus patients with normal hearing. This study aims to investigate if tinnitus patients with normal audiological presentation demonstrate increased intensity dependence at the selected frequencies. METHODS: This study applied auditory cortical evoked potential test to investigate nine tinnitus patients with normal audiological presentation and nine age- and sex-matched healthy subjects without tinnitus. Auditory cortical evoked potentials (N1-P2) were elicited from stimuli at four frequencies (4000, 2000, 1000 and 500 Hz) with five intensities (50, 56, 62, 68 and 74 dB nHL). Intensity dependences by latency of N1 and amplitude of N1-P2 were surveyed at midline electrodes. RESULTS: The results showed that the intensity dependence by latency of N1 to the pooled frequencies at three midline electrodes, e.g. Fz, Cz and Pz, revealed non-significant difference. However, significant differences existed in the intensity dependence of amplitude N1-P2 to the pooled frequencies at the Fz and Cz positions. These differences suggested that tinnitus patients tended to respond less to increased sound intensity and were inclined to weaker intensity dependence. CONCLUSION: Increased intensity dependence of N1-P2 component at the selected frequencies cannot be demonstrated in tinnitus patients with normal hearing. Restated, the edge frequency phenomenon fails to present in tinnitus patients with normal hearing, a different characteristic from tinnitus patients with hearing loss.

Subclavian artery cannulation provides better myocardial protection in conventional repair of acute type A aortic dissection: experience from a single medical centre in Taiwan.

BACKGROUND: Although many reports have detailed the advantages and disadvantages between femoral and subclavian arterial cannulations for acute aortic dissection type A (AADA), the confounding factors caused by disease severity and surgical procedures could not be completely eliminated. We compared femoral and subclavian artery cannulation and report the results for reconstruction of only the ascending aorta. METHODS: From January 2003 to December 2010, 51 AADA cases involving reconstruction of only the ascending aorta were retrospectively reviewed and categorised on the basis of femoral (n = 26, 51%) or subclavian (n = 25, 49%) artery cannulation. Bentall's procedures, arch reconstruction and hybrid operations with stent-grafts were all excluded to avoid confounding factors due to dissection severity. Surgical results, postoperative mortality, and short- and mid-term outcomes were compared between the groups. RESULTS: Subclavian cannulation had a lower incidence of cerebral and myocardial injury and lower hospital mortality than femoral cannulation (8 vs 34%, p = 0.04). Ventilation duration as well as intensive care unit (ICU) and hospital stay were also shorter with subclavian cannulation. Risk factors for hospital mortality included pre-operative respiratory failure (odds ratio: 12.84), peri-operative cardiopulmonary bypass (CPB) time gt; 200 minutes (odds ratio: 13.49), postoperative acidosis (pH < 7.2, odds ratio: 88.63), and troponin I > 2.0 ng/ml (odds ratio: 20.08). The overall hospital mortality rate was 21%. The 40 survivors were followed up for three years with survival of 75% at one year and 70% at three years. CONCLUSIONS: Our results show that subclavian cannulation had a lower incidence of cerebral and myocardial injury as well as better postoperative recovery and lower hospital mortality rates for reconstruction of only the ascending aorta.