Serum protein media are important factors in the manual hexadimethrine bromide (polybrene) test, experience in China.

BACKGROUND AND OBJECTIVES: The use of the manual hexadimethrine bromide (polybrene) test in routine cross-matching after accurately detecting cell grouping and irregular antibodies is prevalent in China. This article reports the importance of serum protein mediums in the performance of the manual hexadimethrine bromide test. MATERIALS AND METHODS: Blood group O red blood cells and Blood group AB and Rh positive serum were collected at random from healthy blood donators, IgG anti-D serum separated from pregnant woman, then tested with each other by the manual hexadimethrine bromide methods in routine tests and some designed corresponding tests with IgG, IgM anti-D monoclonal diagnostic reagents and some serum protein components. RESULTS: Red blood cells that were adjusted to 3-5% suspension by normal saline then only added in 0.7 ml low ionic medium (LIM) and two drops of polybrene solution adhere to the surface of test tubes' bottom when centrifuged, so it was difficult to perform the next approach, but the adherence disappeared when red blood cells' concentrations exceeded 20-30%. Rh positive red blood cells coated by anti-D have the same phenomenon. This adherence can be prevented by serum medium diluted from 1:128 to 1:1024 times by normal saline and hemoglobin medium diluted from 1:32 to 1:128 times, but not by albumin or immunoglobulin medium. The denary logarithm values of the greatest inhibited dilutions of serum and hemoglobin elution between antibody sensitizing red blood cells and the same pre-sensitizing red blood cells tests were no significant difference (P value > 0.05). CONCLUSIONS: The whole serum or serum protein mediums are important factors that can influence successfully performance of the manual hexadimethrine bromide test. So appliance of the manual hexadimethrine bromide test to immunohematology laboratory, such as when performing titrations of serum or plasma, or when testing eluates for antibody activity, this adherence must be considered.     

Molecular identification of pathogenetic IdLNF+1 autoantibody idiotypes derived from the NZBxSWR F1 model for systemic lupus erythematosus

The acceleration of nephritis in SNF(1) mice by CD4(+) T-cell clones reactive with a nephritogenic idiotype, Id(LN)F(1) [1], as well as the ability of anti-Id(LN)F(1) antisera to down-regulate the production of Id(LN)F(+)(1) immunoglobulin (Ig) in vivo and delay nephritis [2], suggests that dysregulation of this idiotype may contribute to the development of SNF(1) nephritis. Herein, we show that a monoclonal Id(LN)F(1)-expressing antibody, 540, significantly (P< or = 0.01) stimulated Id(LN)F(1)-reactive T-cell clones B6 and D2 to proliferate, while other Id(LN)F+1 antibodies did not. Further, injection of 540-producing hybridoma cells into nonautoimmune (SWRxBalb/c)F(1) mice resulted in the deposition of Id(LN)F(+)(1) Ig in the kidneys, in a pattern indicative of early nephritis. To identify the pathogenetic Id(LN)F(1) epitope(s) at the molecular level, we compared the deduced amino acid sequences of the heavy and light chain variable regions of pathogenetic and non-pathogenetic Id(LN)F(1)-expressing Igs 540, 317, and 533. Two overlapping peptides derived from the V(H) sequence of 540 (aa 54-66 and 62-73), which both contain the triple basic amino acid motif K(X)K(X)K, stimulated SNF(1) T cells and T-cell clones B6 and D2. These results further support the involvement of a subset of Id(LN)F(1)-expressing Ig in SNF(1) nephritis.     

Translocation of Enterococcus faecalis strains across a monolayer of polarized human enterocyte-like T84 cells

We used a two-chamber system to study transcytosis of Enterococcus faecalis across monolayers of human colon carcinoma-derived T84 cells, which show structural resemblance to the native intestine. Among 16 E. faecalis isolates from different sources, the well-characterized strain OG1RF and 8 other isolates (2 endocarditis isolates, 1 urine isolate, and all 5 fecal isolates) showed translocation in this assay, while 6 clinical isolates (3 endocarditis and 3 urine isolates), the recipient strain JH2-2, and the control, Escherichia coli DH5alpha, had no detectable translocation. Of two OG1RF mutants involving the previously studied epa (enterococcal polysaccharide antigen) gene cluster, known to be needed for virulence and resistance to killing by polymorphonuclear leukocytes, one epa mutant (TX5179) was unable to translocate, while TX5180, with an epa disruption farther downstream, showed a moderate decrease in translocation relative to that of the wild-type strain OG1RF (P < 0.01), indicating that the epa gene cluster is important for translocation across a T84 monolayer. This observation was confirmed by complementation of the epa mutant (TX5179) with epa genes and restoration of its translocation ability. In conclusion, we have demonstrated translocation of at least some strains of E. faecalis across T84 monolayers, although strains differ considerably in this ability, and we have demonstrated that epa mutations can cause marked changes in successful translocation. These results suggest that this model may be a useful in vitro system for studying the process of translocation from the intestinal tract.     

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.     

GABRD encoding a protein for extra- or peri-synaptic GABAA receptors is a susceptibility locus for generalized epilepsies

A major challenge in understanding complex idiopathic generalized epilepsies has been the characterization of their underlying molecular genetic basis. Here, we report that genetic variation within the GABRD gene, which encodes the GABAA receptor delta subunit, affects GABA current amplitude consistent with a model of polygenic susceptibility to epilepsy in humans. We have found a GABRD Glu177Ala variant which is heterozygously associated with generalized epilepsy with febrile seizures plus. We also report an Arg220His allele in GABRD which is present in the general population. Compared with wild-type receptors, alpha1beta2Sdelta GABAA receptors containing delta Glu177Ala or Arg220His have decreased GABAA receptor current amplitudes. As GABAA receptors mediate neuronal inhibition, the reduced receptor current associated with both variants is likely to be associated with increased neuronal excitability. Since delta subunit-containing receptors localize to extra- or peri-synaptic membranes and are thought to be involved in tonic inhibition, our results suggest that alteration of this process may contribute to the common generalized epilepsies.     

Vancomycin-resistant enterococcal bacteremia: comparison of clinical features and outcome between Enterococcus faecium and Enterococcus faecalis.

BACKGROUND AND PURPOSE: Vancomycin-resistant enterococci (VRE) have emerged as important nosocomial pathogens. This study was conducted to clarify the clinical features and outcome of patients with vancomycin-resistant enterococcal bacteremia. METHODS: Patients with vancomycin-resistant enterococcal bacteremia treated at a medical center in northern Taiwan between November 1998 and July 2006 were reviewed. Clinical and bacteriological characteristics of Enterococcus faecium and Enterococcus faecalis were compared. RESULTS: Twelve patients (6 males and 6 females) were included for analyses. The mean age was 69.3 years (range, 40 to 86 years), and 8 cases (66.7%) were older than 65 years. All patients had underlying disease. Two patients received total hip replacement before development of VRE bacteremia. Twelve patients had prior exposure to broad-spectrum antimicrobial therapy. Ten patients had prior intensive care unit stay and prior mechanical ventilation before VRE bacteremia. All of the patients (n = 12) had an intravascular catheter in place. Bacteremia was caused by E. faecalis in 4 patients and by E. faecium in eight. The portals of entry included urinary tract (8.3%), skin, soft tissue and bone (41.7%) and unknown sources (50.0%). E. faecium showed a higher rate of resistance to ampicillin and teicoplanin than E. faecalis (87.5% vs 0.0%, p=0.01). The 60-day mortality rate was higher in patients with E. faecium bacteremia than E. faecalis bacteremia (62.5% vs 0.0%), although statistical significance was not obtained (p=0.08). CONCLUSIONS: VRE bacteremia may have an impact on the mortality and morbidity of hospitalized patients. Patients with bacteremia caused by vancomycin-resistant E. faecium had a grave prognosis, especially immunosuppressed patients. The prudent use of antibiotics and strict enforcement of infection control may prevent further emergence and spread of VRE.     

遗传算法在256阵元相控阵高强度聚焦超声治疗系统多焦点控制中的应用

阐述了遗传算法优化多点超声聚焦的方法以及球面相控阵声场计算方法。对实验室研发的256阵元相控阵聚焦超声治疗系统作了简介。利用此遗传算法和声场计算方法，对轴上和离轴单焦点以及轴对称六焦点和非轴对称四焦点进行了256阵元相控阵的声场仿真，并观察了实验室研发的256阵元相控阵聚焦超声治疗系统作用于有机玻璃和透明仿体的实验结果。用遗传算法和声场计算方法的仿真和系统实验结果表明，此方法可在实际聚焦手术中准确地控制3维单焦点和3维多焦点。