Effect of levetiracetam on cortical excitability: a transcranial magnetic stimulation study

BACKGROUND AND PURPOSE

We studied the effect of levetiracetam (LEV), an anticonvulsant with a novel mechanism of action, on cortical excitability, measured using transcranial magnetic stimulation (TMS). For this purpose, 38 healthy volunteers were assessed in two TMS sessions, before and after an oral dose of 3000 mg LEV.

METHODS

Resting motor threshold (RMT), intracortical facilitation (ICF) and intracortical inhibition (ICI), cortical silent period (CSP) threshold and duration and motor-evoked potential (MEP) amplitude were calculated.

RESULTS

After treatment with LEV, RMT was increased (mean +/- SD: 63 +/- 14% of the maximum stimulator output) compared with baseline (58 +/- 11%). CSP threshold was decreased after LEV (54 +/- 10%; baseline, 57 +/- 11%). CSP duration was increased after LEV (116 +/- 37 ms; baseline: 102 +/- 33 ms). LEV did not affect ICF or ICI or mean MEP amplitude significantly.

CONCLUSIONS

Our results indicate that LEV modulates some aspects of cortical excitability. Whereas the increase in the RMT most probably reflects the effect of LEV on ion channel activity, effects on the CSP might represent a modulation of GABA receptors at cortical and spinal level.

The impact of human ABO blood groups on human xenoreactive antibody-mediated cytotoxicity and the protective effect of human decay-accelerating factors exogene on swine endothelium

Swine tissue can express antigens similar to human A/B blood types. We evaluated whether the variation in human blood type influences the human xenoreactive antibody-mediated cytotoxicity and modifies the protective effect of human decay-accelerating factor (hDAF) exogene, a complement activation regulator, on swine endothelium.

METHODS

Pig aortic endothelial cells were harvested form normal and hDAF transgenic pigs. Cellular viability was evaluated with an MTT assay.

RESULTS

As compared with that of other human blood types, human serum from blood type O donors induced more prominent cytotoxicity on swine endothelial cells both from hDAF transgenic or normal pigs (P < .05). In addition, this difference of xenoreactive antibody-induced cytotoxicity between treatment with O and other human blood type sera was more evident in hDAF transgenic swine endothelial cells than those of normal pigs (P < .05). The hDAF exogene can significantly protect the endothelial cells from human xenoreactive antibody-mediated cytotoxicty when treated with human serum from AB blood type (P < .05). Our data demonstrated that human ABO blood type significantly affected human xenoreactive antibody-induced cytotoxicity, which may modulate the protective effect of hDAF exogene expression on swine endothelial cells.

Inhibition of VEGF blocks TGF-beta1 production through a PI3K/Akt signalling pathway

Vascular endothelial growth factor (VEGF) is a mediator of airway inflammation and remodelling in asthma. Transforming growth factor (TGF)-beta(1) plays pivotal roles in diverse biological processes, including tissue remodelling and repair in a number of chronic lung diseases. However, there are few studies elucidating the interactions between VEGF and TGF-beta(1) in allergic airway disease. A murine model of allergic airway disease was used to define the mechanism by which VEGF induces subepithelial fibrosis and to investigate a potential relationship between VEGF and TGF-beta(1) and the mechanisms by which VEGF signalling regulates TGF-beta(1) expression in allergic airway disease. The ovalbumin (OVA)-inhaled murine model revealed the following typical pathophysiological features of allergic airway disease in the lungs: increased numbers of inflammatory cells of the airways, airway hyperresponsiveness, increased peribronchial fibrosis, and increased levels of VEGF and TGF-beta(1). Administration of VEGF inhibitors reduced the pathophysiological signs of allergic airway disease and decreased the increased TGF-beta(1) levels and peribronchial fibrosis, including phosphoinositide 3-kinase (PI3K) activity after OVA inhalation. In addition, the increased TGF-beta(1) levels and collagen deposition after OVA inhalation were decreased by administration of PI3K inhibitors. These results suggest that inhibition of vascular endothelial growth factor attenuates peribronchial fibrosis, at least when mediated by regulation of transforming growth factor-beta(1) expression through phosphoinositide 3-kinase/Akt pathway in a murine model of allergic airway disease.

Detection of diverse SCCmec variants in methicillin-resistant Staphylococcus aureus and comparison of SCCmec typing methods

Non-duplicate methicillin-resistant Staphylococcus aureus (MRSA) isolates (n = 436), collected from four hospitals located in three Korean cities between 2001 and 2005, were investigated by SCCmec typing and multilocus sequence typing (MLST). Variations within SCCmec, especially type II, were detected in 165 (37.8%) isolates, and these variants were characterised using four different SCCmec typing methods. The predominant SCCmec type was a type II variant that differed from type II by the absence of a pUB110 insertion. MLST analysis showed that most of the isolates carrying SCCmec variants belonged to ST5.

Binding modes of mammalian hepatic Gal/GalNAc receptors

Mammalian Gal/GalNAc receptors show dramatic preference for three-branched oligosaccharide structures over two- or one-branched counterparts. The spatial arrangement of the Gal residues is extremely important for optimal binding. The three terminal Gal residues in the best triantennary ligand are about 15-30 A apart, and therefore the sugar-combining sites on the receptor may also have the same geometry. The results obtained with synthetic ligands containing Gal or GalNAc are in agreement with this concept. Photoaffinity labelling and GalNAc-lactoperoxidase catalysed iodolabelling of the receptors revealed that the minor subunits (52 and 60 kDa) were more readily labelled than the major subunit (43 kDa). The stoichiometry of binding was determined with synthetic ligands containing GalNAc. The results indicated that each subunit may have two sugar-combining sites. A model for subunit assembly is proposed on the basis of these results and the finding that coexpression of all subunits is necessary for the binding and processing of asialo-orosomucoid in transfected cells, whereas Gal-polylysine can be bound and processed by the cells expressing only the major subunit.

Attitudes towards day-case surgery in Hong Kong Chinese patients

OBJECTIVE

To evaluate attitudes of Chinese patients towards day-case surgery.

DESIGN

Prospective cross-sectional questionnaire survey.

SETTING

District public hospital, Hong Kong.

PATIENTS

Two hundred patients attending a preanaesthetic assessment clinic between 1 January and 30 June 2004 were invited to participate.

MAIN OUTCOME MEASURES

Demographic profiles, understanding and attitudes towards day-case surgery, preference for day-case surgery before and after the experience, postoperative adverse effects, and patient satisfaction.

RESULTS

The mean age of the patients was 28 (standard deviation, 19) years. In all 200 respondents completing the survey, 180 preferred day-case surgery. Important reasons for this view were: shorter duration of hospitalisation, dislike of hospital environments, belief that hospitals are highly infectious, need to look after their families, desire to return to work early, and doctors' advice. Small home environments and belief that day-case surgery was unsafe were not important. Respondents who did not prefer day-case surgery stressed the importance of better care available for hospital in-patients, concerns about surgical complications, postoperative nausea and vomiting, and doctors' advice. Only 11% patients complained of postoperative adverse effects. Demographic characteristics and previous day-case surgery experience did not have any effect on patient preferences. However, experiencing a postoperative adverse effect significantly affected the preference (P=0.005) and satisfaction (P=0.001) of respondents for day-case surgery.

CONCLUSION

Local Chinese patients attending our institution have a high preference for day-case surgery. Postoperative adverse effects might influence the respondents' satisfaction and preference after their surgical experience.

Treatment outcomes of 70 cases of early esophageal carcinoma: 12 years of experience

Early esophageal cancer (EEC) has an excellent prognosis compared to advanced esophageal cancer. Nowadays, endoscopic mucosal resection (EMR) may offer another alternative to cure early cancers of the gastrointestinal tract. We aimed to evaluate the clinical outcomes of EEC in Korea after curative treatments; EMR or surgery. We retrospectively reviewed the medical records of patients diagnosed as EEC from January 1994 to August 2005 at Yonsei University Medical Center, Seoul, Korea. Among 888 patients diagnosed with esophageal cancer, 70 (7.9%) were included as EEC. Among them, 10 patients (14.3%) were treated by EMR, and 50 (71.4%) by operation. The treatment outcomes of EEC in relation to various clinicopathologic factors along with survival rates were analyzed. There were 18 cases (30%) of mucosal lesions and 42 cases (70%) of submucosal lesions. Overall 5-year survival rate was 84.3%. When comparing treatment outcomes between EMR-treated and operated groups, there were no significant differences in complete remission (80%vs. 84%), recurrence (20%vs. 16%) and 5-year survival rate (100%vs. 78.3%). EEC is a potentially curable entity with a good clinical prognosis. EMR can be considered as another treatment arm for EEC, along with surgical resection.

Russell body gastritis associated with Helicobacter pylori infection: a case report

An unusual and rare gastric mucosal lesion histologically consisting of a localised accumulation of Russell bodies and Russell body-containing plasma cells, the so-called Mott cells, has been recognised only recently and termed as "Russell body gastritis". This lesion, despite its densely monomorphous appearance is easily confirmed to be non-neoplastic by its polyclonal immunoreactive pattern to immunoglobulin light chains. However, the aetiology of Russell body gastritis is controversial and hence the optimal treatment for this disease has not been established. Two cases of Russell body gastritis associated with Helicobacter pylori infection are reported, and the possible role of H pylori infection in the pathogenesis is discussed.

A 13-year longitudinal study of the impact of double mutations in the core promoter region of hepatitis B virus on HBeAg seroconversion and disease progression in patients with genotype C chronic active hepatitis

The pathogenic role of core promoter (CP) mutations (T1762/A1764) of hepatitis B virus (HBV) in hepatitis B e antigen (HBeAg) seroconversion or disease progression remains unclear. We investigated the clinical relevance of these mutants over a long-term follow-up period of up to 15 years. In this longitudinal cohort study, 29 HBeAg-positive patients with biopsy-proved chronic active hepatitis without cirrhosis were regularly monitored for >10 years. The viral isolates were characterized, using the frozen liver tissue obtained on the day of biopsy. Long-term outcomes were compared between patients with and without CP mutations of HBV at baseline. HBV genotyping showed that 100% of study subjects were infected with genotype C HBV. During a median follow-up period of 12.5 years, patients without double CP mutations of HBV at baseline showed a tendency towards achieving an earlier HBeAg seroconversion than those with (6.9 vs 9.4 years, P = 0.062) double CP mutations. Double CP mutations at baseline were also significantly associated with the eventual development of cirrhosis or hepatocellular carcinoma (P = 0.013), whereas the absence of double CP mutations predicted inactive carrier status at the last follow-up (P = 0.027). At 10 years, liver-related tests were also significantly better in patients without double CP mutations of HBV than in those with these mutations, as reflected by higher platelet counts and albumin levels (P = 0.036 and P = 0.044, respectively). Double T1762/A1764 mutations are significantly related to liver deterioration in HBeAg-positive genotype C active hepatitis patients. A longer period of immune clearance coupled with delayed HBeAg seroconversion appears to contribute to disease progression in patients harbouring these mutations in the CP region of HBV.

Polyphenol (-)-epigallocatechin gallate protection from ischemia/reperfusion-induced renal injury in normotensive and hypertensive rats

INTRODUCTION

The effect of epigallocatechin gallate (EGCG) in an in vivo renal model of ischemia with reperfusion (I/R) was compared between normotensive (WKR) and hypertensive (SHR) rats.

METHODS

WKR (groups I, II, III) and SHR groups (groups IV, V, VI) were divided into three types. Groups I and IV were sham-operated animals; groups II and V were subjected to 45 minutes of renal I/R; and groups III and VI received 10 mg/kg EGCG intravenously at the time of reperfusion. Three days after renal I/R, we compared renal function markers, malondialdehyde (MDA), and histologic changes.

RESULTS

Following renal I/R, levels of blood urea nitrogen (BUN) and serum creatinine (sCr) were increased and serum creatinine clearance (CrCl) decreased in group V compared to group II (P < .001). Those receiving EGCG treatment (groups III and VI) had decreased BUN and sCr compared to non-EGCG I/R groups (P < .001), but not surprisingly, higher than sham groups. CrCl was lowest in the SHR groups. The MDA was significantly decreased after EGCG treatment (P = .028 in group III, P = .002 in group VI). Following renal I/R, tissue necrosis was more severe among SHR (P < .001). However, the ratio of regeneration to damage significantly increased in SHR after EGCG treatment.

CONCLUSIONS

The reperfusion injury was greater among SHR compared with WKR in terms of renal function, lipid peroxidation, and tissue damage. EGCG treatment significantly ameliorated renal impairment and promoted tissue regeneration following renal I/R.

Influence of genetic and environmental factors on the immunogenicity of Hib vaccine in Gambian twins

The differences in incidence rates of Haemophilus influenzae type b disease and the variation in Hib conjugate vaccine efficacy achieved among different ethnic groups suggest genetic influences on the immune response to Hib vaccine. The serum anti-PRP antibody concentration of 43 monozygotic (MZ) and 147 dizygotic (DZ) twin pairs in the Gambia was measured using a standardised Hib ELISA. Intrapair correlations for MZ and DZ twin pairs were compared and heritability in antibody responses to Hib conjugate vaccine was estimated to be 51% (95% CI: 32-66%), indicating a significant genetic contribution in the response. We conclude that genetic factors may be involved in the variation in immune response to Hib vaccine observed in different populations and may contribute to cases of vaccine failure.

Cloning, purification, and characterization of chitosanase from Bacillus sp. DAU101

A chitosanase-producing Bacillus sp. DAU101 was isolated from Korean traditional food. This strain was identified on the basis of phylogenetic analysis of the 16S rDNA sequence, gyrA gene, and phenotypic analysis. The gene encoding chitosanase (csn) was cloned and sequenced. The csn gene consisted of an open reading frame of 837 nucleotides and encodes 279 amino acids with a deduced molecular weight of 31,420 Da. The deduced amino acid sequence of the chitosanase from Bacillus sp. DAU101 exhibits 88 and 30 % similarity to those from Bacillus subtilis and Pseudomonas sp., respectively. The chitosanase was purified by glutathione S-transferase fusion purification system. The molecular weight of purified enzyme was about 27 kDa, which suggests the deletion of a signal peptide by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pH and temperature optima of the enzyme were 7.5 and 50 degrees C, respectively. The enzyme activity was increased by about 1.6-fold by the addition of 5 or 10 mM Ca(2+). However, Hg(2+) and Ni(+) ions strongly inhibited the enzyme. The enzyme produced, GlcN(2-4), were the major products from a soluble chitosan.

Developing an NLP and IR-based algorithm for analyzing gene-disease relationships

OBJECTIVES

High-throughput techniques such as cDNA microarray, oligonucleotide arrays, and serial analysis of gene expression (SAGE) have been developed and used to automatically screen huge amounts of gene expression data. However, researchers usually spend lots of time and money on discovering gene-disease relationships by utilizing these techniques. We prototypically implemented an algorithm that can provide some kind of predicted results for biological researchers before they proceed with experiments, and it is very helpful for them to discover gene-disease relationships more efficiently.

METHODS

Due to the fast development of computer technology, many information retrieval techniques have been applied to analyze huge digital biomedical databases available worldwide. Therefore we highly expect that we can apply information retrieval (IR) technique to extract useful information for the relationship of specific diseases and genes from MEDLINE articles. Furthermore, we also applied natural language processing (NLP) methods to do the semantic analysis for the relevant articles to discover the relationships between genes and diseases.

RESULTS

We have extracted gene symbols from our literature collection according to disease MeSH classifications. We have also built an IR-based retrieval system, "Biomedical Literature Retrieval System (BLRS)" and applied the N-gram model to extract the relationship features which can reveal the relationship between genes and diseases. Finally, a relationship network of a specific disease has been built to represent the gene-disease relationships.

CONCLUSIONS

A relationship feature is a functional word that can reveal the relationship between one single gene and a disease. By incorporating many modern IR techniques, we found that BLRS is a very powerful information discovery tool for literature searching. A relationship network which contains the information on gene symbol, relationship feature, and disease MeSH term can provide an integrated view to discover gene-disease relationships.

Tuning indistinguishability in Bose-Einstein condensation and new atomic states

The concept of indistinguishability is the key element in quantum statistics. But, are particles really either indistinguishable or distinguishable? Most works begin with the premise that all the particles, for example, in a quantum gas, are indistinguishable. Can we vary the degree of distinguishability in some controlled, continuous manner and see how it affects the behavior of the quantum gas, such as Bose-Einstein condensation (BEC)? We have found a complex parameter with a definite phase that does just that. As it deviates from zero, a gas mixture of originally indistinguishable bosons would divide into several distinct species that undergo BEC individually. Each species is found to be in a new type of atomic state whose spin structure adapts itself to the prevailing densities of the gases in the mixture.

Vermicomposting of cattle and goat manures by Eisenia foetida and their growth and reproduction performance

Vermicomposting is commonly adopted for the treatment of livestock organic wastes. In the present study, two types of livestock manure were used for culturing of the earthworm, Eisenia foetida. Each treatment group consisted of six replicates and worm vermicasts were examined after 5 weeks. The concentrations of total C, P and K in goat manure vermicasts were higher than those in cattle manure vermicasts. Cattle vermicasts had a higher N content than goat vermicasts but the C:N ratio of fresh manure was higher than that of vermicasts for both materials. Earthworm biomass and reproductive performance, in terms of number of worms after 5 weeks of experiment, were higher in cattle manure than in goat manure. The cocoon production per worm in cattle manure was higher than in goat manure. However, the hatchability of cocoons was not affected by manure treatments. In conclusion, cattle manure provided a more nutritious and friendly environment to the earthworms than goat manure.

Posterior pericallosal lipoma extending through the interhemispheric fissure into the scalp via the anterior fontanelle

We report an unusual pericallosal lipoma presenting as scalp mass at birth. The patient had no obvious neurological deficit, but CT and MRI revealed a striking lipoma extending extracranially into the scalp from the interhemispheric fissure via the anterior fontanelle. The corpus callosum was distorted but not dysplastic.

Posterior mediastinal paraganglioma with bilateral adrenal pheochromocytoma

Paraganglioma and adrenal pheochromocytoma are tumors of common origin arising from chromaffin cells. However, it is extremely rare to find mediastinal paraganglioma simultaneously with bilateral adrenal pheochromocytoma. We report a 53-year-old man who was diagnosed with posterior mediastinal paraganglioma and bilateral adrenal pheochromocytoma and who underwent successful excision of the posterior mediastinal mass and bilateral total adrenalectomy.

Vascular endothelial growth factor correlates with matrix metalloproteinase-9 in the pleural effusion

Vascular endothelial growth factor (VEGF) is a potent, multifunctional cytokine that contributes to angiogenesis and inflammation. Matrix metalloproteinase-9 (MMP-9) is one of the major proteolytic enzymes that degrade various components of the extracellular matrix. Few data are available on the potential relationship between VEGF and MMP-9 in the accumulation of pleural effusion. We examined levels of VEGF and MMP-9 by means of enzyme immunoassay, zymographic analysis, and Western blot analysis in the patients with liver cirrhosis, tuberculosis, or lung cancer. The levels of VEGF and MMP-9 were significantly increased in the pleural fluids and sera of patients with tuberculosis and were even higher in patients with lung cancer compared with the patients with liver cirrhosis. A significant correlation was established between the level of VEGF and the level of MMP-9 in the pleural effusion. These results suggest that overproduction of VEGF and MMP-9 is associated with accumulation of the pleural effusion in tuberculosis and lung cancer. The relationship between VEGF and MMP-9 in the pleural effusion may have a role in the pathogenesis of pleural fluid formation.

Imbalance between matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in toluene diisocyanate-induced asthma

BACKGROUND

Toluene diisocyanate (TDI)-induced asthma is an inflammatory disease of the airways characterized by airway remodelling due, at least in part, to an excess of extracellular matrix deposition in the airway wall. The ratio of matrix metalloproteinase-9 (MMP-9) and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1) may be a marker of the balance between airway tissue destruction and repair.

OBJECTIVE

We determined whether an imbalance of the MMP-9 : TIMP-1 molar ratio is present before and/or after challenge with TDI.

METHODS

We used a murine model of TDI-induced asthma to evaluate the MMP-9 and TIMP-1 balance in the lung.

RESULTS

The expression of MMP-9 and TIMP-1 mRNAs and proteins in the lungs increased at 7 h after TDI inhalation and continued for up to 72 h. Immunohistochemical and immunocytological analyses in the lungs of TDI-exposed mice revealed increases of immunoreactive MMP-9 and TIMP-1. There were significant correlations between the levels of MMP-9 or TIMP-1 and the number of neutrophils, lymphocytes, or eosinophils. The molar ratio of MMP-9/TIMP-1 significantly decreased at 7 h after TDI inhalation and continued up to 72 h.

CONCLUSION

These data suggest that TDI-induced asthma may be associated with an imbalance between MMP-9 and TIMP-1, which could be useful as a marker of airway inflammation and airway remodelling in this disease.