[Establishment of a GC and GC/MS method for analysis of fatty acids in human dental plaque]

OBJECTIVE

To study the composition of fatty acids in human dental plaque, a Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC/MS) method was developed.

METHODS

The C17:0 was internal standard and the C16:0 was test standard. Samples of plaque were methanolysis to be fatty acids methyl ester before detection. GC with OV-1 separated the sample for a quantitative analysis. The column size was 25 m x 25 mm. The temperature program was from 80 degrees C to 260 degrees C with 12 degrees C/min. The sample separation was carried out at fused silica capillary column with OV-1 for qualitative analysis by GC/MS. The column size was 23 m x 0.23 mm. The temperature program was from 40 degrees C to 240 degrees C at 6 degrees C/min.

RESULTS

The linear regression equation was y = 0.0138X-0.1182, r = 0.9945, recovery was 90.18%-103.6%, CV intro-day was 2.60, 1.61, 2.20; CV inter-day was; 2.71, 1.69, 1.61. The lowest limit of detection was 0.6 ug. The GC and GC/MS diagram showed that internal standard and fatty acids of plaque have good separation.

CONCLUSION

The method is simple, rapid accurate, and is useful to carry out qualitative and quantitative analyses of fatty acids in dental plaque.

[Construction of plasmids expressing hepatitis E virus antigen fragments and their combinations]

OBJECTIVE

Several different regions of the HEV antigen were expressed in Escherichia coli and their immunological characteristics were simply evaluated.

METHODS

Three coding sequences of immunodominant antigenic regions in structural protein of the hepatitis E virus (ORF2.1: 6287-6403nt, ORF2.2: 6743-7126nt, ORF3: full length of ORF3) were amplified by RT-PCR from the fecal supernatants of macaques experimentally infected with HEV. These three fragments were inserted into the pThioHisC expression vector separately or fused in line by (Gly)n short arms. After identified by DNA sequence analysis, these six recombinant plasmids were transformed into Escherichia coli, and immunology characteristics of expressed antigen fragments were evaluated by Western blotting.

RESULTS

All six genes were successfully expressed in Escherichia coli. Western blotting assay showed that the recombinant proteins specifically reacted with the serum antibody from hepatitis E patient in various degrees.

CONCLUSION

Artificial antigen based on strung epitopes provides a promising strategy for detection and prevention of HEV infection.

[Effects of epidermal growth factor on wound healing of penetrating keratoplasty in rabbits]

OBJECTIVE

To observe the effects of epidermal growth factor (EGF) on wound healing of the penetrating keratoplasty(PKP) in rabbits.

METHODS

Twelve rabbits (24 eyes) were stratified randomly divided into 6 groups and underwent penetrating keratic autoplasy. Liquid scintillation counter was used to measure the incorporation rate of 3H-TdR. Pressure-detector was used to survey the intensity of keratic wound healing. AgNORs staining was used to count the fibroblast cells at keratic wound. HE staining, VG staining, AgNORs staining and transmission electron microscopy were used to observe the morphological changes of keratic wound.

RESULTS

1 The intensity of EGF group on 8 days, 14 days and 21 days after PKP was significantly higher than that of the control group(P < 0.01). 2. The incorporation rate of 3H-TdR in wound healing the EGF group on 14 days and 21 days was obviously higher than that of the control group(P = 0.01). 3. The number of fibroblast cells of EGF were more than that of the control group(P < 0.01) in 8 days.

CONCLUSION

EGF can promote the wound healing in rabbits after PKP.

Astrocytes give rise to oligodendrogliomas and astrocytomas after gene transfer of polyoma virus middle T antigen in vivo

The cells of origin for oligodendrogliomas and astrocytomas are not known but are presumed to be oligodendrocyte and astrocyte precursors, respectively. In this paper we report the generation of mixed gliomas from in vivo transformation of glial fibrillary acidic protein (GFAP)-positive cells (differentiated astrocytes) with polyoma virus middle T antigen (MTA). MTA is a powerful oncogene that activates a number of signal transduction pathways, including those proposed to be involved in gliomagenesis, and has been shown to induce tumors in many cell types. We have achieved transfer of MTA expression specifically to GFAP(+) cells in vivo using somatic cell gene transfer, and find resultant formation of anaplastic gliomas with mixed astrocytoma and oligodendroglioma morphological features. We conclude that GFAP- expressing astrocytes, with appropriate signaling abnormalities, can serve as the cell of origin for oligodendrogliomas, astrocytomas, or mixed gliomas.

[A comparative study of fatty acids in human dental plaque and whole saliva]

This study was intended to carry out qualitative and quantitative analyses of fatty acids in plaque and saliva. Samples of plaque and saliva from 10 volunteers were analyzed for fatty acids by gas-chromatography and gas-chromatography/mass spectrometry. The sample preparation procedure allowed specimens from individual volunteers to be analyzed. The results showed the plaque contained C14.0, C15.0, C16.0, C16.1, C18.0, C18.1, C18.2, C20.0 acids and the saliva contained C16.0, C18.0, C20.0, C16.1, C18.1, C18.2 acids. The concentration of fatty acids in plaque was 35.17 +/- 7.723 micrograms/mg (dry weight); and that in saliva was 13.23 micrograms/ml. Quantitatively, C18.1 and C16.0 acids were the largest fatty acids. These findings imply that the origin and role of the fatty acids in plaque and saliva may be different.

[Repairing peripheral nerve defects by tissue engineering techniques:an experimental study]

OBJECTIVE

To develop a novel effective substitute material or technique to repair peripheral nerve gap.

METHODS

We inoculated expanded Schwann cells (SCs) at re-arranged bio-absorbable polymer polyglycolic acid (PGA) fiber and incubated for two weeks, then we developed a novel tissue-engineered scaffolds. The scaffolds were used as cellular isografts to bridge 15 mm long gap of sciatic nerve in inbred strains of Wistar rats. In an autologous and pure PGA fiber control group, the same surgical procedure was used. Evaluation included general observation, electromyographic examination, muscle measurement, and histological observation of serial sections at 12 weeks after surgery. The total number and density of reinnervation and thickness of myelin sheath was measured by computerized image analysis.

RESULTS

SCs put out a long and thin prominence and migrated along the PGA fibers in spirality or parallel when they divided and finally rank into a cell-chain formation similar to Büngner's band. TEM/SEM and immunohistochemical survey demonstrated that the SCs at PGA fiber also secreted a great deal of ECMs included laminin, which play a very important role in peripheral nerve regeneration. Non-tubular scaffold comprised SCs and laminin (LN) channel in three-dimensional longitudinal rank. Animal transplantation study indicated the sensory and motor functional results of hindlimbs of experimental group rats reached to similar level of those found in nerve autograft control group. The number of reinnervation in the experimental group rats was slightly fewer than that in nerve autograft control group; but the axonal density was just reversal between the two groups because of a large area ischemic necrosis in the center of nerve autografts.

CONCLUSION

This new paradigm offers a potential solution to repairing a long gap of peripheral nerve.

Combined activation of Ras and Akt in neural progenitors induces glioblastoma formation in mice

Gliomas are the most common primary malignant brain tumours and are classified into four clinical grades, with the most aggressive tumours being grade 4 astrocytomas (also known as glioblastoma multiforme; GBM). Frequent genetic alterations in GBMs (refs 2-5) result in stimulation of common signal transduction pathways involving Ras, Akt and other proteins. It is not known which of these pathways, if any, are sufficient to induce GBM formation. Here we transfer, in a tissue-specific manner, genes encoding activated forms of Ras and Akt to astrocytes and neural progenitors in mice. We found that although neither activated Ras nor Akt alone is sufficient to induce GBM formation, the combination of activated Ras and Akt induces high-grade gliomas with the histological features of human GBMs. These tumours appear to arise after gene transfer to neural progenitors, but not after transfer to differentiated astrocytes. Increased activity of RAS is found in many human GBMs (ref. 11), and we show here that Akt activity is increased in most of these tumours, implying that combined activation of these two pathways accurately models the biology of this disease.

[Expression and glycosylation of rotavirus strain SA11 VP4 protein in a recombinant adenovirus]

OBJECTIVE

A modified VP4 gene of rotavirus SA11 strain was expressed by a recombinant human adenovirus.

METHODS

A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consist of human cytomagolovirus promoter and then cloned the gene to transfer human adenovirus type 5 vector. Homologues recombinant was performed by co-transfection to 293 cell line with recombinant plasmid and viral genome using CaPO4 precipitation.

RESULTS

VP4 gene is 2,362 base pair in length mutation was not found in whole VP4 gene sequence. Expressed product in recombinant adnovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both Western blot and immunoprecipitation assays showed that expressed protein molecular weight was higher than wild type VP4 protein and that modified product was corresponding to a glycosylation of VP4 protein.

CONCLUSIONS

It may be a effective method to modify interested gene for enhancing stability, antigenicity and immunogenicity of expressive product.

Activation of

Reversible C(6)F(5) transfer takes place between the boron centers in the anion formed by methide abstraction from [MeZr{N(SiMe(3))(2)}(3)] or [Cp(2)ZrMe(2)] (L(n)M-CH(3) in the reaction scheme) by the perfluorinated diborane 1. The solution chemistry of the metallocenium ion pairs formed from 1 and [Cp(2)ZrMe(2)] is correlated with the observed ethylene polymerization behavior of 1 in comparison to the monoborane B(C(6)F(5))(3), the related diborane 1,2-C(6)H(4)[B(C(6)F(5))(2)](2), and the 9,10-diboraanthracene compound 9,10-(C(6)F(5))(2)C(12)B(2)F(8).

[Establishment of animal model for ischemic facial palsy in rat]

OBJECTIVE

In order to establish animal model for ischemic facial nerve palsy in rats and to observe the intrinsic vascular network of facial nerve in the fallopian canal.

METHOD

Selective vascular embolization of the external carotid artery was performed in rats. The animals were killed at 1 and 30 days after operation respectively. 10% gelatin solution with fluorescent dye were injected into their left ventricles. The changes intrinsic vascular network were observed under inverted fluorescent microscopy.

RESULT

Facial palsy was presented within 5 to 15 min following arterial embolization, the intrinsic capillaries of facial nerve appeared to be thinner and some of them were blocked by microspheres, especially in the labyrinthine segment. Facial palsy almost recovered after 30 days postoperatively. The capillaries returned to be almost normal shape and only few of them were thinner.

CONCLUSION

The establishment of animal model for ischemic facial palsy will make contribution to experimental research and clinical treatment for facial palsy.

[Analysis of organic acids in human dental plaque by means of gas chromatography/mass spectrometry]

The purpose of this study was to investigate the composition of plaque fatty acids in the healthy population. The study was made on 10 volunteers over the age of 18 who were divided into three sub-groups (3-4 individuals). Neither subject exhibited clinical evidence of salivary gland disorder and any medication affecting salivary functions were not used. A sensitive GC/MS method with VG7070E mass spectrometer was developed in our study. The sample separation was carried out on a fused silica capillary column with OV-1. The column size was 23 m x 0.23 mm. The temperature program was as follows: from 40 degrees C to 120 degrees C fast, then from 120 degrees C to 240 degrees C at 6 degrees C/min. The results showed that there were 14 organic acids and isomers present in plaque. They were C12:0, C14:0, C15:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:0 and phenylacetic acid, phenylpropionic acid. The higher content of fatty acids in the sample were C16:0, C18:0, and C18:1. The aromatic acids were detected only in some samples. The odd-numbers fatty acids and aromatic acids were for the first time detected. The origin of organic acids in plaque is an ongoing area of research. Our data clearly identify the bacterial contribution to the organic acids of plaque matrix, which may have a special relationship with bacteria metabolism. The research will help us to understand fatty acids metabolism of dental plaque and to determine their role in the microbial homeostasis of dental plaque.

"Skin-CNS-bladder" reflex pathway for micturition after spinal cord injury and its underlying mechanisms

PURPOSE

A "skin-CNS-bladder" reflex pathway for inducing micturition after spinal cord injury has been established in cat. This reflex pathway which is basically a somatic reflex arc with a modified efferent limb that passes somatic motor impulses to the bladder, has been designed to allow spinal cord injured patients to initiate voiding by scratching the skin.

MATERIALS AND METHODS

The skin-CNS-bladder reflex was established in the cat by intradural microanastomosis of the left L7 ventral root (VR) to the S1 VR while leaving the L7 dorsal root (DR) intact to conduct cutaneous afferent signals that can trigger the new micturition reflex arc. After allowing 11 weeks for axonal regeneration, urodynamic, pharmacological and electrophysiological studies were conducted in pentobarbital or chloralose anesthetized animals.

RESULTS

A detrusor contraction was initiated at short latency by scratching the skin or by percutaneous electrical stimulation in the L7 dermatome. Maximal bladder pressures during this stimulation were similar to those activated by bladder distension in control animals. Electrophysiological recording revealed that single stimuli (0.3 to 3 mA, 0.02 to 0.2 msec duration) to the left L7 spinal nerve in which the efferent axons had degenerated evoked action potentials (0.5 to 1 mV) in the left S1 spinal nerve distal to the anastomosis. In addition, increases in bladder pressure were elicited by trains of the stimuli (5 to 20 Hz, 5 seconds) applied to the L7 spinal nerve. Urodynamic studies including external sphincter EMG recording demonstrated that the new reflex pathway could initiate voiding without detrusor-external urethral sphincter dyssynergia. Atropine (0.05 mg./kg., i.v.) or trimethaphan (5 mg./kg., i.v.), a ganglionic blocking agent, depressed the bladder contractions elicited by skin stimulation. The skin-CNS-bladder reflex could also be elicited after transecting the spinal cord at the L2-L3 or L7-S1 levels.

CONCLUSION

The cross-wired somato-autonomic bladder reflex is effective in initiating bladder contractions and coordinated voiding in cats with an intact neuraxis and can also induce bladder contractions after acute transection of the lumbar spinal cord. The new pathway is mediated by cholinergic transmission involving both nicotinic and muscarinic receptors. It is concluded that somatic motor axons can innervate bladder parasympathetic ganglion cells and thereby transfer somatic reflex activity to the bladder smooth muscle.

Interferon gamma induces upregulation and activation of caspases 1, 3, and 8 to produce apoptosis in human erythroid progenitor cells

Interferon gamma (IFNgamma) induces apoptosis in purified human erythroid colony-forming cells (ECFC) and inhibits cell growth. Fas (APO-1; CD95) and Fas ligand (FasL) mediate apoptosis induced by IFNgamma, because Fas is significantly upregulated by IFNgamma, whereas Fas ligand is constitutively present in the ECFC and neutralization of FasL greatly reduces the apoptosis. Because conversion of caspases from their dormant proenzyme forms to active enzymes has a critical role in transducing a cascade leading to apoptosis, we performed further studies of the expression and activation of caspases in normal human and IFNgamma-treated day-6 ECFC to better understand the mechanism of IFNgamma action in producing this cell death. RNase protection assays showed that the caspase-1, -2, -6, -8, and -9 mRNAs were upregulated by IFNgamma, whereas the caspase-5 and -7 mRNAs were not increased. Western blots showed that FLICE/caspase-8 was upregulated and activated by 24 hours of incubation with IFNgamma. FADD was not similarly altered by incubation with IFNgamma. Western blots of ICE/caspase-1, which might be required for amplification of the initial FLICE activation signal, showed that pro-ICE expression significantly increased after treatment with IFNgamma for 24 hours and cleavage of pro-ICE also increased. CPP32/apopain/caspase-3, responsible for the proteolytic cleavage of poly (ADP) ribose polymerase (PARP), was also studied and treatment of ECFC with IFNgamma resulted in an increased concentration of caspase-3 by 24 hours and a clear induction of enzyme activation by 48 hours, which was identified by the appearance of its p17-kD peptide fragment. The cleavage of PARP was demonstrated by an obvious increase of the 89-kD PARP cleavage product, which was observed at almost the same time as caspase-3 activation in the IFNgamma-treated cells, whereas untreated ECFC showed little change. Peptide inhibitors of the caspase proteins, DEVD-fmk, DEVD-cho, YVAD-cho, and IETD-fmk, were incubated with the ECFC to obtain further evidence for the involvement of caspases in IFNgamma-induced apoptosis. The activation of FLICE/caspase-8 and CPP32/caspase-3 and cleavage of PARP clearly were inhibited, but the reduction of cell growth due to apoptosis, induced by IFNgamma, was only partially blocked by the presence of the inhibitors. These results indicate that IFNgamma acts on ECFC not only to upregulate Fas, but also to selectively upregulate caspases-1, -3, and -8, which are activated and produce apoptosis, whereas the concentrations of FasL and FADD are not demonstrably changed.

The theory of "expelling pathogens regardless of hard stool", a significant contribution of Wu Youke

Though there are famous theories of "assorted Qi", "membranous origin", the contribution of Wu Youke's Wen yi lun (On Warm Pestilence) of the theory of " expelling pathogens regardless of hard stool" (EPRHS) is even more important. The main points of this theory includes: it is essential to expel pathogens at an early stage, while for attacking therapy, expelling pathogens with rhubarb is essential. EPRHS elucidates the significance of expelling pathogens in attacking therapy theoretically, and elevates the efficacy clinically with profound influence in later ages. In the past 2 decades, the early application of rhubarb to elevate the therapeutic effect for the treatment of pneumonia, epidemic meningitis, and Bencephalitis even in the absence of hard constipated stool marks the significance of Wu's such theory.

[Synthesis of hirudin variant 1 (HV1) gene and primary study of expression in yeast]

OBJECTIVE

Hirudin is an extremely efficient and specific thrombin inhibitor. It is clinically used to prevent the formation of thrombus. In this research the hirudin gene was put into yeast system for expression to evaluate the feasibility of artificially synthesized gene expressed in eukaryotic system and study the factor affecting expression level.

METHODS

According to the amino acid sequence of hirudin variant 1 (HV1), the genetic code saccharomyces cerevisiae was used to design and synthesize the HV1 gene. Amplified by PCR, it was inserted into cloning vector pBS-SK(+) and sequenced. Ligation with the signal peptide gene of yeast alpha factor the correct HV1 gene was inserted into yeast expression vector pYC-DE. The recombinant plasmid was transformed into the cell of S. cerevisiae BJ1990 to carry out the primary expression experiment.

RESULTS

In cultured supernatant of screened positive clone the hirudin activity was detected to be 30 ATU/ml. The expression level was higher than HV2 in yeast and HV1 in prokaryotic system. The N terminal amino acid sequence completely matches with natural hirudin.

CONCLUSIONS

It was proved by this study that the synthesized hirudin gene had been expressed in yeast successfully. This result showed that it was a better way to carry out the expression in yeast using synthesized HV1 gene and a stronger promoter.

Isolation of the Aspergillus nidulans sudD gene and its human homologue

We have been studying the heat-sensitive bimD6 mutation of Aspergillus nidulans. At a restrictive temperature, the chromosomes of bimD6 mutant strains fail to attach properly to the spindle microtubules, and the mutant also displays a high rate of chromosome loss. We previously cloned the sudA gene, an extragenic suppressor of the heat-sensitive bimD6 mutation and showed that it coded for a DA-box or SMC protein. SMC proteins have been demonstrated to function in chromosome condensation, segregation and global gene regulation. We have now cloned the sudD gene, another of the extragenic suppressor genes of the bimD6 mutation. The predicted SUDD protein is the founding member of a widely expressed protein family. Similar proteins are found in sequence databases for Saccharomyces cerevisiae, Caenorhabditis elegans, mammals and four species of archaebacteria. We have also cloned and sequenced a human cDNA that encodes the human homologue of SUDD and mapped the gene to 18q11.2. The predicted SUDD proteins from A. nidulans, Homo sapiens and S. cerevisiae all share a variety of features. The predicted proteins are approximately 60000Da in mass and have a serine-plus-threonine content of about 11%. The evolutionary conservation of the proteins suggests an ancient origin and conserved function for these proteins.

[Peak shape distribution rule of high performance liquid chromatography in the end of column under linear and nonideal conditions]

The central moments of chromatographic elution curve are important parameters for describing the column efficiency and chromatographic peak shape. According to the equation of chromatographic dynamics, we can get the second central moment and the third central moment of elution curve of HPLC under linear nonideal conditions. In our work, we investigated the relationships between second central moment, third central moment, coefficient of skewness of components distribution in the end of column and chromatographic column parameters, operation conditions, such as diameter of packing particle, desorption constant, diffusion coefficient in mobile phase, linear velocity of mobile phase, effect of extra column and so on. By means of computer, we discovered that there are no significant differences the second central moment, third central moment and coefficient of skewness for different components with different distribution coefficients. In the column end, therefore, different components have similar peak shape if there exist no obvious extra column effects. The column extra effect which stems from joint line and/or dead volume of detector is an important factor, causing column efficiency lower and peak shape tailing.

[Rapid and simple detection of Ki-ras gene mutations in pancreatic adenocarcinoma by PCR-SSP]

In order to judge whether Ki-ras gene mutations are present and their mutation styles, three kinds of special sequence primers (SSP) for polymerase chain reaction with regard to the mutant styles (CGT, GTT and GAT) at codon 12 were used to study the mutations in frozen tissues of pancreatic adenocarcinoma. The amplification products were studied with conventional electrophoresis using acrylamide gels and stained with ethidium bromide to detect the mutations.

RESULTS

In 23 of 25 frozen pancreatic adenocarcinoma specimens, Ki-ras genes with mutations at codon 12 were found; 2 mutant styles were found in 8 of the 23 samples; no mutations were found in 11 normal pancreatic tissues, 12 benign pancreatic disease tissues and 3 bile duct carcinoma tissues. This method is rapid, convenient, specific as well as sensitive. We conclude that this may become a valuable diagnostic modality for pancreatic carcinoma and for differentiating benign pancreatic diseases from carcinoma.

[Expressing poliovirus (type I) and hepatitis A virus antigens by recombinant vaccinia virus]

A recombinant vaccinia virus expressing PV-I and HAV antigens was constructed. Dot blot and Southern blot confirmed that the recombinant virus genome contained PV-I cDNA and HAV cDNA chimeric fragment. The result of IF indicated that PV-I antigen and HAV antigen were successfully expressed in the mammalian cells infected with the recombinant virus. The expressed PV-I and HAV antigen showed one band which had both PV-I and HAV antigenicities in Western blot. The band was about 120,000(MW). When guinea pigs were immunized with the recombinant virus, PV-I and HAV neutralizing antibodies were induced. The result indicated that the recombinant virus constructed here had bi-valence of PV-I and HAV antigen as well as PV-I and HAV immunogenecities.

Distinct regulatory roles of lymphocyte costimulatory pathways on T helper type-2 mediated autoimmune disease

We assessed the role of CD40-CD40L, cytotoxic T lymphocyte (CTL)A4/CD28-B7s, and CD2-CD48/CD58 lymphocyte costimulatory pathways in the development of mercury chloride (HgCl2)-induced autoimmune disease in mice, which is believed to be mediated by T helper (Th) subset Th2. Inhibition of CD40-CD40-L and CTLA4/CD28-B7s interactions by anti-CD40-L antibody and soluble CTLA4-immunoglobulin (Ig) fusion protein, respectively, abrogated the autoimmune disease without affecting interleukin 4 (IL-4) production, showing the importance of physical contact between T and B lymphocytes in the Th2-mediated process. In contrast, two anti-CD2 antibodies that have been shown to induce immunosuppression of Th1-mediated events exacerbated the autoantibody response and augmented IgG1, IgE, and IL-4 production, transforming a mild mesangial glomerulopathy into a severe systemic immune complex disease. These observations demonstrate that manipulation of lymphocyte accessory counterreceptor interactions may affect the course of Th2-associated autoimmune disease and suggest that signals resulting from CD2 engagement play an essential role in the regulation of the Th1-Th2 effector equilibrium.

Red sensitivity of dichromated cellulose triacetate as a holographic recording material

The red sensitivity of dichromated cellulose triacetate holographic recording material without any dye sensitization is reported. We suggest that the sensitivity is due to the absorption at 590 nm of the intermediate Cr(V) formed in the reducing process of chromium from Cr(VI) to Cr(III). In the experiment, the real-time transmission gratings are recorded with 632.8-nm irradiation from a He-Ne laser.

[Studies of purification, inactivity and immunogenicity of antigenically chimeric poliovirus]

Purified viruses were inactivated with 1:4000 formalin at 37 degrees C for 12d. Before and after inactivation, XF414 with anti-PV-1 and anti-PV-2, XF3 with anti-PV-1 and anti-PV-3 were observed by immunoelectron microscopy and the results were positive. Neutralization inhibition test and D-Ag unit detection were conducted, and the results were as follow: XF414 had type 1 D-Ag 15971 units/ml and type 2 D-Ag 15644 units/ml; XF3 had type 1 D-Ag 13314 units/ml and type 3 D-Ag 15971 units/ml. When rabbits were immunized with XF414 and XF3, they produced bivalent antiserum; i.e. anti-PV-1 and anti-PV-2 induced by XF414 and anti-PV-1 and anti-PV-3 induced by XF3.

[Mouse neurovirulence of antigenic chimeras (type I/II) of polioviruses]

The mouse-adapted Lansing strain of poliovirus type 2 PV-2(L) induces fatal poliomyelitis in mice after intracerebral inoculation, while mice inoculated with Mahoney strain of poliovirus type 1 PV-1(M) show no signs of disease. Previous work had indicated that both the 5' non-translated region of the viral genome and the viral capsid protein, neutralization antigenic site I (N-Ag1), were involved in mouse neurovirulence. In order to further explore the role of N-Ag1 in mouse neurovirulence, antigenic chimeras of two poliovirus strains, XF414 and XF324, were constructed. In the two strains, ten amino acids (in XF414) or 16 amino acids (in XF324) in antigenic site I in Vp1 of PV-I (M) were replaced with a PV-2(L)-specific sequences using a mutagenesis cartridge. Mouse neurovirulence tests indicated that mice cerebral inoculated with XF414 and XF324 developed poliomyelitis leading to paralysis or death. The viruses possessing antigenicity of the inoculating viruses were isolated from cerebral tissues of the paralyzed mice. The results demonstrated that N-Ag1 is an important determinant of poliovirus host range, and may be involved in attachment and penetration of poliovirus (in)to cells of the mouse central nervous system.

Studies on the immunogenicities of intertypic chimeric polioviruses

To study the relationship between structure and antigenicity, two hybrid viruses, XF414 and XF3, were constructed. In XF414, N-Agl of PV1 was replaced by N-Agl of PV2; while in XF3, N-Ag1 of PV1 was replaced by N-Ag1 of PV3. In this study, XF414 and XF3 were cultured on a large scale in primary monkey kidney cells. The viruses were concentrated with PEG, purified with chloroform and Sepharose 2B and inactivated with formaldehyde. Their bivalent antigenicity was confirmed by neutralization inhibition test, immunoelectron microscopy, and rabbit immunization. It was also shown that both XF414 and XF3 can elicit bivalent neutralizing antibodies and that the bivalent antigenicities are not destroyed by formaldehyde inactivation. Such a study can provide a basis for the development of multivalent picornavirus vaccines.

Reliability and validity of a Chinese computerized diagnostic instrument

This paper reports on the development and testing of a new Chinese diagnostic instrument--the Adult Diagnostic Interview Schedule-Present (ADIS-P). This instrument uses a selection of items adapted from DIS and SADS. It is administered within approximately 25 min by a trained clinician using a small portable computer that provides an immediate diagnosis. The instrument was tested on 1,331 patients from six large mental hospitals across the country. The concurrent validity was good: compared to the concensus diagnosis of two senior clinicians (who were blinded to the ADIS-P result), the overall diagnostic accuracy was 83% and the weighted Kappa value was 0.60. The 1 month test-retest reliability was satisfactory (weighted Kappa = 0.55). We conclude that ADIS-P is a convenient, reliable and valid diagnostic instrument.