Oxygen surface exchange properties and surface segregation behavior of nanostructured La0.6Sr0.4Co0.2Fe0.8O3-δ thin film cathodes.

Cathode materials with highly reactive surfaces and long-term stability are required to achieve high-performance solid oxide fuel cells (SOFCs). In this study, a promising cathode material, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), was prepared as a nanostructured thin film using pulsed laser deposition (PLD) on gadolinia-doped ceria (GDC)-buffered YSZ single crystal substrates having (100) and (111) orientations. Characterization revealed intrinsic differences among the as-grown LSCF thin films in terms of dominant crystalline orientation and nanostructure depending on GDC preparation as well as the YSZ substrate orientation. Evaluation of the oxygen exchange properties using the isotope exchange depth profile method revealed that LSCF thin films grown on (111) GDC/YSZ exhibited higher values of the apparent surface exchange coefficient compared to LSCF thin films grown on (100) GDC/YSZ. However, when subjected to long-term annealing at high temperatures, the former exhibited a stronger tendency to surface segregation as compared to the latter. These behaviors are correlated with the intrinsic properties of LSCF thin films, including the nanostructure, the possible effects attributed to SrO activity, and the stability of perovskite surfaces which would drive surface segregation. These results have implications for tailoring the performance of cathode thin films by understanding the dependence of oxygen exchange properties and surface segregation on driving forces such as surface chemistry and nanostructure.

The effects of Patent Blue dye on peripheral and cerebral oxyhaemoglobin saturations.

We measured the effect of Patent Blue dye on oxyhaemoglobin saturations after injection into breast tissue: 40 women had anaesthesia for breast surgery maintained with sevoflurane or propofol (20 randomly allocated to each). Saturations were recorded with a digital pulse oximeter, in arterial blood samples and with a cerebral tissue oximeter before dye injection and 10, 20, 30, 40, 50, 60, 75, 90, 105 and 120 min afterwards. Patent Blue did not decrease arterial blood oxyhaemoglobin saturation, but it did reduce mean (SD) digital and cerebral oxyhaemoglobin saturations by 1.1 (1.1) % and 6.8 (7.0) %, p < 0.0001 for both. The falsely reduced oximeter readings persisted for at least 2 h. The mean (SD) intra-operative digital pulse oxyhaemoglobin readings were lower with sevoflurane than propofol, 97.8 (1.2) % and 98.8 (1.0) %, respectively, p < 0.0001.

Urinary bladder and oesophageal temperatures correlate better in patients with high rather than low urinary flow rates during non-cardiac surgery.

BACKGROUND AND OBJECTIVE: To investigate the effect of urinary flow rate on the urinary bladder temperature, we compared the accuracy and precision of urinary bladder temperature with oesophageal temperature at both high and low urine flow rates. METHODS: Twenty-four patients ASA physical status I or II who were undergoing tympanoplasty were randomly assigned to two groups with different intravenous fluid volumes: high (10 mL kg(-1) h(-1), n = 12) and low (3 mL kg(-1) h(-1), n = 12). General anaesthesia was induced with propofol and maintained with sevoflurane (1.5-2.5%) in nitrous oxide and oxygen. Urinary bladder temperature was measured using a Foley urinary catheter; distal oesophageal temperature was measured using a stethoscope thermocouple. These temperatures were measured every 5 min during surgery and the accuracy and precision of urinary bladder temperature with oesophageal temperature were determined using regression and Bland and Altman analyses. RESULTS: The correlation coefficient for oesophageal and urinary bladder temperature was 0.90 in the high urinary volume group and 0.75 in the low urinary volume group. The offset (oesophageal-urinary bladder) was -0.13 +/- 0.32 degrees C and -0.46 +/- 0.45 degrees C, respectively. CONCLUSION: Urinary bladder temperature appears to be more accurate at high urinary flow rates than at low urinary flow rates for clinical use.

Isovolaemic haemodilution decreases the shivering threshold in rabbits.

BACKGROUND AND OBJECTIVE: The inhibition of thermoregulatory control by anaesthesia is manifested by reduced vasoconstriction and shivering thresholds. As intraoperative bleeding can result in haemodynamic changes, including vasoconstriction, we investigated the effect of experimental bleeding on the shivering threshold in rabbits. METHODS: Twenty-four rabbits were randomly assigned to one of three treatment strategies: (1) no blood removal (control), (2) 5 mL kg(-1) isovolaemic blood removal and (3) 10 mL kg(-1) isovolaemic blood removal. After tracheal intubation under isoflurane anaesthesia, anaesthesia was maintained with 50% nitrous oxide in oxygen. The removed blood volume was replaced with the same volume of warm hydroxyethyl starch colloid solution. Oesophageal temperature was measured as a core temperature at 1-min intervals. After blood removal, the animal's body was cooled at a rate of 2-3 degrees C h(-1) by perfusing water at 10 degrees C through a U-shaped thermode positioned in the colon. Hypothermic shivering was evaluated by visual inspection, and the core temperature at which shivering was triggered was identified as the thermoregulatory threshold for this response. RESULTS: Just before the cooling, the body temperature of the animals was around 38.6 degrees C in all of the three groups. The shivering threshold in the control group was 37.2 +/- 0.2 degrees C (mean +/- SD). The shivering thresholds in the 5 mL kg(-1) (36.9 degrees +/- 0.3 degrees C) and 10 mL kg(-1) (36.5 degrees +/- 0.5 degrees C) blood removal groups were significantly lower and in proportion with the volume of blood removed than that in the control group. CONCLUSION: Isovolaemic haemodilution decreased the shivering threshold in rabbits in proportion with the volume of blood removed.

The use of patient-controlled epidural fentanyl in elderly patients.

We studied whether delivering postoperative analgesia, using a patient-controlled epidural analgesia (PCEA) device was effective and safe in elderly patients. We enrolled 40 patients aged > 65 years (elderly group) and 40 patients aged 20-64 years (young group) scheduled for elective major abdominal surgery. PCEA infusion was started following completion of surgery. Mean (SD) fentanyl consumption (10.7 (3.7) compared with 10.5 (2.7) microg.kg(-1), p = 0.76) and number of times patients pressed the bolus switch (32 (36) compared with 44 (38), p = 0.16) during the first 24 h postoperatively were similar in the two groups. Pain scores, which were similar in both groups at rest, were significantly lower in the elderly on coughing (at 24 h, p < 0.05). In addition, average pain scores were similar at the time of PCEA bolus demands in the two groups. Elderly and young adult patients therefore required similar amounts of patient-controlled epidural fentanyl to produce satisfactory pain relief.

Sonographic detection of secondary MALT lymphoma of the submandibular gland.

This report describes a case of mucosa-associated lymphoid tissue (MALT) lymphoma of the lacrimal glands that recurred in the submandibular salivary glands. Gray-scale sonography showed small hypoechoic nodules, measuring less than 0.5 cm in diameter, in both submandibular glands. The echogenicity and echotexture of the rest of the submandibular glands and of the parotid glands was normal. Power Doppler sonography revealed increased vascularity within the nodules. A sonographically guided aspiration biopsy of the nodules revealed MALT lymphoma. Secondary MALT lymphoma should be considered in the presence of multiple small hypoechoic nodules in the salivary glands in patients with a history of MALT lymphoma at another location.

[Anesthetic management of a child with congenital sensory neuropathy with anhydrosis].

Congenital sensory neuropathy with anhydrosis is a rare disorder characterized by insensitivity to pain with normal tactile perception, self-mutilation, anhydrosis, recurrent unexplained fever, mental retardation and variable autonomic abnormality. We managed a 14-year-old boy with this syndrome who underwent repair of right femur fracture. Anesthesia was induced with propofol and ketamine. Adequate depth of anesthesia was carefully controlled by processed electroencephalogram, and core body temperature was maintained at 37.0 degrees C during the surgery. The patient was well sedated, and nausea and vomiting were not noted postoperatively. Use of droperidol and propofol may be beneficial for anesthetic management of this syndrome, because droperidol exerts residual hypnotic effect postoperatively, and both drugs have antiemetic property.

Head and neck lesions: characterization with diffusion-weighted echo-planar MR imaging.

PURPOSE: To evaluate whether apparent diffusion coefficients (ADCs) calculated from diffusion-weighted echo-planar magnetic resonance (MR) images can be used to characterize head and neck lesions. MATERIALS AND METHODS: Diffusion-weighted echo-planar MR imaging was performed with a 1.5-T MR unit in 97 head and neck lesions in 97 patients. Images were obtained with a diffusion-weighted factor, factor b, of 0, 500, and 1,000 sec/mm(2), and an ADC map was constructed. The ADCs of lesions, cerebrospinal fluid, and spinal cord were calculated. RESULTS: Acceptable images for ADC measurement were obtained in 81 (84%) patients. The mean ADC of malignant lymphomas, (0.66 +/- 0.17[SD]) x 10(-3) mm(2)/sec (n = 13), was significantly smaller (P <.001) than that of carcinomas. The mean ADC of carcinomas, (1.13 +/- 0.43) x 10(-3) mm(2)/sec (n = 36), was significantly smaller (P =.002) than that of benign solid tumors. The mean ADC of benign solid tumors, (1.56 +/- 0.51) x 10(-3) mm(2)/sec (n = 22), was significantly smaller (P =.035) than that of benign cystic lesions, (2.05 +/- 0.62) x 10(-3) mm(2)/sec (n = 10). No significant differences were seen in the mean ADC of cerebrospinal fluid and of spinal cord among four groups of lesions. When an ADC smaller than 1.22 x 10(-3) mm(2)/sec was used for predicting malignancy, the highest accuracy of 86%, with 84% sensitivity and 91% specificity, was obtained. CONCLUSION: Measurement of ADCs may be used to characterize head and neck lesions.

[A successful surgical case of incomplete atrioventricular septal defect with pulmonary dysfunction].

A 58-year-old female with incomplete atrioventricular septal defect was treated successfully with surgery. We repaired the defect by closure of atrioventricular septal defect, suture of cleft and tricuspid valve annuloplasty. We adopted method of minimally invasive cardiac surgery (MICS) expecting to preserve pulmonary function and to perform tracheostomy on early stage. After the operation she recovered with no major complications. It is suggested that MICS is effective method for patients with pulmonary dysfunction.

Thrombus on the intraluminal felt strip. A possible cause of postoperative stroke.

We report a case of a 60-year-old woman who received an operation for acute aortic dissection and who had a postoperative complication of multiple cerebral infarction. Through aggressive investigation using transesophageal echocardiography, a mobile thrombus on the intraluminal felt strip used for the enforcement of the dissecting aortic wall was detected as the possible source of the cerebral thromboembolism. After anticoagulation therapy was started, the mobile thrombus growing on the intraluminal felt strip disappeared, and no new lesions of cerebral thromboembolism occurred.

Parotid masses: prediction of malignancy using magnetization transfer and MR imaging findings.

OBJECTIVE: We determined the most accurate criteria for predicting malignancy of masses in the parotid gland using magnetization transfer ratios. SUBJECTS AND METHODS: Lesion-to-muscle magnetization transfer ratios obtained with a spoiled gradient-recalled acquisition in a steady state sequence with a 1-kHz off-resonance pulse were measured in 72 parotid masses (52 benign lesions, 20 malignant tumors). Various MR imaging findings and lesion-to-muscle magnetization transfer ratios were simultaneously assessed using a logistic model to determine the useful factors for predicting malignancy. We also studied the clinical usage of magnetization transfer ratios. RESULTS: Of the MR imaging findings, poorly defined margins showed the highest accuracy, 81%, with 60% sensitivity and 88% specificity. Of the lesion-to-muscle magnetization transfer ratios, a ratio of greater than 0.71 was most accurate (85%), with 90% sensitivity and 83% specificity. All four recurrent tumors and 10 (91%) of 11 secondary tumors were correctly diagnosed using the magnetization transfer ratio analysis. The logistic model revealed that the margin characteristics (p = 0.084) and lesion-to-muscle magnetization transfer ratios (p < 0.001) were statistically significant predictors for malignancy. A combined criteria of poorly defined margins and a lesion-to-muscle magnetization transfer ratio of greater than 0.71 raised the accuracy to 86% and specificity to 96%, but the sensitivity decreased to 60%. CONCLUSION: A combination of MR imaging findings and lesion-to-muscle magnetization transfer ratios was the most accurate predictor of malignancy.

Effects of cardiotrophin-1 (CT-1) in a mouse motor neuron disease.

Cardiotrophin-1 (CT-1) has potent survival-promoting effects on motor neurons in vitro and in vivo and may be effective in treating motor neuron diseases (MND). We investigated the effects of CT-1 treatment in wobbler mouse MND. Wobbler mice were randomly assigned to receive subcutaneously injected CT-1 (1 mg/kg, n = 18, in two experiments) or vehicle (n = 18, in two experiments) daily, 6 times/week for 4 weeks after clinical diagnosis at age 3 to 4 weeks. Cardiotrophin-1 treatment prevented deterioration in paw position and walking pattern abnormalities. Grip strength declined steadily in the vehicle group, whereas in the CT-1 group it declined at week 1 but increased thereafter to exceed baseline strength by 5% (P = 0.0002) at week 4. Running speed was faster with CT-1 (P = 0.007). Biceps muscle twitch tension, muscle weight, mean muscle fiber diameter, and intramuscular axonal sprouting were significantly greater with CT-1 treatment than with vehicle treatment. Histometry revealed a trend that indicated CT-1 modestly increased the number of immunoreactive motor neurons, as determined by both choline acetyltransferase and c-Ret antibodies, and reduced the number of phosphorylated neurofilament immunoreactive perikarya (P = 0.05). The number of large myelinated motor axons significantly increased with treatment (206 versus 113, P = 0.01). We conclude that CT-1 exerts myotrophic effects as well as neurotrophic effects in a mouse model of spontaneous MND, a finding that has potential therapeutic implications for human MND.

Role of brain-derived neurotrophic factor in wobbler mouse motor neuron disease.

Brain-derived neurotrophic factor (BDNF) is neuroprotective for motoneurons undergoing degeneration, including those in natural motor neuron disease (MND) in wobbler mice. To assess the role of BDNF in this model of MND, endogenous BDNF immunoreactivity was analyzed by semiquantitative video-image analysis. Affected cervical spinal cord motoneurons had significantly greater BDNF immunoreactivity compared to motoneurons of healthy littermates (P = 0.01) and affected lumbar spinal cord motoneurons (P = 0.008 at age 4 weeks; P = 0.005 at age 8 weeks). Neuronal nitric oxide synthase (n-NOS) immunocytochemistry revealed increased immunoreactivity in the affected cervical spinal cord motoneurons. Exogenous BDNF treatment partially inhibited the increased NOS activity, as quantitatively measured by nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry. The mean number of NADPH-d(+) motoneurons in the cervical anterior horn decreased from 3.5 +/- 1.2 to 1.5 +/- 1.2 (P = 0.002). The increase in endogenous BDNF immunoreactivity in the affected spinal cord may be compensatory in diseased motoneurons, yet it appears to still be inadequate because exogenous BDNF treatment is required to suppress increased NOS activity in degenerating motoneurons. Our study indicates that BDNF is important in halting nitric oxide (NO)-mediated motor neuron degeneration, which has potential implications for the treatment of neurodegenerative disorders.

Fulminant and relentless cutaneous necrosis with excruciating pain caused by calciphylaxis developing in a patient undergoing peritoneal dialysis.

A 50-year-old Japanese female with chronic renal failure who had been on continuous ambulatory peritoneal dialysis developed fulminant systemic cutaneous necrosis that began as painful livedo reticularis-like skin lesions on her thighs. Because of disseminated vascular calcification within the muscular layer of her lower limbs, we eventually diagnosed her with calciphylaxis. The skin necrosis progressed rapidly, and she died of sepsis and pneumonia on the 53rd hospital day. In addition to her long-lasting severe hyperparathyroidism and extremely elevated serum phosphorus and calcium levels, mechanical, frictional stimulation inflicted on the local skin and administration of corticosteroids were suspected to have precipitated the calciphylaxis. Our lack of awareness of this disease in its early stages resulted in our missing the chance to do a parathyroidectomy that might have changed the course. It is important to know the clinical features of this rare disease in order to make a diagnosis as early as possible.

[Traumatic diaphragmatic herniation after continuous thoracic drainage: a case report].

We report a case of traumatic diaphragmatic hernia (TDH) resulting from continuous thoracic drainage and was successfully treated by surgical procedures. A 45-year-old man was admitted to our department due to shock after a blunt trauma by a traffic accident. As he revealed left hemothorax on admission, continuous thoracic drainage was performed. Soon after the drainage, diaphragmatic hernia occurred as an incarceration of the spleen into the thoracic cavity. In the literature, 80 cases with TDH have been reported in Japan since 1986. The purpose of this study is to discuss the mechanism of TDH in the acute phase and to consider its appropriate diagnostic tools. The following two results were obtained. (1) TDH may be appeared during the clinical course, especially after a continuous thoracic drainage, in patients with damaged diaphragm by blunt traumas. (2) CT is the most effective tool for the diagnosis of TDH.

[Successful resection of endotracheal metastatic lung cancer using percutaneous cardiopulmonary support system: a case report].

We experienced a rare case of endotracheal metastasis derived from squamous cell lung cancer. The patient was 56 year-old male whose primary lung cancer of the left upper lobe was completely resected. Pathological diagnosis indicated stage IIB and he underwent two cycles of chemotherapy with CDDP + VDS. He had been asymptomatic thereafter, however, two years postoperative chest CT revealed a nodular lesion of the anterior carinal wall. Bronchofiberoptic examination showed same as CT finding and its brushing cytology confirmed squamous cell carcinoma. WE successfully resected his endotracheal metastatic lesion and reconstructed by direct sutures assisted by PCPS (Percutaneous Cardiopulmonary Support System). His postoperative course was uneventful. Majority of the reported cases of endotracheal metastases were treated conservatively as radiation, laser and/or chemotherapy. We conclude that PCPS is useful device for surgical management for selected cases.

Is carotid reconstruction for advanced cancer in the neck a safe procedure?

Head and neck surgeons hesitate to resect the carotid artery because of the postoperative risk of neurologic sequelae. On the other hand, there is no curative therapeutic option for head and neck cancer involving the carotid artery, except for complete tumor removal. A retrospective review of all published articles in the English literature dealing with carotid reconstruction for head and neck cancer from 1987 to 1998 was performed. There were only 11 articles, including our series, that reported outcomes of this procedure. Among the 148 patients of this series, major neuromorbidity was 4.7%, and mortality occurred in 6.8% of the patients. Combined major neuromorbidity and mortality was 10.1%. Because total removal of the advanced cancer is the only therapy that can offer the patients a chance for cure, head and neck surgeons should aggressively perform carotid resection and reconstruction.