Presence of a glycan at a potential N-glycosylation site, Asn-281, of bovine lactoferrin

This work was performed to clarify the differences in glycan moieties between multiple molecular mass forms of bovine lactoferrins (bovine lactoferrins-a and -b). After digestion of both bovine lactoferrins with cyanogen bromide and V8 protease, glycopeptides were successively purified by concavalin A affinity chromatography and HPLC on an octadecylsilyl column. Four glycopeptides glycosylated at Asn-233, -368, -476, and -545 were obtained from both hydrolysates of bovine lactoferrins-a and -b. On the other hand, a glycopeptide glycosylated at Asn-281 was only detected in hydrolysate of bovine lactoferrin-a, indicating that bovine lactoferrin-a possessed five N-glycosylated sites. The glycan linked to Asn-281 of bovine lactoferrin-a was found to consist of fucose, galactose, and N-acetylgalactosamine in addition to mannose and N-acetylglucosamine. HPLC analysis of this glycan on a normal phase column showed that peaks of several glycans were detected. These glycans changed to one major glycan consisting of only mannose and N-acetylglucosamine on exoglycosidase digestion. From these results, this glycan seemed to be of the complex type and possess heterogeneous structure.

[Association of microtubule promoting and binding activity of tau with its phosphorylation sites]

OBJECTIVE

To explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) tau and the inhibition of its biological activity.

METHODS

Ultracentrifugation, chromatography, manual Edman degradation and autosequence techniques were used to prepare and phosphorylate human recombinant tau, isolate and purify 32P tau peptides and determine phosphorylation sites.

RESULTS

(1) Phosphorylation of tau by casein kinase-1 (CK-1), cyclic AMP-dependent protein kinase (PKA) and glycogen synthetase kinase-3 (GSK-3) differentially inhibited its biological activity, and the inhibition of this activity of tau by GSK-3 was significantly increased if tau was prephosphorylated by CK-1 or PKA. The most potent inhibition was seen by a combined phosphorylation of tau with PKA and GSK-3. (2) The treatment of tau by PKA and GSK-3 combination induced phosphorylation of tau at Ser-195, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-356, Ser-404, whereas only Thr-181, Ser-184, Ser-262, Ser-356 and Ser-400 were phosphorylated by GSK-3 alone under the same conditions. Among the above-mentioned phosphorylation sites, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-400 and Ser-404 were seen in Alzheimer tau. The phosphorylation of Ser-262 only slightly inhibited its biological activity, and Ser-198, Ser-199, Ser-202, Thr-231, Ser-235, Ser-400 and Ser-404 also presented in fetal tau which was highly active, suggesting that Thr-205 was the unique site which both caused the potent inhibition of biological activity and specifically presented in AD abnormally phosphorylated tau.

CONCLUSIONS

Phosphorylation of Thr-205 might play a key role in tau pathology in AD.

Regulation of the biosynthesis of N-acetylglucosaminylpyrophosphoryldolichol, feedback and product inhibition

The assembly of the core oligosaccharide region of asparagine-linked glycoproteins proceeds by means of the dolichol pathway. The first step of this pathway, the reaction of dolichol phosphate with UDP-GlcNAc to form N-acetylglucosaminylpyrophosphoryldolichol (GlcNAc-P-P-dolichol), is under investigation as a possible site of metabolic regulation. This report describes feedback inhibition of this reaction by the second intermediate of the pathway, N-acetylglucosaminyl-N-acetylglucosaminylpyrophosphoryldolichol (GlcNAc-GlcNAc-P-P-dolichol), and product inhibition by GlcNAc-P-P-dolichol itself. These influences were revealed when the reactions were carried out in the presence of showdomycin, a nucleoside antibiotic, present at concentrations that block the de novo formation of GlcNAc-GlcNAc-P-P-dolichol but not that of GlcNAc-P-P-dolichol. The apparent K(i) values for GlcNAc-P-P-dolichol and GlcNAc-GlcNAc-P-P-dolichol under basal conditions were 4.4 and 2.8 microM, respectively. Inhibition was also observed under conditions where mannosyl-P-dolichol (Man-P-dol) stimulated the biosynthesis of GlcNAc-P-P-dolichol; the apparent K(i) values for GlcNAc-P-P-dolichol and GlcNAc-GlcNAc-P-P-dolichol were 2.2 and 11 microM, respectively. Kinetic analysis of the types of inhibition indicated competitive inhibition by GlcNAc-P-P-dolichol toward the substrate UDP-GlcNAc and non-competitive inhibition toward dolichol phosphate. Inhibition by GlcNAc-GlcNAc-P-P-dolichol was uncompetitive toward UDP-GlcNAc and competitive toward dolichol phosphate. A model is presented for the kinetic mechanism of the synthesis of GlcNAc-P-P-dolichol. GlcNAc-P-P-dolichol also exerts a stimulatory effect on the biosynthesis of Man-P-dol, i.e. a reciprocal relationship to that previously observed between these two intermediates of the dolichol pathway. This network of inhibitory and stimulatory influences may be aspects of metabolic control of the pathway and thus of glycoprotein biosynthesis in general.

Ginkgo biloba inhibits hydrogen peroxide-induced activation of nuclear factor kappa B in vascular endothelial cells

The present study determined the effects of Ginkgo biloba extract (GBE) on the activation of nuclear factor kappa B (NF-kappaB) and the level of hydrogen peroxide (H2O2) in bovine pulmonary artery endothelial cells (PAEC). H2O2 showed a concentration-dependent activation of NF-kappaB. GBE demonstrated a concentration-dependent suppression of NF-kappaB activated by H2O2. GBE directly scavenged H2O2 in a cell-free system; it also decreased H2O2 levels in PAEC. These results suggest that the inhibitory effect of GBE on H2O2-induced NF-kappaB activation may be caused by its scavenging and suppression of H2O2. Our experiments demonstrate that GBE can inhibit NF-kappaB activation induced by H2O2 and may thus be effective for the prevention or treatment of atherosclerosis and other disorders related to NF-kappaB activation.

Simulated ischemia in flow-adapted endothelial cells leads to generation of reactive oxygen species and cell signaling

We have previously shown that increased reactive oxygen species (ROS) generation occurs with ischemia in the oxygenated lung and have hypothesized that mechanotransduction is the initiating event. In the present study, we developed an in vitro model of oxygenated ischemia by interrupting medium flow to flow-adapted bovine pulmonary artery endothelial cells in an artificial capillary system. Cellular oxygenation during the "ischemic" period was maintained by perfusing medium over the abluminal surface of porous capillaries. Cells were assessed for ROS generation, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) binding activities, and DNA synthesis using dichlorofluorescein fluorescence by flow cytometry and spectrofluorometry, electrophoretic mobility shift assay of nuclear extracts with NF-kappaB-specific or AP-1-specific (32)P-labeled oligonucleotides, and (3)H-thymidine incorporation into DNA. Cells that were flow adapted for 2 to 7 days with 1 to 2 dyne/cm(2) shear stress exhibited a 1.6- to 1.9-fold increase in ROS generation during 1 hour of simulated ischemia compared with continuously perfused cells. This effect was abolished by diphenyleneiodonium chloride (DPI), indicating a role for a flavoprotein such as NADPH oxidase. The increase in ROS generation with ischemia was similar for cells from low and high passages. With ischemia, flow-adapted cells exhibited increases of 1.7-fold in nuclear NF-kappaB and 1.5-fold in nuclear AP-1; these changes were abolished by pretreatment with N-acetylcysteine or DPI. Ischemia for 24 hours resulted in a 1.8-fold increase of (3)H-thymidine incorporation into DNA and a significant increase of cells entering the cell cycle, as indicated by flow cytometry with propidium iodide. We conclude that flow-adapted endothelial cells generate ROS with ischemia that results in activation of NF-kappaB and AP-1 and an increase of DNA synthesis. This effect is not mediated by hypoxia, implicating a role for mechanotransduction in ischemia-mediated cell signaling.

[Forecasting octane numbers of gasoline by NIR spectroscopy and the manufacture of octane number analyzer]

The predictive model of octane numbers, of gasoline was developed by using MLR and PLS method of chemometrics. It is applicable to forecast the MON, RON and PON of gasoline of catalytic cracking, catalytic reforming, alkylating as well as blended products. A near infrared optical multichannel analyzer (NIR-OMA) and a software package of octane number were developed. Combining both mentioned above a NIR-OM octane number analyzer was developed. With this NIR-OMONA one can obtain the MON, RON and PON (antiknock index) data in less than 1/2 minute with an accuracy of 0.6 ON unit and a precision of 0.1 ON unit by using 3-15 mL gasoline sample.

Vitamin E regulates mitochondrial hydrogen peroxide generation

The mitochondrial electron transport system consumes more than 85% of all oxygen used by the cells, and up to 5% of the oxygen consumed by mitochondria is converted to superoxide, hydrogen peroxide, and other reactive oxygen species (ROS) under normal physiologic conditions. Disruption of mitochondrial ultrastructure is one of the earliest pathologic events during vitamin E depletion. The present studies were undertaken to test whether a direct link exists between vitamin E and the production of hydrogen peroxide in the mitochondria. In the first experiment, mice were fed a vitamin E-deficient or-sufficient diet for 15 weeks, after which the mitochondria from liver and skeletal muscle were isolated to determine the rates of hydrogen peroxide production. Deprivation of vitamin E resulted in an approximately 5-fold increase of mitochondrial hydrogen peroxide production in skeletal muscle and a 1-fold increase in liver when compared with the vitamin E-supplemented group. To determine whether vitamin E can dose-dependently influence the production of hydrogen peroxide, four groups of male and female rats were fed diets containing 0, 20, 200, or 2000 lU/kg vitamin E for 90 d. Results showed that dietary vitamin E dose-dependently attenuated hydrogen peroxide production in mitochondria isolated from liver and skeletal muscle of male and female rats. Female rats, however, were more profoundly affected by dietary vitamin E than male rats in the suppression of mitochondrial hydrogen peroxide production in both organs studied. These results showed that vitamin E can directly regulate hydrogen peroxide production in mitochondria and suggest that the overproduction of mitochondrial ROS is the first event leading to the tissue damage observed in vitamin E-deficiency syndromes. Data further suggested that by regulating mitochondrial production of ROS, vitamin E modulates the expression and activation of signal transduction pathways and other redox-sensitive biologic modifiers, and thereby delays or prevents degenerative tissue changes.

[Analysis of products of thymine irradiated by heavy ion beam with capillary gas chromatography]

In this study some chromatographic methods with capillary column, such as GC, GC-MS, GC-FTIR, were used to analyze the products of thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution. Because of the complexity and small amounts of the products after irradiation by heavy ion beams, it is very difficult to separate them, while with the methods of capillary gas chromatography this problem can be overcome. From the results of GC-MS analysis we can determine the molecular weight of the product, and from the results of GC-FTIR analysis we can get structure information of the product. By this way the products such as 5,6-dihydrothymine, 5-hydroxyl-5-methylhydantoin, 5-hydroxyl-6-hydrothymine, 5-hydro-6-hydroxylthymine, 5-hydroxymethyluracil, trans-thymine glycol, cis-thymine glycol and dimers were determined. Though these products are the same as those from thymine irradiated by gamma ray in N2O saturated aqueous solution, the mechanism of heavy ion beam interact ion with thymine aqueous solution is different from that of gamma ray. The main products from thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution are formed by hydroxyl additions between 5-6 band of thymine, while those by gamma ray are dimers of thymine.

Spatially regulated SpEts4 transcription factor activity along the sea urchin embryo animal-vegetal axis

Because the transcription of the SpHE gene is regulated cell-autonomously and asymmetrically along the maternally determined animal-vegetal axis of the very early sea urchin embryo, its regulators provide an excellent entry point for investigating the mechanism(s) that establishes this initial polarity. Previous studies support a model in which spatial regulation of SpHE transcription relies on multiple nonvegetal positive transcription factor activities (Wei, Z., Angerer, L. M. and Angerer, R. C. (1997) Dev. Biol. 187, 71–78) and a yeast one-hybrid screen has identified one, SpEts4, which binds with high specificity to a cis element in the SpHE regulatory region and confers positive activation of SpHE promoter transgenes (Wei, Z., Angerer, R. C. and Angerer, L. M. (1999) Mol. Cell. Biol. 19, 1271–1278). Here we demonstrate that SpEts4 can bind to the regulatory region of the endogenous SpHE gene because a dominant repressor, created by fusing SpEts4 DNA binding and Drosophila engrailed repression domains, suppresses its transcription. The pattern of expression of the SpEts4 gene is consistent with a role in regulating SpHE transcription in the nonvegetal region of the embryo during late cleavage/early blastula stages. Although maternal transcripts are uniformly distributed in the egg and early cleaving embryo, they rapidly turn over and are replaced by zygotic transcripts that accumulate in a pattern congruent with SpHE transcription. In addition, in vivo functional tests show that the SpEts4 cis element confers nonvegetal transcription of a beta-galactosidase reporter gene containing the SpHE basal promoter, and provide strong evidence that the activity of this transcription factor is an integral component of the nonvegetal transcriptional regulatory apparatus, which is proximal to, or part of, the mechanism that establishes the animal-vegetal axis of the sea urchin embryo.

[Analysis of the relationship between the facial skin temperature and blood flow]

The relationship between the blood flow of temperal or facial artery and facial skin temperature was studied in 30 patients with facial nerve paralysis. The facial skin temperature was recorded by infrared thermography, and the blood flow was measured by ultrasonic Doppler flowetry. The results showed, in the same facial region, the greater the volume of blood flow was, the higher the skin temperature stood. After acupuncture on the facial points, the facial blood flow increased and the facial skin temperature rose. The ratios between the increase in facial skin temperature and the in increase in blood flow were 0.9538-1.2835(degrees:ml/second) in four facial regions. These indicate the presence of certain quantitative relationship between the facial blood flow and the skin temperature.

Identification of a new sea urchin ets protein, SpEts4, by yeast one-hybrid screening with the hatching enzyme promoter

We report the use of a yeast one-hybrid system to isolate a transcriptional regulator of the sea urchin embryo hatching enzyme gene, SpHE. This gene is asymmetrically expressed along the animal-vegetal axis of sea urchin embryos under the cell-autonomous control of maternal regulatory activities and therefore provides an excellent entry point for understanding the mechanism that establishes animal-vegetal developmental polarity. To search for transcriptional regulators, we used a fragment of the SpHE promoter containing several individual elements instead of the conventional bait that contains a multimerized cis element. This screen yielded a number of positive clones that encode a new member of the Ets family, named SpEts4. This protein contains transcriptional activation activity, since expression of reporter genes in yeast does not depend on the presence of the yeast GAL4 activation domain. Sequences in the N-terminal region of SpEts4 mediate the activation activity, as shown by deletion or domain-swapping experiments. The newly identified DNA binding protein binds with a high degree of specificity to a SpHE promoter Ets element and forms a complex with a mobility identical to that obtained with 9-h sea urchin embryo nuclear extracts. SpEts4 positively regulates SpHE transcription, since mutation of the SpEts4 site in SpHE promoter transgenes reduces promoter activity in vivo while SpEts4 mRNA coinjection increases its output. As expected for a positive SpHE transcriptional regulator, the timing of SpEts4 gene expression precedes the transient expression of SpHE in the very early sea urchin blastula.

Functional analysis of conserved cysteines in heparan sulfate N-deacetylase-N-sulfotransferases

N-Deacetylase-N-sulfotransferases (NDANST) catalyze the two initial modifications of the polysaccharide precursor in the biosynthesis of heparin and heparan sulfate. These modifications are the gating steps in establishing growth factor protein-binding domains of these glycosaminoglycans. We have undertaken a structure-activity analysis of the 841-amino acid Golgi-luminal portion of the rat liver NDANST to localize the two enzymatic functions. Each activity can be assayed in vitro independently of the other when provided with the appropriate substrate, and N-ethylmaleimide treatment selectively inactivates the deacetylase activity. In this study, dithiothreitol treatment of the rat liver NDANST was shown to inactivate the sulfotransferase function, while stimulating deacetylase activity 2-3-fold over the native protein. Site-directed mutagenesis of the eight cysteine (Cys) residues in the rat liver NDANST that are conserved in the mouse mastocytoma protein produced three important findings regarding the localization of each enzymatic function: 1) derivatization of Cys486 with N-ethylmaleimide resulted in total inactivation of the deacetylase activity based on steric hindrance of the active site (this residue was shown not to be involved in enzymatic catalysis), 2) substitution of either Cys159 or Cys486 with alanine resulted in enhanced activity of the deacetylase to the level obtained by dithiothreitol treatment, and 3) alanine substitution of Cys818 or Cys828 completely inactivated the sulfotransferase activity, while substitution of Cys586 or Cys601 resulted in a 90% loss in activity. These findings suggest that the two enzymatic domains within the NDANST localize to different portions of the protein, with two disulfide pairs toward the COOH-terminal half of the protein necessary for the sulfotransferase activity, and Cys residues within the NH2-terminal half influencing or located near the active site of the deacetylase functionality.

[Statistical analysis of complications of the frontalis aponeurosis flap for correction of complete blepharoptosis]

OBJECTIVE

The cause of and prophylactic measures for the complications of the frontalis aponeurosis flap suspension for correction of blepharoptosis were investigated to improve the operative results.

METHODS

Five hundred and thirteen patients who were found to have complications after frontalis aponeurosis flap suspension for blepharoptosis were studied by follow-up examinations.

RESULTS

Fourteen kinds of postoperative complications were found and cured.

CONCLUSION

Most of the postoperative complications following blepharoptosis correction can be prevented and well treated. The frontalis aponeurosis flap technique is reliable for correction of complete blepharoptosis.

Fructus corni attenuates oxidative stress in macrophages and endothelial cells

The antioxidant effect of a Chinese medicinal herb, Fructus corni extract (FCE), was investigated using models of oxidative stress in macrophages and vascular endothelial cells. Murine macrophages (J774) were incubated with FCE at 37 degrees C and 5% CO2 for 1 hr. Oxidative burst was triggered by zymosan and measured with a fluorescent probe. FCE exhibited a concentration- dependent suppression of oxidative burst. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with FCE for 20 hrs, washed, and then exposed to an organic oxidant t-butyl hydroperoxide (tBHP) for 2 hrs. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay, and cell injury by the release of intracellular lactate dehydrogenase (LDH). Lipid peroxidation products of PAEC were determined by measuring thiobarbituric acid-reactive substances (TBARS). Exposure of PAEC to tBHP resulted in decreased cell viability, increased LDH release, and elevated TBARS. Preincubation of PAEC with FCE significantly reversed these changes. Our results demonstrated that FCE can protect vascular endothelial cells from oxidant injury. The data thus suggest that Fructus corni may be useful for the prevention and/or treatment of disorders associated with oxidative damage.

[Determination of total Ca in the lung tissue of rats by FAAS]

Determination of total Ca in the Lung Tissue of Rats by FAAS was described, with a mixed microemulsion consisting of sodium dodecyl sulfate, N-dodecyl, N-dimethyl benzol ammonium bromide and nonyl phenol polyethyeneoxy ether. Comparing the result of the microemulsion FAAS with that of solution FAAS showed that the former was better than the latter in sensitivity, precision, selectivity and linearity of the calibration curve, with a detection limit of 1.92 microg x cm(-3), relative standard deviation of 1.92% (n = 10) and linear regressive coefficient of 0.9998 of the calibration curve over 0-20 microg x cm(-3) calcium. The method was applied to determine calcium amount in the lung tissue of rats, and the results were in accordance with those odtained by the conventional solution FAAS, in which a sample was reduced to ashes at a high temperature.

[Factors affecting the clinical pregnancy rate in an in vitro fertilization and embryo transfer program]

OBJECTIVE

To analyze the various factors in an in vitro fertilization and embryo transfer (IVF-ET) program which may affect the clinical pregnacy rate.

METHODS

A retrospective study was done on 559 IVF-ET cycles from 1992-Nov. 1995. The indication for treatment was bilateral tubal blockage. The chi 2 analysis of single factor variants with SPSS-PC + V3.0 was used for statistics.

RESULTS

The overall clinical pregnancy rate in 559 cycles was 21.6%. The cause of tubal blockage due to tuberculoses consisted of 28.4%, and 34.9% of secondary sterility had the history of artificial abortion. The changes of environment, the different causes of tubal blockage, the history of previous intrauterine pregnancy did not affect the clinical pregnancy rate. When the number of embryos transferred increased to 5, the clinical pregnancy rate was highest 32.5%. The cumulative embryo score or embryo quality was related significantly with clinical pregnancy rate.

CONCLUSIONS

The number and quality of embryos transferred are important factors affecting the clinical pregnancy rate. However, measures to prevent high-order multiple pregnancy and studies on the survival potential of embryos besides their morphology should be emphasized.

[Study on the mitoxantrone carboxymethyl starch microspheres for hepatic artery chemoembolization]

In this paper, the technology for the preparation of plain carboxymethyl starch microsphere (CMS-MS) was optimized by the uniform design method with CMS-Na as carrier material and p-phthaloyl chloride as acrosslinker. The carboxymethyl starch microsphere loaded mitoxantrone (DHAQ-CMS-MS) was prepared by absorption method. Then, its morphology, size and size distribution, characteristics of drug loading, drug release in vitro, preparation for clinical application and its stability were studied. The pharmacokinetics of DHAQ-CMS-MS in rabbit was also studied. The results showed that the average diameter of the DHAQ-CMS-MS was 75.71 microns, drug loading was 13.21%, expansion ratio in water was 71.94%. The release of DHAQ in vitro from the microspheres was found to fit the model of single exponential function. The suspension prepared in this paper is not only convenient for clinical use, but also favorable for the improvement of the drug stability. The pharmacokinetic parameters obtained from the hepatic atery chemoembolization showed that the DHAQ-CMS-MS group, when compared with the solution group, exhibited a higher blood drug concentration in hepatic vein, its MRT was 1.96 times that of the solution group. As for the result of the peripheral vein, the MRT of the DHAQ-CMS-MS group was 1.95 times that of the solution group. This means that the drug when loaded in microsphere will be concentrated in its targeted site for a longer period, which is favorable for the treatment of hepatic cancer.

[Effect of single alpha-particle on cells]

The mechanisms of biological effect of charged particles in space was studied through the inactivation effect of very low-density charged particles on very low-density cells at different impact parameters. A small type of microbeam facility with alpha-radioactive source and CN track detector were used. A diploid wild type Saccharomyces cerevisiae served as experimental eukaryotic cell. The correlation between cell inactivation and impact parameter of alpha-particles on cells was obtained through a CCD-camera system. The results showed that inactivation range of 1.13 MeV/u alpha-particles on cell-agarose mixture was about 5.5 micrometers, larger than the sum (about 3.l micrometers) of ion track-penumbra radius and yeast cell radius. The cell inactivation rate was 0.36-0.33. It suggests that multi-hit on a cell is necessary for killing it. However, in case of miss, the inactivation rate may not be zero at certain impact parameters.

[Analysis of X-ray images of giant-cell tumor of bone of rare locations]

OBJECTIVE

To analyse X-ray images of giant-cell tumor of rare locations.

METHODS

To retrospectively review the X-ray films, CT scans and arteriograms of 48 cases of surgically and/or pathologically confirmed giant-cell tumor of bone of rare locations.

RESULTS

Of the 48 cases, expansive cystic destructive changes of the bone with soap-bubble like appearence was found in 30 cases, osteolytic destruction in 10 cases, soft tissue mass outside of bone with sinking, flattening and local expanding of bone in 4 cases, invading into neighboring bone in 4 cases, hyperplasia and sclerosis of bone in 3 cases and staining of abnormal blood vessels and tumors in 3 cases.

CONCLUSION

For the diagnosis of giant-cell tumor of bone of rare locations, X-ray plain film is of great value. CT is even better than plain film; arteriogram is helpful for diagnosis and treatment planning.

Fructus corni enhances endothelial cell antioxidant defenses

1. The present study determined the effects of Fructus corni extract (FCE) on the levels of hydrogen peroxide (H2O2) and superoxide anion (O2-), on the glutathione (GSH) redox cycle and on the activities of antioxidant enzymes in bovine pulmonary artery endothelial cells (PAECs). 2. Confluent monolayers of PAECs were incubated with FCE, and oxidative stress was triggered by hypoxanthine and xanthine oxidase (to induce H2O2) or H2O2 (to induce O2-). 3. FCE exhibited a concentration-dependent suppression of H2O2 and O2-. 4. It modulated the GSH redox cycle by increasing the intracellular GSH content, the activities of GSH peroxidase and GSH disulfide reductase, and by decreasing the intracellular level of GSH disulfide. 5. It also increased the activities of superoxide dismutase and catalase. 6. These results demonstrate that FCE can promote a protective antioxidant defense state by affecting some important enzymatic and nonenzymatic oxidant-scavenging systems and may thus be useful for the prevention or treatment of disorders associated with oxidative damage.

[Misdiagnosis of tired fracture of distal segment of femur]

OBJECTIVE

To improve the diagnosis of tired fracture of the distal segment of femur, and to avoid its misdiagnosis.

METHOD

Misdiagnosis of 5 patients with tired fracture of distal segment of the femur was reviewed.

RESULT

Five male patients, aged 18 to 23 years had the lesion for 3 to 6 weeks. They had long tough experience of sports. The lesion was considered at first as osteosarcoma by radiograph and biopsy. It was eventually diagnosed as tired fracture of distal segment of the femur. Symptoms were relieved or disappeared after proper treatment. Follow-up for 7 to 18 months showed good results.

CONCLUSION

The key to avoid misdiagnosis and mistreatment of the fracture is to know its causes, morphological features of fracture healing, and correct pathologic diagnosis.

Stimulation as well as inhibition by antibiotics of the formation of GlcNAc-lipids of the dolichol pathway

The antiobiotics, diumycin, amphomycin, bacitracin, and showdomycin have been shown previously to block the synthesis of GlcNAc-P-P-dolichol and GlcNAc-GlcNAc-P-P-dolichol. In view of inconsistencies in the literature concerning the sites of inhibition, we have reinvestigated the influence of these drugs on the formation of these early intermediates of the dolichol pathway. Unexpectedly, when the individual products of the reactions were examined, instead of inhibition, showdomycin and bacitracin were found to stimulate the formation of GlcNAc-P-P-dolichol, and diumycin stimulated at low concentrations. Three derivatives of showdomycin were examined with similar results, showing stimulations of GlcNAc-P-P-dolichol formation of up to two-fold over controls. Amphomycin specifically inhibited GlcNAc-P-P-dolichol formation, an effect that was reversed by a high concentration of dolichyl phosphate. In contrast, with the exception of amphomycin, each compound directly inhibited the formation of GlcNAc-GlcNAc-P-P-dolichol. Using chemically synthesized GlcNAc-P-P-dolichol as substrate, the kinetics of inhibition of GlcNAc-GlcNAc-P-P-dolichol formation by showdomycin, bacitracin and diumycin was examined. The apparent Ki values calculated from these studies indicated that showdomycin was the most active inhibitor. These findings provide a new understanding of the action of these compounds on the GlcNAc-transferases of the dolichol pathway.

Homology and functional similarity of an hrp-linked pathogenicity locus, dspEF, of Erwinia amylovora and the avirulence locus avrE of Pseudomonas syringae pathovar tomato

The "disease-specific" (dsp) region next to the hrp gene cluster of Erwinia amylovora is required for pathogenicity but not for elicitation of the hypersensitive reaction. A 6.6-kb apparent operon, dspEF, was found responsible for this phenotype. The operon contains genes dspE and dspF and is positively regulated by hrpL. A BLAST search revealed similarity in the dspE gene to a partial sequence of the avrE locus of Pseudomonas syringae pathovar tomato. The entire avrE locus was sequenced. Homologs of dspE and dspF were found in juxtaposed operons and were designated avrE and avrF. Introduced on a plasmid, the dspEF locus rendered P. syringae pv. glycinea race 4 avirulent on soybean. An E. amylovora dspE mutant, however, elicited a hypersensitive reaction in soybean. The avrE locus in trans restored pathogenicity to dspE strains of E. amylovora, although restored strains were low in virulence. DspE and AvrE are large (198 kDa and 195 kDa) and hydrophilic. DspF and AvrF are small (16 kDa and 14 kDa) and acidic with predicted amphipathic alpha helices in their C termini; they resemble chaperones for virulence factors secreted by type III secretion systems of animal pathogens.

[Displaying of infrared thermogram of temperature character on meridians]

In this work we have observed the skin temperature of central line of the back and chest-abdomen on the human body truck by the infrared thermography. Here care the results: (a) Of all the volunteers, 57.1% central lines of the back and 7.7% central lines of the chest-abdomen of the volunteers are the longitudinal high thermal lines in normal state. (b) After moxibustion at Mingmen (GV 4) point, the temperature of 70.4% central lines of the back is going up. After moxibustion at Zhongwan (CV 12) point, the temperature of 56.0% central lines of the chest-abdomen is going up. The high thermal lines are longer and their continuity is hotter after moxibustion. (C) The lines on the back which are about 20 approximately 50 centimetres are longer than those on the chest-abdomen which are about 10-30 centimetres. The results suggest that the high thermal lines are the objective display of the temperature character on the Governor and Conception vessel. The formation of high thermal line may have some relationship with the compact connective tissue or microcirculation.

The SpHE gene is downregulated in sea urchin late blastulae despite persistence of multiple positive factors sufficient to activate its promoter

Previous studies of the regulatory region of the SpHE (hatching enzyme) gene of the sea urchin Strongylocentrotus purpuratus (Wei, Z., Angerer, L.M., Gagnon, M.L. and Angerer, R.C. (1995) Characterization of the SpHE promoter that are spatially regulated along the animal-vegetal axis of the sea urchin embryo. Dev. Biol. 171, 195-211) have shown that approximately 330 bp is necessary and sufficient to promote high level expression in embryos of transgenes that reproduce the spatially asymmetric pattern of endogenous gene activity along the maternally determined animal-vegetal embryonic axis. Furthermore, SpHE regulatory elements appear to be redundant since several different combinations are sufficient to elicit strong promoter activity and many subsets function like the endogenous gene only in non-vegetal cells of the blastula (Wei, Z., Angerer, L.M. and Angerer, R.C. (1997) Multiple positive cis-elements regulate the asymmetric expression of the SpHE gene along the sea urchin embryo animal-vegetal axis. Dev. Biol., 187, 71-88). Here we demonstrate by in vivo footprinting that many cis elements on the endogenous promoter are occupied when the gene is active in early blastulae, but the binding of corresponding trans factors is significantly reduced when the gene becomes inactive in late blastulae. In addition, downregulation of the promoter is accompanied by a transition from a non-nucleosomal to a nucleosome-like chromatin structure. Surprisingly, in vitro DNase I footprints of the 300 bp promoter using nuclear protein extracts from early and late blastulae are not detectably different and neither this sequence, nor a longer one extending to -1255, reproduces the loss of endogenous SpHE transcriptional activity after very early blastula stage. These observations imply that temporal repression of SpHE transcription involves a decrease in accessibility of the promoter to activators that are nevertheless present in nuclei and capable of activating transgene promoters. Temporal, but not spatial, downregulation is therefore likely to be regulated by negative activities functioning outside the -1255 promoter region which may serve as direct repressors or mediate an inactive chromatin structure.

[Immunohistochemical study of p53, c-erbB-2 and nm23 proteins in human gastric cancer]

OBJECTIVE

To evaluate p53, c-erbB-2 and nm23 oncoproteins in diagnosis of gastric cancer.

METHODS

The expression of p53, c-erbB-2 and nm23 oncoproteins was detected immunohistochemically in 141 surgically resected specimens and 93 endoscopic biopsy specimens of gastric cancer.

RESULTS

The positive rate of p53, c-erbB-2 and nm23 immunoreactivity was 45.8-56.3%, 18.3-31.2% and 72.9%-81.3% respectively. No immunoreactivity was observed in the tumor-adjacent normal mucosa and non-tumor biopsy specimens. The presence of c-erbB-2 was correlated with the size of tumor, grade of tumor differentiation and Lanren classification. Patients with c-erbB-2 positive tumor had lower 5-year survival rate. The expression of nm23 was negatively correlated with the depth of invasion, and lymphnode metastasis. The positive rates of p53, c-erbB-2 and nm23 had no statistical difference between biopsy and resected specimens.

CONCLUSION

Determination of p53, c-erbB-2 and nm23 oncoproteins immunohistochemically might be useful in the diagnosis and differential diagnosis, clinical staging, and predicting prognosis of gastric cancer.

Effect of jiawei shenqi dihuang tang on the content of urinary protein in patients with diabetic nephropathy

42 cases of diabetic nephropathy (DN) diagnosed as the type of kidney deficiency and blood stasis were treated with Jiawei Shenqi Dihuang Tang. The therapeutic effect demonstrated that various kinds of symptoms and sings were significantly improved. There was significant difference in the qualitative and quantitative examinations of urinary protein between pre- and post-treatment (P < 0.05).

[Insulin growth factor I in the development of ovarian follicles]

OBJECTIVE

To investigate the role of insulin growth in factor-1 (IGF-1) in the development of ovarian follicles under the stimulation of gonadotropins in an in-vitro fertilization (IVF) program.

METHODS

Radioimmuoasssy was used to determine the levels of sex hormones and IGF-1 in the serum and follicular fluid samples. In situ hybridyzation was used to detect the expression of IGF-1 and IGF-1 receptor (IGF-1R) in the granulosa cell obtained from follicular aspiration in women undergoing IVF egg retrieval procedures.

RESULTS

(1) Levels of plasma IGF-1 increased with the development of follicles (P < 0.001); follicular fluid (FF) IGF-1 levels were lower than those of matched plasma; FF-IGF-1 decreased with increase of follicle numbers (P < 0.01), e.g. in patients with less than 2 follicles (diameter > or = 15 mm) at the tine of ovum pick-up the FF-IGF-1 levels were much higher than patients with more than 2 follicles (P < 0.05). (2) Significant negative correlation was found between plasma IGF-1 and plasma E2 and also between FF-IGF-1 and FF-follicle-stimulating hormone (FSH) during ovum pick-up (P < 0.01). (3) IGF-1 mRNA was not, while IGF-1R mRNA was found to be present in the human granulosa cells taken at ovum pick-up.

CONCLUSIONS

Plasma IGF-1 production might be stimulated by gonadotropins and distributed into the ovarian follicles by diffusion from peripheral circulation, acting upon the granulosa cells and therefore plays a complementary role with the gonadotropins in the regulation of follicular development.

Multiple positive cis elements regulate the asymmetric expression of the SpHE gene along the sea urchin embryo animal-vegetal axis

The mechanism that establishes the maternally determined animal-vegetal axis of sea urchin embryos is unknown. We have analyzed the cis-regulatory elements of the SpHE gene of Strongylocentrotus purpuratus, which is asymmetrically expressed along this axis, in an effort to identify components of maternal positional information. Previously, we defined a regulatory region that is sufficient to provide correct nonvegetal expression of a beta-galactosidase reporter gene (Wei, Z., Angerer, L. M., Gagnon, M. L., and Angerer, R. C., Dev. Biol. 171, 195-211, 1995). We have now analyzed this region intensively in order to determine if the spatial pattern is controlled by nonvegetal-positive activities or by vegetal-negative activities. The regulatory sequences, except the basal promoter, were mutated by either deletion or sequence replacement. None of these mutations resulted in ectopic beta-gal expression in vegetal cells, showing that no single negative cis element is responsible for the lack of vegetal SpHE transcription. Surprisingly, even short segments of the regulatory region containing only several identified cis elements also direct nonvegetal expression. Furthermore, the SpHE basal promoter functions effectively in vegetal cells in combination with cis-acting elements derived from the PMC-specific gene, SM50. We conclude that the spatial pattern of SpHE transcription is achieved by multiple positive activities concentrated in nonvegetal cells. The vegetal expression of SM50 also is regulated only by positive activities (Makabe, K. W., Kirchhamer, C. V., Britten, R. J., and Davidson, E. H., Development 121, 1957-1970, 1995). A chimeric promoter containing both SpHE and SM50 regulatory sequences is active ubiquitously, suggesting that these regulators are not reciprocally repressive. These observations suggest a model in which the SpHE and SM50 genes are activated by separate sets of positive maternal activities concentrated, respectively, in nonvegetal and vegetal domains of the early embryo.

[The application of artificial neural network method in diagnose and classify research on functional disease of the esophagus]

This paper applied a typical artificial neural network model, that is Back-Propagation Model, to the diagnose and classify research on functional disease of the esophagus, and achieved good results in clinical practice.

[Regulation of ovarian follicular development by epidermal growth factor in IVF superovulation cycles]

OBJECTIVE

To study the role of epidermal growth factors (EGFs) in the regulation of ovarian follicular development in in vitro fertilization (IVF) superovulation cycles.

METHODS

In situ hybridyzation and immunochemistry were used to locate EGF, transforming growth factor alpha (TGF alpha) and their receptor (EGFR) in 10 normal ovarian specimens and in 5 granulosa cell samples obtained from IVF egg retrieval procedure. Radioimmunoassay was used for 6 sex hormones and radioreceptor assay for EGFs (mainly including EGF and TGF alpha) determinations in the serum and follicular fluid.

RESULTS

(1) EGF was not detected in the ovary, while EGFR and TGF alpha were found to be present in human granulosa cells. (2) Serum EGFs levels increased with the development of follicles, and EGFs levels in the follicular fluid were higher than those of the matched plasma. No correlation was found between EGFs and sex hormones.

CONCLUSIONS

TGF alpha but not EGF might be synthesized locally, acting on the granulosa cells in an autocrine fashion through EGFR in granulosa cells. Serum EGFs levels (including EGF and TGF alpha) might be stimulated by exogenous gonadotropins.

Optical pulse compression to 5 fs at a 1-MHz repetition rate

We report on the characterization and compression of the white-light continuum produced by injection of a 13-fs pulse from a cavity-dumped self-mode-locked Ti:sapphire laser into a single-mode fiber. Pulses as short as 5 fs were generated at repetition rates up to 1 MHz.

[Basic ovarian status and follicular response to superovulation stimulation in an in vitro fertilization and embryo transfer program]

OBJECTIVE

To study the relationship between patient age, cycle day 3 basal ovarian status, serum estradiol (E2) level and the ovarian response in an in vitro fertilization and embryo transfer (IVF-ET) program.

METHOD

102 cases and 102 cycles of IVF-ET patients with regular menstrual period and normal cycle day 3 basal follicular-stimulating hormone (FSH < 20 IU/L) level were studied. The same superovulation regimen was employed. The ovarian response was classified as low when follicle number (diameter > 10 mm) was fewer than 3 on the day of hCG injection, moderate when the number was 3-14, and high when follicle number exceeded 14.

RESULTS

(1) Patients older than 35 years tended to be low responders; women younger than 30 years usually responded well with production of more than 15 follicles. (2) The number of cycle day 3 follicles was positively correlated with the number after stimulation with gonadotropin. When total basal follicle number in both ovary exceeded 20, ovarian an hyperstimulation syndrome should be watched out. (3) On cycle day 3 the diameter of the largest follicle was negatively correlated with the ovarian response. In low responders the diameter of the largest follicle was usually larger than 4 mm. (4) Despite of the different size and number of the cycle day 3 follicles the serum E2 level was quite similar.

CONCLUSION

Age and basal ovarian status including the number and size of the antral follicles are valuable factors to be considered in the prediction of ovarian response to the same gonadotrophic stimulation protocol.

[Experimental research on the prediction of human body thermal responses in special hot environment]

The assessment of thermal environment is very important in the research of human body-thermal environment system. On the basis of systematic study, the characteristics and the components of human body-thermal environment system have been analyzed, the stationary mathematical model of human body-thermal environment system was established. Prediction and Assessment System for Thermal Environment (PASTE system) was developed. It consists of thermal environment monitor and simulator based on the IBM PC/XT computer with suitable hardware and software. Thermal environment monitor can measure fifteen parameters continuously including dry bulb temperature, dewpoint temperature, air velocity and thermal radiation in six directions. The simulator can simulate different heat exchange processes of human body-thermal environment system and human thermal responses. PASTE system is integrated with monitor and computer simulator. Test results showed that the differences between experimental result and predicted result were about +/-10%.

Sulfated malto-oligosaccharides bind to basic FGF, inhibit endothelial cell proliferation, and disrupt endothelial cell tube formation

The interaction of basic FGF (bFGF) with heparin, heparan sulfate and related sugars can potentiate or antagonize bFGF activity, depending on the size of the saccharide used. Oligosaccharides based on heparin structures, as small as six sugar residues, have been demonstrated to bind to bFGF and block its activity, while larger structures (> 10 sugar residues) tend to potentiate bFGF. In this study we have synthesized a series of compounds designed to test the requirements of size and sulfation for binding of oligosaccharides to bFGF. These oligosaccharides are not derived from heparin, but rather, are linear chains of glucose linked alpha 1-4 (malto-oligosaccharides) that have been chemically sulfated. In addition to bFGF binding, these compounds were tested for their ability to block basic functions of endothelial cells that are known to be mediated, at least in part, by bFGF. We report that the ability of sulfated malto-oligosaccharides to block binding of bFGF to heparan sulfate was dependent on the size (at least a tetrasaccharide is required), and the degree of sulfation. The activity profile in the bFGF ELISA closely correlated with the ability of these compounds to block REEC or HMVEC tube formation on Matrigel. There was a similar relationship of size and sulfation to the ability of the sulfated malto-oligosaccharides to inhibit endothelial cell growth for most human and rat EC types tested. The single exception was REEC cell growth. One isolate of these cells was stimulated by sulfated malto-oligosaccharides rather than inhibited by them, while a second isolate was neither stimulated nor inhibited. This stimulation showed no correlation with inhibition of bFGF binding in the ELISA assay, suggesting that growth of this cell type was probably not dependent on bFGF. Compounds derived from this series of sulfated, malto-oligosaccharides have the potential to function as bFGF antagonists, are relatively easy to produce, and possess relatively low anticoagulant properties.

Hybridization properties of oligodeoxynucleotide pairs bridged by polyarginine peptides

The hybridization properties of a series of probes, based on two 9mer oligodeoxynucleotides (designated as I and II) having an appended oligoarginine chain (Rn) to produce peptide-oligonucleotide conjugates or peptide-bridged oligonucleotide pairs (e.g. Rn-I or II-Rn-I), were investigated. For the double-linked probes, we found that the peptide bridge induces the two 9mers to bind complementary single-stranded DNA or RNA targets with substantially enhanced thermal stability. The resulting hybrid with complementary DNA was found to assume a 1:1 complex in the B conformation as judged by UV mixing curves and CD spectroscopy. Complexes of single or double-linked probes with complementary RNA exhibited sensitivity to RNase H digestion. The influence of the identity and chirality of the repeating unit in the bridge, the length of the bridge, the gap size and the salt concentration on the hybridization properties of this new class of oligonucleotide probes was also studied. Our data reveal that these compounds exhibit properties that should prove useful in the development of antisense strategies.

Gel shift assay: demonstration of enhanced binding of oligo(delta)-L-ornithine-oligodeoxynucleotide conjugates to complementary DNA and RNA

An increase in melting temperature for DNA:DNA duplexes had been observed previously (Zhu et al. Antisense Res. Dev. 3:349-356, 1993) when an oligo(delta)ornithine moiety was covalently appended to a short oligodeoxynucleotide. We now report the analysis of duplex formation by electrophoretic gel shift analysis. In the particular example studied, an increase in Tm of 4 degrees C was found to correspond to about a fivefold increase in binding constant. A similar enhancement by the appended cationic peptide was observed when the target strand was RNA. The use of a competitive assay format for avoidance of adsorptive loss at low concentrations (< 10(-7)M) of the oligonucleotide-oligo(delta)ornithine conjugate is presented.

[Trabeculectomy combined with extracapsular cataract extraction and posterior chamber intraocular lens implantation]

PURPOSE

To evaluate the effect of trabeculectomy combined with extacapsular cataract extraction and posterior chamber intraocular lens implantation (triple surgeries) on the patients of coexisting cataract and glaucoma.

METHODS

18 cases (19 eyes) of coexisting cataract and glaucoma treated by the triple surgeries were reviewed. Mean follow-up was 14.7 months (rangs from 2 to 20 months).

RESULTS

Intraocular pressure was controlled satisfyingly in all cases except one case required additional treatment of the anti-glaucoma drug. 78.9% of patients achieved 0.3 or better visual acuity. The operation complications consist of anterior uveitis and hyphaema. However, all of them were controlled within 14 days.

CONCLUSION

The triple surgeries are safe and have definite effect on controlling the IOP and improving visual acuity.

Drug-induced heat-shock preconditioning improves postischemic ventricular recovery after cardiopulmonary bypass

BACKGROUND

Heat-stress preconditioning of mammalian heart has been found to confer protection against ischemic reperfusion injury. Heat shock is generally provided by warming the animal by mechanical means, which is often impractical in a clinical setting. Amphetamine, a sympathomimetic drug, can elevate the body temperature as a result of enhanced endogenous lipolysis. In this study, we examined the effects of heat shock induced by amphetamine on postischemic myocardial recovery in a setting of coronary revascularization for acute myocardial infarction.

METHODS AND RESULTS

Adult Yorkshire swine were injected with amphetamine (3 mg/kg IM) (n = 12), and body temperature was continuously monitored. For control studies, the pigs were injected with saline (n = 12). Five swine in each group were killed after 3 hours to obtain biopsies of vital organs to measure heat-shock protein (HSP) mRNAs. After 40 hours, the remaining 7 pigs in each group were placed on cardiopulmonary bypass, and the isolated, in situ heart preparations were subjected to 1 hour of occlusion of the left anterior descending coronary artery followed by 1 hour of global hypothermic cardioplegic arrest and 1 hour of reperfusion. Postischemic myocardial performance was monitored by measuring left ventricular (LV) pressure, its dP/dt, myocardial segment shortening, and coronary blood flow. Cellular injury was examined by measurement of creatine kinase release. The antioxidant enzymes superoxide dismutase and catalase were also assayed. Amphetamine treatment was associated with the induction of mRNAs for HSP 27, HSP 70, and HSP 89 in all the vital organs, including heart, lung, liver, kidney, and brain. Amphetamine also enhanced superoxide dismutase and catalase activities in the heart. Significantly greater recovery of LV contractile functions was noticed, as demonstrated by improved recovery of LV developed pressure (61% versus 52%), LV dP/dtmax (52% versus 44%), and segment shortening (46.2% versus 10%) and reduced creatine kinase release in the amphetamine group.

CONCLUSIONS

The results demonstrate that amphetamine can induce whole-body heat shock that can precondition the heart, enhancing cellular tolerance to ischemia-reperfusion injury. Amphetamine is a sympathomimetic drug that may be used for preconditioning.

An enzyme-linked immunosorbent assay using biotinylated heparan sulfate to evaluate the interactions of heparin-like molecules and basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) is a member of the heparin-binding growth factor family that interacts with cell surface heparan sulfate (HS) proteoglycans and extracellular matrix heparin. Here we report the development of a simple and sensitive assay that used biotinylated HS or heparin to bind to bFGF coated onto 96-well microtiter plates. Bound labeled HS or heparin was reacted with enzyme-linked streptavidin and results were recorded as optical density. Increased molar excess of biotin resulted in increased incorporation of biotin and higher signal without compromising binding. Glycosaminoglycans and modified heparins were assayed for their ability to compete with biotinylated HS for binding to bFGF. Inhibition of that binding by heparin and HS but not by chondroitin sulfate A or C, dermatan sulfate, or keratan sulfate demonstrated the specificity of the glycosaminoglycan binding. Structural modifications of heparin produced various degrees of inhibition with high structural specificity. Although removal of N-sulfates or 2,3-O-sulfate groups resulted in significant loss of inhibition, removal of 6-O-sulfates had little affect on binding. Carboxyl reduction or N-acetylation following N-desulfation produced heparinoids with moderate changes in binding capacity. Results from this assay are in agreement with previous data from our laboratory and reports from other researchers with respect to the specificity of glycosaminoglycan binding to bFGF and the role of 2,3-O- and 6-O-sulfate groups of heparin. The flexibility of this assay, in both the amount of label incorporated and the variability of solid substrate, makes this an excellent tool to study other heparin binding proteins.

Characterization of the SpHE promoter that is spatially regulated along the animal-vegetal axis of the sea urchin embryo

To understand how the maternally determined animal-vegetal polarity of the sea urchin embryo is established, we have begun to examine the regulatory apparatus of the gene encoding the Strongylocentrotus purpuratus hatching enzyme (SpHE). Previous studies have shown that the pattern of SpHE mRNA accumulation reflects the animal-vegetal developmental axis in that transcription is strongly upregulated during early cleavage in more animal blastomeres, but not in those around the maternally specified vegetal pole of the 16-cell embryo [Reynolds et al., Development 114, 769-786 (1992)]. Tests of SpHE promoter function in vivo using chloramphenicol acetyltransferase and beta-galactosidase enzymatic reporters define a regulatory region within several hundred nucleotides of the transcription initiation site. This region is sufficient to mediate both strong expression in the early blastula and spatially correct transcription. However, neither this region nor longer upstream sequences are sufficient to reproduce the transcriptional downregulation after very early blastula stage that is observed for endogenous genes. Biochemical assays of protein-DNA interactions within the regulatory region identify at least nine sites binding at least six different factors. These cis elements include Otx (an orthodenticle homologue), CCAAT, ets-related, and three unidentified motifs. Deletions and/or replacements of these cis-elements, alone and in combination, indicate that no single factor is essential for SpHE promoter activity, but instead that various combinations of subsets of these elements are capable of eliciting levels of transcription similar to those of the unaltered regulatory region. This density of regulatory elements is consistent with the intense transcription of endogenous SpHE genes during cleavage.

Low-power phase conjugation in push-pull azobenzene compounds

Push-pull azobenzene compounds were synthesized by the diazocoupling reaction, and low-power phase conjugation of azobenzene-compound-doped poly(methyl methacrylate) films was studied with a He-Ne laser at 632.8 nm. It is shown that this kind of polymer has appreciable third-order optical nonlinearity, with a chi((3)) of approximately 10(-4) esu in the tail of absorption.

[Determination of modulus of elasticity of human periodontal membrane]

The modulus of elasticity of periodontal membrane, as an essential parameter indicating the mechanical character of periodontal membrane, is very important in biomechanical studies (e.g. finite element stress analysis and photoelastic analysis) of dental restoration. However, determination of modulus of elasticity of human periodontal membrane has not been reported in China, and there are differences among the foreign reports. In this study, 135 periodontal samples were collected from fresh teeth and alveoli of 6 healthy adults. Drawing and compressing test were performed. The results showed that the tensile modulus of elasticity of human periodontal membrane is between 3.35 and 4.59MPa and the compress modulus of elasticity 0.5402(+/- 0.348) MPa.

Enhancement of cardiac function by cyclocreatine in models of cardiopulmonary bypass

This study tests the hypothesis that the administration of cyclocreatine prior to global ischemia enhances recovery of cardiac function during reperfusion. Two models were used. First, in a Langendorff-working heart model of normothermic cardioplegic arrest, rats (n = 6 per group) were injected intravenously with saline or cyclocreatine (600, 300, or 150 mg/kg). After 30 min or 2 h, hearts were excised and perfused in the Langendorff mode for 5 min and then in the working heart mode for 20 min. Normothermic arrest was induced by infusing warm St. Thomas solution once; then hearts were kept at 37 degrees C for 40 min. Following arrest, hearts were reperfused in the Langendorff mode for 15 min and then in the working mode for 30 min. Cyclocreatine consistently produced significantly better recovery of aortic flow and cardiac output compared to that of saline hearts. Second, in an intact canine model of cold cardioplegic arrest, adult mongrel dogs (n = 3 to 6 per group) underwent aortic cross-clamping for 1 h, followed by reperfusion on bypass for 45 min and off bypass for 4 h. Dogs were injected intravenously with saline or cyclocreatine (500 mg/kg) for 1 h before experiment. Post-bypass segmental contractility and cardiac output were significantly better in cyclocreatine hearts compared to that of controls. In a limited study, after a 3 h aortic cross-clamp time, cyclocreatine hearts achieved 91% baseline function while control hearts failed after 2 h. Results of this study suggest that cyclocreatine, without inotropic or chronotropic effect, protects the heart from global ischemic injury.

Biological effects of carbon ions with medium energy on plant seeds

The biological effects of 46.6 MeV/u 12C6+ ions on four kinds of plant seeds were studied at the Heavy Ion Research Facility in Lanzhou (HIRFL), Institute of Modern Physics (IMP), Academia Sinica. The results show that germination of the seeds is inhibited by exposure to ions. In root tip cells of irradiated seeds, a great variety of chromosomal aberrations were observed. Sensitivities in terms of inhibition of germination and induction of chromosomal aberrations in the four species are correlated.