Extracellular matrix regulates human airway smooth muscle cell migration

Extracellular matrix proteins regulate the survival and proliferation of smooth muscle cells. Their effect on airway smooth muscle cell migration is not known. Their role in leukotriene-primed (0.1 microM leukotriene E4) chemotaxis of cultured human airway smooth muscle cells towards platelet-derived growth factor BB (1 ng.mL(-1)) was investigated. Migration of cells was greater on membranes coated with collagens III and V and fibronectin compared to collagen I, elastin and laminin (all 10 microg.mL(-1)). Concentration-dependent promotion of migration was observed on collagen I (1,000>10 microg.mL(-1)), which was associated with increased phosphorylation of Src kinase. This was not observed on laminin or elastin. The role of Src kinase was further confirmed by demonstrating that its inhibitor, PP1 analogue (1 microM), inhibited chemotaxis. Collagen I itself was not a chemoattractant; however, haptokinesis was observed when cells were primed with leukotriene E4, and haptotaxis when cells were primed with platelet-derived growth factor. The priming effect of leukotrienes on chemotaxis was not elicited by promoting adhesion, increasing surface expression of beta1, alphav and alpha5 integrin, or Src kinase phosphorylation. These experiments demonstrate that the extracellular matrix, along with growth factors and cysteinyl leukotrienes, can regulate human airway smooth muscle cell migration. This may be relevant in the remodelling process in chronic airway diseases, such as asthma.

Anaerobic bio-hydrogen production using pre-heated river sediments as seed sludge

Anaerobic bio-hydrogen production is the focus in the field of bio-energy resources. In this paper, a series of batch experiments were conducted to investigate the effects of several factors on anaerobic bio-hydrogen producing process carried out by pre-heated river sediments. The results showed that several factors such as substrate and its concentration, temperature and the initial pH value could affect the anaerobic bio-hydrogen production in different levels. At 35 degrees C and the initial pH of 6.5, using glucose of 20,000 mg COD/L as substrate, the highest hydrogen production of 323.8 ml-H2/g TVS in a 100 ml batch reactor was reached, the specific hydrogen production rate was 37.7 ml-H2/g TVS h, and the hydrogen content was 51.2%. Thereafter using the same pre-heated river sediments as seed sludge, continuous anaerobic bio-hydrogen production was achieved successfully in a lab-scale CSTR with gas-separator. At the organic loading rate of 36 kg COD/m3 d, the highest hydrogen production was 6.3-6.7 l-H2/l-reactor d, the specific hydrogen production was 1.3-1.4 mol-H2/mol-glucose, and the hydrogen content in the gas was 52.3%. The effluent of the bio-reactor contained some small molecular organics, mainly including ethanol, acetate, butyrate and their molar proportion is 1:1:0.6.

An autosomal genomic scan for loci linked to type 2 diabetes in northern Han Chinese

We report the results of a genome-wide scan conducted in 219 individuals from 34 large multiplex nuclear pedigrees from the northern Han Chinese population at an average resolution of about 10 cM. Nonparametric two-point and multipoint linkage analyses were performed to detect evidence of linkage with type 2 diabetes in this study. On chromosome 1 four regions showed evidence of linkage with type 2 diabetes in northern Han Chinese. Of these regions a marker D1S193 (73 cM) showed evidence of linkage (two-point nonparametric linkage 2.409), and another region (around 190 cM) was a replication of several other studies performed in different ethnic populations. Evidences of linkage have been confirmed by typing additional markers (average distance 1-5 cM) flanking these two positive regions on chromosome 1. We also found indication of linkage with type 2 diabetes on chromosomes 2, 10, 12, 18, 20, and 22 by two-point linkage analyses.

Cochlear function in Prestin knockout mice

Gross-potential recordings in mice lacking the Prestin gene indicate that compound action potential (CAP) thresholds are shifted by approximately 45 dB at 5 kHz and by approximately 60 dB at 33 kHz. However, in order to conclude that outer hair cell (OHC) electromotility is associated with the cochlear amplifier, frequency selectivity must be evaluated and the integrity of the OHC's forward transducer ascertained. The present report demonstrates no frequency selectivity in CAP tuning curves recorded in homozygotes. In addition, CAP input-output functions indicate that responses in knockout mice approach those in controls at high levels where the amplifier has little influence. Although the cochlear microphonic in knockout mice remains approximately 12 dB below that in wild-type mice even at the highest levels, this deficit is thought to reflect hair cell losses in mice lacking prestin. A change in OHC forward transduction is not implied because knockout mice display non-linear responses similar to those in controls. For example, homozygotes exhibit a bipolar summating potential (SP) with positive responses at high frequencies; negative responses at low frequencies. Measurement of intermodulation distortion also shows that the cubic difference tone, 2f(1)-f(2), is approximately 20 dB down from the primaries in both homozygotes and their controls. Because OHCs are the sole generators of the negative SP and because 2f(1)-f(2) is also thought to originate in OHC transduction, these data support the idea that forward transduction is not degraded in OHCs lacking prestin. Finally, application of AM1-43, which initially enters hair cells through their transducer channels, produces fluorescence in wild-type and knockout mice indicating transducer channel activity in both inner and outer hair cells.

[Application of nasal endoscope in diagnosis and treatment of epistaxis]

OBJECTIVE

To investigate the indication for diagnosis and treatment of epistaxis under nasal endoscope.

METHOD

The data of 226 epistaxis cases were analized. Under nasal endoscope: 126 cases were packed, 78 cases were treated with microwave, laser cautery, 42 cases were operated.

RESULT

An outstanding visutization was afforded by nasal endoscope and operation conveniencly, diagnosis correctively.

CONCLUSION

We think it is an excellent method to examine and treat epistaxis and worthy to be recommented.

Axonal regeneration into acellular nerve grafts is enhanced by degradation of chondroitin sulfate proteoglycan

Although the peripheral nerve has the potential to regenerate after injury, degenerative processes may be essential to promote axonal growth into the denervated nerve. One hypothesis is that the nerve contains growth inhibitors that must be neutralized after injury for optimal regeneration. In the present study, we tested whether degradation of chondroitin sulfate proteoglycan, a known inhibitor of axon growth, enhances the growth-promoting properties of grafts prepared from normal donor nerves. Excised segments of rat sciatic nerve were made acellular by freeze-killing before treatment with chondroitinase ABC. Chondroitinase-dependent neoepitope immunolabeling showed that chondroitin sulfate proteoglycan was thoroughly degraded throughout the treated nerve segments. In addition, neuronal cryoculture assays revealed that the neurite-promoting activity of acellular nerves was significantly increased by chondroitinase treatment. Control and chondroitinase-treated acellular nerves were then used as interpositional grafts in a rat nerve injury model. Axonal regeneration into the grafts was assessed 4 and 8 d after implantation by growth-associated protein-43 immunolabeling. At both time points, the number of axons regenerating into acellular grafts treated with chondroitinase was severalfold greater than in control grafts. Growth into the chondroitinase-treated grafts was pronounced after only 4 d, suggesting that the delay of axonal growth normally associated with acellular grafts was attenuated as well. These findings indicate that chondroitinase treatment significantly enhanced the growth-promoting properties of freeze-killed donor nerve grafts. Combined with the low immunogenicity of acellular grafts, the ability to improve axonal penetration into interpositional grafts by preoperative treatment with chondroitinase may be a significant advancement for clinical nerve allografting.

Confirmation of susceptibility gene loci on chromosome 1 in northern China Han families with type 2 diabetes

OBJECTIVE

To confirm previous effort to identify type 2 diabetes susceptibility genes in a Northern Chinese population by conducting a new genome scan with both an increased number of type 2 diabetes families and a new set of microsatellite markers within the previously localized regions.

METHODS

A genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, we obtained size information for all loci, and then a further study was done by both parametric and non-parametric linkage analysis to investigate the P values and Z values of these loci.

RESULTS

We surveyed 34 microsatellite markers which distributed within 5 regions along chromosome 1, and a total of 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci. All P values of the 8 loci were lower than 0.05, and the highest Z value was 2.17. A very interesting finding is that all 5 markers at the p- terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, were identified to have a low P value of less than 0.05, which suggests that this region may contain multiple susceptibility genes. Regions 4 and 5 also confirmed the previous findings, and we narrowed these two regions to a 2.7 cM and 2.5 cM regions, respectively.

CONCLUSIONS

We further confirmed the results gained in the previous genome-wide scan using an increased number of NIDDM families and a new set of microsatellite markers lying within the initially localized regions. The fact that all 5 loci at the p- terminal region displayed a low P value of less than 0.05 suggests that more than 1 susceptibility gene may reside in this region.

Fudenine, a C-terminal truncated rat homologue of mouse prominin, is blood glucose-regulated and can up-regulate the expression of GAPDH

Messenger RNA differential display was applied to screen for the blood glucose-regulated genes in SD rat skeletal muscle. The rat homologue of the mouse prominin was thus identified. Comparing to its mouse and human homologues, fudenine was C-terminal truncated due to a single nucleotide deletion. However, its mitochondrial energy transfer signature peptide PQDLVKKLI remained intact. Fudenine, an 592-amino acid containing, 66-kDa glycoprotein, is a novel plasma membrane protein with four transmembrane segments flanking by two large glycosylated extracellular domains. Although it is devoid of the last transmembrane domain comparing to its homologues, fudenine also locates in cell membrane by transfection of fusion plasmid pFudenine-EGFP into CBRH7919 cell and L-6TG cell. Overexpression of fudenine in CBRH7919 cell line up-regulated the mRNA level of GAPDH (3-phosphate glyceraldehyde dehydrogenase), while long-term glucose exposure resulted to reduced GAPDH expression. Since high blood glucose level induced the expression of fudenine in skeletal muscle, which in turn up-regulated the expression of GAPDH, we propose that fudenine might be a candidate gene for diabetes mellitus.

The effect of chemical carcinogenesis on rat glutathione S-transferase P1 gene transcriptional regulation

To investigate mechanisms of rat glutathione S-transferase P1 gene (rGSTP1) expression regulation during chemical carcinogenesis. we studied enhancer elements located in the region between -2.5 kb to -2.2 kb. The region was upstream from the start site of transcription and was divided into two major fragments, GPEI and GPEII. The GPEII fragment was further divided into two smaller fragments, GPEII- I and GPEII-2. Using a luciferase reporter system, we identified a strong enhancer of GPEI and a weak enhancer of GPEII in HeLa and a rat hepatoma cell line CBRH79 19 cell. The enhancer of GPEII was located within the GPEII-I region. Chemical stimulation by glycidyl methatylate (GMA) and phorbol 12-o-tetradecanoate 13-acetate (TPA) analysis revealed that induction of rGSTP1 expression was mainly through GPEI. Although H2O2 could enhance GPEII enhancer activity, the enhancement is not mediated by the NF-kappaB factor that bound the NF-kappaB site in GPEII. Using electrophoretic mobility shift assays (EMSA) and the UV cross-linking assays, we found that HeLa and CBRH7919 cells had proteins that specifically bound GPEI core sequence and a 64 kDa protein that interacted with GPEII-1. The cells from normal rat liver did not express the binding proteins. Therefore, the trans-acting factors seem to be closely related to GPEI, GPEII enhancer activities and may play an important role in high expression of rGSTPI gene.

[grp75 protects cells from injuries caused by glucose deprivation]

To elucidate the functions of grp75, CHL cells over-expressing grp75 are cultured in glucose-free medium in order to simulate energy metabolic stress. Their susceptibilities to injuries caused by glucose deprivation are assessed by trypan blue exclusion, LDH leakage measurement and cytometry analysis. Data shows a stronger resistance to glucose deprivation among cells over-expressing grp75 than among cells constitutively expressing grp75. The outcome suggests that grp75 can protect cells from injuries caused by glucose deprivation.

Chemical-regulated, site-specific DNA excision in transgenic plants

We have developed a chemical-inducible, site-specific DNA excision system in transgenic Arabidopsis plants mediated by the Cre/loxP DNA recombination system. Expression of the Cre recombinase was tightly controlled by an estrogen receptor-based fusion transactivator XVE. Upon induction by beta-estradiol, sequences encoding the selectable marker, Cre, and XVE sandwiched by two loxP sites were excised from the Arabidopsis genome, leading to activation of the downstream GFP (green fluorescent protein) reporter gene. Genetic and molecular analyses indicated that the system is tightly controlled, showing high-efficiency inducible DNA excision in all 19 transgenic events tested with either single or multiple T-DNA insertions. The system provides a highly reliable method to generate marker-free transgenic plants after transformation through either organogenesis or somatic embryogenesis.

[Fudenine, relative to blood glucose-control, is a novel membrane protein]

OBJECTIVE

To determine whether Fudenine is a novel membrane protein.

METHODS

Green fluorescence protein(GFP) was used to localize Fudenine in vivo. GFP, as a control, was targeted to cytoplasm. Epithelial cell, CBRH7919, and non-epithelial cell, L-6TG, were cultured and transiently transfected by using the lipofectamine reagent. After 48 h, intact cells were examined with fluorescence microscope for Fudenine.

RESULTS

Reporter plasmid pEGFP-N1, as a control, was expressed and localized to cytoplasm. But Fudenine, driven by the cytomegalovirus promoterenhancer contained in the pEGFP-N1 vector, was overexpressed and targeted to cellular membrane.

CONCLUSIONS

Fudenine is a novel membrane protein. It may play the similar role with its homologues AC133 antigen and prominin in human and mouse, respectively. It might be involved in signaling transduction and regulate blood glucose metabolism in vivo.

Isolation of genes related to blood glucose-control in rat skeletal muscle

OBJECTIVE

To isolate genes related to blood glucose-control using Sprague Dawley (SD) rat skeletal muscle.

METHODS

Differential gene expression between glucose stimulated and non-glucose stimulated SD rat skeletal muscle was obtained by the differential display (DD) method, Slot blotting hybridization and Northern blot hybridization.

RESULTS

Several new genes that are differentially expressed in glucose stimulated and non-glucose stimulated SD rat skeletal muscle were isolated. 74 were verified by slot analysis from 181 gene tags isolated. Of them, 33 were cloned and sequenced, and homologous analysis and application for GenBank Access Number were carried out. 21 expressed sequence tag (EST) representing novel genes was confirmed by Northern blot analysis. A total of 9 novel genes showed significant differential expression patterns.

CONCLUSIONS

Using improvements and modifications of the differential display technique, a labor- and cost-saving route was used to identify new genes related to blood glucose-control. We investigated differentially expressed genes at the whole body level instead of the culture cell level, to ensure experimental results closer to the normal physiological state. This technique may be valid in wide-spread application to other related research.

Technical advance: An estrogen receptor-based transactivator XVE mediates highly inducible gene expression in transgenic plants

We have developed an estrogen receptor-based chemical-inducible system for use in transgenic plants. A chimeric transcription activator, XVE, was assembled by fusion of the DNA-binding domain of the bacterial repressor LexA (X), the acidic transactivating domain of VP16 (V) and the regulatory region of the human estrogen receptor (E; ER). The transactivating activity of the chimeric XVE factor, whose expression was controlled by the strong constitutive promoter G10-90, was strictly regulated by estrogens. In transgenic Arabidopsis and tobacco plants, estradiol-activated XVE can stimulate expression of a GFP reporter gene controlled by the target promoter, which consists of eight copies of the LexA operator fused upstream of the -46 35S minimal promoter. Upon induction by estradiol, GFP expression levels can be eightfold higher than that transcribed from a 35S promoter, whereas the uninduced controls have no detectable GFP transcripts, as monitored by Northern blot analysis. Neither toxic nor adverse physiological effects of the XVE system have been observed in transgenic Arabidopsis plants under all the conditions tested. The XVE system thus appears to be a reliable and efficient chemical-inducible system for regulating transgene expression in plants.

Cbln3, a novel member of the precerebellin family that binds specifically to Cbln1

Precerebellin (Cbln1) is the precursor of the brain-specific hexadecapeptide cerebellin. Although cerebellin has properties of a conventional neuropeptide, its function is controversial because Cbln1 has structural features characteristic of circulating atypical collagens. Cbln1 is related to the three subunits of the complement C1q complex. Therefore, we hypothesized that Cbln1 participated in analogous heteromeric complexes with precerebellin-related proteins. Using LexA-Cbln1 as bait in a yeast two-hybrid screen, we isolated a cDNA encoding a novel Cbln1-related protein, designated Cbln3. The gene encoding cbln3 had the same intron-exon structure as cbln1 but mapped to a different mouse chromosome (14). The deduced amino acid sequence of Cbln3 was 55% identical to Cbln1 and also contained a C1q signature domain and signal sequence for secretion. In addition to binding avidly to Cbln3, Cbln1 also formed homomeric complexes. In contrast, Cbln3 homomeric association was weak. These interactions exhibited specificity because C1qB bound to neither Cbln1 nor Cbln3. Like cbln1, cbln3 was expressed in the cerebellum and dorsal cochlear nucleus in which it was detected in granule neurons. Because Cbln1 and Cbln3 are coexpressed in the brain and interact avidly, they may function as a secreted heteromeric complex in vivo.

The Lurcher mutation identifies delta 2 as an AMPA/kainate receptor-like channel that is potentiated by Ca(2+)

Neurodegeneration in Lurcher (Lc) mice results from constitutive activation of delta 2, a subunit of ionotropic glutamate receptors (GluRs) with unknown natural ligands and channel properties. Homo-oligomeric channels of GluR-delta2 with the Lurcher mutation (GluR-delta 2(Lc)) expressed in human embryonic kidney 293 cells showed a doubly rectifying current-voltage relation reminiscent of the block by intracellular polyamines in AMPA/kainate channels. Similarly, the fraction of the total current carried by Ca(2+) was approximately 2-3%, comparable with that found in Ca(2+)-permeable AMPA/kainate channels. Currents through GluR-delta 2(Lc) channels were also potentiated by extracellular Ca(2+) in a biphasic manner, with maximal potentiation occurring at physiological concentrations of Ca(2+). We examined the functional role of the Q/R site in GluR-delta 2(Lc) by replacing glutamine with arginine. Analogous to AMPA/kainate receptors, GluR-delta 2(Lc)(R) channels showed no voltage-dependent block by intracellular polyamines and were nominally impermeable to Ca(2+). The potentiation by Ca(2+), however, remained intact. Hence, GluR-delta 2(Lc) channels are functionally similar to the AMPA/kainate receptor channels, consistent with the high-sequence identity shared by these subunits within the channel-lining M2 and M3 segments. Furthermore, potentiation by Ca(2+) and a permeability to Ca(2+) comparable with that of AMPA/kainate receptors provide a possible cause for cell death in Lurcher mice and may contribute to cerebellar long-term depression under physiological conditions.

[Screening the trans-action factors binding to the enhancer element of rat GST-P by yeast one-hybrid system]

OBJECTIVE

To investigate the diversity of the mechanisms of rat glutathione S-transferase P (GST-P) gene expression regulation and the relation between rat GST-P gene expression and carcinogenesis. To search the trans-action factors binding to the enhancer element of rat GST-P (glutathione S-transferase P enhancer, GPE I).

METHODS

We searched the trans-action factors binding to GPE I using yeast one-hybrid system, and analyzed the DNA sequence by sequencing and computer search.

RESULTS

Two positive clones pYGPE1 and pYGPE2 were obtained. The homologies of the insert sequence of pYGPE1 nucleotide and amino acid sequences with rat c-jun cDNA were 99% and 100% respectively; the homologies of the insert sequence of pYGPE2 nucleotide and amino acid sequences with rat mitochondrial adenine nucleotide translocase cDNA were 99% and 100% respectively.

CONCLUSIONS

Rat c-Jun and mitochondrial adenine nucleotide translocase can bind to the GPE I core sequence, and they perhaps are the trans-action factors of GPE I.

[Dynamic observation and clinical significance of integrated traditional Chinese and Western medicine on interleukin-2 system, T cell and erythrocyte immune system in patients of lung cancer]

OBJECTIVE

To study the dynamic changes and its clinical significance of integrated traditional Chinese and western medicine (TCM-WM) on IL-2 system, T cell and erythrocyte immune system in patients of lung cancer.

METHODS

Forty-eight cases with lung cancer were randomly divided into two groups: TCM-WM group (group I) and the chemotherapy group (group II); and 20 healthy subjects were simultaneously compared. The relevant immune indices, clinical symptoms and signs, changes of solid tumor and living quality were dynamically observed.

RESULTS

(1) The serum IL-2 level of lung cancer patients were significantly lower, while sIL-2R level higher than that of the healthy subjects. And they were raised and lowered respectively after treatment, especially in the group I, but different from the control group yet. And there were highly negative correlation between IL-2 and sIL-2R levels. (2) The percentage of CD3, CD4 and the ratio CD4/CD8 were decreased markedly in both groups, except CD8 which was increased markedly. And the percentage of RBC-C3b RR was obviously lower, while that of RBC-ICR was obviously higher. But the above-mentioned indices could be improved after treatment, especially in the group I, and there were highly positive correlation between CD4/CD8 ratio and RBC-C3bRR. (3) After treatment, all above-mentioned indices were changed significantly to their corresponding opposites. However, in regard to the degree of improvement, the patients of group I were in a better position than those of group II. At the same time, improvement of their clinical symptoms and signs, change of solid tumor and living quality also showed advantageous.

CONCLUSION

The therapeutic superiority of TCM-WM on lung cancer may be related with the modulation on immune function. Thus we can say that the effect of TCM-WM is better than that of chemotherapy alone.

KORRIGAN, an Arabidopsis endo-1,4-beta-glucanase, localizes to the cell plate by polarized targeting and is essential for cytokinesis

The formation of the cell plate, a unique structure in dividing plant cells, is pivotal for cytokinesis. A mutation in the Arabidopsis KORRIGAN (KOR) gene causes the formation of aberrant cell plates, incomplete cell walls, and multinucleated cells, leading to severely abnormal seedling morphology. The mutant, designed kor1-2, was identified as a stronger allele than the previously identified kor1-1, which appears to be defective only in cell elongation. KOR1 encodes an endo-1,4-beta-d-glucanase with a transmembrane domain and two putative polarized targeting signals in the cytosolic tail. When expressed in tobacco BY2 cells, a KOR1-GFP (green fluorescence protein) fusion protein was localized to growing cell plates. Substitution mutations in the polarized targeting motifs of KOR1 caused the fusion proteins to localize to the plasma membrane as well. Expression of these mutant genes in kor1-2 plants complemented only the cell elongation defect but not the cytokinesis defect, indicating that polarized targeting of KOR1 to forming cell plates is essential for cytokinesis. Our results suggest that KOR1 plays a critical role during cytokinesis.

KORRIGAN, an Arabidopsis endo-1,4-beta-glucanase, localizes to the cell plate by polarized targeting and is essential for cytokinesis

The formation of the cell plate, a unique structure in dividing plant cells, is pivotal for cytokinesis. A mutation in the Arabidopsis KORRIGAN (KOR) gene causes the formation of aberrant cell plates, incomplete cell walls, and multinucleated cells, leading to severely abnormal seedling morphology. The mutant, designed kor1-2, was identified as a stronger allele than the previously identified kor1-1, which appears to be defective only in cell elongation. KOR1 encodes an endo-1,4-beta-d-glucanase with a transmembrane domain and two putative polarized targeting signals in the cytosolic tail. When expressed in tobacco BY2 cells, a KOR1-GFP (green fluorescence protein) fusion protein was localized to growing cell plates. Substitution mutations in the polarized targeting motifs of KOR1 caused the fusion proteins to localize to the plasma membrane as well. Expression of these mutant genes in kor1-2 plants complemented only the cell elongation defect but not the cytokinesis defect, indicating that polarized targeting of KOR1 to forming cell plates is essential for cytokinesis. Our results suggest that KOR1 plays a critical role during cytokinesis.

Maintenance of CD8(+) T-cell memory following infection with recombinant sindbis and vaccinia viruses

CD8(+) T-cell memory is critical for protection against pathogens poorly controlled by humoral immunity. To characterize two distinct vaccine vectors, the acute and memory CD8(+) T-cell responses to an HIV-1 epitope (p18) expressed by recombinant vaccinia (vp18) and Sindbis (SINp18) viruses were compared. Whereas 9 to 13% of CD8(+) splenocytes were p18 specific during the acute response to vp18, 4% were induced by SINp18 as revealed by class I tetramer staining. Increased T-cell activation by vp18 was confirmed by higher numbers of both p18-specific IFN-gamma-secreting splenocytes and activated CD8(+) and CD4(+) T cells. Although higher frequencies of p18-specific CD8(+) T cells during primary responses correlated with higher frequencies during memory, the overall decline was only two- to threefold during the transition to memory, demonstrating equally efficient maintenance of memory in SINp18- as in vp18-immune mice. Despite modest in vivo activation, SINp18-induced CD4(+) T cells secreted substantial amounts of IFN-gamma and IL-2, potentially contributing to sustained CD8(+) memory. Collectively the data indicate that Sindbis virus recombinants provide effective vaccines for inducing protective memory CD8(+) T cells in the absence of the extensive inflammation and replication associated with vaccinia virus.

Chemical-inducible systems for regulated expression of plant genes

Chemical regulation of transgene expression presents a powerful tool for basic research in plant biology and biotechnological applications. Various chemical-inducible systems based on de-repression, activation and inactivation of the target gene have been described. The utility of inducible promoters has been successfully demonstrated by the development of a marker-free transformation system and large-scale gene profiling. In addition, field applications appear to be promising through the use of registered agrochemicals (e.g. RH5992) as inducers.

[HLA-DQ molecules associated with myasthenia gravis in Chinese patients]

Myasthenia Gravis (MG) is an autoimmune disease which is a neuromuscular disorder of autoimmune origin. MG in different races or ethnic groups has different genetic susceptibility. To search for the associations of MG in the Chinese patients with HLA-DQ molecules, PCR-RFLP method was employed for genotyping HLA-DQA1 and -DQB1 genes of MG patients and the normal Chinese. The distributions of alleles of DQA1 and DQB1 in the normal Chinese and the MG patients were listed. The DQB allele, DQB1 * 0302 was positively associated with MG (RR = 2.990, Pc = 0.0307), and a negative association was found for DQA1 * 0501 (RR = 0.4166, Pc = 0.0315). DQ haplotype DQA1 * 0301-DQB1 * 0302 was significantly increased in patients when compared to controls (RR = 7.727, Pc = 0.0109).

[Study on GMA-DNA adducts in vivo]

OBJECTIVE

To investigate whether glycidly mechacrylate (GMA-DNA) adducts can be produced in various organs of rat in vivo.

METHODS

Rats divided into 5 groups were orally administrated with mutagen, GMA 31.25, 62.5, 125, 250 mg/kg respectively for 14 days. DNA adducts produced in liver, kidney, white blood cells and testis had been analyzed by nuclease P1 mediated 32P-postlabelling method.

RESULTS

Several GMA-DNA adducts were formed in various organs (in white blood cells, 4 types, liver and kidney, 3 types and testis 1 type). The amount of GMA-DNA adducts increased with GMA dosage within 0-125 mg/kg dosages, degree of the overall level of GMA-DNA adducts in various organs were kidney > liver > white blood cells > testis. N3-methacrylate-2-hdroxypropyl-deoxycytidine monophosphate was found in kidney, liver and white blood cells.

CONCLUSIONS

GMA with electrophilic group could react with negatively charged centers on DNA and form GMA-DNA adducts.