Mapping the MRI voxel volume in which thermal noise matches physiological noise--implications for fMRI

This work addresses the choice of the imaging voxel volume in blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). Noise of physiological origin that is present in the voxel time course is a prohibitive factor in the detection of small activation-induced BOLD signal changes. If the physiological noise contribution dominates over the temporal fluctuation contribution in the imaging voxel, further increases in the voxel signal-to-noise ratio (SNR) will have diminished corresponding increases in temporal signal-to-noise (TSNR), resulting in reduced corresponding increases in the ability to detect activation induced signal changes. On the other hand, if the thermal and system noise dominate (suggesting a relatively low SNR) further decreases in SNR can prohibit detection of activation-induced signal changes. Here we have proposed and called the "suggested" voxel volume for fMRI the volume where thermal plus system-related and physiological noise variances are equal. Based on this condition we have created maps of fMRI suggested voxel volume from our experimental data at 3T, since this value will spatially vary depending on the contribution of physiologic noise in each voxel. Based on our fast EPI segmentation technique we have found that for gray matter (GM), white matter (WM), and cerebral spinal fluid (CSF) brain compartments the mean suggested cubical voxel volume is: (1.8 mm)3, (2.1 mm)3 and (1.4 mm)3, respectively. Serendipitously, (1.8 mm)3 cubical voxel volume for GM approximately matches the cortical thickness, thus optimizing BOLD contrast by minimizing partial volume averaging. The introduced suggested fMRI voxel volume can be a useful parameter for choice of imaging volume for functional studies.

Nuclear Translocation of SMAD3 May Enhance the TGF-β/SMADS Pathway in High Glucose Circumstances

OBJECTIVES

Posttransplant diabetes mellitus is one of the most frequent complications after kidney transplantation. It is considered to be one cause of chronic allograft nephropathy. This study sought to investigate the effects of high glucose on the expression and nuclear translocation of Smad3, which is an important signal mediator involved in the fibrotic signal pathway.

METHODS

The established rat renal mesangial cell line HBZY-1 was cultured in medium with various concentrations of glucose (4.5 mg/mL, 9.0 mg/mL, or 13.5 mg/mL), which was collected at 7, 14, or 21 days. The total expression of Smad3, including both inner and outer nucleus proteins was examined by Western blot analysis. The nuclear translocated Smad3, representing only the inner nucleus protein, was detected by immunofluorescence staining observed under a laser confocal scanning microscope.

RESULTS

No significant difference in the total Smad3 expression was demonstrated by Western blot analysis among the three groups of HBZY-1 cells at various concentration of glucose after 7, 14, or 21 days. There was no fluorescence detected in the nucleus at day 7 by immunofluorescence staining; however, robust positive expression of Smad3 was detected at days 14 and 21.

CONCLUSION

As a restricted Smads member, Smad3 protein might not be upregulated in the presence of high glucose. However, with prolonged culture time, Smad3 translocates from cytoplasm to nucleus, which may be a pivotal step in the fibrotic signal pathway.

[Establishment of Z-HL16C cell line.]

BACKGROUND

To establish and study the nature and the application of Z-HL16C cell line.

METHODS

The cell line was continuously passed, frozen stored and recovered. Its application was expanded and the cell type was identified.

RESULTS

The cell line had an epithelial-cell-like shape, the size appeared uniform, the cell boundary was distinct. It has been continuously passed, frozen stored and recovered for ten years. Its recovery rate was about 90%. It has been proved to be sensitive to the tested viruses which were enteroviruses (Polio, Cox, Echo), influenza viruses, parainfluenzaviruses, adenoviruses, measles virus. This cell line has been identified as a cancerization cell.

CONCLUSION

The cell line Z-HL16C has been stably established, it has a broad spectrum in sensitivity for culturing viruses.

Evolution of spin-wave excitations in ferromagnetic metallic manganites

Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic A1-xA'xMnO3 manganites (where A and A' are rare- and alkaline-earth-metal ions), which when combined with previous work elucidate the systematics of the interactions as a function of carrier concentration x, on-site disorder, and strength of the lattice distortion. The long-wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange (J4/J1) that controls the zone boundary magnon softening changes systematically with x, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.

Establishment of a cervical cancer model via inoculating SiHa Cells into humanized severe combined immunodeficient mice

PURPOSE OF INVESTIGATION

To establish a human papillomavirus (HPV) 16 positive cervical cancer model in the humanized severe combined immunodeficient (SCID) mouse.

METHODS

A HPV16 positive cervical carcinoma cell line (SiHa) was transplanted subcutaneously into SCID mice (SiHa-SCID); human peripheral blood lymphocyte (Hu-PBL) was transplanted intraperitoneally (Hu-PBL-SCID), Hu-PBL was transplated intraperitoneally and SiHa subcutaneously (Hu-PBL-SiHa-SCID), and, PBS was transplanted subcutaneously (PBS-SCID) as a control. The biological and immunological features were investigated.

RESULTS

The transplanted tumor grew slowly and no metastasis was found. The survival time of Hu-PBL-SiHa-SCID was significantly longer than that of SiHa-SCID. HPV16 DNA could be detected in all of the tumor tissues, but not in peripheral blood and organ tissues. Human serum IgG levels in Hu-PBL-SCID and Hu-PBL-SiHa-SCID were significantly elevated following immuno-reconstructed time elongating, and significantly higher in Hu-PBL-SiHa-SCID than those in Hu-PBL-SCID. The numbers of human CD3+, CD4+ and CD8+ T cells were significantly increased in the peripheral blood and spleen of Hu-PBL-SiHa-SCID and Hu-PBL-SCID mice, and significantly higher in Hu-PBL-SiHa-SCID than those of Hu-PBL-SCID mice. The weight of the spleen was significantly increased in Hu-PBL-SiHa-SCID. Tumor infiltrating lymphocytes (TILs) and human CD4+ T cells were detected in Hu-PBL-SiHa-SCID but not in SiHa-SCID mice. The spleen cells of Hu-PBL-SiHa-SCID mice displayed significantly stronger cytotoxicity to target cells than those of SiHa-SCID mice. No graft-versus-host disease (GVHD) was found in either Hu-PBL or Hu-PBL-SiHa-SCID mice.

CONCLUSION

A HPV16 positive cervical carcinoma model has been successfully established in SCID mice. This model can perfectly simulate the biological features of spontaneous human cervical cancer, and present anti-tumor immune response after the human immune system is reconstructed.

Fibroblast growth factors 7 and 10 are expressed in the human embryonic pancreatic mesenchyme and promote the proliferation of embryonic pancreatic epithelial cells

AIMS/HYPOTHESIS

The fibroblast growth factor (FGF) family consists of 22 members. In rodents, several FGFs are expressed in the pancreas, where they participate in epithelial-mesenchymal interactions. Our objective was to describe the pattern of expression of FGFs in the human embryonic pancreas and to analyse their effect on pancreas development.

METHODS

The expression of FGFs was analysed by RT-PCR. To investigate the cell types expressing FGF7 and FGF10, we separated epithelial from mesenchymal cells using immunomagnetic beads linked to E-cadherin antibodies and performed real-time PCR. The effect of FGF7 and FGF10 on proliferation of human embryonic pancreatic epithelial cells was evaluated in vitro by measuring BrdU incorporation.

RESULTS

We found that different FGFs are expressed in the human embryonic pancreas, and we focused on FGF7 and FGF10. We defined a new approach to separating epithelial cells (containing the pancreatic progenitor cells) from mesenchymal cells. This allowed us to demonstrate that human embryonic pancreatic mesenchymal cells express both FGF7 and FGF10. We next demonstrated that FGF7 and FGF10 were able to induce the proliferation of the epithelial cells in vitro.

CONCLUSION/INTERPRETATION

These findings indicate that it is now possible to efficiently separate human embryonic pancreatic epithelial from mesenchymal cells, an important step to characterize and expand progenitor cells. This method allowed us to demonstrate that human embryonic pancreatic mesenchyme expresses FGF7 and FGF10 that act on epithelial cells to activate their proliferation. Such growth factors could thus be used to expand human embryonic pancreatic epithelial cells.

Order parameter criticality of the d = 3 random-field Ising antiferromagnet Fe0.85Zn0.15F2

The critical exponent beta=0.16+/-0.02 for the random-field Ising model order parameter is determined using extinction-free magnetic x-ray scattering for Fe0.85Zn0.15F2 in magnetic fields of 10 and 11 T. The observed value is consistent with other experimental random-field critical exponents, but disagrees sharply with Monte Carlo and exact ground state calculations on finite-sized systems.

Alpha-glucosidase inhibition from a Chinese medical herb (Ramulus mori) in normal and diabetic rats and mice

Alpha-glucosidase inhibitors are oral antidiabetic drugs. A traditional Chinese medical herb, Sangzhi (Ramulus mori), appears to have properties similar to those of alpha-glucosidase inhibitors. The effects of an aqueous extract of Shangzhi (SZ) were studied in normal and alloxan diabetic rats and mice, and these results compared with those for acarbose, an alpha-glucosidase inhibitor. In our grade-dose studies, SZ was found to lower and prolong the zenith of blood glucose concentration (ZBG) after sucrose or starch loading and stabilize blood glucose levels in fasting normal and alloxan diabetic mice. After 2 weeks of SZ administration with high-calorie chow or a normal diet, the fasting and non-fasting blood glucose concentrations in alloxan diabetic mice and rats were decreased. In alloxan rats, the blood fructosamine concentration was lowered. Results for acarbose and SZ were similar. These indicate that SZ has alpha-glucosidase inhibitory effects.

Optimization of 4-phenylamino-3-quinolinecarbonitriles as potent inhibitors of Src kinase activity

Subsequent to the discovery of 4-[(2,4-dichlorophenyl)amino]-6,7-dimethoxy-3-quinolinecarbonitrile (1a) as an inhibitor of Src kinase activity (IC(50) = 30 nM), several additional analogues were prepared. Optimization of the C-4 anilino group of 1a led to 1c, which contains a 2,4-dichloro-5-methoxy-substituted aniline. Replacement of the methoxy group at C-7 of 1c with a 3-(morpholin-4-yl)propoxy group provided 2c, resulting in increased inhibition of both Src kinase activity and Src-mediated cell proliferation. Analogues of 2c with other trisubstituted anilines at C-4 were also potent Src inhibitors, and the propoxy group of 2c was preferred over ethoxy, butoxy, or pentoxy. Replacement of the morpholine group of 2c with a 4-methylpiperazine group provided 31a, which had an IC(50) of 1.2 nM in the Src enzymatic assay, an IC(50) of 100 nM for the inhibition of Src-dependent cell proliferation and was selective for Src over non-Src family kinases. Compound 31a, which had higher 1 and 4 h plasma levels than 2c, effectively inhibited tumor growth in xenograft models.

[Geographic distribution and feature of Yersinia pestis plasmid isolated from Yunnan province]

OBJECTIVE

To analysis the molecular-epidemiological feature of Yersinia pestis plasmid isolated from Yunnan.

METHODS

One thousand and twenty strains of Y. pestis isolates from 44 counties of Yunnan province in China and the border of China-Myanmar using Kado and Liu method and detected by agrose gel electrophoresis.

RESULTS

Results showed that these strains from Yunnan province carried 9 kinds of plasmids with molecular weights about 3.93, 6.05, 22.97, 35.65, 45.35, 64.82, 74.59, 111.36 and 129.55 x 10(6). Of these, three kinds of 3.93, 35.65 and 111.36 x 10(6) were found very specific, only reported in Yunnan. The plasmid profile could be divided into 10 types according to the plasmid content. Type I-V were common and had a clustering nature in geographic distribution.

CONCLUSION

Based on the plasmid profile, the epidemic districts of plague could be divided into several independent plague foci, suggesting that the resurgence of domestic rat caused plague epidemics might have several hidden plague foci as the result of epidemics since 1982 in Yunnan.

Elevated interleukin-13 in patients with active lupus nephritis

OBJECTIVE

To investigate the significance of interleukin-13 (IL-13) in patients with active lupus nephritis (LN).

METHODS

Ten healthy volunteers and 16 patients with active LN were included in this study. The protein level of IL-13 in plasma was examined by enzyme linked immunosorbent assay (ELISA), and gene expression of IL-13 in peripheral blood mononuclear cells (PBMCs) by reverse transcription polymerase chain reaction (RT-PCR). Expression of IL-13 mRNA in renal tissue was studied by in situ hybridization (ISH) techniques.

RESULTS

The level of IL-13 in plasma and the expression of IL-13 mRNA in PBMCs were significantly higher in LN patients than those in the controls (P < 0.001). Increased expression of IL-13 mRNA was detected in renal tissue of active LN patients compared to those in the controls (P < 0.001). Analysis of the linear correlation indicated that the level of IL-13 mRNA in the tubulointerstitial area in patients with active LN correlated with the concentration of serum creatinine (Scr), the glomerular activity index (GAI), the activity index of tubulointerstitium, and the level of serum C3 (P < 0.05 for each).

CONCLUSION

The elevation of IL-13 may play an important role in the molecular pathogenesis of active LN.

[Determination of triacontanol and octacosanol in fenglasu and fenglasu capsules by capillary gas chromatography]

OBJECTIVE

The method was established for the determination of triacontanol and octacosanol in fenglasu and fenglasu capsules.

METHODS

The solvent was chloroform. The internal standard was hexatriacontanol. Using SIMPLCITY-1 capillary column, flame ionization detector was specified, injector temperature was 300 degrees C, and the column temperature rise by programming. [Initial temperature was 240 degrees C, maintaining 1 min and then rising the temperature (5 degrees C.min-1) to 300 degrees C for 15 min]. The flow rate of Nitrogen was 27 ml.min-1.

RESULTS

The calibration curves were linear in the range of 0.4-1.6 mg/ml for triacontanol(r = 0.999), 0.2-0.6 mg/ml for octacosanol(r = 0.9996) respectively. The average recovery (n = 9) was 99.2% for triacontanol (RSD = 1.15%), 99.91% for octacosanol (RSD = 1.40%).

CONCLUSION

The method is rapid, accurate and reliable for the quality control of fenglasu and fenglasu capsules.

Induction of alpha-calcitonin gene-related peptide mRNA expression in rat dorsal root ganglia by heat stress involves the heme oxygenase-1/carbon monoxide pathway

SD rats were pretreated with whole body hyperthermia (rectal 42 degrees C) for 15 min. The level of calcitonin gene-related peptide (CGRP) in plasma, and alpha- and beta-CGRP mRNA as well as heme oxygenease-1 and heme oxygenase-2 mRNA in dorsal root ganglia were determined by radioimmunoassay and semi-quantitative reverse-transcription polymerase chain reaction, respectively. Heat stress induced only the expression of alpha-CGRP or heme oxygenease-1 but not beta-CGRP or heme oxygenase-2 mRNA, and the release of CGRP and induction of alpha-CGRP mRNA expression were abolished by pretreatment with Zinc protoporphyrin IX, the heme oxygenase inhibitor, or methylene blue, the inhibitor of soluble guanylate cyclase. These results indicate that induction of alpha-CGRP mRNA expression in rat DRG by heat stress involves the heme oxygenase-1/carbon monoxide pathway.

Differential expression of Tie-2 receptors and angiopoietins in response to in vivo hypoxia in rats

In this study, we assessed the effects of in vivo hypoxia on the expression of Tie-2 receptors and angiopoietins in various organs of conscious rats and correlated these effects with the expression of hypoxia-inducible factor-1 (HIF-1). RT-PCR and Southern blotting were used to amplify mRNA expression of angiopoietin-1, -2, and -3, Tie-2, and HIF-1 alpha in tissues of normoxic and hypoxic (fraction of inspired oxygen of 9--10% for either 12 or 48 h) rats. Hypoxia provoked a decline in angiopoietin-1 mRNA and Tie-2 mRNA, protein, and phosphorylation levels in the lung, liver, cerebellum, and heart but not in the kidney and diaphragm. In comparison, hypoxia raised the levels of angiopoietin-2 mRNA in the cerebellum and angiopoietin-3 mRNA in the lung, kidney, and diaphragm. HIF-1 alpha mRNA was abundant in most organs of normoxic rats but was significantly induced in the kidney and diaphragm of hypoxic rats. We conclude that in vivo hypoxia exerts inhibitory effects on the activity of the angiopoietin-1/Tie-2 receptor pathway through reduction of angiopoietin-1 and upregulation of angiopoietin-2 and -3. Induction of angiopoietin-3 in the kidney and diaphragm of hypoxic rats could be mediated through the HIF-1 transcription factor.

6-Substituted-4-(3-bromophenylamino)quinazolines as putative irreversible inhibitors of the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor (HER-2) tyrosine kinases with enhanced antitumor activity

A series of new 6-substituted-4-(3-bromophenylamino)quinazoline derivatives that may function as irreversible inhibitors of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor (HER-2) tyrosine kinases have been prepared. These inhibitors have, at the C-6 position, butynamide, crotonamide, and methacrylamide Michael acceptors bearing water-solublilizing substituents. These compounds were prepared by acylation of 6-amino-4-(3-bromophenylamino)quinazoline with unsaturated acid chlorides or mixed anhydrides. We show that attaching a basic functional group onto the Michael acceptor results in greater reactivity, due to intramolecular catalysis of the Michael addition and/or an inductive effect of the protonated basic group. This, along with improved water solubility, results in compounds with enhanced biological properties. We present molecular modeling and experimental evidence that these inhibitors interact covalently with the target enzymes. One compound, 16a, was shown to have excellent oral activity in a human epidermoid carcinoma (A431) xenograft model in nude mice.

[Detection of telomerase activity in laryngeal carcinoma and the association between telomerase activity and lymphatic metastasis]

OBJECTIVE

To investigate the telomerase activity in human laryngeal squamous cell carcinomas (LSCC) and the association between telomerase activity and lymphatic metastasis.

METHOD

Telomerase activity was determined in 47 specimens of LSCC and 10 specimens of laryngeal inflammatory polyps using PCR-ELISA.

RESULT

Telomerase activity was detected in 39 of 47 (83%) LSCC, but was not detected in all 10 laryngeal inflammatory polyps. There were significant differences between them (P < 0.01). Telomerase activation in LSCC with positive cervical lymph node involvement appeared to be higher (13 out of 13 cases, 100%) than in LSCC with negative cervical lymph node involvement (26 out of 34, 76.47%), (P < 0.05).

CONCLUSION

Telomerase is activated frequently in LSCC and may become a biomarker of LSCC. The detection of telomerase activity in LSCC may have some value for predicting metastasis potential and prognosis and can guide the clinical practices applying selective neck dissection.

[The clinic treatment of traumatic optic neuropathy]

OBJECTIVE

To observe the visual outcome of traumatic optic neuropathy treated with optic canal decompression surgery and medication.

METHOD

15 patients, suffering from traumatic optic neuropathy, had received medication and optic canal decompression surgery through the approach of ethmoid and sphenoid sinus. The vision acuity was divided into 5 grades: no light perception, light perception, finger movement, counting fingers, vision > or = 0.1, the vision acuity improvements reaching 2 grades or more were determined as effective. All patients were followed up for intervals of 1 month and 6 months.

RESULT

The total efficient rate is 57.4%, no intraoperative or postoperative complications were encountered. Being followed up 6 months, 2 cases, who underwent respectively the operation 8, 11 days after trauma, felt no light perception.

CONCLUSION

The approach through ethmoid and sphenoid sinus have the merits such as safety, less damage and larger operative field. Timely medication, megacorticosteroid therapy mainly, may play a good role in alleviating optic nerve edema and restoring its function. Comprehensive therapy may be an ideal treatment to traumatic optic neuropathy.

MEK (MAPKK) inhibitors. Part 2: structure–activity relationships of 4-anilino-3-cyano-6,7-dialkoxyquinolines

A series of 4-anilino-3-cyano-6,7-dialkoxyquinolines with different substituents attached to the 4-anilino group has been prepared that are potent MEK (MAP kinase kinase) inhibitors. The best activity is obtained when a phenyl or a thienyl group is attached to the para-position of the aniline through a hydrophobic linker, such as an oxygen, a sulfur, or a methylene group. The most active compounds show low nanomolar IC(50)'s against MEK (MAP kinase kinase), and have potent growth inhibitory activity in LoVo cells (human colon tumor line).

[Surgery of the skull base assisted by sinus endoscope]

OBJECTIVE

To explore the feasibility and clinical value of the endoscopic operations around the skull base.

METHODS

A retrospective study was made of 44 cases treated by endoscopic operations. Twenty-five cases underwent intranasal endoscopic operations.

RESULTS

Forty of 44 cases were cured by one-stage surgery. One case of cartridge foreign body clamped in clivus was not successfully removed; only window operation and puncture biopsy were done in another case of pituitary adenoma; high cranial pressure has not been completely reduced after operation in the third case with relapsing craniopharyngioma a companied with obstructive hydrocephalus. One case of sphenoidal malignant adenoma involving saddle based and extended laterally was partly resected. Complications were follows: cerebrospinal fluid rhinorrhea in 2 cases, diabetes insipidus in 1 case, all of them were cured by conservative treatment; nasal septum perforation in 1 case, without any treatment.

CONCLUSIONS

The endoscopic skull base surgery by intranasal approach is feasibility. Intranasal approach has direct path, slight wound and no wound in face. Combined with operation microscope, sinus endoscope can make up for its limits.

[Genetic instability in cancer tissues analyzed by RAPD PCR]

In five kinds of tumors, total 128 specimens were analyzed by RAPD (random amplified polymorphic DNA) PCR with nine 10-base arbitrary primers for detecting instabilities of DNA and chromosome and screening new molecular markers coupled to putative or unknown oncogenes and/or tumor suppressor genes. Bands representing instabilities have been recovered and purified from agarose and cloned into pCAPs vector, and further labeled by DIG as probes for analysis of Southern blot, Northern blot and Sequencing. Results revealed that sample 5 and 3 of the gastric cancers showed the highest genomic changes and the average detectability in five sorts of cancers was up to at least 40% (42.2%-49.4%), and that there were significant differences in the ability of each primer to detect genomic instability, which ranged from 27% to 68%. Despite the highest detectability of genetic instability (68%) in tumor tissues, primer 2 could produce stable profiles of DNA bands in normal tissue genome with good reproducibility. On the contrary, primer 8 was of the lowest one (27%). Band B of single copy found to be allelic losses in gastric and colon cancers according to RFLP analysis was of a novel sequence and registered by Gen-Bank (Accession Number AF151005). Therefore the genetic instabilities often concentrated on some special locuses of chromosome e.g. repetitive sequences etc. and coupled to carcinogenesis. It was impossible or difficult to get great achievements for cancer treatments with the procedure of gene therapy only to one oncogene or one tumor suppressor gene because the extensive DNA variations occurred during the progression of tumor. RAPD assay connected with other techniques was a good tool for the detection of genomic instabilities and direct screening of some new molecular markers related to tumor suppressor genes or oncogenes.

Effects of temperature and air pollutants on cardiovascular and respiratory diseases for males and females older than 65 years of age in Tokyo, July and August 1980-1995

We studied exposures to higher daily maximum temperatures and concentrations of air pollutants in Tokyo during the summer months of July and August from 1980 to 1995 and their effects on hospital emergency transports for cardiovascular and respiratory diseases for males and females > 65 years of age. Cardiovascular diseases were angina, cardiac insufficiency, hypertension, and myocardial infarction. Respiratory diseases were asthma, acute and chronic bronchitis, and pneumonia. Except for pneumonia, daily maximum temperatures were not associated with hospital emergency transports. Increasing daily maximum temperatures, however, were associated with decreased hospital emergency transports for hypertension. Concentrations of nitrogen dioxide or particulate matter < or = 10 microm, however, were associated with daily hospital emergency transports for angina, cardiac insufficiency, myocardial infarction, asthma, acute and chronic bronchitis, and pneumonia. For cardiac insufficiency, hypertension, myocardial infarction, asthma, chronic bronchitis, and pneumonia, the expected daily number of emergency transports per million were greater for males than for females. For angina and acute bronchitis, there were no differences for the expected daily numbers of emergency transports per million between males and females.

Effects of temperature and air pollutants on cardiovascular and respiratory diseases for males and females older than 65 years of age in Tokyo, July and August 1980-1995

We studied exposures to higher daily maximum temperatures and concentrations of air pollutants in Tokyo during the summer months of July and August from 1980 to 1995 and their effects on hospital emergency transports for cardiovascular and respiratory diseases for males and females > 65 years of age. Cardiovascular diseases were angina, cardiac insufficiency, hypertension, and myocardial infarction. Respiratory diseases were asthma, acute and chronic bronchitis, and pneumonia. Except for pneumonia, daily maximum temperatures were not associated with hospital emergency transports. Increasing daily maximum temperatures, however, were associated with decreased hospital emergency transports for hypertension. Concentrations of nitrogen dioxide or particulate matter < or = 10 microm, however, were associated with daily hospital emergency transports for angina, cardiac insufficiency, myocardial infarction, asthma, acute and chronic bronchitis, and pneumonia. For cardiac insufficiency, hypertension, myocardial infarction, asthma, chronic bronchitis, and pneumonia, the expected daily number of emergency transports per million were greater for males than for females. For angina and acute bronchitis, there were no differences for the expected daily numbers of emergency transports per million between males and females.

Fluorescent microsphere-based readout technology for multiplexed human single nucleotide polymorphism analysis and bacterial identification

Large-scale human genotyping requires technologies with a minimal number of steps, high accuracy, and the ability to automate at a reasonable cost. In this regard, we have developed a rapid, cost-effective readout method for single nucleotide polymorphism (SNP) genotyping that combines an easily automatable single-tube allele-specific primer extension (ASPE) with an efficient high throughput flow cytometric analysis performed on a Luminex 100 flow cytometer. This robust technique employs an ASPE reaction using PCR-derived target DNA containing the SNP and a pair of synthetic complementary capture probes that differ at their 3' end-nucleotide defining the alleles. Each capture probe has been synthesized to contain a unique 25-nucleotide identifying sequence (ZipCode) at its 5' end. An array of fluorescent microspheres, covalently coupled with complementary ZipCode sequences (cZipCodes), was hybridized to biotin-labeled ASPE reaction products, sequestering them for flow cytometric analysis. ASPE offers both an advantage of streamlining the SNP analysis protocol and an ability to perform multiplex SNP analysis on any mixture of allelic variants. All steps of the assay are simple additions of the solutions, incubations, and washes. This technique was used to assay 15 multiplexed SNPs on human chromosome 12 from 96 patients. Comparison of the microsphere-based ASPE assay results to gel-based oligonucleotide ligation assay (OLA) results showed 99.2% agreement in genotype assignments. In addition, the microsphere-based multiplex SNPs assay system was adapted for the identification of bacterial samples by both ASPE and single base chain extension (SBCE) assays. A series of probes designed for different variable sites of bacterial 16S rDNA permitted multiplex analysis and generated species- or genus-specific patterns. Seventeen bacterial species representing a broad range of gram-negative and gram-positive bacteria were analyzed within 16 variable sites of 16S rDNA sequence. The results were consistent with the published sequences and confirmed by direct DNA sequencing.

On the mechanism of the protective effects of nitroglycerin and nicorandil in cardiac anaphylaxis

Previous investigations have shown that nitric oxide donors and nicorandil can suppress allergic reaction. In the present study, the protective effects of nitroglycerin and nicorandil on cardiac anaphylaxis were examined. Presensitized guinea-pig hearts challenged with specific antigen caused a marked decrease in coronary flow (CF), left ventricular pressure (LVP) and its derivatives (+/-dp/dtmax), increase in heart rate, and prolongation of P-R interval. Nitroglycerin (300 nM) or nicorandil (100 microM) markedly increased the content of calcitonin gene-related peptide (CGRP) concomitant with a significant improvement of the cardiac dysfunction and alleviation of the extension of P-R interval. Nicorandil at a concentration of 100 microM also inhibited the sinus tachycardia and histamine release. The protection afforded by nitroglycerin was abolished by glibenclamide, a blocker of ATP-sensitive potassium channels, or by CGRP8-37, the selective CGRP receptor antagonist, or by pretreatment with capsaicin, which depletes endogenous CGRP. The inhibitory effect of nicorandil on cardiac anaphylaxis was abolished only by glibenclamide but not by pretreatment with capsaicin. These results suggest that nitroglycerin and nicorandil possess a protection of cardiac anaphylactic injury. The present study also suggests that the protective effect of nitroglycerin may be related to stimulation of CGRP release and opening the KATP channel, and that the effect of nicorandil is mainly due to the activation of the KATP channel.

Synthesis and Src kinase inhibitory activity of a series of 4-phenylamino-3-quinolinecarbonitriles

Screening of a directed compound library in a yeast-based assay identified 4-[(2,4-dichlorophenyl)amino]-6,7-dimethoxy-3-quinolinecarbonitrile (2a) as a Src inhibitor. An enzymatic assay established that 2a was an ATP-competitive inhibitor of the kinase activity of Src. We present here SAR data for 2a which shows that the aniline group at C-4, the carbonitrile group at C-3, and the alkoxy groups at C-6 and C-7 of the quinoline are crucial for optimal activity. Increasing the size of the C-2 substituent of the aniline at C-4 of 2a from chloro to bromo to iodo resulted in a corresponding increase in Src inhibition. Furthermore, replacement of the 7-methoxy group of 2a with various 3-heteroalkylaminopropoxy groups provided increased inhibition of both Src enzymatic and cellular activity. Compound 25, which contains a 3-morpholinopropoxy group, had an IC(50) of 3.8 nM in the Src enzymatic assay and an IC(50) of 940 nM for the inhibition of Src-dependent cell proliferation.

Flow cytometric platform for high-throughput single nucleotide polymorphism analysis

We have developed a rapid, cost-effective, high-throughput readout for single nucleotide polymorphism (SNP) genotyping using flow cytometric analysis performed on a Luminex 100 flow cytometer. This robust technique employs a PCR-derived target DNA containing the SNP, a synthetic SNP-complementary ZipCode-bearing capture probe, a fluorescent reporter molecule, and a thermophilic DNA polymerase. An array of fluorescent microspheres, covalently coupled with complementary ZipCode sequences (cZipCodes), was hybridized to the reaction products and sequestered them for flow cytometric analysis. The single base chain extension (SBCE) reaction was used to assay 20 multiplexed SNPs for 633 patients in 96-well format. Comparison of the microsphere-based SBCE assay results to gel-based oligonucleotide ligation assay (OLA) results showed 99.3% agreement in genotype assignments. Substitution of direct-labeled R6G dideoxynucleotide with indirect-labeled phycoerythrin dideoxynucleotide enhanced signal five- to tenfold while maintaining low noise levels. A new assay based on allele-specific primer extension (ASPE) was validated on a set of 15 multiplexed SNPs for 96 patients. ASPE offers both the advantage of streamlining the SNP analysis protocol and the ability to perform multiplex SNP analysis on any mixture of allelic variants.

[Technique and advance of comprehensive two-dimensional gas chromatography]

Many analytical problems require more resolution than the conventional single column chromatographic technique can provide. In such cases the separation power can be enhanced by using more than one separation technique or mechanism. The sample is then dispersed in different time dimensions. The resolution obtained depends strongly on the difference between these dimensions. The highest resolution is gained when there is no correlation between the separations, the dimensions being orthogonal to each other. Comprehensive two-dimensional gas chromatography (GC x GC) provides a true orthogonal separation system in which a modulator serially couples two columns containing dissimilar stationary phases. It focuses and subsequently reinjects components eluting from the first column into the second one. The system generates a peak capacity that is approximately equal to the product of the peak capacities of the two individual separation systems. In this paper, technique and instrumental considerations of GC x GC are discussed. The three designs of contemporary GC x GC systems are presented and compared. A number of typical applications on complex samples such as petroleum products and environmental pollutants are also cited. Finally, the future perspectives of GC x GC are simply discussed.

[Pharyngeal passage tube treatment for obstructive apnea syndrome]

OBJECTIVE

To investigate the therapeutical effect of pharyngeal passage tube for OSAS.

METHODS

Fifty-seven patients were treated during May 1995 to August 1999. All patients were examined by GKD-405 A polysomnography for apnea index (AI), hypnea index (HI), AHI (AI + HI) at cetera 7 items index before and after pharyngeal passage tube treatment.

RESULTS

After treatment, the longest time of apnea shortened from (54.82 +/- 20.83) s to (25.74 +/- 9.50) s, the AHI lessened from 70.82 +/- 18.06 to 30.00 +/- 10.10, the oxygen desaturation increased from (62.36 +/- 11.53)% to (78.68 +/- 12.09)%. After treatment, the recorded parameters showed obvious therapeutical effect (P < 0.05-0.001, t values is from 2.20 to 15.29, the snore loudness of all patients dropped from (84.32 +/- 18.51) dB to (32.64 +/- 10.16) dB. The therapeutical successful rate was 87.72%. The long-term use rate (over 6 months) was 72.73%.

CONCLUSION

The pharyngeal passage tube has obvious effect for patients suffering from severe OSAS. It is recommended for the treatment of OSAS as a conservative method.

Inhibitors of src tyrosine kinase: the preparation and structure-activity relationship of 4-anilino-3-cyanoquinolines and 4-anilinoquinazolines

Src is a nonreceptor tyrosine kinase involved in signaling pathways that control proliferation, migration, and angiogenesis. Increased Src expression and activity are associated with an increase in tumor malignancy and poor prognosis. Several quinolines and quinazolines were identified as potent and selective inhibitors of Src kinase activity.

Inhibition of cardiac tumor necrosis factor-alpha production by calcitonin gene-related peptide-mediated ischemic preconditioning in isolated rat hearts

Previous investigations have demonstrated that calcitonin gene-related peptide (CGRP) plays an important role in the mediation of ischemic preconditioning in rats. In the present study, we examined signal transduction pathways of CGRP-mediated ischemic preconditioning. Thirty minutes of global ischemia and 40 min of reperfusion caused a dramatic decrease in myocardial function, and a significant increase in the release of cardiac creatine kinase in the coronary effluent and in the content of tumor necrosis factor-alpha (TNF-alpha) in myocardial tissues. However, ischemic preconditioning (three cycles of 5-min ischemia and 5-min reperfusion) or pretreatment with CGRP for 5 min dramatically improved the recovery of cardiac function, and reduced the release of cardiac creatine kinase and the TNF-alpha content. The effect of ischemic preconditioning was abolished by CGRP-(8-37), the selective CGRP receptor antagonist, and by capsaicin, which depletes sensory nerve neurotransmitter content, but was unaltered by treatment with glibenclamide, a blocker of the ATP-sensitive potassium (K(ATP)) channel. The protective effects of exogenous CGRP-induced preconditioning were also not blocked by glibenclamide. These results suggest that the cardioprotective effects afforded by CGRP-mediated ischemic preconditioning are related to inhibition of cardiac TNF-alpha production, but not to activation of the K(ATP) channel.

[Identification of a new molecular marker related to tumorigenesis of the stomach and small intestine]

OBJECTIVE

Screening and identification of molecular markers associated with tumorigenesis of the gastrointestinal tract.

METHODS

Techniques of random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), Southern blot and Northern blot, gene cloning and sequencing were employed to reveal new molecular markers from tumors of different origins.

RESULTS

Of 32 RAPD fragments possibly associated with tumorigenesis, 29 were cloned into pCAPs vector. Further analysis by Southern blot revealed that the majority of the cloned fragments was repetitive sequences. Among the remaining single-copy fragments, one was found deleted in malignant tumors of the stomach and small intestine. It did not hybridize with mRNA extracted from blood lymphocyte and cultured fibroblasts. Sequence analysis indicated that this single-copy fragment contained a motif similar to eukaryotic cis-acting "CACA" box promoter. At its downstream there was an "ATG" transcription activator codon. No homologous sequence was found in the GenBank and it was therefore accepted by the GenBank. (Accession Number: AF151005).

CONCLUSION

A single-copy fragment containing cis-acting "CACA" box has been identified, which might be the upstream of a new tumor suppressor gene deleted in tumors of the stomach and small intestine.

[Trannasal-transsphenoidal endoscopic surgery of the sphenoid sinus and the sella turcica]

OBJECTIVE

The primary objective of this study is reporting our experience with transnasal endoscopic technique to management of the sphenoidal and the sellar lesions.

METHOD

Forty one patients were management under endoscope who suffered from pituitary adenomas, craniopharyngioma and sphenoidal lesions, et al.

RESULTS

In forty one cases of the sphenoidal and the sellar lesions, thirty two surgeries were successful. One patient died of bleeding, five developed the foramen of nasal septum, the adhesion of nasal cavity was complicated in three patients.

CONCLUSION

The endoscope has the advantage of improved visualization, angled view, and a wide panoramic perspective. The transnasal-transspheniodal endoscopic technique is a effective, minimally invasive approach. But there are its disadvantages and occurred severe complication. Surgeons should be understood its feasibility, limits and indication.

Light-induced down-regulation of the rat class 1 dynein-associated protein robl/LC7-like gene in visual cortex

Dynein and kinesin are the main microtubule-dependent motors that mediate intracellular movement in eukaryotic organisms. We have cloned a full-length cDNA encoding rat dynein light chain protein, robl/LC7-like (class 1), from visual cortex. We found that rat robl/LC7-like gene is highly expressed in neocortex and displays the unusual feature of being rapidly down-regulated by sensory stimulation. This effect was seen at both mRNA and protein levels in visual cortex, being detectable in as little as 45 min after the onset of visual stimulation. Down-regulation by sensory stimulation was also found within ocular dominance columns of area V1 in monocularly deprived monkeys. Our results suggest a high turnover rate of the robl/LC7-like protein and the presence of a repressor mechanism in neurons that is tightly coupled to synaptic stimulation.

4-Anilino-6,7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor kinase and their bioisosteric relationship to the 4-anilino-6,7-dialkoxyquinazoline inhibitors

The synthesis and SAR of a series of 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor (EGF-R) kinase are described. Condensation of 3, 4-dialkoxyanilines with ethyl (ethoxymethylene)cyanoacetate followed by thermal cyclization gave, regiospecifically, 6,7-dialkoxy-4-oxo-1, 4-dihydroquinoline-3-carbonitriles. Chlorination (POCl(3)) followed by the reaction with substituted anilines furnished the 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of EGF-R kinase. An alternate synthesis of these compounds starts with a methyl 3, 4-dialkoxybenzoate. Nitration followed by reduction (Fe, NH(4)Cl, MeOH-H(2)O) gave a methyl 2-amino-4,5-dialkoxybenzoate. Amidine formation using DMF-acetal followed by cyclization using LiCH(2)CN furnished a 6,7-dialkoxy-4-oxo-1,4-dihydroquinoline-3-carbonitrile, which was transformed as before. Compounds containing acid, ester, amide, carbinol, and aldehyde groups at the 3-position of the quinoline ring were also prepared for comparison, as were several 1-anilino-6,7-dimethoxyisoquinoline-4-carbonitriles. The compounds were evaluated for their ability to inhibit the autophosphorylation of the catalytic domain of EGF-R. The SAR of these inhibitors with respect to the nature of the 6,7-alkoxy groups, the aniline substituents, and the substituent at the 3-position was studied. The compounds were further evaluated for their ability to inhibit the growth of cell lines that overexpress EGF-R or HER-2. It was found that 4-anilinoquinoline-3-carbonitriles are effective inhibitors of EGF-R kinase with activity comparable to the 4-anilinoquinazoline-based inhibitors. A new homology model of EGF-R kinase was constructed based on the X-ray structures of Hck and FGF receptor-1 kinase. The model suggests that with the quinazoline-based inhibitors, the N3 atom is hydrogen-bonded to a water molecule which, in turn, interacts with Thr 830. It is proposed that the quinoline-3-carbonitriles bind in a similar manner where the water molecule is displaced by the cyano group which interacts with the same Thr residue.

[Process monitoring the synthesis of N-dichloroacetyloxazolidine by thin-layer chromatography]

A thin-layer chromatographic procedure has been developed for the monitoring and identification of the synthesis of N-dichloroacetyloxazolidine by dichloroacetyl chloride, an alcoholamine and a ketone. The determination of reaction was made on the plates at room temperature. The reaction liquid was spotted on the silica gel G thin-layer plate and developed using solvent system, dichloromethane-methanol(10:1, V/V), until the solvent front migrated 10 cm from the starting spot. Then, the separated spots(raw materials and product) were scanned in iodine. About 1 hour, the raw material spots disappeared gradually and the product spots became clear, then the reaction had basically completed. Compounds A, B, C and D had Rf values of 0.71, 0.76, 0.75 and 0.79 respectively. The repeatability of Rf value was good. The TLC procedure has also been developed for the identification of the recrystallization of crude product. After recrystallization, there was one spot on the plate. Then, the products were confirmed by IR, 1HNMR and elemental analysis. The separation conditions were easily obtained. This method is simple, rapid, sensitive and reproducible.

Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice

Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.

[Investigation of a gas chromatographic column system for the on-line analysis of gaseous components in de-propane tower of pyrolysis equipment]

Multi-dimensional gas chromatograph has become an important process analyzer due to the advantages of high resolution and fast speed. According to the production requirement, a gas chromatographic column switching system has been investigated for the on-line analysis of gaseous components from high-pressure and lower-pressure de-propane towers of pyrolysis equipment. By using two different injection times on three injectors, and fore-flush and back-flush techniques, C2-hydrocarbons, propane, propene, methylacetylene, propadiene and C4-hydrocarbons can be separated on 7 columns in 7 minutes. The practical application showed the developed column system is suitable for the on-line monitoring of the production process.

A protein kinase C-independent pathway leading to c-Jun-dependent expression of 100-kDa Ras GTPase-activating protein in JEG-3 human choriocarcinoma cells

Although the 100-kDa Ras GTPase-activating protein (p100 RasGAP) has been reported to exist specifically in human placental trophoblasts, the molecular mechanisms responsible for regulating its expression remain unclear. In this study we used okadaic acid, an inhibitor of serine/threonine phosphatase 1 and 2 A, as a probe to explore the signaling pathway regulating the expression of p100 RasGAP in JEG-3 human placental choriocarcinoma cells. Treatment of JEG-3 cells with okadaic acid provoked dose- and time-dependent stimulation of p100 RasGAP expression without marked modification of expression of p120 RasGAP, another isoform of RasGAP. Co-treatment of cells with okadaic acid and the protein kinase C activator, phorbol 12-myristate 13-acetate, exerted an additive effect on p100 RasGAP induction. Moreover, the response of the p100 RasGAP de novo synthesis to okadaic acid was not affected by the selective inhibitor of protein kinase C, GF 109203X. Thus this study identified a novel signaling pathway regulating p100 RasGAP expression, which is independent of protein kinase C. In addition, okadaic acid treatment resulted in the activation of ERK2 (p42 MAP kinase) and the induction of both c-Jun and c-Fos proteins without activating JNK (c-Jun NH2-terminal kinase). Significantly, blockade of c-Jun expression with antisense c-jun oligonucleotides suppressed p100 RasGAP expression. Taken together, it is concluded that okadaic acid induces the expression of p100 RasGAP protein in JEG-3 cells preceded by activation of ERK and AP-1 cascade, and that this okadaic acid-induced p100 RasGAP expression is independent of protein kinase C-mediated pathway but requires c-Jun/AP-1 function.

Molecular maps of neural activity and quiescence

The rapid accumulation of inducible transcription factors (ITFs), such as c-Fos and Zif268, in activated neurons combined with histological methods that offer detection at the cellular level are key features that have led to their wide use in visualizing activated neurons. There are two major drawbacks of ITFs that limit their use in the CNS--cell-type expression specificity and stimulus-transcription coupling uncertainty. Recent technical advances in the field of molecular activity mapping now permit dual-labeling approaches that help resolve some of these ambiguities and identify neurons that are activated by different sensory stimuli. Furthermore, the recent identification of the robl/LC7-like gene, which shows immediate-early repression after stimulation, may have utility in functional mapping where it can be used to delineate quiescent neurons and serve as a complement to molecular activity markers.

Temperature and air pollution as risk factors for heat stroke in Tokyo, July and August 1980-1995

Heat stroke is associated with prolonged exposures to high air temperatures that usually occur in the summer months of July and August in Tokyo, Japan. Also during July and August, residents of Tokyo are often exposed simultaneously to high concentrations of air pollutants. To assess the impacts of these combined exposures, daily numbers of heat stroke emergency transport cases/million residents for Tokyo were stratified by gender and three groups: 0-14, 15-64; and > 65 years of age, for the months of July and August in 1980-1995. A regression model was constructed using daily maximum temperature (Tmax) and daily average concentrations of NO2 and O3 as model covariates. Classification indices were added to make it possible to compare the expected number of heat stroke cases by age and gender. Lag times of 1-4 days in Tmax and air quality covariates and terms to account for interactions between pairs of model covariates were also included as additional risk factors. Generalized linear models (GLMs), assuming a Poisson error structure for heat stroke emergency transport cases, were used to determine which covariates were significant risk factors for heat stroke for the three age groups of males and females. Same-day Tmax and concentrations of NO2 were the most significant risk factors for heat stroke in all age groups of males and females. The number of heat stroke emergency transport cases/million residents was greater in males than in females in the same age groups. The smallest number of heat stroke emergency transport cases/million residents occurred for females 0-14 years of age and the greatest number of heat stroke emergency transport cases/million residents occurred for males > 65 years of age.

[Anatomic investigation of facial canal related to middle ear surgery]

OBJECTIVE

To avoid hurting facial nerve in middle ear surgery.

METHOD

20 adult head cadavers with 40 sides tempotal bone were dissected and investigated.

RESULT

1. Prevalence of dehiscent facial nerve canal was 32.5% (13/40), while 2.5% (1/40), 27.5% (11/40), 7.5%(3/40) incidence facial nerve canal were found in the labyrinthine, horizontal, vertical segment respectively. 2. Distance between the vertical portion of facial nerve and posterior semicircular canal was 0.62-5.08(2.48 +/- 0.63) mm. Interspace between the vertical portion of facial nerve and tympanic chorda was 0-4.62 (2.12 +/- 0.76) mm at the level of tympanic ditch, while interspace between the vertical portion of facial nerve and tympanic ditch was 2.96-8.82 (5.86 +/- 1.62) mm. 3. Distance between horizontal portion of facial nerve and lateral semicircular canal was 0-3.02 (1.92 +/- 0.84) mm. Interspace between horizontal portion of facial nerve and stapedial board was 0.92-4.06(2.14 +/- 0.90) mm.

CONCLUSION

Familiarity with facial nerve procession should be favorable to decrease facial paralysis with middle ear surgery.

Mechanisms of spiroplasma genome variation associated with SpV1-like viral DNA inferred from sequence comparisons

Genomes of Spiroplasma citri strains have rearranged frequently during their evolution, partly due to multiple integrated sequences of spiroplasma viruses. To understand better the role of viral sequences in genome evolution, we examined available nucleotide sequences of viruslike elements in the S. citri chromosome. Comparison of integrated and nonintegrated sequences of spiroplasma virus SpV1-C74 DNA suggested that it is an encapsidated form of the circular transposition intermediate belonging to an insertion sequence (IS3) family member. One SpV1-C74 viral DNA fragment was identified as interrupting the remains of a DNA adenine modification methylase gene. A viral DNA insertion of SpV1-R8A2 B DNA had hallmarks of having suffered an internal deletion by a site-specific recombination system. Homologous recombination likely was responsible for several deletions within viral DNA. A homologous recombination event was inferred between part of a viral DNA insertion and a similar chromosomal sequence. Dispersed sequences from SpV1-like C4 open reading frames (ORFs) were identified as involved in a complex deletion-inversion event. Thus, SpV1-like sequences likely have altered spiroplasma genomes by inserting within active genes, destroying their function, by providing targets for site-specific recombination, by mediating deletions of sequences adjacent to their integration sites, and by providing targets for homologous recombination, leading to inversions.

Evidence for a novel RasGAP-associated protein of 105 kDa in both mature trophoblasts and differentiating choriocarcinoma cells

A novel tyrosine-phosphorylated, RasGAP-associated protein of 105 kDa (p105) is found in normal human term placental trophoblasts, as well as in JEG-3 human choriocarcinoma cells induced to differentiate by okadaic acid (OA). This p105 RasGAP-associated protein is distinct from other RasGAP-associated proteins described so far, none of which has either a molecular size close to p105 or a trophoblastic cell origin. The p105 appears, accompanied by p120 and p100 RasGAP expression, after OA treatment of JEG-3 cells but is almost undetectable in the absence of stimulation. Moreover, the p105 is the first discovered RasGAP-associated protein bound to p100 RasGAP. The natural occurrence of the p105 in normal mature trophoblasts isolated from human term placenta suggests that it may be linked to the differentiation state of human trophoblasts. Hence, this p105 RasGAP-associated protein might be considered a marker of human trophoblast differentiation.

[Surgical reconstruction of laryngeal and tracheal stenosis]

OBJECTIVE

Reconstruction of laryngotracheal stenosis.

METHOD

According to the pathologic condition of the larynx and trachea, various surgical procedures were designed for the treatment of laryngotracheal stenosis. These techniques included endoscopic management, laser therapy and laryngotrachoetomy with autogenous tissue and stent.

RESULT

Among 36 patients, 32 were decannulated. The success rate was 88.8%.

CONCLUSION

In order to improve the curation effects of laryngjotrachal stenosis, the choice of surgical procedure must be individualized to the pathologic condition of larynx and trachea, as well as the experience of the surgeon. Learning previous successful experience is also very important for a good result.

[Determination of 2,4-dinitrophenol by solid-phase microextraction coupled to GC/MS]

Solid-phase microextraction coupled GC/MS was investigated for the determination of 2,4-dinitrophenol in aqueous sample. Analytes were extracted by a 85 microns polyacrylate coated fiber. The fiber was then transferred into the injector of GC. Analytes were thermally desorbed and detected by GC/MS. The influences of several parameters on SPME procedure have been studied. The optimization condition was obtained: directly sampling in the water sample with the extraction period was 30 min and the desorption time 3 min at 270 degrees C. Acidification by hydrochloric acid (pH 2) and saturated salt were necessary for the best sensitivity. The precision of SPME is better than that of liquid-liquid extraction. This method is a fast, simple, and pre-concentration-free technique, which is suitable for detecting 2,4-dinitrophenol in water sample.

[Development of column switching systems in industrial gas chromatography]

According to the home-made requirement of column switching systems in 23 industrial gas chromatographs in 300,000 Tons of olefin plant, based on the research work of the expert system on gas chromatography and movement laws of compounds of interest in columns, the suitable stationary phases were defined, and the column switching systems were designed by using combined cutting techniques which consist of backflushing, fore-flushing and heart cutting, and by controlling column lengths, flows, flow directions and temperatures. The practical applications showed the column systems satisfy the on-line monitoring requirement of the production process and can be used continually for 1-3 years.

The phytopathogenic mollicute-insect vector interface: a closer look

ABSTRACT Spiroplasma citri, transmitted by phloem-feeding leafhoppers, moves from the gut lumen through the gut wall, hemolymph, and salivary glands and multiplies in insect tissues. Nontransmissible lines were deficient in their ability to cross these barriers. Molecular analysis revealed extensive chromosomal rearrangements between the transmissible and nontransmissible spiroplasma lines including a large chromosomal inversion and deletions of about 10 kb at each inversion border. One open reading frame of the deleted region, cloned from the transmissible strain BR3-3X, encodes an integral membrane protein of 58 kDa that shares limited sequence similarity with major adhesin proteins of two zoopathogenic mycoplasmas. Adhesion of spiroplasmas to cultured leafhopper cells was inhibited by proteases, suggesting that adherence to host cells is mediated by spiroplasma membrane protein(s). A hypothetical model for insect transmission of phytopathogenic mollicutes is presented.