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.

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.

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.

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.

The presence of CD5LOW+NK cells in normal controls and patients with pulmonary tuberculosis.

CD5 antigen is present on all normal alpha beta T cells and some B cells. Human NK cells do not usually express CD5 antigen, but we found a subset of CD5LOW+ (low density of CD5) NK cells in some patients with pulmonary tuberculosis. Unlike CD5-NK cells, most CD5LOW+NK cells had HLA-DR. We observed few CD5LOW+NK cells in the normal controls and some in the large granular lymphocyte (LGL) population purified by Percoll density centrifugation. Sorted CD5LOW+NK populations were LGL. The CD5LOW+NK cells had high lytic activity on K562 cells in a 4-h 51chromium release assay. Our results indicate that there is a previously unidentified subset of NK cells.

Spontaneous cytokine overproduction by peripheral blood mononuclear cells from patients with myelodysplastic syndromes and aplastic anemia.

We studied spontaneous cytokine production by peripheral blood mononuclear cells (PBMC) obtained from 14 patients with aplastic anemia (AA) and 28 various myelodysplastic syndromes (MDS). The levels of interleukin-6, interleukin-1 beta, and tumor necrosis factor-alpha in cultured PBMC were measured by ELISA. The average levels of these cytokines were higher in AA or in refractory anemia (RA) than in RA with excess of blasts (RAEB) or in RAEB in transformation (RAEB-T). Marked cytokine overproduction was observed in RA as well as in AA. High cytokine levels were observed in hypocellularity and low blast cell counts in the bone marrow. These results may suggest that the increase of cytokines may be a reactive response in hypocellular bone marrow.

Increased proliferation of eosinophil clusters in myelodysplastic syndromes.

A patient with myelodysplastic syndromes (MDS) developed eosinophilia during treatment with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). To study the mechanism of this eosinophilia, we investigated the proliferation of eosinophil colony-forming units (CFU-Eo) in nine patients and four healthy controls. Eosinophil clusters increased significantly in the patients (P < 0.01) compared with controls, but eosinophil colonies were not different between controls and MDS patients. In addition, the eosinophil clusters were significantly increased with rhGM-CSF in MDS patients compared with controls, although serum GM-CSF concentrations were similar in both groups. These results suggest that eosinophil clusters are increased in MDS either through abnormal progenitor proliferation or hypersensitivity to GM-CSF.

Influence of dialysis membranes on the development of dialysis associated osteoarthropathy.

The influence of the dialysis membrane and the patients' ages on the development of dialysis osteoarthropathy was studied in 25 patients who had been on hemodialysis for more than 10 years. The patients were dialyzed with cuprophane membranes, and then treated with polyacrylonitrile AN 69. Radiolucent bone cysts (at least 5 mm in diameter in the wrists and at least 10 mm in the shoulders or hips) were evaluated by X-ray and confirmed by CT scan. The patients with bone cysts (N = 9) had been exposed significantly more to cuprophane dialysis and significantly less to AN 69 dialysis than the patients without bone cysts (N = 16). There was no significant difference in the total duration of dialysis between the two groups. The average age was significantly greater in patients with bone cysts than in patients without bone cysts. The severity of the cystic bone lesions correlated positively with the patient's age and the duration of dialysis using cuprophane membranes, and negatively with the duration of dialysis using AN 69. These findings suggest that the development of dialysis osteoarthropathy may be related to both age and the use of cuprophane membranes. Hemodialysis using AN 69 may prevent, or at least postpone the development of dialysis amyloidosis.

In vitro proliferative and differentiated responses of lymphoma cells to PHA and IL-4 in a patient with intermediate lymphocytic lymphoma.

We carried out in vitro B cell colony assays, with phytohemagglutinin-P (PHA-P) and IL-4, on B cells from one intermediate lymphocytic lymphoma (ILL) patient and four chronic lymphocytic leukemia (CLL) patients. Peripheral blood B cells from the ILL patient responded to PHA and IL-4, they proliferated, and differentiated into cells with plasmacytoid cell morphology. They lost the CD19 surface antigen after 10 day co-culture with PHA and IL-4. The bone marrow of this ILL patient contained atypical plasma cells with multiple nuclei. Peripheral blood B cells from the four CLL patients responded to PHA, but IL-4 did not increase PHA-induced B cell colony formation in these cells. The CLL cells did not differentiate into plasma cells, and they were clearly different from the ILL cells in morphology, as shown by scanning electron microscope examination. Since this study was performed on cells from only one ILL patient, further examination of cells from many patients might be necessary to confirm the difference between ILL and B cell-type CLL.

The increase of CD5LOW+NK cells in patients with multiple myeloma and plasmacytoma.

CD5 antigen is present on all normal alpha beta T cells and some B cells. Human NK cells do not usually express CD5 antigen, but we found a novel subset of CD5LOW (low density of CD5) positive (CD5LOW+) natural killer cells (NK cells) in patients with multiple myeloma (MM) and plasmacytoma. To detect CD5LOW+NK cells, we examined the lymphocytes of 23 patients with MM and plasmacytoma by flow cytometry. Five out of 23 patients had CD5LOW+NK populations. These patients had many more NK cells than the other patients in the peripheral blood and bone marrow. The CD5LOW+NK cells had CD2, low density of CD8, CD16 and CD56, but no CD3, CD19, or CD20. Most of the CD5LOW+NK cells had HLA-DR, unlike the CD5-NK cells. Sorted CD5LOW+CD16+ populations were large granular lymphocytes (LGL). The CD5LOW+NK cells had some lytic activity on K562 cells in a 4-hour 51Cr release assay. Our results indicate that there is a novel subset of NK cells in some patients with MM and plasmacytoma and that CD5LOW+NK cells may be associated with NK cell activation.

Possible differentiation treatment with aclacinomycin A in acute myelomonocytic leukemia refractory to conventional chemotherapy.

A patient with acute myelomonocytic leukemia (M4 in FAB classification) refractory to various kinds of intensive chemotherapy was intravenously administered low doses (7 or 14 mg/m2) of aclacinomycin-A (ACM-A) daily. This increased mature neutrophils and monocytes and decreased leukemia cells in the peripheral blood. Pelger Huet-like nuclear anomaly, observed in the neutrophils, suggested the leukemic nature of these cells. The in vivo findings were clearly correlated with the in vitro results in which ACM-A could induce myelomonocytic differentiation of the leukemia cells. During the course of the treatment, the patient achieved and maintained good general condition for more than nine months after the initiation of the treatment. In clinical trials, nine patients, five with acute myeloid leukemia (AML) and four with myelodysplastic syndrome (MDS), were treated with low doses of ACM-A. Five patients, three AML and two MDS, responded to the treatment. The results suggest that low doses of ACM-A may induce in vivo differentiation of leukemia cells, and may be a potential therapeutic strategy in the treatment of AML or MDS that is refractory to conventional chemotherapy.

Carotid resection and reconstruction for advanced cervical cancer.

Patients with advanced cervical cancers often have direct invasion of their carotid arteries. The prognosis for these patients with nonsurgical therapy is extremely poor. Because complete tumor removal is the only therapy that can offer these patients a chance for cure, carotid resection should be performed. We performed carotid resection and reconstruction on nine patients with advanced cervical cancers. Of these patients, none suffered from severe neurologic postoperative complications such as permanent hemiplegia. Three of the nine patients have been disease free for more than 24 months. These three patients would not have survived without carotid resection. Further study will show the usefulness of carotid resection and reconstruction in decreasing the morbidity and mortality in patients with cervical cancer involving the carotid artery.

Studies on T-cell colony formation in chronic renal failure (CRF) patients.

In order to study the possibility of abnormal differentiation and proliferation of T-cell precursors in chronic renal failure (CRF), we studied T-cell colony formation in CRF patients. The two-step monolayer method, with phytohemagglutinin-P as the inducer, was used for T-cell colony formation. In our results, colony formation was markedly reduced in CRF patients in comparison with normal controls, with about half of the former showing no colony growth. All cases showed a significant increase in colony numbers with in vitro plasmapheresis (the replacement of autologous plasma in the culture system with normal AB plasma). A significant increase in colony numbers was also seen with the addition of exogenous interleukin-2 (IL-2). The addition of IL-2 in the presence of normal plasma, in particular, induced an increase in colony numbers to near the levels in normal subjects. These results suggest that T-cell precursors exist in near normal numbers in CRF patients and that there are uremic inhibitors in the plasma. A reduced production of IL-2 is also indicated. These factors may be involved in the pathogenesis of immunodeficiency in CRF patients.

Deisovalerylblastmycin produced by Streptomyces SP.

A new antifungal antibiotic was isolated from the fermentation broth of Streptomyces sp. 5140-A1. Degradation studies of the crystalline antibiotic, m.p. 186 approximately 188 degrees C, C21H28O8N2, suggested Piricularia oryzae and less toxicity against killfish than antimycin A--blastmycin antibiotics.

Signal transduction inhibitors, hibarimicins, A, B, C, D and G produced by Microbispora. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties.

Strain TP-AO121 which produces a complex of novel tyrosine kinase inhibitors designated hibarimicins A, B, C, D and G was considered to be a new subspecies of Microbispora rosea, and the name, Microbispora rosea subsp. hibaria, was proposed. Hibarimicins A, B, C and D specifically inhibited the src tyrosine kinase activity without affecting protein kinase A or protein kinase C. They also showed in vitro anti-Gram-positive bacterial and antitumor activities. The molecular formulae of hibarimicins A, B, C, D and G were assigned to be C85H112O37, C85H112O37, C83H110O36, C85H112O38, and C85H112O39 respectively.

Signal transduction inhibitors, hibarimicins A, B, C, D and G produced by Microbispora. II. Structural studies.

The structure of hibarimicins A, B, C, D and G which are inhibitors for tyrosine specific protein kinase are determined using spectroscopic techniques. Hibarimicins described in this report consist of a common aglycon and six deoxyhexoses. The aglycon contains a highly oxidized naphtylnaphthoquinone as a chromophore. Among them, hibarimicin B was identical with angelmicin B.

Therapeutic effect of taurine in congestive heart failure: a double-blind crossover trial.

In a double-blind, randomized, crossover, placebo-controlled study, we investigated the effects of adding taurine to the conventional treatment in 14 patients with congestive heart failure for a 4-week period. Compared with placebo, taurine significantly improved the New York Heart Association functional class (p less than 0.02), pulmonary crackles (p less than 0.02), and chest film abnormalities (p less than 0.01). A benefit of taurine over placebo was demonstrated when an overall treatment response for each patient was evaluated on the basis of clinical examination (p less than 0.05). No patient worsened during taurine administration, but four patients did during placebo. Pre-ejection period (corrected for heart rate) decreased from 148 +/- 14 ms before taurine treatment to 137 +/- 12 ms after taurine (p less than 0.001), and the quotient pre-ejection period/left ventricular ejection time decreased from 47 +/- 9 to 42 +/- 8% (p less than 0.001). Side effects did not occur in the patients during taurine. The results indicate that addition of taurine to conventional therapy is safe and effective for the treatment of patients with congestive heart failure.

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.