CreA modulates the XlnR-induced expression on xylose of Aspergillus niger genes involved in xylan degradation.

The expression of the feruloyl esterase gene faeA, the alpha-glucuronidase gene aguA, the endoxylanase gene xlnB, and the beta-xylosidase gene xlnD from Aspergillus niger on xylose was studied in a wild-type strain and in a CreA mutant. A decrease in expression of all four genes was observed with increasing xylose concentrations in the wild-type strain, whereas expression levels in the CreA mutant were not influenced. The results in the wild type indicated that xylose concentrations higher than 1 mM resulted in repression of the expression of the xylanolytic genes tested mediated by the carbon catabolite repressor protein CreA. On xylose, the expression levels of the xylanolytic genes were therefore not only determined by induction via XlnR, but also by repression via CreA. The genes tested were not influenced to the same extent by XlnR or CreA, resulting in specific expression levels and patterns for each individual gene.     

High dose propofol enhances red cell antioxidant capacity during CPB in humans

PURPOSE: To compare low vs. high dose propofol and isoflurane on red cell RBC antioxidant capacity in patients during aortocoronary bypass surgery (ACBP). METHODS: Twenty-one patients, for ACBP, were anesthetized with sufentanil 0.5-10 microg x kg(-1) and isoflurane 0-2%; ISO = control; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 1-2.5 mg x kg(-1) bolus then 100 microg x kg(-1) min(-1) before, and 50 microg x kg(-1) x min(-1) during CPB (LO; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 2-2.5 mg x kg(-1) bolus then 200 microg x kg(-1) x min(-1) (HI; n = 7). Venous blood was drawn pre- and post-induction, after 30 min CPB, 5, 10, and 30 min of reperfusion, and 120 min post-CPB to measure red cell antioxidant capacity (malondialdehyde (MDA) production in response to oxidative challenge with t-butyl hydrogen peroxide) and plasma propofol concentration. Pre- induction blood samples were analyzed for antioxidant effects of nitrates on red cells. The tBHP concentration response curves for RBC MDA in ISO, LO and HI were determined. RESULTS: Preoperative nitrate therapy did not effect RBC MDA production. Perioperative RBC MDA production was similar in ISO and LO groups. Sustained intraoperative decrease in RBC MDA was seen with propofol 8.0+/-2.4 - 11.8+/-4.5 microg x ml(-1) in HI (P<0.05-0.0001). MDA production vs. log plasma propofol concentration was linear in HI dose. CONCLUSIONS: During CPB, RBC antioxidant capacity is enhanced and maintained with HI dose propofol. Propofol, at this dose, may prove useful in protecting against cardiopulmonary ischemia-reperfusion injury associated with ACBP.     

Detection of muscarinic receptors in the human lung using PET.

The characterization of pulmonary muscarinic receptors with PET is still in its infancy. Because approximately 70% of the lungs consists of air and pulmonary muscarinic receptor densities are low, ligands with high receptor affinity are required to obtain reasonable signal-to-noise ratios on PET images. Therefore, the potent 11C-labeled muscarinic antagonist N-methyl-piperidin-4-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate methiodide ([R]-VC-002) was developed. We administered this radioligand to four healthy human volunteers to examine its suitability for studying pulmonary muscarinic receptors in vivo. METHODS: [11C]VC-002 (185 MBq, specific activity > 7.4 TBq/mmol) was intravenously injected on 2 separate days, with an interval of at least 1 wk. On the first day the volunteers were not pretreated, but on the second day they received the anticholinergic glycopyrronium bromide (Robinul; 2 x 0.1 mg intravenous) 25 and 30 min before the injection of the radiopharmaceutical. C[15O]O scans (approximately 740 MBq [20 mCi] by inhalation) were acquired before the receptor scan to calculate pulmonary blood volume. RESULTS: On PET images of the thorax, the lungs were clearly visible. After the volunteer was pretreated with glycopyrronium bromide, pulmonary uptake of the radioligand was reduced to 32%+/-12% of the control value at 60 min postinjection and the lungs could no longer be seen. (R)-[11C]-VC-002 was rapidly cleared from plasma and was slowly metabolized during the time course (60 min) of the PET scan. The fraction of radioligand representing parent compound decreased from 99.9% at the time of injection to 82% at 40-60 min postinjection, both in the presence and absence of Robinul. Pulmonary tissue-to-plasma ratios, calculated on a count-per-minute-per-gram basis, reached a plateau value of 17.8+/-1.2 at 40-50 min postinjection. CONCLUSION: [11C]VC-002 appears to be suitable for in vivo studies of pulmonary cholinoceptors.     

The diagnostic value of electroencephalography in mild senile Alzheimer's disease.

OBJECTIVE: We investigated the diagnostic value of the visually assessed electroencephalogram (EEG) in patients with mild Alzheimer's disease (AD), using the grand total of EEG (GTE) score. METHODS: Forty-nine non-demented control subjects with and without minimal cognitive impairment from the general population and 86 probable AD patients (NINCDS-ADRDA criteria), consecutively referred to a memory clinic, participated in this study. RESULTS: Frequency of rhythmic background activity (P<0.05), diffuse slow activity (P<0.001), and reactivity of the rhythmic background activity (P<0.001) were statistically significant related to the diagnosis control subject or AD patient, using logistic regression analysis with adjustment for age and sex. When these subscores were used to confirm the diagnosis of AD, thus at high specificity of 89.1% (GTE cut-off point of 3), the sensitivity was 44.6% and positive predictive value was 88.1%. Incremental ruling-in and ruling-out curves showed a maximum diagnostic gain of 38% for a positive test result at a prior probability ranging from 30 to 40%. At high pretest probability levels of 80-90%, the diagnostic gain for a positive test result was low, varying from 7 to 14%. CONCLUSION: In conclusion, the visually assessed EEG may give a clinically meaningful contribution to the diagnostic evaluation of AD when there is diagnostic doubt.     

First experiences with an accelerated CMV antigenemia test: CMV Brite Turbo assay.

BACKGROUND: Cytomegalovirus disease is still a major problem in immunocompromised patients, such as bone marrow or kidney transplantation patients. The detection of viral antigen in leukocytes (antigenemia) has proven to be a clinically relevant marker of CMV activity and has found widespread application. Because most existing assays are rather time-consuming and laborious, an accelerated version (Brite Turbo) of an existing method (Brite) has been developed. The major modification is in the direct lysis of erythrocytes instead of separation by sedimentation. OBJECTIVE: In this study the Brite Turbo method has been compared with the conventional Brite method to detect CMV antigen pp65 in peripheral blood leukocytes of 107 consecutive immunocompromised patients. RESULTS: Both tests produced similar results. Discrepancies were limited to the lowest positive range and sensitivity and specificity were comparable for both tests. CONCLUSIONS: Two major advantages of the Brite Turbo method could be observed in comparison to the original method: assay-time was reduced by more than 50% and only 2 ml of blood was required. An additional advantage was the higher number of positive nuclei in the Brite Turbo method attributable to the increased number of granulocytes in the assay. Early detection of CMV infection or reactivation has become faster and easier with this modified assay.     

三维超声心动图测定机械瓣瓣口面积初步经验

观察三维超声心动图测定机械瓣瓣口面积的可行性。方法１１例机械瓣置换病例,用任意 切面（ａｎｙｐｌａｎｅ）３ＤＥ测定机械瓣瓣口有效面积,将测定值与多普勒超声心动图（ＤＥ）测定的有效瓣口面积（包括实测值和文献报道测值）及生产厂商提供的离体瓣口面积比较。     

Transport of proteolipid protein to the plasma membrane does not depend on glycosphingolipid cotransport in oligodendrocyte cultures

The possibility that transport of proteolipid protein (PLP) from its site of synthesis to the plasma membrane is dependent on cotransport with (sulfo)galacto-cerebrosides was investigated in primary cultured oligodendrocytes and Chinese hamster ovary (CHO) cells expressing PLP. Sulfation was inhibited by growing oligodendrocytes in the presence of a competitive inhibitor of this process, sodium chlorate. Under these circumstances, sulfatide synthesis was inhibited by 85%. Nevertheless, PLP was still delivered to the plasma membrane in quantitative amounts. Furthermore, when PLP was expressed in CHO cells, which normally synthesize very low amounts of galactosyl ceramide (GalCer) and no sulfatide, PLP was transported to the plasma membrane. Moreover, in CHO cells coexpressing PLP and ceramide galactosyl transferase, PLP cell surface labeling was unaltered. Noting that it has been demonstrated that proteins destined for the apical surface of epithelial cells colocalize with glycolipid-enriched microdomains, we isolated detergent-insoluble membrane complexes from cultured oligodendrocytes. We found, however, that most of the PLP is present in the detergent-soluble fraction and, furthermore, that PLP could not be chased into or out of the insoluble fraction. Taken together, these data make it very likely that in oligodendrocytes PLP transport takes place irrespective of the presence of glycosphingolipids GalCer and sulfatide. J. Neurosci. Res. 51:371–381, 1998. © 1998 Wiley-Liss, Inc.