Human anti-JC virus serum reacts with native but not denatured JC virus major capsid protein VP1

The immunoreactivity of human anti-JC virus (JCV) serum against the major capsid protein VP1 of JCV was analyzed by Western blot, dot blot, and hemagglutination inhibition (HAI) assays. JCV-positive human serum reacted with native but not denatured JCV major capsid protein VP1, as demonstrated by dot blot and Western blot. Rabbit antiserum raised against native JCV capsid had immunoreactivities similar to those of human anti-JCV serum. These results indicate that the antigenecity of native and denatured JCV VP1 is different. In addition, both JCV-positive human serum and rabbit antiserum raised against native JCV capsid protein inhibited the hemagglutination activity of JCV capsid particles. In contrast, rabbit antiserum raised against denatured JCV VP1 did not inhibit hemagglutination. These findings reveal that denaturation may alter the antigenic epitopes of JCV VP1. Therefore, keeping the JCV capsid protein native appears to be essential for serological or other immunological analyses of the virus.     

Artificial cell microcapsules containing genetically engineered E. coli DH5 cells for in-vitro lowering of plasma potassium, phosphate, magnesium, sodium, chloride, uric acid, cholesterol, and creatinine: a preliminary report

Lowering of plasma Mg, P, Na, Cl, uric acid, cholesterol, and creatinine is required in renal failure and other diseases. In this preliminary report, we studied the ability of artificial cells microencapsulated genetically engineered E. coli DH5 cells in lower K, Mg, P, Na, Cl, uric acid, cholestrol, creatinine, and billirubin from plasma in-vitro. Result shows that this novel approach has the ability to significantly lower these metabolites from the plasma in-vitro.     

Differential vasomotor action of noradrenaline, serotonin, and histamine in isolated basilar artery from rat and guinea-pig

Vasomotor effects of the amines, serotonin (5-hydroxytryptamine; 5-HT), noradrenaline (NA) and histamine, were studied in isolated basilar arteries (BA) of the rat and guinea-pig in vitro. 5-HT produced marked contraction in rat BA, about 70% of that induced by high (124 mM) K+ solution. This response was inhibited by the specific 5-HT2 receptor antagonist, ketanserin, with a pA2 value of 9.35. In the guinea-pig, 5-HT caused only moderate contraction amounting to 30% of that produced by K+. Ketanserin at concentrations up to 10(-6) M showed a comparatively small, non-surmountable inhibition of the contraction. EC50 values for 5-HT in the guinea-pig and rat were 5.65 x 10(-8) M and 3.70 x 10(-7) M, respectively. NA had no effect on rat BA, but moderately contracted guinea-pig BA. The contraction was not altered by yohimbine but was inhibited by prazosin. Histamine contracted guinea-pig BA with a maximum that was 110% of the K+-induced contraction. It was not changed by the H2 antagonist, cimetidine. The H1 antagonist, pyrilamine, caused competitive inhibition with a pA2 of 9.20 at a slope of 0.94. In preconstricted rat BA, histamine induced vasodilatation in a concentration-dependent manner. The H1 agonist, pyridylethylamine (PEA), and the H2 agonist, impromidine, dilated less effectively than histamine. The vasodilatation induced by histamine was inhibited by the H2 antagonist, cimetidine, and to a smaller extent by the H1-receptor antagonist, pyrilamine. Removal of the endothelium abolished the vasodilator effect of PEA but not that of impromidine. In vessels with intact endothelium, the vasodilatation caused by histamine was slightly reversed by pyrilamine, which did not affect the dilatation in endothelium denuded vessels. Cimetidine markedly reversed this vasodilator effect in both intact and endothelium denuded preparations; in the latter the counteraction was almost complete. In precontracted guinea-pig vessels, histamine failed to induce dilatation even in the presence of the H1 antagonist, pyrilamine. Thus, 5-HT-induced contraction is mediated by 5-HT2 receptors in the rat and probably by 5-HT1 receptors in the guinea pig. NA failed to contract rat BA but contracted guinea-pig BA through alpha 1 receptors. Histamine was a potent dilator agent in rat BA through a combination of both H1 and H2 receptors. The dilatation mediated by the H1 receptors, but not that mediated by H2 receptors, was endothelium-dependent. Histamine caused strong vasoconstriction in the guinea-pig BA through H1 receptors.     

Inhibition of phospholipase A2 (PLA2) activity by nifedipine and nisoldipine is independent of their calcium-channel-blocking activity

The effects of several calcium antagonists on phospholipase A₂ (PLA₂) activity were examined. Nifedipine and nisoldipine inhibited a cell-free preparation of PLA₂ in a dose-dependent manner with maximal inhibition of 71–77% observed at 100M. More potent or equipotent dihydropyridine calcium antagonists such as nitrendipine and felodipine did not inhibit PLA₂ activity. In addition, nondihydropyridine calcium antagonists such as diltiazem, verapamil, and cinnarazine failed to reduce PLA₂ activity markedly. Nifedipine and nisoldipine also reduced PLA₂ activity in intact mouse peritoneal macrophages where PLA₂ activity was monitored by free [¹⁴C]arachidonic acid release from [¹⁴C]arachidonic acid-prelabeled cells. When levels of PGE₂ and LTC₄ were measured by radioimmunoassay, it was found that the synthesis of these two metabolites was concomitantly inhibited by nifedipine and nisoldipine. In vivo, nifedipine and nisoldipine inhibited tetradecanoylphorbol acetate (TPA) induced ear edema. UV irradiation of nifedipine and nisoldipine (which destroys the slow caicium-channel-blocking activity of these compounds) did not result in a loss of PLA₂ inhibitory activity. In fact, in both instances the UV-irradiated forms of nifedipine and nisoldipine were slightly more potent PLA₂ inhibitors than the parent compound alone. We therefore conclude that the ability of nifedipine and nisoldipine to inhibit PLA₂ was direct and unrelated to their actions on slow calcium channels.     

Clinical characteristics of renal transplant recipients that underwent urologic surgery for de novo disease before and after transplantation

The pre-transplantation goal of the urologist is the optimization of urinary tract condition. Therefore, urologic surgery may be needed before or after renal transplantation. We analyzed the results of urologic surgery performed because of de novo urologic diseases. Between January 1986 and January 2001, 281 patients underwent renal transplantation, and 23 urologic surgical procedures were performed on 21 transplant recipients before or after renal transplantation because of de novo urologic diseases. By review the major reasons for urologic surgery in recipients were polycystic kidney diseases, vesicoureteral reflux, and dysfunctional voiding disorders. Nineteen surgical corrective procedures were done average 2.9 months before transplantation. The mortality rate was 10.5%. Four patients underwent urologic surgery at an average 57.5 months after transplantation. We highlight the fact that patients with uremia are vulnerable to surgical complications, and conclude that more intensive longterm urologic follow-ups should be conducted on recipients.     

Hepatitis B virus genotype C prevails among chronic carriers of the virus in Korea

Hepatitis B virus (HBV) is one of the major causative agents of chronic liver diseases in Korea. HBV has been classified into 8 genotypes by a divergence of >8% in the entire genomic sequence, and have distinct geographic distributions. There are limited data on the relevance between HBV genotypes and clinical outcomes in Korea. To investigate the clinical feature relating to HBV genotype in Korea, a total 120 serum samples with HBsAg (65 from Seoul and 55 from the other city in Korea) were obtained from each 30 chronic HBV carriers with asymptomatic carrier (ASC), chronic hepatitis (CH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). HBV genotype was determined by either enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies against genotype-specific epitopes in the preS2-region or the direct sequencing of small S gene. HBV genotypes were determined in 105 (87.5%) of 120 samples. HBV genotype C was identified in all HBV carriers with ASC, CH, LC, and HCC. Genotypes A, B, D, E, F and G were not detected in any of them. Genotype C HBV prevails predominantly among chronic carriers of the virus in Korea, irrespective of their clinical stages of liver disease and geographic origin.     

Kinetics of the phenotype and function of murine peritoneal macrophages following acute inflammation

This study was undertaken to have a better understand for the process and the underlying mechanisms to limitmacrophage activation and population of activated macrophages.A comprehensive kinetics of cytokineproduction was performed in murine peritoneal macrophages recovered from Balb/c mice at various timeduring the course of an intraperitoneal injection with thioglycollate (TG).The expression of cell surfacemolecules such as MHC-Ⅰ,MHC-Ⅱ,B7-1 and B7-2 of these macrophages were also determined by flowcytometry.The present findings of our research suggested that the population of activated macrophages and theactivation of macrophages (including cytokines production and expression of cell surface functional molecules)were strictly controlled during inflammation process.This is one of the important mechanisms to retain the hosthomeostasis.Cellular & Molecular Immunology.2004;1(1):57-62.     

The reliability and validity of Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version- Korean version (K-SADS-PL-K)

In order to develop a structured and objective diagnostic instrument, authors completed: (1) the translation and back translation of the Korean version of the Kiddie-Schedule for Affective Disorders and Schizophrenia - Present and Lifetime Version (K-SADS-PL) and (2) the examination of its validity and reliability of the K-SADS-PL-Korean version (K-SADS- PL) when used with Korean children. A total of 91 study subjects were recruited from child and adolescent psychiatry outpatient clinics. Clinical diagnoses were used as a gold standard for the examination of validity of K-SADS-PL-K. Consensual validity of threshold and sub-threshold diagnoses were good to excellent for attention-deficit/hyperactivity disorder (ADHD), fair for tic and oppositional defiant disorders, and poor to fair for anxiety and depressive disorders. Inter-rater and test-retest reliabilities were fair to excellent for ADHD and tic disorder. The significant correlations between the K-SADS-PL-K and Korean Child Behavior Checklist (K-CBCL) were found, which provided additional support for the concurrent validity of the K-SADS-PL-K. Sensitivities varied according to the diagnostic categories, but specificities remained high over all diagnoses, suggesting that the K-SADS-PL-K is a desirable confirmatory diagnostic tool. The results of this study suggest that the K-SADS-PL-K is an effective instrument for diagnosing major child psychiatric disorders, including ADHD, behavioral disorders and tic disorders in Korean children. Future studies will examine the validity and reliability of the K-SADS-PL-K in larger samples, including adolescents and community samples on a variety of child and adolescent psychiatric disorders.     

Pseudotype hepatitis C virus enters immature myeloid dendritic cells through the interaction with lectin

Dendritic cells (DC) are the most potent antigen-presenting cells that regulate immune responses. One of the mechanisms for hepatitis C virus (HCV) persistence is the ability of HCV to suppress DC function. Direct HCV infection to blood DC has been implicated for DC dysfunction. To clarify the susceptibility of each DC subset to HCV, we used pseudotype vesicular stomatitis virus (VSV) coated with chimeric HCV envelope glycoproteins (E1 and E2). We demonstrate that pseudotype VSV enters myeloid DC (MDC) but not plasmacytoid DC (PDC). The highest efficiency of pseudotype VSV entry to MDC was observed when MDC were cultured with GM-CSF. Such efficiency decreased when MDC are matured with the treatment of IL-4, CpG oligodeoxynucleotide, or CD40 ligand. Mannan inhibited pseudotype VSV entry to MDC, but Ca(2+) chelators failed to do so. These results show that pseudotype VSV possessing HCV-E1 and E2 enters immature MDC through the interaction with lectins in a Ca(2+)-independent manner.