Mobilization of heavy metals from Le An River sediment

The release of sediment-bound heavy metals can have a significant influence on river water quality. Generally speaking, variations of pH and oxygen are among the most important chemical factors that affect the mobility of sediment-bound metals. Recent research has indicated that sulfide, measured as acid-volatile sulfide (AVS), is an important partitioning component of heavy metals. We determined the metal release potential of sediments from the Le An River which receives drainage from a major copper mining operation. We found that the in-situ Cu, Pb, Zn, Cd and As concentrations of the Le An River sediments below the mine are much higher than are the global background values, but that Ni was not elevated. There is potential for mobilization of bound metals to the overlying water, the order of metal release ratio in terms of pH dependencies is Zn > Cu > Cd approximately Pb. Sulfide is not a major binding component for metals in Le An River sediment. It is more likely that the iron and manganese oxides are the most important metal binding components in the sediments of the Le An River.

[Evaluation on cytotoxicity of gallium alloy]

Cytotoxicity is an important indicator to the biocompatibility of biomaterials. In this study, the cytotoxicity of Gallium alloy was evaluated by the method of cell relative growth rate in vitrousing L-929 mouse fibroblast. The cell relative growth rate of Gallium alloy was the absorbency ratio between the solution of Gallium alloy and negative control. The relative growth rates of Gallium aloy were converted into the scores of cytotoxicity. It was found from the results that Gallium alloy had no cytotoxicity.

[Effects of Squama manitis on cardiac systolic function and platelet aggregation]

OBJECTIVE

To study the effect of Squama Manitis(S. M.) on cardiac function and platelet aggregation in vitro.

METHOD

Isolated working rat hearts were prepared, and cardiac performance was measured before and after adding S. M. in the Krebs-Hensleit(K-H) perfusion buffer. Controls with K-H buffer were also investigated. Rich platelet plasma and Poor platelet plasma were centrifuged from the blood of 15 patients with coronary heart disease. Each sample was divided into three parts for use by three groups: control, group of S. M. and group of aspirin. Platelet aggregation was stimulated by adenosine diphosphate.

RESULT

LVSP, +dP/dtmax and CO of isolated working rat hearts were significantly increased after treating with S. M. liquor. S. M. had no obvious effect on -dP/dtmax and LVEDP. These parameters did not change significantly in the control. Percentages of platelet aggregation were significantly lower in the group of S. M. and the group of aspirin as compared with the control.

CONCLUSION

S. M. increases cardiac systolic function, has positive inotropic effect on myocardium and inhibits platelet aggregation.

The glycogen phosphorylase-2 promoter binding protein in Dictyostelium is replication protein A

During Dictyostelium development, glycogen degradation is a crucial event that provides glucose monomers used in the synthesis of the essential structural components for cellular differentiation. The product of the developmentally regulated glycogen phosphorylase-2 gene (gp2) catalyzes the degradation. DNA-binding proteins were found to bind to a regulatory site of the gp2 gene in a stage-dependent pattern. Gel-shift analysis of undifferentiated amoebae cell extract revealed a protein migrating at 0.40 Rf, while 17 hour differentiated cell extract produced a species migrating at 0.32 Rf. Both the 0.32 and 0.40 Rf proteins were purified and found to consist of three subunits of 18, 35 and 62 kDa (for 0.40 Rf) or 81 kDa (for 0.32 Rf). Data base searches identified the protein as the Dictyostelium homologue of replication protein A (DdRPA). Amino acid sequence analysis showed identity between the 62 and 81 kDa subunits. Incubation of cell-free extracts under appropriate conditions at low pH, resulted in conversion of the 81 kDa to the 62 kDa subunit. Northern blot analysis revealed that the levels of expression of the large subunit of DdRPA were constant throughout differentiation and the size of the mRNA was the same at all stages of development. The results raise the possibility that pH induced post-translational modifications of DdRPA are involved in events that halt cell proliferation and induce differentiation in Dictyostelium.

Intestinal inflammation reduces expression of DRA, a transporter responsible for congenital chloride diarrhea

The pathogenesis of diarrhea in intestinal inflammatory states is a multifactorial process involving the effects of inflammatory mediators on epithelial transport function. The effect of colonic inflammation on the gene expression of DRA (downregulated in adenoma), a chloride-sulfate anion transporter that is mutated in patients with congenital chloridorrhea, was examined in vivo as well as in an intestinal epithelial cell line. DRA mRNA expression was diminished five- to sevenfold in the HLA-B27/beta2m transgenic rat compared with control. In situ hybridization showed that DRA, which is normally expressed in the upper crypt and surface epithelium of the colon, was dramatically reduced in the surface epithelium of the HLA-B27/beta2m transgenic rat, the interleukin-10 (IL-10) knockout mouse with spontaneous colitis, and in patients with ulcerative colitis. Immunohistochemistry demonstrated that mRNA expression of DRA reflected that of protein expression in vivo. IL-1beta reduced DRA mRNA expression in vitro by inhibiting gene transcription. The loss of transport function in the surface epithelium of the colon by attenuation of transporter gene expression, perhaps inhibited at the level of gene transcription by proinflammatory cytokines, may play a role in the pathogenesis of diarrhea in colitis.

[Investigation of HGV infection in various populations in Guangxi]

In order to understand the situation of HGV infection in various populations in Liuzhou prefecture of Guangxi, Zhuangzu Autonomous Region, and also to compare the HGV, HBV, HCV infections between intravenous drug abusers and healthy persons (those for physical examination, the same below), the anti-HGV, -HCV and HBVM (HBsAg, HBsAb, HBeAg, HBeAb, HBcAb) were detected by ELA and, besides, tested further the 20 anti-HGV seropositive cases for HGV-RNA by RT-nPCR. The results showed that in the populations tested, the HGV seropositive rate was 9.8% (106/1079), separately they were 23.8% (5/21), 21.1% (23/109), 12.5% (6/48), 12.0% (6/50), 12.0% (20/166), 9.3% (3/32), 8.2% (34/413), 4.3% (6/140), and 3.0% (3/100) in liver cirrhosis, intravenous drug abusers, repeated blood and blood products transfused patients, hepatocellularcarcinoma patients, viral hepatitis, haemodialysis patients, healthy persons, paid blood donors and healthy pregnant women respectively. In intravenous drug abusers, the HGV, HBV, HCV infection rate were 21.2% (23/109), 75.3% (82/109) and 7.3% (8/109) respectively, while they were 8.2% (9/109), 20.1% (22/109), and 1.8% (2/109) in healthy persons respectively. These data showed that Liuzhou prefecture of Guangxi was HGV high epidemic area, HGV infection rate was higher in populations of intravenous drug abusers, viral hepatitis, liver cirrhosis and repeatedly blood and blood products transfused patients, even in pregnant women the HGV infection also occurred. There was a significant difference of HGV, HBV, HCV infection rates between intravenous drug abusers and healthy persons (P < 0.005).

Corrosion resistance and ion dissolution of titanium with different surface microroughness

In vitro corrosion resistance and ion dissolution of commercial pure titanium with different surface microroughness are studied adopting constant potential meter and atomic absorption spectroscopy. In terms of the surface roughness, titanium samples are divided into 5 groups: smooth surface, machining surface, 2 different microroughness surfaces and macrorough surface. Each group contains three category samples under different treatments: natural oxidation (24 h exposure to air), oxidation under 400 degrees C (400 degrees C, 45 min thermal oxidation), oxidation under 700 degrees C (700 degrees C, 45 min thermal oxidation). In Hanks corrosion media, comparative studies through constant potential anode polarization curves and titanium release rates of the 5 groups of Ti samples demonstrates that oxidation under 400 degrees C best increase corrosion resistance and decrease ion release sharply, oxidation under 700 degrees C is better than natural oxidation. Ti samples with a different surface roughness all have good corrosion resistance and their corrosion resistance drop with the raising of surface roughness. Comparing with macrorough surface and machining surface, microrough surfaces have better corrosion resistance and a lower ion release rate which are similar to those of smooth surfaces. Moreover, the corrosion resistance of machining surface Ti is the lowest. It is hypothesized that surface treatment methods such as surface thermal oxidation, surface aging and so on will improve the corrosion resistance and decrease the ion release rate of rough surface effectively by increasing the thickness of surface protection film, improving its structural uniformity and facilitating the formation of ordered, compact surface protection film.

The amiloride-sensitive epithelial sodium channel alpha-subunit is transcriptionally down-regulated in rat parotid cells by the extracellular signal-regulated protein kinase pathway

Previous studies have shown that an inducible Raf-1 kinase protein, DeltaRaf-1:ER, activates the mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK)-signaling pathway, which is required for the transformation of the rat salivary epithelial cell line, Pa-4. Differential display polymerase chain reaction was employed to search for mRNAs repressed by DeltaRaf-1:ER activation. Through this approach, the gene encoding the alpha-subunit of the amiloride-sensitive epithelial sodium channel (alpha-ENaC) was identified as a target of activated Raf-1 kinases. alpha-ENaC down-regulation could also be seen in cells treated with 12-O-tetradecanoyl-1-phorbol-13-acetate (TPA), indicating that the repression of steady-state alpha-ENaC mRNA level was dependent upon the activity of protein kinase C, the target of TPA, as well. Pretreatment of cells with a specific inhibitor of the ERK kinase pathway, PD 98059, markedly abolished the down-regulation of alpha-ENaC expression, consistent with the hypothesis that the ERK kinase-signaling pathway is involved in TPA-mediated repression. Moreover, through the use of transient transfection assays with alpha-ENaC-reporter and activated Raf expression construct(s), we provide the first evidence that activation of the ERK pathway down-regulates alpha-ENaC expression at the transcriptional level. Elucidating the molecular programming that modulates the expression of the alpha-subunit may provide new insights into the modulation of sodium reabsorption across epithelia.

[A kind of method for measuring absorbance spectrum with dual beam light and one detector]

A kind of method of measuring spectral transmittivity with source compensated is introduced in this paper. It detects simultaneously intensity of source and transmission light with dual light road and one detector by means of the characters of selective frequence amplifing and coherent detection of a lock-in amplifier. The experimental result shows that the method is excellent on overcoming shake of a source and improving signal-to-noise ratio.

The NH2 terminus of the herpes simplex virus type 1 regulatory protein ICP0 contains a promoter-specific transcription activation domain

The transcriptional program of herpes simplex virus is regulated by the concerted action of three immediate-early (alpha) proteins, ICP4, ICP27, and ICP0. The experiments described in this study examine the role of the acidic amino terminus (amino acids 1 to 103) of ICP0 in gene activation. When tethered to a DNA binding domain, this sequence activates transcription in the yeast Saccharomyces cerevisiae. Deletion of these amino acids affects the ability of ICP0 to activate alpha-gene promoter reporters in transient expression assays, while it has little or no effect on a beta- and a gamma-gene reporter in the same assay. Viruses that express the deleted form of ICP0 (ICP0-NX) have a small-plaque phenotype on both Vero cells and the complementing cell line L7. Transient expression and immunofluorescence analyses demonstrate that ICP0-NX is a dominant negative form of ICP0. Immunoprecipitation of ICP0 from cells coinfected with viruses expressing ICP0-NX and ICP0 revealed that ICP0 oligomerizes in infected cells. These data, in conjunction with the finding that ICP0-N/X is dominant negative, provide both biochemical and genetic evidence that ICP0 functions as a multimer in infected cells.

[Research of eximer laser-excited fast speed spectrochemical analysis]

Experimental method including XeCl eximer Laser-excited, optical multichannel analyzer (OMA) combined with the simultaneous spectrum widen technique was introduced in this paper. We programed data acquisition software and tested alloy-steel sample. The acquisition result of 150nm simultaneous spectrum was showed. The charaterics and significances of our research were discussed.

[Application of simple OMA system for rapid spectrochemical quantitative analysis to steel sample composition]

In this paper, the experimental method and characteristic of a simple optical multichannel analyzer (OMA) system used for rapid spectrochemical quantitative analysis was introduced. Mangangese and chromium contents in different steel samples were measured. The reliability of experimental results was discussed according to the mathematical statistics theory. Analytical results were compared with those of chemical and ICP analysis.

[An observation on antiviral effect of IFN--alpha N1 (Wellferon) in patients with chronic hepatitis B]

In order to observe the antiviral effect of IFN-alpha N1(Wellferon, British Glaxowellcome Company) on CHB, each 50 cases of CHB were selected as the therapy group and the control group. The patients in the therapy group were administrated with 3MU of IFN-alpha N1 once a day for one week, and then 3MU of IFN-alpha N1 three times weekly for 11-23 weeks, whereas the patients in the control group did not receive any antiviral treatment. At 3 months, the serum alanine transaminsae(ALT) was decreased to normal level in 84%(42/50) cases of the therapy group, while only in 46% (23/50) cases of the control group (P < 0.01). The negative seroconversion rate of HBeAg was 56.7% (17/30) and 10.8% (4/37), of HBV DNA was 36.4%(12/33) and 5.9% (1/17) in therapy and control groups respectively. There was obvious difference in two groups. The results suggest that IFN-alpha N1 is satisfying antiviral drug for CHB patients or patients non-responsive to other IFNs.

Effect of baffles and a louvered bypass on the airflow and the convective patterns of contaminant inside a fume hood

Various numerical predictions are given for the containment testing of fume hoods with internal baffles of different size and at different locations and with a louvered bypass. The numerical predictions were compared with experimental data and a fairly good agreement for the air velocity was found, although there was only qualitative agreement for the concentration of the contaminant. It was found that the level of contaminant leakage at the working aperture depended not only on the size of the recirculating airflow behind the fume hood sash but also on the blockage caused by the baffles inside the fume hood near the exhaust duct. Finally, some new suggestions for the design of the fume hood have been proposed. However, before implementing these suggestions it is essential that either experimental testing be performed, or the cost-effective alternative of using numerical predictions for containment testing, to determine accurately the level of contaminant leakage from the working aperture.

[Effect of -6 degrees bed-rest on T-lymphocyte proliferation and cytokines production in human]

In this study, the effect of -6 degrees head-down bed-rest on proliferation of T lymphocyte stimulated by phytohemagglutinin, a kind of polyclone T cell activators and cytokines production were observed. The results showed: after 2 d bed-rest, proliferation of T lymphocyte stimulated by phytohemagglutinin decreased significantly; the activity of interleukin-2 trended to decrease; the expression of interleukin-2 receptor tended to increase; the production of interleukin-6 decreased significantly. After 6 d bed-rest, T lymphocyte proliferation restored to normal; the activity of interleukin-2 and expression of interleukin-2 receptor had no change; the production of interleukin-6 decreased significantly. This result demonstrated that -6 degrees bed-rest can decrease T lymphocyte proliferation function, and this decrease may be caused by the reduction of cytokines secretion.

Large-scale temporal gene expression mapping of central nervous system development

We used reverse transcription-coupled PCR to produce a high-resolution temporal map of fluctuations in mRNA expression of 112 genes during rat central nervous system development, focusing on the cervical spinal cord. The data provide a temporal gene expression "fingerprint" of spinal cord development based on major families of inter- and intracellular signaling genes. By using distance matrices for the pair-wise comparison of these 112 temporal gene expression patterns as the basis for a cluster analysis, we found five basic "waves" of expression that characterize distinct phases of development. The results suggest functional relationships among the genes fluctuating in parallel. We found that genes belonging to distinct functional classes and gene families clearly map to particular expression profiles. The concepts and data analysis discussed herein may be useful in objectively identifying coherent patterns and sequences of events in the complex genetic signaling network of development. Functional genomics approaches such as this may have applications in the elucidation of complex developmental and degenerative disorders.

Cluster analysis and data visualization of large-scale gene expression data

The discovery of any new gene requires an analysis of the expression context for that gene. Now that the cDNA and genomic sequencing projects are progressing at such a rapid rate, high throughput gene expression screening approaches are beginning to appear to take advantage of that data. We present a strategy for the analysis for large-scale quantitative gene expression measurement data from time course experiments. Our approach takes advantage of cluster analysis and graphical visualization methods to reveal correlated patterns of gene expression from time series data. The coherence of these patterns suggests an order that conforms to a notion of shared pathways and control processes that can be experimentally verified.

[Spectroscopic diagnostic of atmospheric pressure argon microwave induced plasma]

Atmospheric argon microwave-induced plasma (Ar-MIP) sustained by a surfatron was obtained. Emission spectra and characteristics of argon metastable (1Sj) were studied with an optical multichannel analyer (OMA-3, 1460) under different experimental condition. Excitation mechanism of the plasma was discussed.

Neurotrophins stimulate chemotaxis of embryonic cortical neurons

During mammalian cortical development, neuronal precursors proliferate within ventricular regions then migrate to their target destinations in the cortical plate, where they organize into layers. In the rat, most cortical neuronal migration occurs during the final week of gestation (Bayer et al, 1991; Jacobson, 1991). At this time (E15-E21), reverse transcriptase-polymerase chain reaction demonstrated that cortical homogenates contain mRNA encoding brain derived neurotrophic factor (BDNF) and the catalytic form of its high-affinity receptor, TrkB. Immunocytochemistry and in situ hybridization of sections revealed that the catalytic TrkB receptors predominantly localize to regions containing migratory cells. Many TrkB+ cells exhibited the classic morphology of migrating neurons, suggesting that TrkB ligands play a role in cortical neuronal migration. We analysed whether TrkB ligands influence the motility of embryonic cortical cells (from E15-E21) using a quantitative in vitro chemotaxis assay. High-affinity TrkB ligands (BDNF and NT4/5) stimulated chemotaxis (directed migration) of embryonic neurons at concentrations ranging from 1 to 100 ng/ml. NT-3, a low-affinity TrkB ligand, only stimulated significant migration at high concentrations (> or =100 ng/ml). Peak migration to BDNF was observed at gestational day 18 (E18). BDNF-induced chemotaxis was blocked by either tyrosine kinase inhibitor, K252a, or the Ca2+-chelator, BAPTA-AM, suggesting that BDNF-induces motility via autophosphorylation of TrkB receptor proteins and involves Ca2+-dependent mechanisms. BDNF-stimulation of increased cytosolic Ca2+ was confirmed with optical recordings of E18 cortical cells loaded with Ca2+ indicator dye. Thus, signal transduction through the TrkB receptor complex directs neuronal migration, suggesting that, in vivo, BDNF exerts chemotropic effects that are critical to morphogenesis of the cortex.

[Rapid spectrochemical qualitative analysis of simple OMA system]

Simple optical multichannel analyzer (OMA) system which is formed by ordinary one dimension CCD camera, spectrograph and microcomputer was introduced in this paper. Spectrochemical analysis feasible of this OMA system was studied. The applied software programed, by us can realize wavelength calibration, spectral line identification and give out automatically the results of qualitative and semidefinite quantity analysis.

[Biocompatibility evaluation of Ti50Ni50-xCux shape memory alloys (I)--corrosion resistance]

By means of electrochemical methods, the corrosion resistance of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2, 4,6,8) was investigated. It is discovered that repassivation potential of Ti50Ni50-xCux (x = 2,4,6,8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. This means that the added Cu raises the repassivation of TiNi shape memory alloys and improves corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2,4,6,8) alloys increase with the rising solution pH value, but the repassivation potentials keep constant. The added Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1,2,4,6,8) alloys are irrelevant to its Cu content and the values are almost the same as that of TiNi alloys.

[Microrough surface and its bio-effects of metallic biomaterials (II)--bio-effects of microrough surface of metallic biomaterials]

As for bio-effect of microrough surface of metallic biomaterials, seven aspects are reviewed in this article: i.e., the relationship between microrough surface (MRS) and corrosion resistance, ion release rate; the relationship between MRS and inflammation; the relationship between MRS and epithelium cells, fibroblast cells; the relationship between MRS and soft tissue; the relationship between MRS and bone; the relationship between MRS and blood tissue; the relationship between MRS and microorganism, contamination, decontamination. To sum up, MRS has its advantages in biocompatibility.

Effect of simulated weightlessness on TNF-alpha production and the response of bone marrow cells to GM-CSF in rats

The purpose of this experiment was to investigate the effect of 15 and 30 d simulated weightlessness (SWL) on tumor necrosis factor-alpha(TNF-alpha) production secreted by macrophage stimulated with lipopolysaccharide(LPS) and the ability of bone marrow cells to respond to granulocyte/monocyte colony-stimulating factor(GM-CSF) in tail-suspension rats. The TNF-alpha production was assessed by radioimmunoassay. The ability of bone marrow cells to respond to GM-CSF was measured by 3H-TdR incorporation method. The results showed that after 15 d SWL, TNF-alpha production showed a tendency to decrease; and that after 30 d SWL, the decrease became significant (P < 0.05). The results also demonstrated that the ability of bone marrow cells to respond to GM-CSF decreased significantly after 15 d SWL (P < 0.01); and there was no significant change after 30 d SWL. It suggested that SWL could depress immune function, and that reduction of TNF-alpha production might be related to bone marrow cell proliferation function.

Anatomical gradients in proliferation and differentiation of embryonic rat CNS accessed by buoyant density fractionation: alpha 3, beta 3 and gamma 2 GABAA receptor subunit co-expression by post-mitotic neocortical neurons correlates directly with cell buoyancy

Development of the CNS occurs as a complex cascade of pre-programmed events involving distinct phases of cell proliferation and differentiation. Here we show these phases correlate with cells of specific buoyant densities which can be readily accessed by density gradient fractionation. Sprague-Dawley dams were pulse-labelled with bromodeoxyuridine (BrdU) and selected regions of embryonic (E) CNS tissues at E11-22 dissociated with papain into single-cell suspensions. Proliferative cell populations were assessed by anti-BrdU and propidium iodide staining using flow cytometry. Cell differentiation was evaluated using molecular and immunocytochemical probes against mRNAs and antigens differentiating the neuroepithelial, neuronal and glial cell lineages. The results show the emergence of distinctive spatiotemporal changes in BrdU+ populations throughout the CNS during embryonic development, which were followed by corresponding changes in the cellular distributions of antigens distinguishing specific cell types. Fractionation of neocortical cells using discontinuous Percoll gradients revealed that an increasing number of cells increase their buoyancy during corticogenesis. Immunocytochemical and molecular characterization showed that the proliferative and progenitor cell populations are for the most part associated with lower buoyancy or higher specific buoyant densities (> 1.056 g/ml) whereas the post-mitotic, differentiated neurons generally separated into fractions of higher buoyancy or lower specific buoyant densities (< 1.043 g/ml). Immunostaining with antibodies against several GABAA receptor subunits (alpha 3, beta 3, gamma 2) revealed that the highest percent (70-90%) of immunopositive cells could be identified in the most buoyant, differentiating neurons found in the cortical plate/subplate regions, with the lowest percent of the immunopositive cells found in the least buoyant, proliferative and progenitor cell populations originating from the ventricular/subventricular zones. Taken together, these results indicate that buoyant density is a distinguishing characteristic of embryonic CNS cells transforming from primarily proliferative to mainly differentiating, and that fractionation of these cells according to their buoyant densities provides rapid access to the properties of specific cell lineages during the prenatal period of CNS development.

[Microrough surface and its bio-effects of metallic biomaterials (I)--microrough surface of metallic biomaterials]

In this paper, four aspects of microrough surface of metallic biomaterials are reviewed: the preparation of microrough surface, the technology of surface roughness measurement, the parameters of roughness and the microrough surface bio-effect.

The plasma concentrations of lidocaine after slow versus rapid administration of an initial dose of epidural anesthesia

We measured venous blood concentrations of lidocaine in 15 patients undergoing lower abdominal or extremity surgery after epidural injection of lidocaine. Patients were divided into either an infusion group (Group I, n = 6) or a bolus injection group (Group II, n = 9). We administered 15 ml of 2% lidocaine into the epidural space at 1 mL/min in Group I and at 1 mL/3 in Group II. Venous blood was drawn at 3, 6, 9, 12, 15, 18, 21, 30, 60, and 90 min after injection for measurement of plasma lidocaine concentrations. The peak plasma concentration (Cmax) of lidocaine in Group I was significantly less than that in Group II (P < 0.0005). We conclude that slow epidural infusion can produce a lower Cmax of lidocaine compared with that of a bolus administration and thereby decrease the potential for systemic toxicity of the local anesthetic.

Oct-1 and CCAAT/enhancer-binding protein (C/EBP) bind to overlapping elements within the interleukin-8 promoter. The role of Oct-1 as a transcriptional repressor

Interleukin-8 (IL-8), a potent neutrophil chemoattractant, can be expressed at high levels by many different cell types after immune stimulation. In contrast, expression of IL-8 in these same cells is virtually absent in the unstimulated state, demonstrating the tight regulation of the IL-8 gene. Although much is known about how this gene is transcriptionally activated after immune stimulation, little is known about the regulation of the IL-8 promoter in the absence of immune activation. In this study we examine how the IL-8 promoter is transcriptionally regulated in the uninduced state and how these mechanisms are altered in response to immune stimulation by IL-1beta. Electrophoretic mobility shift assay and transfection studies show that the IL-8 promoter is transcriptionally regulated by both positive and negative elements. Although the nuclear factor-kappaB (NFkappaB) element regulates only inducible activity of the IL-8 promoter in response to stimulation with IL-1beta, the AP-1 and CCAAT/Enhancer-binding Protein (C/EBP) elements influence both basal and inducible activities. In contrast to these three positive regulatory elements, the binding of the ubiquitously expressed POU-homeodomain transcription factor, Oct-1, strongly represses transcriptional activity of the IL-8 promoter by binding independently to an element overlapping that of C/EBP.

Electrochemical and histomorphometric evaluation of the TiNiCu shape memory alloy

By means of electrochemical and quantitative histomorphometric methods, the corrosion resistance and tissue biocompatibility of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) were investigated. It is discovered that the repassivation potential of Ti50Ni50-xCux (x = 2, 4, 6, 8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. Namely, the addition of Cu raises the repassivation potential of TiNi shape memory alloys and improves their corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys increase with solution pH value, but the repassivation potentials keep constant. The adding of Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys are irrelevant to its Cu content and the values are almost the same as those of TiNi alloys. The connective tissue layer covering the plates is statistically significantly thicker for Ti50Ni42Cu8 plates (p < 0.05) than that of Ti50Ni50, Ti50Ni48Cu2, Ti50Ni44Cu6 plates after one month. The numbers of connective tissue cells, polynucleated cells, macrophages and round cells are higher for Ti50Ni42Cu8 plates than those of the other three types of plates, but no statistically significant differences are detected. There are no significant differences on tissue reaction parameters after two and three months among four alloys. After one, two and three months implantation, no corrosion is observed on the plates surfaces. A preliminary conclusion can be drawn that Ti50Ni50-xCux (x = 2, 6, 8) shape memory alloys have good biocompatibility.

Repression of the alpha0 gene by ICP4 during a productive herpes simplex virus infection

During a productive infection by herpes simplex virus type 1 (HSV-1), ICP4, the major regulatory protein encoded by the alpha4 gene, binds to its transcription initiation site and represses the accumulation of alpha4 RNA. Evidence suggests that the degree of repression by ICP4 is a function of the absolute distance of an ICP4 binding site 3' from a TATA box. However, repression of HSV-1 gene expression by ICP4 through binding sites located 5' of TATA boxes, as in the case of the alpha0 gene, has not been adequately addressed. To this end, recombinant alpha0 promoters with various arrays of ICP4 binding sites flanking the alpha0 TATA box were constructed and recombined into the HSV-1 genome. Our results demonstrate the following. (i) Destruction of the endogenous alphaO ICP4 binding site, located 5' of the TATA box, results in derepression of alpha0 protein and RNA accumulation in infected Vero cells. (ii) The degree of alpha0 derepression is equivalent to that reported for the alpha4 gene following destruction of the ICP4 binding site at the alpha4 mRNA cap site in HSV-1. (iii) Introduction of an ICP4 binding site at the alpha0 mRNA cap site represses the accumulation of alpha0 RNA greater than threefold relative to the wild type. (iv) Changes in the abundance of alpha0 protein and RNA in infected cells do not affect replication or growth of HSV-1 in tissue culture. Our findings are consistent with the conclusion that alpha0 transcription is repressed by ICP4. These results demonstrate that repression by ICP4 can occur through binding sites located 5' of virus gene TATA boxes in HSV-1. Thus, models addressing repression of HSV-1 gene expression by ICP4 should incorporate the role of binding sites located 5', as well as 3', of virus gene TATA boxes.

Noninvasive indexes of cardiac systolic and diastolic function in hyperthyroid and senescent mouse

The mouse is a common model for transgenic manipulation, however, their small size has made hemodynamic study difficult. A noninvasive 10-MHz pulsed Doppler probe was used to measure aortic and mitral flow velocities in anesthetized, intact mice to study the effects of aging and hypethyroidism (induced by thyroxine) one systolic and diastolic cardiac function. In 10 hyperthyroid mice peak aortic velocity (PAV, an index of systolic function) was 34% higher than in 10 control mice (108 +/- 2 vs. 80 +/- 3 cm/s, P < 0.05). The ratio of early to late mitral filling velocity (E/A ratio, an index of diastolic function) was 47% higher (5.6 +/- 0.8 vs. 3.8 +/- 0.2, P < 0.05) in the hyperthyroid mice. In six old (30 mo) mice PAV was similar to eight young (4 mo) mice (73 +/- 3 vs. 75 +/- 3 cm/s), but the E/A ratio was 59% lower (1.8 +/- 0.3 vs. 4.4 +/- 0.4, P < 0.05). Despite a wide range of observed heart rates, the systolic and diastolic parameters of the groups were clearly separated. We conclude that cardiac systolic and diastolic function in mice, measured by pulsed Doppler ultrasound, are similar to larger species both in magnitude and in their response to hyperthyroidism and aging.

Developmental kinetics of GAD family mRNAs parallel neurogenesis in the rat spinal cord

GABA (gamma-amino butyric acid), a fast-acting synaptic transmitter in the mature CNS, is synthesized from glutamate by GAD (glutamic acid decarboxylase). We have developed an ultrasensitive PCR technique to quantify the expression of GAD-related mRNAs during the development of the rat cervical spinal cord and have localized them using in situ hybridization. GAD65, GAD67, and an alternatively spliced variant of GAD67, EP10, were quantified each day from embryonic (E) day 11 through E21, and at postnatal days 0, 7, 14, and adult. GAD65 and GAD67 mRNAs were detected at E11 and increased exponentially over three orders of magnitude during embryonic development, then declined approximately threefold in the first-2 postnatal weeks. While the exponential growth phase coincided with the progressive appearance of GAD67 in situ signals in both the ventral and dorsal cord, the postnatal decline coincided with the virtual disappearance of expression in the ventral region. EP10 expression was prominent in the embryo, then declined markedly together with the mRNA encoding the neuroepithelial stem cell marker, nestin. The concerted appearance of GAD-related mRNAs paralleled transcripts encoding neuronal markers (light and heavy neurofilaments) and also closely correlated with the expression of GABA, mRNAs encoding GABAA receptor subunits, and depolarizing responses to GABA. We have used the results on GAD-related mRNA expressions to formulate a simple, minimal mathematical model that accounts for their kinetics in terms of positive and negative feedback loops.

[Combined operation for the foreign body in the eye complicated with traumatic cataract: an analysis of 88 cases]

The foreign body in the eye complicated with traumatic cataract is one of the common causes of blindness. The rate of blindness ranges from 20% to 48.9%. This paper analyses combined operation for 88 cases of foreign body in the eye with traumatic cataract. The visual acuity below 0.05 accounted for 85.2% of the cases before operation and reduced to 27.3% after operation. Postoperatively, the corrected visual acuities were from 0.06 to 1.5 in 73.3% of the cases and 0.6 to 1.5 in 22.7% respectively. The patients should be treated with combined operation earlier. The way of operation depends on the property and the location of foreign body and the situation of lens. Chinese-Western medicine treatment should be used postoperatively to control the tissue response. Combined operation can improve the effect, reduce the complication, the number of operation and decrease medical expenses.

Effect of son preference and population policy on sex ratios at birth in two provinces of China

Two samples of births were used to examine the effect of son preference and population policy on sex ratios in Hebei and Shaanxi provinces of China. The results from all births to women aged 15-49 in the 1985 In-Depth Fertility Survey indicated a strong son preference but no clear policy impact on sex ratios at different birth orders. In a sample of selected births during 1975-84 to women aged 40 or under, the mixed influences of son preference and population policy were clearly reflected in the high and rising overall ratios at birth, and the increasing sex ratios with parity. Possible explanations for these findings are discussed.

[Vitrectomy combined with intravitreal injection of drugs for the management of advanced suppurative endophthalmitis]

Sixty cases (60 eyes) of advanced suppurative endophthalmitis treated by a combination of vitrectomy and intravitreal injection of drugs (antibiotics or/and corticosteroids) were investigated perspectively. Of the 60 cases, 43 were infected after trauma, 12 were infected after surgical procedures, while the others were of unknown causes. During the follow-up period of 1/2-5 years, 57 cases (95%) retained functioning eyes, the postoperative visual acuity of 34 eyes (57%) being 0.05 or better and the postoperative visual acuity of 17 eyes (28%) 0.4 to 1.0. The advantages of the therapeutic regimen are analyzed. We believe that it is the most effective therapy for suppurative endophthalmitis. The timing of the operation and the factors influencing the results are discussed. This report also presents our clinical experiences in the management of advanced suppurative endophthalmitis.

Regulation of fat body mitochondrial respiration in Periplaneta americana by a novel factor from the corpus cardiacum

Respiration of fat body (Periplaneta americana) mitochondria is increased by pretreatment of the tissue with corpus cardiacum (CC) extract. The magnitude of the increase depends on the type of substrate supplied for oxidation. With 5 mM pyruvate the respiration increased 22%, decreasing to 0 with 1 mM pyruvate. In contrast, 50 microM and 0.2 mM palmitic acid supported an increase in CC-stimulated respiration of 14 and 44%, respectively. Unlike crude CC extract, the synthetic hyperglycemic peptides CCI and CCII failed to alter the respiratory activity of fat body mitochondria. In common with the action of CC extract pretreatment of the fat body in vitro with 10(-5) M cyclic AMP, 10(-5) M 8-bromo-cyclic AMP, or 10(-5) M forskolin increased mitochondrial respiration approximately 30%. Octopamine (10(-4) M) elicited a response similar to that obtained with CC extract. Neither 10(-5) M cyclic AMP nor 10(-5) M 8-bromo-cyclic AMP stimulated respiration when applied directly to the mitochondria. These results suggest that the factor in CC extract manifests its effect intracellularly through the activation of a cyclic AMP-dependent protein kinase. This interpretation is also based on the finding that diamide, an inhibitor of protein kinase, inhibits CC-dependent and cyclic AMP-dependent mitochondrial respiration. The physiological role of the CC factor responsible is not known.

[Steroid alkaloids from stems and leaves of Fritillaria ussuriensis Maxim]

Three crystalline chemical components were isolated from the stems and leaves of Fritillaria ussuriensis by column chromatographic technique. On the basis of the IR, MS and 1HNMR spectra, the structure has been identified as pingbeimine B, pingbeimine C and pingbeininoside.

[Bacteriologic studies of the occurrence of Chlamydia psittaci in organs of swine and in aborted swine fetuses]

By inoculation of embryonating chicken eggs via the yolk sac route Chlamydia psittaci was grown from 11 lungs of 45 pigs with pneumonia (24.4%). From the lungs of 55 pigs with other diseases the organism was isolated in five cases (9.1%). Chlamydiae were not detectable by cultural methods in the uterine mucosa of 87 sows, arthritic joints of 30 store pigs and in aborted fetuses. A commercial available enzyme amplified immunoassay indicated the presence of chlamydial antigen in mucosal scrapings from the uterus of two sows and in the fetal membranes as well as fetal organs in one case of porcine abortion.

[Management of foreign bodies in transparent lens and a long-term follow-up--the analysis of 25 cases]

25 cases of foreign bodies in transparent lens are reported in this paper. The foreign bodies retained in transparent lens are rare intraocular foreign bodies. In all cases, the foreign bodies were magnetic and the injured lens had local opacity. In 20 cases of them, the foreign bodies were removed by different magnets according to the different sites of the foreign bodies retained in transparent lens. In most cases the effect was sufficient. The patients were followed-up postoperatively during different period. The visual acuity was quite good. Effect of the foreign bodies on the transparent lens, and the management of the foreign bodies in transparent lens and the operative methods for removal of the foreign bodies in the transparent lens are discussed.

[The analysis of foreign bodies in the anterior chamber in 165 cases]

One hundred and sixty-six eyes of 165 patients with foreign bodies in the anterior chamber who were treated at our center from 1966 to 1988 were retrospectively reviewed. Among them there were 109 eyes with nonmetal foreign bodies, 55 eyes with metal foreign bodies and three eyes with foreign bodies of unknown nature. Most of these foreign bodies were stone or iron. 83.6% of the patients were in the age range from 7 to 40 years, and the left eyes were affected more than the right eyes. Mostly, the foreign bodies were located on the surface of iris (97 cases) and at the anterior chamber angle (40 cases). The rates of blindness were 27.8% and 16.3% before and after operation. The postoperative visual acuity were: 0.05-0.2 in 27 eyes, 0.3-0.9 in 66 eyes, greater than 1.0 in 43 eyes and the rest of the eyes lower than 0.05. The presurgery treatment such as miosis and reduction of intraocular pressure, the selection of operative methods according to the nature, size, location of the foreign bodies and tissue wrapped up were discussed. If combined procedures should be done, it is better to remove the foreign bodies first and then perform the operation for complications.