Dehalogenation of chlorinated hydroxybiphenyls by fungal laccase

We have investigated the transformation of chlorinated hydroxybiphenyls by laccase produced by Pycnoporus cinnabarinus. The compounds used were transformed to sparingly water-soluble colored precipitates which were identified by gas chromatography-mass spectrometry as oligomerization products of the chlorinated hydroxybiphenyls. During oligomerization of 2-hydroxy-5-chlorobiphenyl and 3-chloro-4-hydroxybiphenyl, dechlorinated C---C-linked dimers were formed, demonstrating the dehalogenation ability of laccase. In addition to these nonhalogenated dimers, both monohalogenated and dihalogenated dimers were identified.

Impact of plasmapheresis on platelet hemostatic capacity in healthy voluntary blood donors detected by the platelet function analyzer PFA-100

Previous flow cytometry studies showed that platelet activation may occur during cytapheresis, cardiopulmonary bypass and hemodialysis. The aim of this pilot study was to determine if the impact of plasmapheresis leads to alterations in platelet hemostatic capacity. Plasmapheresis was carried out in 30 volunteers using an Autopherese C (Baxter) and an MCS3p (Haemonetics). Blood samples were collected and analyzed immediately before and after plasmapheresis. As a result of the plasmapheresis on the Autopherese C, the mean closure time (CT) for collagen/epinephrine (Col/Epi) increased from 118.2 +/- 25.1 to 149.9 +/- 35.0 s and from 88.7 +/- 16.9 to 98.5 +/- 26.3 s for collagen/ADP (Col/ADP), respectively. Seven subjects showed impaired CTs after plasmapheresis for Col/Epi. For Col/ADP, five subjects showed impaired CTs after apheresis. Statistical analysis (McNemar test) showed a significant difference before and after apheresis for Col/Epi (P = 0.024) but not for Col/ADP (P = 0.088). Similar results were shown for plasmapheresis carried out with the MCS3p. These findings show that plasmapheresis can cause an impairment of platelet function in healthy volunteers as measured by the PFA-100, an effect of so far unknown clinical significance.

Reconstructive urology in the nordic countries--a hospital questionnaire survey

A hospital survey of adult reconstructive urologic surgery in the Nordic countries is presented. The response rate was 80% and included most general hospitals and university clinics. Despite similarities between the healthcare systems of the various countries several differences were found. Cystectomy was performed in a large number of institutions in all countries except Denmark. The annual number of orthotopic bladder substitutions per institution was calculated as three to four (range of medians for each country) and the number of continent cutaneous diversions as two to seven. Open urethral procedures were performed more frequently in Sweden than in the other countries. Surgery for penile curvature and implantation of three-component prostheses for erectile dysfunction was more commonly performed in Denmark and Iceland compared to Sweden.

Surface-induced dissociation on a MALDI-ion mobility-orthogonal time-of-flight mass spectrometer: sequencing peptides from an "in-solution" protein digest

Peptide sequencing by surface-induced dissociation (SID) on a MALDI-ion mobility-orthogonal TOF mass spectrometer is demonstrated. SID of approximately 100-fmol amounts of model peptides HLGLAR (m/z 666.8), gramicidin S (m/z 1142.5), and bovine insulin b chain (m/z 3495.5) was accomplished using hydrocarbon-coated gold grids and approximately 20-eV collision energies. The current version of the instrument achieves a mobility resolution of approximately 20 and TOF mass resolution better than 200. Peptide sequences of four peptides from a tryptic digest of cytochrome c (approximately 1 pmol deposited) were obtained. The advantage of IM-SID-o-TOF-MS is that a single experiment can be used to simultaneously measure the molecular weights of the tryptic peptide fragments (e.g., peptide mass mapping) and partial sequence analysis, (e.g., real-time tandem mass spectrometry.)

Sharp transients in the EEGs of non-epileptic adult patients receiving sevoflurane

OBJECTIVE

In this article unexpected EEG findings are described which were observed during EEG monitoring under sevoflurane anesthesia.

METHOD

In seven non-epileptic adult patients sevoflurane was administered as inhalation anesthetic during routinely performed surgical operations. The EEG was recorded continuously as part of the standard monitoring process and served mainly as a dosage guide for anesthetics/narcotics.

MAIN OUTCOME MEASURE

Occurrence of sharp transients in the EEG resembling distinctive waves which can be seen in epileptic disorders.

RESULTS

In six of the seven patients under 8.0% sevoflurane, sharp transients were observed which appeared in very deep EEG stages, mostly with endtidal sevoflurane concentrations of 4.8-5.9%. The findings are in accordance with observations in non-epileptic children from our clinic.

CONCLUSIONS

The clinical significance of the observed EEG pattern under sevoflurane anesthesia is still unclear. Taking into consideration that convulsive and nonconvulsive status epilepticus can be followed by signs of brain damage, it would appear to be important to further investigate the phenomenon.

[Value of EEG monitoring in intensive care patients in plastic surgery--indications and experiences]

EEG monitoring can be performed at the patients' bedside and it is a valuable support in therapeutic decision making providing unique information about the functional state of the brain. Due to newer technical developments, EEG monitoring can be conducted rather easily. In this article, indications for EEG monitoring in plastic surgical patients are presented: controlling the level of sedation, use in states of increased intracranial pressure, screening the cerebral state in comatose patients, diagnosis and therapy of epileptic seizures, and the search for circumscribed cerebral abnormalities. Furthermore, practical experience with the use of the new EEG monitor Narcotrend, which is provided with an automatic EEG classification, is described.

[Epileptoform EEG activity: occurrence under sevoflurane and not during propofol application]

In a 62-year-old female patient without a history of epileptic seizures EEG monitoring (EEG monitor: Narcotrend) was routinely performed during propofol/remifentanil and during sevoflurane/remifentanil/nitrous oxide anaesthesia. In the first course of anaesthesia after a bolus of propofol 1% a continuous EEG slowing was followed by a burst suppression pattern without occurrence of epileptiform activity throughout this sequence. During the second course of anaesthesia the sevoflurane concentration was increased from 2 to 8 % by volume. After 5 min epileptiform activity appeared in the EEG at an endtidal concentration of 5.9% by volume.

Thymomas alter the T-cell subset composition in the blood: a potential mechanism for thymoma-associated autoimmune disease

Thymomas are the only tumors that are proven to generate mature T cells from immature precursors. It is unknown, however, whether intratumorous thymopoiesis has an impact on the peripheral T-cell pool and might thus be related to the high frequency of thymoma-associated myasthenia gravis. This study shows, using fluorescence-activated cell sorting-based analyses and T-cell proliferation assays, that thymopoiesis and T-cell function in thymomas correspond with immunologic alterations in the blood. Specifically, the proportion of circulating CD45RA(+)CD8(+) T cells is significantly increased in patients with thymoma compared with normal controls, in accordance with intratumorous T-cell development that is abnormally skewed toward the CD8(+) phenotype. Moreover, it is primarily the proportion of circulating CD45RA(+)CD8(+) T cells that decreases after thymectomy. The results also demonstrate that T cells reactive toward recombinant autoantigens are distributed equally between thymomas and blood, whereas T-cell responses to foreign antigen (ie, tetanus toxoid) are seen only among circulating T cells and not among thymoma-derived T cells. These functional studies support the hypothesis that thymopoiesis occurring within thymomas alters the peripheral T-cell repertoire. Because many thymomas are enriched with autoantigen-specific T cells, a disturbance of circulating T-cell subset composition by export of intratumorous T cells may contribute to paraneoplastic autoimmune disease arising in patients with thymoma. (Blood. 2000;96:3872-3879)

Protein kinase C beta1 is implicated in the regulation of neuroblastoma cell growth and proliferation

To investigate a putative involvement of protein kinase C (PKC) isoforms in supporting neuroblastoma cell proliferation, SK-N-BE(2) neuroblastoma cells were transfected with expression vectors coding for the C2 and V5 regions from different PKC isoforms. These structures have been suggested to inhibit the activity of their corresponding PKC isoform. The PKC fragments were fused to enhanced green fluorescent protein to facilitate the detection of transfected cells. Expression of the C2 domain from a classical PKC isoform (PKCalpha), but not of C2 domains from novel PKCdelta or PKCepsilon, suppressed the number of neuroblastoma cells positive for cyclin A and bromodeoxyuridine incorporation. This indicates a role for a classical isoform in regulating proliferation of these cells. Among the V5 fragments from PKCalpha, PKCbetaI, and PKCbetaII, the PKCbetaI V5 had the most suppressive effect on proliferation markers, and this fragment also displaced PKCbetaI from the nucleus. Furthermore, a PKCbeta-specific inhibitor, LY379196, suppressed the phorbol ester- and serum-supported growth of neuroblastoma cells. There was a marked enhancement by LY379196 of the growth-suppressive and/or cytotoxic effects of paclitaxel and vincristine. These results indicate that PKCbetaI has a positive effect on the growth and proliferation of neuroblastoma cells and demonstrate that inhibition of PKCbeta may be used to enhance the effect of microtubule-interacting anticancer agents on neuroblastoma cells.

The role of microsatellite instability in gastric low- and high-grade lymphoma development

DNA mismatch repair genes and their dysfunction as evidenced by microsatellite instability (MSI) play an important role in the pathogenesis of a variety of tumors, most prominently hereditary nonpolyposis colorectal cancer (HNPCC). However, their role in development of extranodal lymphomas has not been established yet. We therefore evaluated for MSI 25 gastric low-grade marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue type and 31 gastric high-grade diffuse large B-cell lymphomas (DLBCLs) with 29 and 118 microsatellites, respectively. Compared with HNPCC, the overall level of MSI was much lower with a mean of 2.6% MSI-positive repeats in the DLBCLs; the frequency of MSI showed a tendency to increase with age (P = 0.01), as did MSI variability (P = 0.02). Low-grade mucosa-associated lymphoid tissue lymphomas displayed even less MSI (sevenfold) than DLBCLs (P = 0.009). MSI frequency thus increases with the transition from low- to high-grade disease and with age; it does not seem to initiate lymphomagenesis. Other microsatellites than those typically mutated in HNPCC frequently revealed MSI in these lymphomas, especially dinucleotide repeats on chromosomes 3, 5, and 18. To facilitate rapid screening of lymphomas for MSI and to establish a tool for future MSI frequency comparisons, we recommend to use repeats D3S1261, D3S1530, D5S346, D17S250, D18S474, and DCC.

Tumor biology of mucosa-associated lymphoid tissue lymphomas

Extranodal lymphomas arising at mucosal sites exhibit clinicopathological features that suggest a closer relationship of these tumors to the structure and function of mucosa-associated lymphoid tissue (MALT) than to lymph nodes. The factors that induce MALT in these tissues are operative in early MALT lymphoma development and the progressive independence on T-cell help defines late stages of MALT lymphoma genesis.

VIDAS enzyme-linked immunoflourescent assay for detection of Listeria in foods: collaborative study

The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.

Epileptiform activity in the EEGs of two nonepileptic children under sevoflurane anaesthesia

Two case reports of nonepileptic children are presented, who developed paroxysmal EEG potentials in routinely performed EEG recordings during inhalation of sevoflurane, 7 and 8% by volume respectively. Taking into account several reports from the literature about epileptiform potentials or convulsive movements under similar conditions, it seems to be important to investigate carefully the circumstances under which these phenomena appear as well as possible clinical consequences.

Rings in the Planetesimal Disk of beta Pictoris

The nearby main-sequence star beta Pictoris is surrounded by an edge-on disk of dust produced by the collisional erosion of larger planetesimals. Here we report the discovery of substructure within the northeast extension of the disk midplane that may represent an asymmetric ring system around beta Pic. We present a dynamical model showing that a close stellar flyby with a quiescent disk of planetesimals can create such rings, along with previously unexplained disk asymmetries. Thus we infer that beta Pic's planetesimal disk was highly disrupted by a stellar encounter in the last hundred thousand years.

Genetic aberrations common in gastric high-grade large B-cell lymphoma

Genetic aberrations associated with the development of extranodal high-grade large B-cell lymphoma originating in the stomach have not been fully identified yet. We analyzed 31 such lymphomas using 73 microsatellite markers for allelic imbalance and microsatellite instability. The highest frequency (42%) of loss of heterozygosity (LOH) was found on the long arm of chromosome 6. We identified 2 LOH hot spots on 6q21-22.1 and 6q23.3-25, flanked by markers D6S246-D6S261 and D6S310-D6S441, respectively, containing putative tumor suppressor genes (TSGs). These 6q aberrations were found to be the sole allelic imbalance in 1 patient only; they were mostly accompanied by additional abnormalities. Several known TSGs, namely, the APC, p15/p16, p53, and DCC genes, were found to suffer frequent LOH during lymphomagenesis. LOH was also detected in regions containing putative TSGs on 7q and 13q14. Frequent amplification of genomic material was found in the 2p, 3q27 at the BCL-6 gene locus, 6p, 7q, 11q23-24 at the MLL gene locus, and 18q regions. Analysis of the pattern of occurrence of these aberrations revealed an association of the amplification of the MLL gene region with LOH at the p53 locus (P =.02). Only low frequency of microsatellite instability (MSI) was detected in these lymphomas and MSI incidence increased with age (P =.01). Karyotypic instability thus plays the main role in the development of gastric high-grade large B-cell lymphoma. Common genetic aberrations responsible for lymphomagenesis are deletions of 6q, loss of p53, and amplification of the 3q27 and the MLL gene regions. (Blood. 2000;95:1180-1187)

Metabolic evaluation and medical management of upper urinary tract stone disease. Guidelines from the Scandinavian Cooperative Group for Urinary Stones

A set of simple guidelines for metabolic evaluation and medical/dietary management of patients with urolithiasis is presented. The evaluation scheme is based on the documented risk factors in the Nordic area and the results of controlled clinical trials, and takes its basis in the severity of the stone disease in the individual stone patient. The initial evaluation in all patients aims at diagnosing conditions with a definitive metabolic, infectious or anatomical/functional cause of stone formation (MIAF urolithiasis). Patients with MIAF urolithiasis are treated according to the nature of the underlying disease. Having excluded/diagnosed MIAF urolithiasis, patients with idiopathic calcium nephrolithiasis remain, and in this group, which comprises approximately 85% of the total stone population in the Scandinavian region, only those with a complicated stone disease are subjected to additional evaluation, which aims at identifying underlying pathophysiological derangements for which medical therapy has been proven to be effective in controlled clinical trials.

H+ -PPases: a tightly membrane-bound family

The earliest known H+-PPase (proton-pumping inorganic pyrophosphatase), the integrally membrane-bound H+-PPi synthase (proton-pumping inorganic pyrophosphate synthase) from Rhodospirillum rubrum, is still the only alternative to H+-ATP synthase in biological electron transport phosphorylation. Cloning of several higher plant vacuolar H+-PPase genes has led to the recognition that the corresponding proteins form a family of extremely similar proton-pumping enzymes. The bacterial H+-PPi synthase and two algal vacuolar H+-PPases are homologous with this family, as deduced from their cloned genes. The prokaryotic and algal homologues differ more than the H+-PPases from higher plants, facilitating recognition of functionally significant entities. Primary structures of H+-PPases are reviewed and compared with H+-ATPases and soluble PPases.

Etiology and incidence of pressure ulcers in surgical patients

This experimental study was designed to identify the etiology of pressure ulcers in a surgical sample and to evaluate a special OR mattress overlay in preventing pressure ulcer development. Surgical patients (N = 413) were randomized to receive "usual perioperative care" or the new mattress overlay. Over six postoperative days, 89 patients (21.5%) developed pressure ulcers, primarily stage I. Only 2% developed stage II or IV ulcers. Patients with ulcers were statistically older, had diabetes, were smaller in body mass, had lower Braden Scale scores on admission, and used the new mattress overlay (P < .02). Pressure ulcers that presented as "burns" or ecchymosis did not deteriorate to stage III or IV ulcers during the study. The mattress overlay was not effective in preventing pressure ulcer development.

Interindividual heterogeneity in the hypoxic regulation of VEGF: significance for the development of the coronary artery collateral circulation

BACKGROUND

The coronary artery collateral circulation may be beneficial in protecting against myocardial ischemia and necrosis. However, there is a tremendous interindividual variability in the degree of new collateral formation in patients with coronary artery disease. The basis for this interindividual heterogeneity is not understood. In this study we test the hypothesis that failure to generate collateral vessels is associated with a failure to appropriately induce with hypoxia or ischemia the angiogenic factor, vascular endothelial growth factor (VEGF).

METHODS AND RESULTS

We correlated the VEGF response to hypoxia in the monocytes harvested from patients with coronary artery disease with the presence of collaterals visualized during routine angiography. We found that there was a highly significant difference in the hypoxic induction of VEGF in patients with no collaterals compared with patients with some collaterals (mean fold induction 1.9+/-0.2 versus 3.2+/-0.3, P<0.0001). After subjecting the data to ANCOVA, using as covariates a number of factors that might influence the amount of collateral formation (ie, age, sex, diabetes, smoking, hypercholesterolemia), patients with no collaterals still have a significantly lower hypoxic induction of VEGF than patients with collaterals.

CONCLUSIONS

This study provides evidence in support of the hypothesis that the ability to respond to progressive coronary artery stenosis is strongly associated with the ability to induce VEGF in response to hypoxia. The observed interindividual heterogeneity in this response may be due to environmental, epigenetic, or genetic causes. This interindividual heterogeneity may also help to explain the variable angiogenic responses seen in other conditions such as diabetic retinopathy and solid tumors.

Guanylyl cyclases with the topology of mammalian adenylyl cyclases and an N-terminal P-type ATPase-like domain in Paramecium, Tetrahymena and Plasmodium

We cloned a guanylyl cyclase of 280 kDa from the ciliate Paramecium which has an N-terminus similar to that of a P-type ATPase and a C-terminus with a topology identical to mammalian adenylyl cyclases. Respective signature sequence motifs are conserved in both domains. The cytosolic catalytic C1a and C2a segments of the cyclase are inverted. Genes coding for topologically identical proteins with substantial sequence similarities have been cloned from Tetrahymena and were detected in sequences from Plasmodium deposited by the Malaria Genome Project. After 99 point mutations to convert the Paramecium TAA/TAG-Gln triplets to CAA/CAG, together with partial gene synthesis, the gene from Paramecium was heterologously expressed. In Sf9 cells, the holoenzyme is proteolytically processed into the two domains. Immunocytochemistry demonstrates expression of the protein in Paramecium and localizes it to cell surface membranes. The data provide a novel structural link between class III adenylyl and guanylyl cyclases and imply that the protozoan guanylyl cyclases evolved from an ancestral adenylyl cyclase independently of the mammalian guanylyl cyclase isoforms. Further, signal transmission in Ciliophora (Paramecium, Tetrahymena) and in the most important endoparasitic phylum Apicomplexa (Plasmodium) is, quite unexpectedly, closely related.