Coherent THz synchrotron radiation from a storage ring with high-frequency RF system

The generation of brilliant, stable, and broadband coherent synchrotron radiation (CSR) in electron storage rings depends strongly on ring rf system properties such as frequency and gap voltage. We have observed intense coherent radiation at frequencies approaching the THz regime produced by the MIT-Bates South Hall Ring, which employs a high-frequency S-band rf system. The measured CSR spectral intensity enhancement with 2 mA stored current was up to 10,000 times above background for wave numbers near 3 cm(-1). The measurements also uncovered strong beam instabilities that must be suppressed if such a very high rf frequency electron storage ring is to become a viable coherent THz source.

[Effect of mica granule on the expression of gene-protein associated with cancer in gastric mucosa tissue of chronic atrophic gastritis rats]

OBJECTIVE

To research the regulative effect of mica monomer granule preparation on the expression of gene associated with cancer in gastric mucosa tissue of experimental chronic atrophic gastritis (CAG) rats.

METHOD

To treat experimental CAG rats using mica monomer granule preparation with three different dosage-high, moderate and low level respectively. To observe the expression changes of mutant antioncogene-p53 gene-protein, oncogene p21, antioncogene p16 and anti-apoptosis gene bcl-2 in gastric mucosa of CAG rats by two-step ways of EnVision system in immunohistochemical method.

RESULT

There was the tendency that mica monomer granule preparation with three different dosage could decrease the expression of p53 as well as p21, and mica had the obvious regulative effects on deletion of p16 and high-expression of bcl-2. It could also alleviate the inflammation of gastric mucosa and promote the regeneration of gland.

CONCLUSION

The treatment and reversion action of mica on chronic atrophic gastritis is probably related with the regulative effect on the expression of gene associated with cancer.

World-first implantable aortic valvo-pump (IAVP) with sufficient haemodynamic capacity

For better anatomic and physiologic fitting, a novel implantable aortic valvo-pump (IAVP) has been developed. A valvo-pump is a micro axial flow impeller pump, which has the same dimensions and function, as well as the same location, of a valve. Therefore, IAVP needs no inlet and outlet tubes, no additional anatomic occupation, and has less physiologic disturbance to natural circulation compared with the traditional bypass left ventricular assist device (LVAD). The device has a stator and a rotor. The stator consists of a motor coil with an iron core and an outflow guide vane; the rotor includes driven magnets and impeller. There is neither bearing nor strut in both the pump and the motor. In order to reduce the attractive force between the rotor and the stator, so as to enhance the durability of the performance, the rotor magnets were minimized without reducing the driving torque and efficiency of the motor. The impeller vane was designed according to a three-dimensional and analytical method, for preventing stasis and turbulence. The largest outer diameter is 24.7 mm and the length at this point is 12.4 mm. The total weight is 40 g (including the rotor of 11 g). The consumed power is 7 W (14 V x 0.5 A) at 15 000 rpm. This rotating speed stays unchanged during haemodynamic testing together with a pulsatile centrifugal pump, which imitates a failing ventricle. The maximal flow cross IAVP reaches over 10 l min(-1) and the pressure head at 0 l min(-1) can be as large as 80 mmHg. At flow rate of 4 - 8 l min(-1), IAVP enlarges the flow c. 1 l min(-1) and meanwhile increases the pressure about 10 mmHg. The pressure pulsatility generated by the pulsatile centrifugal pump remains 40 mmHg after passing IAVP. By first animal experimental trial the device was sewed in aortic position of an 80 kg pig without harm to adjacent tissue and organs. IAVP promises to be a viable alternative to natural donor heart for heart transplantation in the future.

A novel mouse model for colitis-associated colon carcinogenesis induced by 1,2-dimethylhydrazine and dextran sulfate sodium

AIM: To develop an efficient animal colitis-associated carcinogenesis model and to detect the expression of β -catenin and p53 in this new model.

METHODS: Dysplasia and cancer were investigated in mice pretreated with a single intraperitoneal injection of 20 mg/kg body mass of 1,2-dimethylhydrazine prior to three repetitive oral administrations of 30 g/L dextran sulfate sodium to give conditions similar to the clinically observed active and remission phases. Immunohistochemical staining of β - catenin and p53 was performed on paraffin-imbedded specimens of animals with cancer and/or dysplasia, those without dysplasia and the normal control animals.

RESULTS: At wk 11, four early-invasive adenocarcinomas and 36 dysplasia were found in 10 (90.9%) of the 11 mice that underwent 1,2-dimethylhydrazine-pretreatment with 3 cycles of 30 g/L dextran sulfate sodium-exposure. Dysplasia and/or cancer occurred as flat lesions or as dysplasia-associated lesion or mass (DALM) as observed in humans. Colorectal carcinogenesis occurred primarily on the distal portion of the large intestine. No dysplasia and/or cancer lesion was observed in the control groups with 1,2-dimethylhydrazine pretreatment or 3 cycles of 30 g/L dextran sulfate sodium exposure alone. Immunohistochemical investigation revealed that β -catenin was translocated from cell membrane to cytoplasm and/or nucleus in 100% of cases with dysplasia and neoplasm, while normal membrane staining was observed in cases without dysplasia and the normal control animals. Nuclear expression of p53 was not detected in specimens.

CONCLUSION: A single dose of procarcinogen followed by induction of chronic ulcerative colitis results in a high incidence of colorectal dysplasia and cancer. Abnormal expression of β -catenin occurs frequently in dysplasia and cancer. This novel mouse model may provide an excellent vehicle for studying colitis-related colon carcinogenesis.

Conformational Features and Anion-Binding Properties of Calix[4]pyrrole: A Theoretical Study

The conformational preference of calix[4]pyrrole and its fluoride and chloride anion-binding properties have been investigated by density functional theory calculations. Geometries were optimized by the BLYP/3-21G and BLYP/6-31G methods, and energies were evaluated with the BLYP/6-31+G method. To model the effect of medium, the SCIPCM solvent model was also employed. Four typical conformations of the parent substituent-free calix[4]pyrrole were studied. Both in the gas phase and in CH(2)Cl(2) solution, the stability sequence is predicted to be 1,3-alternate > partial cone > 1,2-alternate > cone. The cone conformation is predicted to be about 16.0 and 11.4 kcal/mol less stable in the gas phase and CH(2)Cl(2) solution, respectively. This is mainly due to electrostatic repulsions arising from the all-syn pyrrole/pyrrole/pyrrole/pyrrole arrangement present in this conformer. The existence of possible 1:1 and 1:2 anion-binding modes were explored in the case of fluoride anion, and the factors favoring the 1:1 binding mode are discussed. The calculated binding energy for fluoride anion is about 15 kcal/mol larger than that for chloride anion. The calculated binding energy for chloride anion agrees with the experimental value very well. The presence of meso-alkyl substituents destabilizes the cone conformer with respect to the 1,3-alternate conformer and, therefore, reduces the anion-binding affinity by 3-4 kcal/mol. The strength of N-H- - -anion hydrogen bonds in the various structures subject to study were estimated on the basis of the calculated anion-binding energies and the predicted structural deformation energies of substituent-free calix[4]pyrrole.

Genistein, a tyrosine kinase inhibitor, reduces EGF-induced EGF receptor internalization and degradation in human hepatoma HepG2 cells

In this work, using the ECL Western blotting assay system, it was found that genistein, a specific tyrosine kinase inhibitor, was able to inhibit EGF-induced EGF receptor degradation and tyrosine phosphorylation in human hepatoma HepG2 cells. This inhibition was increased with increasing genistein concentration. With treatment of HepG2 cells with genistein at 37 degrees C for 30 min, the amount of internalized EGF, which was measured by the detection of the sorting of 125I-EGF in the cells, was remarkably decreased. Under the same conditions, in cells untreated with genistein, the degradation of EGF was significantly increased. After preincubation of HepG2 cells with and without genistein for 120 min at 37 degrees C, the ratio between degraded and released EGF was 16 and 24, respectively. These results suggest that EGF-induced internalization and degradation of EGF-EGF receptor complexes in HepG2 cells depend on EGF receptor tyrosine kinase activity.

Detection of EGF-induced EGF receptor degradation and tyrosine phosphorylation in intact cells

In this work, a simple, sensitive, and non-isotopic assay system for the detection of EGF-induced EGF receptor degradation and tyrosine phosphorylation in intact cells is described. In this system, boiling Laemmli sample buffer was directly added to cultured Chang liver cells to stop the reactions in the cells stimulated by EGF and to make whole-cell extracts. The effects of EGF concentration and incubation time on the EGF-induced degradation and tyrosine phosphorylation of EGF receptor were successfully determined using monoclonal anti-EGF receptor, recombinant anti-phosphotyrosine peroxidase conjugate, and enhanced chemiluminescence (ECL) Western blotting assay system. Unlike other assay systems, the use of radioisotopes was avoided in this determination. The assay system is linear up to 100 micrograms sample protein from whole-cell extracts for the detection of EGF receptor and EGF-induced autophosphorylation. This assay may be easily adopted for identification of other growth factor receptors and phosphotyrosine-containing proteins in intact cells, using appropriate anti-growth factor receptor antibodies.

EGF receptor in human Chang liver and hepatoma HepG2 cells

Epidermal growth factor (EGF) receptor was detected in the human Chang liver and human hepatoma HepG2 cells. Both cell lines were found to be able to bind EGF. The expression of EGF receptor in Chang liver and HepG2 cells was 1.3 x 10(5) EGF receptors/cell and 1.8 x 10(5) EGF receptors/cell, respectively. In both cells, this receptor was identified by ECL Western blotting using monoclonal anti-EGF receptor antibody and by immunohistochemical assay using polyclonal anti-EGF receptor antibody. Some of internalized EGF was recycled in Chang liver cells, but not in HepG2 cells.

[Study on relationship between nail-fold microcirculation and histopathology of patients with vocal cord polyp and blood stasis syndrome]

Nail-fold microcirculation of 50 vocal cord polyp patients was observed and compared with hoarseness patients without vocal cord polyp. The results showed that peripheral microcirculation was disturbed in the vocal cord polyp patients. Histopathologic observation of 200 vocal cord polyp patients was made. It was found that principal pathologic change concentrated on the lamina propria mucosae of vocal cord and the most prominent manifestation was disturbance of topical microcirculation of Reinke's layer. In microcirculation aspect, the relationship between polyp of vocal cord and the Blood Stasis Syndrome was confirmed, and pathogenic mechanism of vocal cord polyp was discussed.

Comparison of the sensitivity of different India inks staining of electro-blotted proteins on filter membranes

The sensitivity of different brands of India ink for staining proteins blotted onto filter membranes is described. Proteins that are electro-blotted onto filter membranes show better retention than those dot-blotted alone. Higgins engrossing waterproof black ink No. 893 can detect protein at a concentration as low as 5 ng which is much more sensitive than Coomassie blue. The nitrocellulose membrane from S&S is ideal for blotting proteins and gives low levels of background staining. The sensitivity of protein staining is however, affected by the types of India ink, ink concentrations, staining times and membrane lots. India ink is also found to be useful for staining circulating immune complexes separated by SDS-PAGE and electro-blotted onto filter membranes.

Yeast artificial chromosome cloning in the glycerol kinase and adrenal hypoplasia congenita region of Xp21

The adrenal hypoplasia congenita (AHC) and glycerol kinase (GK) loci are telomeric to the Duchenne muscular dystrophy locus in Xp21. We developed a pair of yeast artificial chromosome (YAC) contigs spanning at least 1.2 Mb and encompassing the region from the telomeric end of the Duchenne muscular dystrophy (DMD) locus to beyond YHX39 (DXS727), including the genes for AHC and GK. The centromeric contig consists of 13 YACs reaching more than 600 kb from DMD through GK. The telomeric contig group consists of 8 YACs containing more than 600 kb including the markers YHX39 (DXS727) and QST-59 (DXS319). Patient deletion breakpoints in the region of the two YAC contigs define at least eight intervals, and seven deletion breakpoints are contained within these contigs. In addition to the probes developed from YAC ends, we have mapped eight Alu-PCR probes amplified from a radiation-reduced somatic cell hybrid, two anonymous DNA probes, and one Alu-PCR product amplified from a cosmid end, for a total of 26 new markers within this region of 2 Mb or less. One YAC in the centromeric contig contains an insert encompassing the minimum interval for GK deficiency defined by patient deletion breakpoints, and this clone includes all or part of the GK gene.

[Analysis of hysterectomies in 118 obstetric cases]

During a period of 36 years, the rate of hysterectomy was 0.054% of all obstetric patients in our hospital, 0.0446% of cesarean section cases, and 0.005% of vaginal deliveries respectively. From 50 s to 80 s, the cesarean section rate greatly increased while the hysterectomy rate in parturition decreased. The indications for cesarean hysterectomy change from ruptured uterus, abruptio placenta and intrapartum infection to uterine atony highly increased placenta or myoma of the uterus. Cesarean hysterectomy rate due to splitting of uterine wound after cesarean section highly increased in 80 s. Bleeding for more than 1,000 ml during operation accounted for 62.7% of them. However, operative complication rate reached to 11.8%. To reduce cesarean hysterectomy rate, we suggest emphasizing maternal health care, use of uterine packing to lessen bleeding and careful management of operation as important means for reducing uterine incision wound splitting after cesarean section.

Treatment of growth hormone deficient patients with recombinant somatropin for 1 year: results of a Chinese multicentre trial

Fifty-nine patients with idiopathic growth hormone deficiency were included in a Chinese multicentre trial of recombinant somatropin, 0.5-0.7 IU/kg/week s.c. given in six or seven divided doses. The height velocity increased from 2.8 +/- 1.0 cm/year to 13.1 +/- 2.5 cm/year during 1 year of treatment, and typical catch-up growth was observed. The increase in height SDS for chronological age was significant, but the increase in height SDS for bone age was not statistically significant. No adverse reactions to the treatment were recorded. Recombinant somatropin was shown to be very effective and safe during the first year of therapy in patients with growth hormone deficiency.

Structural studies of a hornet venom allergen antigen 5, Dol m V and its sequence similarity with other proteins

The primary structures and the disulfide-bond pairings of two chromatographic forms A and B of a venom protein from white-faced hornet (Dolichovespula maculata) were determined. This protein, designated as antigen 5 (Dol m V), has 204-205 amino acid residues and it contains 4 disulfide bonds. This protein is an allergen in man but its biologic function in hornet is not yet known. Dol m V is found to have partial sequence similarity with pathogenesis-related proteins from tobacco and tomato leaves and with a sperm-coating protein from rat epididymis.