Isolation, antiproliferation on tumor cell and immunomodulatory activity of BSP-I, a novel bursal peptide from chicken humoral immune system

The bursa of Fabricius (BF) is acknowledged as central humoral immune organ unique to birds. Our purpose was to identify the potential function of a novel bursal-derived bioactive peptide. A bursal septpeptide (BSP-I), EPASGMM, first isolated from BF, reduced MCF and Hela tumor cells proliferation, and enhanced antitumor factor p53 luciferase activity and protein expression. Further, we found the significantly immune inducing function of BSP-I on antigen-specific immune response in BALB/c mice intraperitoneally immunized with inactivated avian influence virus (AIV, H(9)N(2) subtype) vaccine, including of enhancing the antibody (IgG, the isotypes IgG1 and IgG2a) production, and stimulating cytokines IL-4 and IFN-γ level, and inducing T cell immunophenotyping and lymphocyte proliferation. These results suggested that as the bioactive peptide from avian humoral immune system, various biological function of BSP-I may have far-reaching implication on immune system significance, which might provide novel insight on linking between humoral immune system and development of effective immunotherapeutic strategies for treating human cancers diseases.

Mutation of putative N-linked glycosylation sites in Japanese encephalitis virus premembrane and envelope proteins enhances humoral immunity in BALB/C mice after DNA vaccination

Swine are an important host of Japanese encephalitis virus (JEV). The two membrane glycoproteins of JEV, prM and E, each contain a potential N-linked glycosylation site, at positions N15 and N154, respectively. We constructed plasmids that contain the genes encoding wild-type prME (contain the signal of the prM, the prM, and the E coding regions) and three mutant prME proteins, in which the putative N-linked glycosylation sites are mutated individually or in combination, by site-directed mutagenesis. The recombinant plasmids were used as DNA vaccines in mice. Our results indicate that immunizing mice with DNA vaccines that contain the N154A mutation results in elevated levels of interleukin-4 secretion, induces the IgG1 antibody isotype, generates greater titers of anti-JEV antibodies, and shows complete protection against JEV challenge. We conclude that mutation of the putative N-glycosylation site N154 in the E protein of JEV significantly enhances the induced humoral immune response and suggest that this mutant should be further investigated as a potential DNA vaccine against JEV.

The Meq oncoprotein of Marek's disease virus interacts with p53 and inhibits its transcriptional and apoptotic activities

Background

Marek's disease virus (MDV) is an oncogenic herpesvirus, which causes malignant lymphoma in chickens. The Meq protein of MDV, which is expressed abundantly in MDV-infected cells and in Marek's disease (MD) tumor cells, functions as a transcriptional activator and has been proposed to play an important role in oncogenic transformation. Preliminary studies demonstrated that Meq is able to bind p53 in vitro, as demonstrated using a protein-binding assay. This observation prompted us to examine whether the interaction between Meq and p53 occurs in cells, and to investigate the biological significance of this interaction.

Results

We confirmed first that Meq interacted directly with p53 using a yeast two-hybrid assay and an immunoprecipitation assay, and we investigated the biological significance of this interaction subsequently. Exogenous expression of Meq resulted in the inhibition of p53-mediated transcriptional activity and apoptosis, as analyzed using a p53 luciferase reporter assay and a TUNEL assay. The inhibitory effect of Meq on transcriptional activity mediated by p53 was dependent on the physical interaction between these two proteins, because a Meq deletion mutant that lacked the p53-binding region lost the ability to inhibit p53-mediated transcriptional activity and apoptosis. The Meq variants L-Meq and S-Meq, but not VS-Meq and ∆Meq, which were expressed in MD tumor cells and MDV-infected cells, exerted an inhibitory effect on p53 transcriptional activity. In addition, ∆Meq was found to act as a negative regulator of Meq.

Conclusions

The Meq oncoprotein interacts directly with p53 and inhibits p53-mediated transcriptional activity and apoptosis. These findings provide valuable insight into the molecular basis for the function of Meq in MDV oncogenesis.

Probing the mechanisms of chronotype using quantitative modeling

The physiological mechanisms underlying interindividual differences in chronotype have yet to be established, although evidence suggests both circadian and homeostatic processes are involved. A physiologically based model is developed by combining models of the sleep-wake switch and circadian pacemaker, providing a means of examining how interactions between these systems affect chronotype. Specifically, chronotype is shown to depend on the relative influences of homeostatic and circadian drives, with a stronger homeostatic drive causing morningness. Changes to intrinsic circadian and homeostatic properties, including homeostatic clearance and production rates, and circadian period and amplitude, are also shown to affect chronotype. These results provide a framework for explaining several experimentally observed phenomena, including age-related morningness, adolescent eveningness, and familial advanced and delayed sleep-phase disorders. Additionally, experimental studies have shown that healthy adults on the extremes of the morningness-eveningness spectrum fall into two subtypes: those whose circadian phase markers are unaffected by chronotype, and those whose circadian phase markers track their chronotype. The model demonstrates that this spectrum likely results from interindividual differences in homeostatic kinetics in the first group, and differences in circadian period in the second group. Physiologically based modeling can thus guide diagnosis of sleep pathologies.

Isolation and potential immunological characterization of TPSGLVY, a novel bursal septpeptide isolated from the bursa of Fabricius

The bursa of Fabricius is central immune organ unique to birds, and the extract is immunocompetent in stimulating B cell differentiation and enhancing antibody production. However, except for bursin, the active peptides from the bursa of Fabricius are little reported. In the paper, a novel bursal septpeptide (BSP-II) with the amino acids sequence of TPSGLVY was identified and similar to the MGC53864 protein of Gallus gallus. We investigated the effects of BSP-II on the immune response in terms of the antibodies titers (IgG1 and IgG2alpha), the levels of interferon-gamma and interleukin-4 cytokines, spleen cell lymphocyte proliferation, and the T-lymphocyte subtype composition. It was noteworthy that BSP-II potentiates the Th1 and Th2-type immune responses in dose-dependent manner. BSP-II had specific enhancing effects on the hybridoma SP2/0 cell proliferation at two different serum concentrations (20% and 5%), but had no connection with the dose of BSP-II. The antibody secreting level of hybridoma SP2/0 cells rose in 5% and 20% serum when the concentrations of BSP-II increased. Also, BSP-II had effect on the viabilities of tumor cells (Hela and SP2/0). All the results indicated that BSP-II was able to significantly induce various immune responses and involved in the cell viability of different tumor cell lines. Our observations implied that BSP-II might be a novel biological active factor from the bursa of Fabricius with immunomodulatory activities.

Immunomodulatory activities of a new pentapeptide (Bursopentin) from the chicken bursa of Fabricius

The bursa of Fabricius (BF) is a central immune organ in birds, and some peptides from chicken BF have demonstrated important immune functions. Here, a new 626.27 Da pentapeptide, Bursopentin (BP5, Cys-Lys-Arg-Val-Tyr) was isolated and purified by reverse-phase high-performance liquid chromatography. In this study, we examined the effects of BP5 on antigen-specific immune response in BALB/c mice sensitized with inactivated avian influenza virus (AIV) [A/Duck/Jiangsu/NJ08/05 (AIV H9N2 subtype)]. The results suggested that BP5 enhanced anti-hemagglutinin antibody (IgG, the isotypes IgG1 and IgG2a) production, induced both of Th1- (IL-2 and IFN-γ) and Th2-type (IL-4 and -10) cytokines, increased proliferations of splenic lymphocyte subsets CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+) and B cells, and enhanced cytotoxic T-lymphocyte activity of the activated splenocytes against NIH3T3 cells. The effects of BP5 on the proliferation of isolated T- and/or B-cell populations of BALB/c mice were assessed, and the data suggested that BP5 promoted spleen lymphocyte proliferation by activating B cells directly and T cells indirectly. Further analysis revealed that B-lymphocyte proliferation induced by BP5 is mediated by reactive oxygen species generated from thiol auto-oxidation of BP5. Furthermore, our data indicated that protein kinase C, mitogen-activated protein kinase, and nuclear factor kappa B are involved in the signal transductions during the BP5-induced B lymphocyte proliferation. This study indicates that BP5 could be a potential immunomodulator for future immuno-pharmacological use.

Design and evaluation of a multi-epitope peptide against Japanese encephalitis virus infection in BALB/c mice

Epitope-based vaccination is a promising means to achieve protective immunity and to avoid immunopathology in Japanese encephalitis virus (JEV) infection. Several B-cell and T-cell epitopes have been mapped to the E protein of JEV, and they are responsible for the elicitation of the neutralizing antibodies and CTLs that impart protective immunity to the host. In the present study, we optimized a proposed multi-epitope peptide (MEP) using an epitope-based vaccine strategy, which combined six B-cell epitopes (amino acid residues 75-92, 149-163, 258-285, 356-362, 373-399 and 397-403) and two T-cell epitopes (amino acid residues 60-68 and 436-445) from the E protein of JEV. This recombinant protein was expressed in Escherichia coli, named rMEP, and its protective efficacy against JEV infection was assessed in BALB/c mice. The results showed that rMEP was highly immunogenic and could elicit high titer neutralizing antibodies and cell-mediated immune responses. It provided complete protection against lethal challenge with JEV in mice. Our findings indicate that the multi-epitope vaccine rMEP may be an attractive candidate vaccine for the prevention of JEV infection.

[Influence of fusion protein of IBDV VP2 and chicken interleukin-2 on immune response in chicken]

In order to research immunogenicity of the recombinant rVP2-IL-2 fusion protein, we obtained the rVP2-IL-2 fusion protein using Pichia pastoris expression system, and then evaluated its potential to induce immune responses in chicken. The effect was determined in the form of protective anti-IBDV VP2 titers, antibodies (IgG1 and IgG2a), lymphocyte proliferation, the levels of interferon-gamma and interleukin-4 cytokines, and challenge experiment. Antibody titers and proliferation lymphocyte level suggested that the fusion protein could elicit specific humoral immune and cellular immune responses, antibody sub-type results indicated that the rVP2-IL-2 fusion protein induced secretion both of IgG1 and IgG2a. The seem result elicited from cytokines ELISA test, secretion of both of Th1 (gamma-IFN) and Th2 (IL-4) were induced by the rVP2-IL-2 fusion protein. Challenge experiment result shown that chicken immunized the rVP2-IL-2 fusion protein obtained 85% protection. These results confirm that the fusion protein enhances the protection against IBDV through both humoral and cell-mediated immunity, and thus could serve as a candidate for the development of IBDV subunit vaccine.

[Expression of bursin receptor on membranes of hybridoma cell and identification of binding peptide of bursin from 12-merrandom phage display peptide library]

OBJECTIVE

Bursin (BS) could greatly promote the production of monoclonal antibody in hybridoma cell. We studied the interaction between BS and hybridoma cell.

METHODS

Fluorescence microscopy, Laser Scanning Confocal Microscope (LSCM) and fluorescence activated cell sorter (FACS) were used.

RESULTS

Fluorescence microscopy revealed specific binding of FITC-BS to hybridoma cell. FACS analysis demonstrated that the binding was specific, saturable and reversibility. BS was used as target protein to screen its binding peptides from 12-mer random phage display peptide library. After four rounds of biopanning, 20 phage clones were randomly selected and identified. ELISA and competitive inhibition test results indicated that 2 phage clones were identified as positive clones. The amino acid sequences analysis shown that the sequences were ACTKHLCLLQPL or MSCNDTLCLLPN, which sharing a conservative sequence LCLL. In vitro experiments suggested that the two binding peptides can inhibit BS specific binding to hybridoma cell.

CONCLUSION

These results confirmed that existence of BS receptor in the membrane of hybridoma cell, which involved in hybridoma cell secreting monoclonal antibody signal pathway.

Space charge effects in field emission nanodevices

Electron field emission from a single nanoemitter is a barrier tunneling, quantum mechanical process that can, therefore, be described by the well-known Fowler-Nordheim (FN) equation. At high emission current densities, however, the space charge caused by the cathode may affect the current density-voltage (J-V) characteristics predicted by the FN theory. In this study, we theoretically investigated the effect of space charge on FE nanodevices, including diode and triode structures. The J-V characteristics of FE nanodevices were obtained by analytically (diode structures) or numerically (triode structures) solving the coupled FN equation and Poisson's equation. We discuss the behavior of FE nanodiodes and nanotriodes displaying different geometries, dimensions and work functions of their emitter materials. In the high current density region, space charge plays an important role in FE nanodevices; the threshold current density of space-charge limitation is related to the electric field distributions. Besides, our theoretical results are in good agreement with the experimental results reported previously.

[Biological character of porcine circovirus type 2 with site mutation at interferon stimulation reaction element (ISRE) like region in Rep gene promoter]

OBJECTIVE

To explore the biological function of the interferon stimulation reaction element (ISRE) like motif CTGAAAACGAAAGA within porcine circovirus type 2 (PCV2) Rep promoter.

METHODS

Two recombinant PCV2 strains, namely PCV2 1740(G-C) and PCV2 1741(A-T), were constructed by transfecting PK15 cells with site-mutated infectious clone of PCV2 strain Denta. Replication character, genetic stability and reactive character to porcine interferon alpha (poIFN-alpha) were compared among parental PCV2 and the two mutant viruses.

RESULTS

The ISRE like motif in Rep promoter was not necessary for the replication of PCV2 because two site-mutated viral genome clones both produced infectious virus. In contrast to parental PCV2, the viral antigen positive PK15 cells of the two site-mutated PCV2 were decreased. PCV2 1740(G-C) was genetically stable in the PK15 cell while PCV2 1741(A-T) was found to have another two nucleotide mutated from 1744AC1745 to 1744TT1745 between 3rd and 7th passage in the PK15 cell. After treated with 100 U/mL porcine interferon alpha, the viral antigen positive PK15 cells and virus genomes of parental PCV2 and two site-mutated viruses were both increased. But the enhancement rate of the two site-mutated PCV2 was significantly lower than parental PCV2.

CONCLUSION

Site-mutation of ISRE like motif in Rep promoter decreased the replication and poIFN-alpha induced enhancement of PCV2 in PK15 cells. According to these above results, it maybe speculated that ISRE like motif in PCV2 Rep gene promoter contain a functional element and it may contribute to the interferon inducible enhancement of virus replication in PK15 cells.

Phase I/II study evaluating early tolerance in breast cancer patients undergoing accelerated partial breast irradiation treated with MammoSite balloon breast brachytherapy catheter using a two-day dose schedule

Abstract #5131

Purpose: Initial phase I/II results utilizing balloon brachytherapy to deliver accelerated partial breast irradiation (APBI) in only 2-days in patients with early stage breast cancer are presented.
 Materials and Methods: From 3/2004 – 8/2007, 45 patients received adjuvant radiation therapy after lumpectomy with balloon brachytherapy in a phase I/II trial delivering 2800 cGy in 4 fractions of 700 cGy to a depth of 1 cm from the applicator surface. Inclusion criteria for the protocol included: (1) patient age > 40 years, (2) pathological confirmation of stage 0/I/II breast carcinoma, (3) > 3 cm tumor size, (4) < 3 pathologically positive lymph nodes, and (5) negative margins (per NSABP criteria). Toxicities were evaluated using the NCI CTAE v3.0 scale and cosmesis (Harvard Criteria) was documented at > 6 months.
 Results: The median age was 66 years (48-83) and median skin spacing was 12 mm (8-24). The median follow-up was 11.4 months (5.4-48 mo) with 20 patients (44%) followed greater than one year, 11 (24%) greater than 2 years and 6 (13%) greater than 3 years. At < 6 mo (n=45), grade II toxicity rates were 9% radiation dermatitis (n=4), 13% breast pain (n=6), 2% edema (n=1), and 2% hyperpigmentation (n=1). Grade III breast pain was reported in 13% (n=6). At > 6 months (n=43), grade II radiation dermatitis, induration, and hypopigmentation were 2% (n=1), grade III breast pain was reported in 2% (n=1). Infection was 16% (n=7) at < 6 mo and 2% (n=1) at > 6 mo. Of these pts, only 4% (n=2) had a positive culture, whereas the others were treated empirically due to brisk erythema. Persistent seroma > 6 months was 30% (n=13). FN was seen in 9% (n=4), but only 1 pt required treatment. Rib fracture was seen in 5% (n=2). Cosmesis was good/excellent in 96% and fair in 4%.
 Conclusions: Treatment with balloon brachytherapy using a 2-day dose schedule resulted acceptable rates of grade II/III chronic toxicity rates and similar cosmetic results observed with standard 5-day APBI schedule.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5131.

Synthesis design of artificial magnetic metamaterials using a genetic algorithm

In this article, we present a genetic algorithm (GA) as one branch of artificial intelligence (AI) for the optimization-design of the artificial magnetic metamaterial whose structure is automatically generated by computer through the filling element methodology. A representative design example, metamaterials with permeability of negative unity, is investigated and the optimized structures found by the GA are presented. It is also demonstrated that our approach is effective for the synthesis of functional magnetic and electric metamaterials with optimal structures. This GA-based optimization-design technique shows great versatility and applicability in the design of functional metamaterials.

Low-loss propagation in Cr4+:YAG double-clad crystal fiber fabricated by sapphire tube assisted CDLHPG technique

Cr4+:YAG double-clad crystal fiber with an uniform 10-microm core was fabricated by using a sapphire tube as a heat capacitor to stabilize the power fluctuation of the CO2 laser in the co-drawing laser-heated pedestal growth system. The uniformity of the fiber core showed a factor of 3 improvement compared to that without the use of sapphire tube. The variation of the core diameter is within the +/-1.35-degree adiabatic criterion and has a autocorrelation length of 1.7 mm. The measured propagation loss is only 0.02 dB/cm. The sapphire tube also reduces the vertical temperature gradient during the crystal fiber growth process so the 10-microm crystal core exhibits a smooth perimeter. The sapphire tube assisted system can be applied to the growth of many other optical crystal materials.

Molecular cloning and sequence analysis of the duck enteritis virus UL5 gene

Duck enteritis virus (DEV) is a herpesvirus that causes an acute, contagious, and fatal disease. In the present article, the DEV UL5 gene was cloned and sequenced from a vaccine virus. According to the consensus sequence of herpesvirus UL5 and UL3 gene degenerate oligonucleotide primers were designed and were used in the polymerase chain reaction (PCR) to amplify DNA products with 4577 bp in size. DNA sequence analysis revealed a 2568 bp open reading frame (ORF) encoding a 855 amino acid polypeptide homologous to herpesvirus UL5 proteins. The DEV UL5 gene has a base composition of 769 adenine (29.95%), 556 cytosine (21.65%), 533 guanine (20.76%) and 710 thymine (27.65%). Sequence comparison revealed that the nucleotide sequence of the DEV UL5 gene was highly similar to other alphaherpesviruses. Phylogenetic tree analysis showed that the fifteen herpesviruses viruses analyzed fell into four large groups, and the duck enteritis virus itself branched and was most closely related to meleagrid herpesvirus 1, gallid herpesvirus 2 and gallid herpesvirus 3 subtrees.

[Characterization of murine leukemia virus recombinants bearing PRRSV GP5 glycoproteins]

The highly virulent PRRSV isolate strain HN-1/06 was cultivated on Marc-145. To study the viral entry mechanisms, the GP5 gene of PRRSV isolate was amplified by RT-PCR and cloned into pcDNA3.0 to generate the expressing plasmid pcDNA-GP5. pcDNA-GP5 was transfected into 293T by the calcium phosphate precipitation method. Analysis of flow cytometry confirmed that the GP5 proteins were expressed in surface of the 293T cells. Then 293T cells were transfected with pcDNA-GP5, pHIT60 and pHIT111 plasmids to generate pseudotyping virus. The pseudotyping virus supernatant was harvested 48 hours post-transfection and was detected by Western blotting and infection assay. Western blotting indicated that the GP5 glycoproteins were incorporated into the retroviral pseudotyped virus. Infection assay showed that the pseudotyped virus infected 293T and Mark-145 cell. The pseudotyped virus could be used to further study infectious mechanism of PRRSV.

[Construction and biological characteristic for the recombinant modified vaccinia virus ankara co-expressing modified GP5 and M protein of porcine reproductive and respiratory syndrome virus]

Modified ORF5 (MORF5) and ORF6 gene of PRRSV were cloned into two multiple cloning sites of MVA transfer vector pLR-gpt to construct the recombinant plasmid pLR-MORF5/ORF6. Homologous recombination between pLR-MORF5/ORF6 and the wtMVA on BHK-21 cell line was mediated with liposome by infecting the cell with 0.01 MOI wtMVA two hours before transfecting the recombinant plasmid into the cell. When the cytopathic effect (CPE) was obvious, virus was collected from the cell plate and the recombinant virus was selected with drug selecting medium (2% MXHAT). After 12 cycles of selection, rMVA with a selection marker Eco gpt was obtained and named as rMVAgpt-MGP5/M. By infecting BHK-Cre expressing Cre recombinant enzyme, the Eco gpt marker in rMVAgpt-MGP5/M was deleted and this rMVA was named as rMVA-MGP5/M. The insertion of MORF5 and ORF6 into the MVA genome was confirmed with PCR analysis and the expression of MGP5 and M protein was identified with Western blot and IFA. Through biological study on the recombinant MVA, no obvious difference was observed between rMVA-MGP5/M and the wtMVA regarding to the CPE and growth curve. The recombinant MVA constructed in this study could coexpress the modified GP5 and M protein and the expressed product had good immunocompetence. Furthermore, the insertion of the MORF5 and ORF6 into MVA genome had no obvious effect on the replication and biological characteristics of this virus.

[Prokaryotic expression of N-terminal antigenic domain of duck plague virus gB protein and the establishment of putative indirect ELISA assay]

Based on the antigenic analysis of duck plague virus (DPV) gB protein, we designed a pair of primers to amplify the gene fragment encoding high antigenic domain of DPV N-terminal gB protein from the DPV genome. The cloned gene was digested with EcoR I and Hind III and then inserted into pET32a vector to obtain the recombinant pET-gB1 plasmid. The recombinant plasmid was transformed into E. coli BL21, and expressed in very high level after induced with IPTG. The expressed product was analyzed by SDS- PAGE and Western blotting. The result indicated that the fusion protein (pET-gB1) existed as inclusion body, which was about 42.4kDa and showed specific immunoreactivity with anti-DPV sera. The recombinant gB1 protein was purified with His-Bind resin protein purification procedure. Then an indirect ELISA was established to detect antibody against DPV with the purified gB1 protein as the coating antigen. The result showed that the optimal concentration of coated antigen was 6.5 microg/mL and the optimal dilution of serum was 1 : 80. The positive criterion of this ELISA assay was OD(the tested serum) > 0.4 and OD(the tested serum)/OD(the negative serum) > 2.0. The ELISA was done on 700 sera that were preserved in Shandong, Jiangsu Provinces, and were detected by igB1-ELISA and iDPV-ELISA with duck plague virus as the coating antigen respectively. The agreement ratio between the two methods was 95.6%.

Co-expressing GP5 and M proteins under different promoters in recombinant modified vaccinia virus ankara (rMVA)-based vaccine vector enhanced the humoral and cellular immune responses of porcine reproductive and respiratory syndrome virus (PRRSV)

The porcine reproductive and respiratory syndrome virus (PRRSV) has three major structural proteins which designated as GP5, M, and N. Protein GP5 and M have been considered very important to arouse the humoral and cellular immune responses against PRRSV infection and proposed to be the excellent candidate proteins in the design of PRRS bioengineering vaccine. There were some attempts on expressing GP5 or M in DNA vaccine and adenovirus to arouse humoral and cellular immune responses, but few papers have been reported on that the immune response can be difference because of the expression patterns of GP5 and M proteins in the recombinant virus. In this article, four recombinant viruses that expressed GP5 and M proteins of PRRSV in the modified vaccinia virus ankara (MVA) with different expression patterns were made. In these recombinant virus (rMVAs), GP5 and M proteins were expressed in MVA in the same virus but under the control of two promoters (rMVA-GP5/M), or as a fusion protein under one promoter (rMVA-GP5-M), or separately (rMVA-GP5 and rMVA-M). The humoral and cellular immune responses for the four recombinant viruses were evaluated with mouse model. Every mouse was inoculated with 5 x 10(5) TCID50 of the different rMVAs and boosted 3 weeks later. Neutralizing antibody titers for each group were detected with virus neutralization test assay weekly after the primary inoculation for 13 weeks to evaluate the humoral immune response. The production of gamma interferon (IFN-gamma), interleukin-2 (IL-2), and interleukin-4 (IL-4) was detected in splenocytes of rMVA-inoculated mice at 30, 60, and 90 days post inoculation to evaluate the cellular immune response. Results showed that rMVA-GP5 and rMVA-M cannot induce obvious humoral and cellular immune responses; rMVA-GP5-M inoculated group developed better immune responses than rMVA-GP5 and rMVA-M inoculated groups; however, mice inoculated with rMVA-GP5/M maintained the strongest cellular response against PRRS and consistently enhanced the anti-PRRSV humoral responses. The strategy of co-expressing PRRSV GP5 and M protein in MVA under the control of different promoters might be an attractive method for future PRRSV vaccine design.

Heterologous expression of FMDV immunodominant epitopes and HSP70 in P. pastoris and the subsequent immune response in mice

Mycobacterium tuberculosis heat shock protein70 (HSP70) is a major antigen with both chaperone and cytokine functions. It has been used as an adjuvant to induce or potentiate humoral and cellular immunity, both in the form of a mixture with peptide antigens, and as a fusion protein. We have evaluated the effects of HSP70 on foot and mouth virus (FMDV) subunit vaccines. FMDV VP1, and a synthetic multi-epitope FMDV (EG), and VP1-HSP70 and EG-HSP70 fusion proteins were all heterologously expressed in the yeast Pichia pastoris, and used as antigen in mice. The recombinant VP1 and EG alone was able to induce both humoral and marginal cell-mediated immune responses, while the HSP70 fusions markedly enhanced both the humoral and cell-mediated immune responses. The most prominent immune responses arose from vaccination with the EG-HSP70 fusion product. Both fusion protein-induced Th1-like cytokine (IFN-gamma) and Th2-like cytokine (IL-4) were identified.

Optimal design of integrally gated CNT field-emission devices using a genetic algorithm

A method to optimize the focusing quality of integrally gated CNT field-emission (FE) devices by combining field-emission modeling and a computational intelligence technique, genetic algorithm (GA), is proposed and demonstrated. In this work, the e-beam shape, as a characteristic parameter of electron-optical properties, is calculated by field-emission simulation modeling. Using a design tool that combines GA and physical modeling, a set of structural and electrical parameters for four FE device groups, including double-gate, triple-gate, quadruple-gate and quintuple-gate type, were optimized. The resultant FE devices exhibit satisfactory e-beam focusabilities and the extracted parameters with the best performance for each type of FE device were represented to be fabricated by a VLSI technique. The GA-based automatic design parameter extraction will significantly benefit the design of integrated electron-optical systems for versatile vacuum micro- and nano-electronic applications.

Improved field emission properties of thiolated multi-wall carbon nanotubes on a flexible carbon cloth substrate

In this paper we report the observation of enhanced field emission properties from thiolated multi-wall carbon nanotubes (MWCNTs) produced by a simple and effective two-step chemical surface modification technique. This technique implements carboxylation and thiolation on the MWCNTs synthesized by microwave plasma chemical vapor deposition (MPCVD) on the flexible carbon cloth substrate. The resulting thiolated MWCNTs were found to have a very low threshold field value of 1.25 V µm(-1) and a rather high field enhancement factor of 1.93 × 10(4), which are crucial for applications in versatile vacuum microelectronics.

[Construction and the immunogenicity of the recombinant Modified Vaccinia Virus Ankala co-expressing ORF4, ORF5 and ORF6 genes of porcine reproductive and Respiratory Syndrome Virus NJ-a strain]

To develop investigate the recombinant MVA(rMVA) vaccines against PRRSV infection, the ORF4, ORF5 and ORF6 of PRRSV NJ-a strain were subcloned into the MVA transfer vector p II LR and the resultant recombinant vector was called p II LR-ORF4/ORF5/ORF6. The rMVA was generated by transfecting MVA-infected BHK-21 cells with the recombinant vector and screened by plaque purification after X-gal staining. After six rounds of purification, insertion of PRRSV GP4, GP5 and M genes into the MVA genome was confirmed by PCR analysis and expression of the three proteins was identified by Western-blot and IFA. Each of the tested mice was inoculated with 5 x 10(5) TCID(50)/mouse of the rMVA-GP4/GP5/M and boosted 3 weeks later. Neutralization assay showed that PRRSV-specific neutralizing antibodies were detectable at 3 weeks and reached the highest titer (2(5)) by 8 weeks after the primary vaccination, which maintained stable until the end of the experiment. The significant lymphocyte proliferation responses were also observed in mice immunized with rMVA-GP4/GP5/M. These results indicate the rMVA co-expressing PRRSV ORF4, ORF5 andORF6 genes may be an attractive candidate vaccine for preventing PRRSV infection.

[Synthesis of hybrid antimicrobial peptide CecA-mag gene and it's secretion expression in Pichia pastoris]

According to the partiality codon of Pichia pastoris, hybrid antimicrobial peptide CecA-mag gene was synthesized and cloned into pPICZa-A to construct the recombinant expression vector pPICZa-A-CA. The SacI-linearized plasmid pPICZalpha-A-CA was transformed into P. pastoris SMD1168 by electroporation. Under the control of the promoter AOX'(alcoholoxidase') , an approximately 1.9kDa cecA-mag protein was expressed. Antibacterial assays demonstrated that cecA-mag had broad spectrum of antimicrobial property against Gram-positive as well as Gram-negative bacteria especially showed potent antibacterial activity against ampicillin resistant bacteria, such as pathogenic E. coli. In addition, the hybrid antibacterial peptide showed an extreme heat stable and acid stable characteristic. These results suggest that the P. pastoris expression system can be used to produce large quantities of fully functional cecA-mag for both research and industrial purpose. Based on these characteristics, the recombinant antibacterial peptide cecA-mag displays application foreground in the field of prevention of disease, and can be used as additives of animal feedstuff and so on.

[Construction of phage antibody library with predetermined CDR3 gene and screening of humanized Fab of anti-human integrin alphanubeta3 monoclonal antibody]

AIM

To construct phage antibody library with predetermined CDR3 and to screen humanized Fab of anti-human integrin alphanubeta(3) monoclonal antibody (mAb) by epitope guided selection.

METHODS

LCDR3 gene of mAb E10 was inserted into human light chain variable region gene library. Hybrid phage antibody library was constructed by cloning E10 chimeric Fd gene and human light chain variable region gene into pComb3. Humanized light chain gene was obtained by screening against human integrin alphanubeta(3). Likewise, humanized Fab were gained by panning human phage antibody library, which was constructed by cloning humanized light chain gene and human heavy chain Fd gene with E10 HCDR3 into pComb3.

RESULTS

Three humanized Fab clones was obtained by screening hybrid phage antibody library and human phage antibody library, which contained 2.1x10(6), 2x10(7) colony forming units, respectively. Indirect ELISA and competitive inhibition ELISA analysis demonstrated that three humanized Fab antibody had specific binding activity with human integrin alphanubeta(3). The strongest anti-human integrin alphanubeta(3) reactive D5 clone was sequenced and sequencing analysis showed that the V(kappa) and V(H) were derived from VKIII and VHI, respectively.

CONCLUSION

Humanized Fab of anti-human integrin alphanubeta(3) mAb has been successfully obtained by phage display technology which lays the foundation for further clinical research.

Fusion expression of major antigenic segment of JEV E protein-hsp70 and the identification of domain acting as adjuvant in hsp70

Hsp70 potentiates specific immune responses to some antigenic peptides fused to it. A recombinant hsp70 protein expression vector in methylotrophic yeast, Pichia pastoris, was developed that fused the major antigenic segment of Japanese encephalitis virus (JEV) E protein to the amino terminus of Mycobacterium tuberculosis hsp70. The C-terminal peptide binding domain of hsp70 stimulated Th1-polarizing cytokines, CC chemokines and an adjuvant effect. However, the N-terminal ATPase domain (hsp70 1-358) failed to stimulate any of these cytokines or chemokines. Based on these data, a vector was constructed that permits the fusion of major antigenic segment of E protein to the amino terminus of peptide binding domain of hsp70. Antibody titers, lymphocytes proliferation, the level of mIL-2 or mIFN-gamma and neutralizing antibodies in immunized mice showed that antigenicity of E-binding domain fusion protein was almost as effective as E-hsp70 fusion protein and more effective than carrier protein hsp70 alone. In eliciting a humoral and cellular immune response, both fusion proteins were more powerful than the major antigenic segment of E protein alone, but less effective than the segment administered with Freund's adjuvant.

[Detection for the antiviral activity and primary application of the chicken gamma interferon in yeast Pichia pastoris]

To obtain recombinant chicken interferon gamma (ChIFN-gamma) with natural antivirus bioactivity in yeast Pichia pastoris eukaryotic expression system, the cDNA of chicken interferon gamma mature protein was synthesized by reverse transcription-polymerase chain reaction (RT-PCR)from the total mRNA of the lymphocyte from chicken blood, which stimulated with Con A for 4 to approximately 10 hours. The 493 bp nucleotide sequence of chicken interferon gamma mature protein was cloned into expression vector pPICZa-A, which had been cleaved between EcoR I and Xba I . After linearized by BstX I, the recombinant vector was transferred into yeast Pichia pastoris, strain X33. The recombinant strain was isolated and identified by polymerase chain reaction. After induced by methanol, the recombinant protein was examined by SDS-PAGE. The result of SDS-PAGE analysis in the concentrated fermentation supernatant showed that the molecular weight of the recombinant protein was approximate 16kDa, two recombinants were conformed to secrete chicken interferon gamma(16kDa). The classical experiment of detection for interferon activity (cell pathological Effect Inhibition Assay)and the preliminary result of therapy proved that the recombinant protein is of good antivirus activity. So far chicken interferon gamma had been expressed highly in E. coli, but it tend to form biologically inactive inclusion bodied combined with difficulties in refolding, so the recombinant chicken gamma interferon with natural antivirus bioactivity produced in yeast expression system is the best way, the recombinant interferon gamma have great practical value and application foreground.

Depression and Somatic Symptoms within the Farming Community

The relationship between somatic symptoms and depression was investigated in a population of farm operators and their spouses. The sample consisted of principal farm operators and their spouses from northeastern Colorado. There were a total of 709 participants who completed data relevant for our analyses. Exploratory and confirmatory factor analyses were conducted on the symptom inventory, and suggested a two-factor structure. One of the factors consisted of symptoms of a psychological nature, and the other consisted of physical symptoms. While both of the factors were significantly correlated with depression, the factor with psychological items was more strongly related to depression. Gender differences in the symptom factor structure were investigated, and only a few minor differences were found. Gender differences in relationships between the somatic symptom factors and depression were also investigated and were not found. Implications for farm operators, spouses, and rural healthcare providers were discussed.

Molecular phylogenetic studies on an unnamed bovine Babesia sp. based on small subunit ribosomal RNA gene sequences

The 18S small subunit ribosomal RNA (18S rRNA) gene of an unnamed Babesia species (designated B. U sp.) was sequenced and analyzed in an attempt to distinguish it from other Babesia species in China. The target DNA segment was amplified by polymerase chain reaction (PCR). The PCR product was ligated to the pGEM-T Easy vector for sequencing. It was found that the length of the 18S rRNA gene of all B. U sp. Kashi 1 and B. U sp. Kashi 2 was 1699 bp and 1689 bp. Two phylogenetic trees were, respectively, inferred based on 18S rRNA sequence of the Chinese bovine Babesia isolates and all of Babesia species available in GenBank. The first tree showed that B. U sp. was situated in the branch between B. major Yili and B. bovis Shannxian, and the second tree revealed that B. U sp. was confined to the same group as B. caballi. The percent identity of B. U sp. with other Chinese Babesia species was between 74.2 and 91.8, while the percent identity between two B. U sp. isolates was 99.7. These results demonstrated that this B. U sp. is different from other Babesia species, but that two B. U sp. isolates obtained with nymphal and adultal Hyalomma anatolicum anatolicum tick belong to the same species.

[Influence of JEV E-HSP70 (Mycobacterium tuberculosis) fusion protein on immune response in BALB/c mice]

JEV infection can cause severe central nerve system disease which result in high mortality or developing permanent neurological sequelae in more than half of the survivors. The envelope (E) protein of JEV is the major antigen peptide fused to it. A recombinant hsp70 protein expression vector pPICZalpha-E-HSP70 in methylotrophic yeast Pichia pastoris was developed that permits major antigenic segment of JEV E protein fused to the amino terminus of M. tuberculosis hsp70. This core vector avoided inclusion bodies formed in Escherichia coli and complex purification. Moreover,it ruled out contamination of LPS. Two other vectors pPICZalpha-E and pPICZalpha-HSP70 were also constructed. The two vectors were constructed by routine molecular technique. All vectors were transformed into yeast X-33 by electroporation. Expression of the fusion protein in yeast was induced by the addition of methanol every 24 hours and analysed by SDS-PAGE and western blot. Major antigenic segment of E protein was produced at a yield of 290 mg per litter of culture, hsp70 protein at a yield of 178 mg per litter of culture and E-HSP70 fusion protein at a yield of 33 mg per litter of culture in methylotrophic yeast Pichia pastoris. To examine cell and body immune response after BALB/c mice were immunized with E-hsp70 fusion protein expressed in Pichia pastoris, there were three groups with ten mice in each group. 5.7 microg (50pmol) of E-hsp70 fusion protein, 2.2 microg (50pmol) major antigenic segment of E protein and a mixture of hsp70 and major antigenic segment of E protein (1:1) including 3.5 microg (50pmol) Hsp70 and 2.2 microg (50pmol) major antigenic segment of JEV E protein were used per mouse i.p. on day 0 and day 21. The production of mIL-2 was quantitated by semi-quantitative RT-PCR. Besides, proliferation of lymphocytes was measured by MTT and titers of antibody was determined by ELISA. These data show that the fusion protein is a more powerful antigen than major antigenic segment of JEV E protein. So it also illustrates the effectiveness of hsp70 in eliciting a humoral and cellular response to an attached molecule in the absence of adjuvant and affirms the potential utility of hsp70 in vaccine development.

[Modification of hybrid antimicrobial peptide CecA-mil gene and its over-secretion expression in Pichia pastoris]

According to the partiality codon of Pichia pastoris, hybrid antimicrobial peptide CecA-mil gene was reconstructed, synthesized and cloned into pPICZalpha-A to construct the recombinant expression vector pPICZa-A-CM. The pPICZalpha-A-CM was transformed into yeast host strain X-33. Under the control of the promoter AOX1 (alcohol oxidase 1), a approximately 1.9 kD cecA-mil protein was expressed with the high level of 245 microg/mL after optimized the requirements for the flask-shaking culture fermentation of the Pichia pastoris rX-33/pPICZalpha-A-CM. The hybrid antibacterial peptide had a broad spectrum antibacterial activity on both gram-positive and gram-negative bacteria, especially showed potent antibacterial activity against ampicillin-resistant and kanamycin- resistant bacteria, such as Staphylococcus aureus (cowan I) and pathogenic E. coli (O1) from chicken. In addition, the hybrid antibacterial peptide showed an extreme heat-stable and acid-stable characteristic. Based on these characteristics, the recombinant antibacterial peptide CecA-mil display application foreground in the field of antisepsis of food, prevention of disease, additives of animal feedstuff and so on.

[The prokaryotic expression and the establishment of the putative indirect ELISA assay for the HA gene for avian influenza virus (AIV) H5N1 subtype]

Using a pair of specific primers designed according to the relevant nucleotide sequence from GenBank, the HA1 gene of H5N1 subtype AIV was amplified with PCR method. The PCR product was cloned into pET-32a(+) to get a prokaryotic recombinant plasmid pET-HA1. The target gene was successfully expressed in the host cell BL21 (DE3) when induced with IPTG. The expression was optimized with proper inducing conditions of 0.8 mmol/L IPTG and 3 hours induction. The highest expression of the target protein added up to 32.7% of the total bacterial protein. Western blot analysis proved the recombinant protein has good reactive ability against H5N1 subtype AIV positive serum. The optional working circumstances for the iHA-ELISA assay (antigenicity concentration: 4 microg/mL; serum dilution: 1:200) was tried out with chess titration. The positive criterion of this ELISA assay is OD(the tested serum) > 0.5 and OD(the tested serum)/OD(the negative serum) > 2.0.

A comparison of small-subunit ribosomal RNA gene sequences of bovine Babesia species transmitted by Haemaphysalis spp. in China

The ribosomal small-subunit RNA gene sequences of six Chinese Babesia stocks infective to cattle, including a Babesia bigemina isolate, a B. bovis isolate, two B. ovata isolates, a Babesia sp. Wenchuan isolate and a B. major isolate, were compared and analyzed. The target DNA segment was amplified by polymerase chain reaction and the product ligated into the pGEM-T Easy vector for sequencing. The length of the 18S rRNA gene of all Babesia species involved in this study varied between 1,653 and 1,693 bp. The phylogenetic trees were inferred based on the 18S rRNA sequence of the Chinese isolates as well as other species of Babesia available in GenBank. The results showed that the B. ovata transmitted by Haemaphysalis longicornis and Babesia sp. Wenchuan isolate were confined to the same group as B. ovata Korea, with an identity among them of >96.5%, while B. major transmitted by H. punctata was situated in another branch, and identity with other bovine Babesia species was less than 92.5%. B. ovata should, therefore, be a valid species, differing from B. major according to the 18S rRNA gene sequence.

Mixed cystic gliosarcoma and primitive neuroectodermal tumor: a case report

The clinical and pathologic features of a mixed (composite) gliosarcoma and primitive neuroectodermal tumor occurring in a 54-year-old male are presented. A large cyst and the presence of Rosenthal fibers are also unusual features of this tumor. To our knowledge, such a morphologically variegated tumor has not previously been reported.

The prevalence and spectrum of alpha and beta thalassaemia in Guangdong Province: implications for the future health burden and population screening

AIM

Thalassaemia is a good candidate disease for control by preventive genetic programmes in developing countries. Accurate population frequency data are needed for planning the control of thalassaemia in the high risk Guangdong Province of southern China.

METHODS

In total, 13397 consecutive samples from five geographical areas of Guangdong Province were analysed for both haematological and molecular parameters.

RESULTS

There was a high prevalence of carriers of alpha thalassaemia (8.53%), beta thalassaemia (2.54%), and both alpha and beta thalassaemia (0.26%). Overall, 11.07% of the population in this area were heterozygous carriers of alpha and beta thalassaemia. The mutation spectrum of alpha and beta thalassaemia and its constitution were fully described in this area. This study reports the true prevalence of silent alpha thalassaemia in the southern China population for the first time. In addition, two novel mutations that give rise to alpha thalassaemia, one deletion resulting in beta thalassaemia, and a rare deletion (--(THAI) allele) previously unreported in mainland China were detected. The frequency of the most common mutation, the Southeast Asian type of deletion (--(SEA), accounting for 48.54% of all alpha thalassaemias) was similar to the total of two alpha(+) thalassaemia deletions (-alpha(3.7) and -alpha(4.2), accounting for 47.49% of alpha thalassaemia).

CONCLUSION

Both alpha and beta thalassaemia are widely distributed in Guangdong Province of China. The knowledge gained in this study will enable the projected number of pregnancies at risk to be estimated and a screening strategy for control of thalassaemia to be designed in this area.

Cardiac complications of enterovirus rhombencephalitis

BACKGROUND

Epidemics of enterovirus 71 infection have caused the death of many children throughout the world. Rhombencephalitis, brain stem encephalitis, and heart failure were present in all of the fatal cases. However, no evidence of myocarditis was noted in the heart specimens, and the mechanism of heart failure remains unknown.

AIMS

To characterise the presentation of cardiac complications in children with enterovirus rhombencephalitis and discuss its pathogenesis.

METHODS

Ninety one consecutive patients with enterovirus rhombencephalitis underwent echocardiography. Of these, 17 patients (nine male, eight female; median age 14 months, range 4-57 months) with left ventricular dysfunction were studied.

RESULTS

Tachycardia was noted in all patients and systemic hypertension in 12. Muscle-brain fraction of creatine kinase was >5% in 14 patients. Plasma norepinephrine and epinephrine levels were significantly raised in the three patients in whom these were analysed. Electrocardiographic abnormalities were noted in eight patients. Pulmonary oedema was complicated in 15 patients. The initial ejection fraction of the left ventricle was 22-58% (mean 37%, SD 11%). All patients deteriorated to hypotensive shock within 12 hours and 13 died. Heart specimens from seven patients showed no evidence of myocarditis, but significant coagulative myocytolysis, myofibrillar degeneration, and cardiomyocyte apoptosis were observed.

CONCLUSIONS

Acute heart failure was noted in 19% of patients with enterovirus rhombencephalitis, which had a fatality rate of 77%. It was not caused by myocarditis but possibly by neurogenic cardiac damage.

[Construction of pseudorabies virus SH strain with gE-gI gene partial deletion mutant including GFP reporter gene]

On the basis of cloning and indentifying gE-gI gene of pseudurabie virus SH strain, the transfer plasmid vector was constucted in order to get the gE-gI gene partial deletion mutant. At first, gE gene and gI gene were cloned into pUC18, constructed the pgEI vector. Then, the 5' terminal sequence of gE gene was deleted 363bp using the restrict endonuclease in gE gene. The GFP expressing cassette was inserted into the deleting site. The recombinant plasmid pgEI including GFP reporter gene deleted part of gE-gI gene was constructed. BHK-21 cell which was infected with PRV-SH for 1-2h were tansfected with the complex of pgEI-GFP and DOTAPA deletion mutant was selected and purified many times in BHK-21 cell through GFP. Inoculation of mice with 2.0X107 PFU of the recombinant virus revealed that mice were partly protected against challenge with PRV-SH containing 2MLD.

Causal inference on the difference of the restricted mean lifetime between two groups

When comparing survival times between two treatment groups, it may be more appropriate to compare the restricted mean lifetime, i.e., the expectation of lifetime restricted to a time L, rather than mean lifetime in order to accommodate censoring. When the treatments are not assigned to patients randomly, as in observational studies, we also need to account for treatment imbalances in confounding factors. In this article, we propose estimators for the difference of the restricted mean lifetime between two groups that account for treatment imbalances in prognostic factors assuming a proportional hazards relationship. Large-sample properties of our estimators based on martingale theory for counting processes are also derived. Simulation studies were conducted to compare these estimators and to assess the adequacy of the large-sample approximations. Our methods are also applied to an observational database of acute coronary syndrome patients from Duke University Medical Center to estimate the treatment effect on the restricted mean lifetime over 5 years.

The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin

It is known that the peptide corresponding to the N-terminal beta-hairpin of ubiquitin, U(1-17), can populate the monomeric beta-hairpin conformation in aqueous solution. In this study, we show that the Gly-10 that forms the bulge of the beta-turn in this hairpin is very important to the stability of the hairpin. The deletion of this residue to desG10(1-16) unfolds the structure of the peptide in water. Even under denaturing conditions, this bulge appears to be important in maintaining the residual structure of ubiquitin, which involves tertiary interactions within the sequence 1 to 34 in the denatured state. We surmise that this residual structure functions as one of the nucleation centers in the folding process and is important in stabilizing the transition state. In accordance with this idea, deleting Gly-10 slows down the refolding and unfolding rate by about one half.

Effects of turn residues in directing the formation of the beta-sheet and in the stability of the beta-sheet

The designed peptide (denoted 20-mer, sequence VFITS(D)PGKTYTEV(D)PGOKILQ) has been shown to form a three-strand antiparallel beta-sheet. It is generally believed that the (D)Pro-Gly segment has the propensity to adopt a type II' beta-turn, thereby promoting the formation of this beta-sheet. Here, we replaced (D)Pro-Gly with Asp-Gly, which should favor a type I' turn, to examine the influence of different type of turns on the stability of the beta-sheet. Contrary to our expectation, the mutant peptide, denoted P6D, forms a five-residue type I turn plus a beta-bulge between the first two strands due to a one amino-acid frameshift in the hydrogen bonding network and side-chain inversion of the first beta-strand. In contrast, the same kind of substitution at (D)Pro-14 in the double mutant, denoted P6DP14D, does not yield the same effect. These observations suggest that the SDGK sequence disfavors the type I' conformation while the VDGO sequence favors a type I' turn, and that the frameshift in the first strand provides a way for the peptide to accommodate a disfavored turn sequence by protruding a bulge in the formation of the beta-hairpin. Thus, different types of turns can affect the stability of a beta-structure.

Intraocular lens implantation after penetrating keratoplasty

PURPOSE

We evaluated the clinical results of nonsimultaneous penetrating keratoplasty, cataract extraction, and intraocular lens (IOL) implantation (two-stage surgery) for combined corneal disease and cataract.

METHODS

Twenty-six eyes of 24 patients with an average age of 46 years who underwent two-stage surgery were studied retrospectively. Variables included visual acuity, refractive status, specular microscopy before and after IOL implantation (6 months), and the occurrence of graft failure. Astigmatism was corrected by suture removal and relaxing incision. The mean follow-up after IOL placement was 16 months.

RESULTS

Unaided visual acuity was 20/100 or better in 22 (83%) eyes after the second procedure. Twenty-one (81%) eyes had an aided visual acuity of at least 20/40. The mean refractive and absolute errors were -1.49 +/- 1.39 diopters (D) and 1.55 +/- 1.30 D, respectively. The mean keratometric and refractive cylinders were 3.50 D and 2.26 D, respectively. Nineteen (73%) eyes had a spherical equivalent refraction within 2 D of emmetropia. Anisometropia (> or =3 D) occurred in four (15%) eyes. The endothelial cell density, the coefficient of variation, and the percentage of hexagonal cells documented by specular microscopy were not significantly different before and after IOL implantation. Complications included three rejections, two cases of herpetic recurrence, and one late decompensation. Two graft failures (8%) occurred after secondary surgery.

CONCLUSION

The two-stage surgery is a safe and effective modality.

The use of high-dose-rate brachytherapy alone after lumpectomy in patients with early-stage breast cancer treated with breast-conserving therapy

PURPOSE

We present the preliminary results of our in-house protocol using outpatient high-dose-rate (HDR) brachytherapy as the sole radiation modality following lumpectomy in patients with early-stage breast cancer.

METHODS AND MATERIALS

Thirty-seven patients with 38 Stage I-II breast cancers received radiation to the lumpectomy cavity alone using an HDR interstitial implant with (192)Ir. A minimum dose of 32 Gy was delivered on an outpatient basis in 8 fractions of 4 Gy to the lumpectomy cavity plus a 1- to 2-cm margin over consecutive 4 days.

RESULTS

Median follow-up is 31 months. There has been one ipsilateral breast recurrence for a crude failure rate of 2.6% and no regional or distant failures. Wound healing was not impaired in patients undergoing an open-cavity implant. Three minor breast infections occurred, and all resolved with oral antibiotics. The cosmetic outcome was good to excellent in all patients.

CONCLUSION

In selected patients with early-stage breast cancer, treatment of the lumpectomy cavity alone with outpatient HDR brachytherapy is both technically feasible and well tolerated. Early results are encouraging, however, longer follow-up is necessary before equivalence to standard whole-breast irradiation can be established and to determine the most optimal radiation therapy technique to be employed.

Accelerated treatment of breast cancer

PURPOSE

Radiation therapy (RT) restricted to the tumor bed, by means of an interstitial implant, and lasting 4 to 5 days after lumpectomy was prospectively evaluated in early-stage breast cancer patients treated with breast-conserving therapy (BCT). The goals of the study were to determine whether treatment time can be reduced and whether elective treatment of the entire breast is necessary.

MATERIALS AND METHODS

Between January 1993 and January 2000, 174 cases of early-stage breast cancer were managed with lumpectomy followed by RT restricted to the tumor bed using an interstitial implant. Each brachytherapy patient was matched with one external-beam RT (ERT) patient derived from a reference group of 1,388 patients treated with standard BCT. Patients were matched for age, tumor size, histology, margins of excision, absence of an extensive intraductal component, nodal status, estrogen receptor status, and tamoxifen use. Median follow-up for both the ERT and brachytherapy groups was 36 months.

RESULTS

No statistically significant differences were noted in the 5-year actuarial rates of ipsilateral breast treatment failure or locoregional failure between ERT and brachytherapy patients (1% v 0%, P =.31 and 2% v 1%, P =.63, respectively). In addition, there were no statistically significant differences noted in rates of distant metastasis (6% v 3%, P =.24), disease-free survival (87% v 91%, P =.55), overall survival (90% v 93%, P =.66), or cause-specific survival (97% v 99%, P =.28).

CONCLUSION

Accelerated treatment of breast cancer using an interstitial implant to deliver radiation to the tumor bed alone over 4 to 5 days seems to produce 5-year results equivalent to those achieved with conventional ERT. Extended follow-up will be required to determine the long-term efficacy of this treatment approach.

Impact of boost technique on outcome in early-stage breast cancer patients treated with breast-conserving therapy

We reviewed our institution's experience treating early-stage breast cancer patients with breast-conserving therapy (BCT) to determine the impact of boost technique on outcome. A total of 552 patients with stage I and II breast cancer were managed with BCT. All patients were treated with a partial mastectomy and radiation therapy (RT). RT consisted of 45 Gy to 50 Gy external beam irradiation to the whole breast followed by a boost to the tumor bed using either electrons (232 patients), photons (15 patients), or an interstitial implant (316 patients). Local control and cosmetic outcome was compared among three patient groups based on the type of boost used. Forty-one patients had a recurrence of cancer in the treated breast for 5-, 10-, and 13-year actuarial local recurrence rates of 2.8%, 7.5%, and 11.2%, respectively. There were no significant differences in the local recurrence rates or cosmetic outcome using electrons, photons, or an interstitial implant. On multivariate analysis, only young age and margin status were associated with local recurrence. Stage I and II breast cancer patients undergoing BCT can be effectively managed with electron, photon, or interstitial implant boost techniques. Long-term local control and cosmetic outcome are excellent regardless of which boost technique is used.

Neonatal fungemia caused by Hansenula anomala: a case report

Hansenula anomala, an ascosporogenous yeast of the class Ascomycetes, is a free-living organism isolated from the environment. It is also a part of the normal or transient flora of the human throat and alimentary tract. It has been recognized as an opportunistic pathogen and its infection is very rare. A premature infant, a victim of right femoral osteomyelitis and right hip arthritis caused by oxacillin-resistant Staphylococcus aureus, was found to have developed H. anomala fungemia just before the initiation of the antimicrobial therapy with teicoplanin. Antifungal agents (fluconazole and amphotericin B) were prescribed for 10 days despite the absence of clinical sign of systemic fungal infection. His general condition remained good, with a subsequent sterile blood culture. The patient was discharged after completing 5 weeks of antimicrobial therapy, and he remained well during follow-up at our outpatient clinics. Here, we also review the risk factors, the clinical presentations, and the therapeutic strategies of H. anomala infection in the literature.

Structural characterization of a mutant peptide derived from ubiquitin: implications for protein folding

The formation of the N-terminal beta-hairpin of ubiquitin is thought to be an early event in the folding of this small protein. Previously, we have shown that a peptide corresponding to residues 1-17 of ubiquitin folds autonomously and is likely to have a native-like hairpin register. To investigate the causes of the stability of this fold, we have made mutations in the amino acids at the apex of the turn. We find that in a peptide where Thr9 is replaced by Asp, U(1-17)T9D, the native conformation is stabilized with respect to the wild-type sequence, so much so that we are able to characterize the structure of the mutant peptide fully by NMR spectroscopy. The data indicate that U(1-17)T9D peptide does indeed form a hairpin with a native-like register and a type I turn with a G1 beta-bulge, as in the full-length protein. The reason for the greater stability of the U(1-17)T9D mutant remains uncertain, but there are nuclear Overhauser effects between the side chains of Asp9 and Lys 11, which may indicate that a charge-charge interaction between these residues is responsible.

Trace Metals' abnormalities in hemodialysis patients: relationship with medications

A multicenter collaborative study was performed to investigate the prevalence of abnormal blood contents of 6 trace metals, copper (Cu), zinc (Zn), aluminum (Al), lead (Pb), cadmium (Cd), and mercury (Hg), in hemodialysis (HD) patients and to analyze their relationship with the medications, such as CaCO3, Ca acetate, Al containing phosphate-binding agents, 1,25-dihydroxy vitD3, 1-hydroxy vitD3, and erythropoietin (EPO), as well as hematocrit level, by chi-square statistics. From 6 medical centers in Taiwan, we included 456 patients in maintenance HD for more than 4 months for this study, and they had continued the previously mentioned medications for at least 3 months. Blood samples were collected before initiating HD, and atomic absorption spectrophotometry was used to measure plasma levels of Cu, Zn, and Al as well as whole blood levels of Pb, Cd, and Hg. Three hundred seventy-five (78%) of the HD patients had low plasma Zn levels, that is, <800 microg/L, and the mean (+/-SD) concentration was 705.8 (+/-128.23) microg/L in all subjects. One hundred forty-one (31%) of the HD patients had high plasma Al, that is, >50 microg/L, and the mean (+/-SD) was 44.30 (+/-28.28) microg/L in all subjects. Three hundred thirty-three (73%) of the dialysis patients had high Cd levels, that is, >2.5 microg/L, and the mean (+/-SD) was 3.32 (+/-1.49) microg/L in all subjects. The majority of HD patients had normal blood levels of Cu, PB, and Hg. Only 21 (4. 6%), 5 (1.1%), and 3 (0.06%) patients had elevated blood levels of Cu, Pb, and Hg, respectively. Their mean (+/-SD) blood concentration of Cu, Pb, and Hg were 1,049.78 (+/-233.25) microg/L, 7.45 (+/-3.95) microg/dL, and 3.17 (+/-25.56) microg/L, respectively. Three patients had elevated plasma Hg concentrations, that is, 546, 12.6, and 24.0 microg/L, respectively. In the 152 normal healthy age and sex matched control group, the blood levels of Al, Cd, and Pb were all significantly lower than the HD patients. However, the levels of Cu and Zn were higher in the control group. The Hg level was not significantly different in both groups. There was no statistical difference between patients with normal and abnormal blood levels of trace metals in various medications except Al containing phosphate binder. The Al containing phosphate binder users had significantly higher plasma Al levels (54.71 +/- 26.70 versus 41.15 +/- 28.03 microg/L, p < 0.001) and hematocrit levels (29.61 +/- 4.61 versus 27. 81 +/- 3.91, p < 0.0005). There was no statistical correlation between erythropoietin (EPO) dose and hematocrit level in these patients. In conclusion, the blood level of trace metals of these HD patients except Al was not related to their medications. However, caution must be exercised in interpreting this result as dose and duration of medication; efficiency of HD and water treatment may play an important role. Otherwise, environmental factors, diet, and the aging process may contribute to the trace metal burden in uremia. Thus, Zn and Cu are abundant in seafood, and Cd is abundant in contaminated plants such as rice.

Invasive Streptococcus pneumoniae infections of children in central Taiwan

We carried out a retrospective study on childhood invasive pneumococcal infections (IPI) diagnosed from the January 1990 through the April 2000 at a medical center in central Taiwan. Their clinical features, outcome of the patients and the resistance patterns of the isolates were analyzed. A total of 95 clinical isolates from 72 patients younger than 14 years of age were included in this study. Of these 72 patients, 51 had bacteremia, 28 meningitis, 14 bacteremic pneumonia, 12 pleural empyema, eight otitis media, four arthritis, three sinusitis, two periorbital abscesses, one deep neck infection, one psoas muscle abscess, one peritonitis, one urinary tract infection, and one cutaneous infection. Ancillary diagnostic tests, including Gram stain smears and latex agglutination tests, were applied and the sensitivities were 86.2% and 54.3%, respectively. The prevalence rate of penicillin nonsusceptible Streptococcus pneumoniae has increased dramatically since 1995 in central Taiwan, with rates of 5.6% and 74.1% before and after 1995, and the overall mortality rate was 20.8% and 53.3% respectively. Ten of 19 children (52.6%) with pneumococcal meningitis who survived had long-term sequelae.

Cardiac manifestations of fatal enterovirus infection during the 1998 outbreak in Taiwan

BACKGROUND

An outbreak of hand-foot-and-mouth disease caused by enterovirus infection occurred in Taiwan in 1998 and more than 70 infants and children with fulminant courses died. We compared the cardiac manifestations of fatal cases with patients who survived the enterovirus infection.

METHODS

A total 187 patients with enterovirus infection were treated at Taichung Veterans General Hospital between April and June 1998. Enterovirus infection was diagnosed by history, clinical features, polymerase chain reaction study and/or viral culture. Cardiac examinations including complete physical examinations, electrocardiography and echocardiography were performed on seven cases (group I) with or without central nervous system (CNS) involvement, 30 patients with CNS involvement (group II), and 150 patients without CNS involvement (group III).

RESULTS

There were no significant differences in sex distribution, days of fever, heart rate, systemic blood pressure or time from the onset of symptoms to hospital admission among the three groups. All group I patients had features of acute congestive heart failure, pulmonary edema and neurologic signs except one who presented with right-sided heart failure and neurologic signs. The echocardiographic findings of group I were a lower fractional shortening, lower ejection fraction, and more severe and higher incidence of mitral regurgitation (p < 0.01) than in groups II and III, but there were no significant differences in end-systolic wall stress, left ventricular end-diastolic internal dimension and incidence of pericardial effusion among the three groups.

CONCLUSIONS

We conclude that seven infants and children (group I) died due to either severe cardiomyopathy or encephalopathy. The possible pathogenesis of enterovirus infection leading to death is reviewed and analyzed.