A highly color-stability white organic light-emitting diode by color conversion within hole injection layer

We demonstrated a novel-structure white organic light-emitting devices (WOLEDs) composed of a greenish blue fluorescent emitting layer and a red fluorescent dye-doped hole injection layer. The spectra of WOLEDs show no change at a wide range current density operation and long-term continuous operation. We concluded that carriers recombined inside the emitting layer in the WOLEDs to produce a greenish blue electroluminescence (EL), and a part of the EL was absorbed by the red fluorescent guest doped hole injection layer and converted into red photoluminescence (PL); the whole white emission from the device was a mixture of the greenish blue EL and red PL.

Supercooling of aqueous NaCl and KCl solutions under acoustic levitation

The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions.

TIMP-2 upregulates RECK expression via dephosphorylation of paxillin tyrosine residues 31 and 118

We previously demonstrated that TIMP-2 increases the association of Crk with C3G and via subsequent activation of Rap1 enhances the expression of RECK, a membrane-anchored MMP inhibitor. In the present study, we investigate the mechanism of how the TIMP-2 signal is transduced from the alpha3beta1 integrin receptor to the Crk-C3G-Rap1 molecular complex. TIMP-2 treatment of human microvascular endothelial cells (hMVECs) increased the phosphorylation levels of Src at Tyr-527, the negative regulatory site, through enhanced association of Src with Csk. This results in the reduction of Src kinase activity and dephosphorylation of paxillin at Tyr-31/118, the target sites for Src kinase phosphorylation and also the binding sites for the downstream effector Crk. Such TIMP-2 effects accompany the disassembly of paxillin-Crk-DOCK180 molecular complex and, in turn, Rac1 inactivation. On the contrary, levels of paxillin-Crk-C3G complex formation are not reduced, rather slightly increased, which is consistent with our previous finding. Therefore, TIMP-2-mediated inhibition of Src kinase activity leads to the signaling switch from Rac1 to Rap1, thereby leading to enhanced RECK expression.

A new triple crossover triangle (TXT) motif for DNA self-assembly

A new triple crossover triangle (TXT) motif was conceived on the basis of the DNA triple crossover (TX) motif. The new motif is rigid and triangular prism-shaped, out of which 1-D, 2-D, and 3-D DNA structures can be assembled. The 1-D TXT array was self-assembled and was observed by the TEM with negative staining by uranyl acetate. The architectural schemes for 2-D and 3-D structures are presented.

The characteristics of tolerogenic plasmacytoid dendritic cells stimulated with interleukin-3

This study focused on whether bone marrow would differentiate tolerogenic dendritic cells (DCs) by comparing interleukin-3 (IL-3) DCs (induced by IL-3+IL-4) with GM-CSF DCs (induced by GM-CSF+IL-4, generating myeloid DCs). Mouse bone marrow progenitors were induced in vitro to differentiate into DCs by exposure to IL-3. The morphology and yields of IL-3 DCs and GM-CSF DCs were compared by scanning electron microscopy and laser scanning confocal microscopy. Immunohistochemistry and flow cytometer (FCM) were used to identify immune phenotypes. The results showed that IL-3 DCs and GM-CSF DCs both expressed the specific marker DEC-205 with about 80% and 70% purity, respectively. IL-3 DCs had similar morphology as plasma cells, but a different immune phenotype, namely, CD80(-), CD86(-), CD14(-), and MHC class II(+). IL-3 DCs remained in the costimulatory molecule-deficient state when TNF-alpha was supplemented into the culture. We therefore propose that IL-3 induces a high purity and yield of DCs from bone marrow. Since IL-3 DCs possess a tolerogenic phenotype (MHC class II(+), B7(-)), they may induce alloantigen-specific hyporesponsiveness in vitro.

Stable Transformation of CHO Cells and Human NARP Cybrids Confers Oligomycin Resistance (olir) Following Transfer of a Mitochondrial DNA–Encoded olirATPase6 Gene to the Nuclear Genome: A Model System for mtDNA Gene Therapy

Point and deletion mutations and a general depletion of mammalian mitochondrial DNA (mtDNA) give rise to a wide variety of medical syndromes that are refractory to treatment, possibly including aging itself. While gene therapy directed at correcting such deficits in the mitochondrial genome may offer some therapeutic benefits, there are inherent problems associated with a direct approach. These problems are primarily due to the high mitochondrial genome copy number in each cell and the mitochondrial genome being "protected" inside the double-membrane mitochondrial organelle. In an alternative approach there is evidence that genes normally present in the mitochondrial genome can be incorporated into the nuclear genome. To extend such studies, we modified the Chinese Hamster Ovary (CHO) mtDNA-located ATPase6 gene (possessing a mutation which confers oligomycin resistance- oli(r)) by altering the mtDNA code to the universal code (U-code) to permit the correct translation of its mRNA in the cytoplasm. The U-code construct was inserted into the nuclear genome (nucDNA) of a wild type CHO cell. The expressed transgene products enabled the transformed CHO cell lines to grow in up to 1000 ng mL(-1) oligomycin, while untransformed sensitive CHO cells were eliminated in 1 ng mL(-1) oligomycin. This approach, termed allotopic expression, provides a model that may make possible the transfer of all 13 mtDNA mammalian protein-encoding genes to the nucDNA, for treatments of mtDNA disorders. The CHO mtATPase6 protein is 85% identical to both the mouse and human mtATPase6 protein; these proteins are highly conserved in the region of the oligomycin resistance mutation. They are also well conserved in the regions of the oligomycin resistance mutation of the mouse, and in the region of a mutation found in Leigh's syndrome (T8993G), also called NARP (neurogenic weakness, ataxia, retinitis pigmentosum). It is likely that the CHO oli(r) mtATPase6 Ucode construct could impart oligomycin-resistance in human and mouse cells, as well as function in place of the mutant ATPase subunit in a NARP cell line. Preliminary experiments on human cybrids homoplasmic for the NARP mutation (kindly supplied by D.C. Wallace), transformed with our construct, display an increased oligomycin resistance that supports these suppositions.

Dynamics of acoustically levitated disk samples

The acoustic levitation force on disk samples and the dynamics of large water drops in a planar standing wave are studied by solving the acoustic scattering problem through incorporating the boundary element method. The dependence of levitation force amplitude on the equivalent radius R of disks deviates seriously from the R3 law predicted by King's theory, and a larger force can be obtained for thin disks. When the disk aspect ratio gamma is larger than a critical value gamma(*) ( approximately 1.9 ) and the disk radius a is smaller than the critical value a(*) (gamma) , the levitation force per unit volume of the sample will increase with the enlargement of the disk. The acoustic levitation force on thin-disk samples ( gamma</= gamma(*) ) can be formulated by the shape factor f(gamma,a) when a</= a(*) (gamma) . It is found experimentally that a necessary condition of the acoustic field for stable levitation of a large water drop is to adjust the reflector-emitter interval H slightly above the resonant interval H(n) . The simulation shows that the drop is flattened and the central parts of its top and bottom surface become concave with the increase of sound pressure level, which agrees with the experimental observation. The main frequencies of the shape oscillation under different sound pressures are slightly larger than the Rayleigh frequency because of the large shape deformation. The simulated translational frequencies of the vertical vibration under normal gravity condition agree with the theoretical analysis.

Removal of fluoride from water by carbon nanotube supported alumina

This paper describes a new adsorption material carbon nanotube supported alumina, used for fluoride removal from water. The effects of calcination temperature, alumina loading and pH on fluoride removal capacity were investigated. The optimum calcination temperature for preparing the adsorbents is 450 degrees C and the largest adsorption capacity takes place at alumina loading of 30 wt%. The broad pH range of 6.0-9.0 with high adsorption capability suggests that carbon nanotube supported alumina have great potential applications in practice. The adsorption data at different pH were well fitted to the Freundlich isotherm. The kinetic studies show that the adsorption reaction of fluoride removal by carbon nanotube supported alumina can be described by a second orderrate equation.

Eutectic growth under acoustic levitation conditions

Samples of Pb-Sn eutectic alloy with a high density of 8.5 x 10(3) kg/m(3) are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of "lamellas-broken lamellas-dendrites." This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface.

Levitation of iridium and liquid mercury by ultrasound

Single-axis acoustic levitation of the heaviest solid (iridium, rho=22.6 g cm(-3)) and liquid (mercury, rho=13.6 g cm(-3) on the Earth is achieved by greatly enhancing both the levitation force and stability through optimizing the geometric parameters of the levitator. The acoustically levitated Pb-Sn eutectic alloy melt (rho=8.5 g cm(-3)) is highly undercooled by up to 38 K, which results in a microstructural transition of "lamellae-broken lamellae-dendrites." The drastic enhancement of levitation capability indicates a broader application range of single-axis acoustic levitation.

Dependence of acoustic levitation capabilities on geometric parameters

A two-cylinder model incorporating boundary element method simulations is developed, which builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator with reference to wavelength. This model proves to be successful in predicting resonant modes of the acoustic field and explaining axial symmetry deviation of the levitated samples near the reflector and emitter. Concave reflecting surfaces of a spherical cap, a paraboloid, and a hyperboloid of revolution are investigated systematically with regard to the dependence of the levitation force on the section radius R(b) and curvature radius R (or depth D) of the reflector. It is found that the levitation force can be remarkably enhanced by choosing an optimum value of R or D, and the possible degree of this enhancement for spherically curved reflectors is the largest. The degree of levitation force enhancement by this means can also be facilitated by enlarging R(b) and employing a lower resonant mode. The deviation of the sample near the reflector is found likely to occur in case of smaller R(b), larger D, and a higher resonant mode. The calculated dependence of levitation force on R, R(b), and the resonant mode is also verified by experiment and finally demonstrated to be in good agreement with experimental results, in which considerably a strong levitation force is achieved to levitate an iridium sphere which has the largest density of 22.6 g/cm(3).

[MRI artifacts caused by keepers in a dental arch]

OBJECTIVE

This research was designed to observe the degree of artifacts caused by 1-4 keepers.

METHODS

Samples were imaged in a living human subject by 0.15 Tesla MR devices in sagital plane. Results were analyzed and the maximal diameters of artifacts were measured.

RESULTS

The maximal diameters of the artifacts caused by 1-4 keepers were 101-109.6mm.

CONCLUSION

Even with four keepers in the dental arch, the degree of artifact is still limited.

Activation of the Jnk signaling pathway by a dual-specificity phosphatase, JSP-1

The mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli, such as growth factors, hormones, and cytokines, and to a wide variety of environmental stresses. The MAPKs, which are stimulated by phosphorylation of a TXY motif in their activation loop, are components of signal transduction cascades in which sequential activation of protein kinases culminates in their activation and their subsequent phosphorylation of various effector proteins that mediate the physiological response. MAPKs are also subject to dephosphorylation and inactivation, both by enzymes that recognize the residues of the TXY motif independently and by dual specificity phosphatases, which dephosphroylate both Tyr and Ser/Thr residues. We report the identification and characterization of a novel dual specificity phosphatase. Contrary to expectation, this broadly expressed enzyme did not inactivate MAPKs in transient cotransfection assays but instead displayed the capacity to function as a selective activator of the MAPK Jnk, hence the name, Jnk Stimulatory Phosphatase-1 (JSP-1). This study illustrates a new aspect of the regulation of MAPK-dependent signal transduction and raises the possibility that JSP-1 may offer a different perspective to the study of various inflammatory and proliferative disorders associated with dysfunctional Jnk signaling.

Effects of environmental factors on the seasonally change of phytoplankton populations in a closed freshwater pond

The effect of environmental factors affecting the population dynamic of phytoplankton population was studied seasonally in a closed freshwater pond with the natural water of Lake Kasumigaura, Japan. The predominant phytoplankton species in the pond were classified as Oscillatoria tenuis, Synedra ulna, Chlamydomonas cingulata and Cyclotella kutzingiana, with dominant species of Melosira italica, Synechococcus sp. and Cryptomonas ovata. The most important limiting factor for filament length and cell size of most of the phytoplankton community was temperature. Availability of most nutrients had profound effects on the phytoplankton growth as nonlimiting factors. Based on our results, it is suggested that cell cycle progression was also temporally regulated by a multiplicity of external factors such as temperature, nutrients, dissolved oxygen (DO) and pH. At high pH and high temperature, consistent increase of cell division of some phytoplanketers such as Synedra, Cyclotella, Chlamydomonas and Melosira occurs, and there also may be species-specific responses for other species of phytoplankters. In addition, the cell divisions of phytoplankters are differentially regulated in different phytoplankton species.

Molecular cloning of a Bacteroides caccae TonB-linked outer membrane protein identified by an inflammatory bowel disease marker antibody

Commensal enteric bacteria are a required pathogenic factor in inflammatory bowel disease (IBD), but the identity of the pertinent bacterial species is unresolved. Using an IBD-associated pANCA monoclonal antibody, a 100-kDa protein was recently characterized from an IBD clinical isolate of Bacteroides caccae (p2Lc3). In this study, consensus oligonucleotides were designed from 100-kDa peptides and used to identify a single-copy gene from the p2Lc3 genome. Sequence analysis of the genomic clone revealed a 2,844-bp (948 amino acid) open reading frame encoding features typical of the TonB-linked outer membrane protein family. This gene, termed ompW, was detected by Southern analysis only in B. caccae and was absent in other species of Bacteroides and gram-negative coliforms. The closest homologues of OmpW included the outer membrane proteins SusC of Bacteroides thetaiotaomicron and RagA of Porphyromonas gingivalis. Recombinant OmpW protein was immunoreactive with the monoclonal antibody, and serum anti-OmpW immunoglobulin A levels were elevated in a Crohn's disease patient subset. These findings suggest that OmpW may be a target of the IBD-associated immune response and reveal its structural relationship to a bacterial virulence factor of P. gingivalis and periodontal disease.

[Clinicopathologic analysis of ovarian serous and mucinous borderline tumors]

OBJECTIVE

To understand the clinicopathological features of ovarian borderline tumors and evaluate the significance of various histological appearances.

METHODS

Forty-five patients with borderline tumors were analyzed retrospectively. The stage distribution was stage I, 34 patients, stage II, 4 patients and stage III, 7 patients.

RESULTS

Forty-five cases of borderline tumors accounted for 25.4% of ovarian epithelial malignant tumors. The ratio of serous borderline tumors (SBTs) to mucinous borderline tumors (MBTs) was approximately 1:1.3. Nine of eleven SBTs with exophytic growth presented peritoneal implants, of which two were invasive and seven noninvasive. Two SBTs and 1 MBT recurred after 5, 4, and 1 years respectively. Thirty-three cases were followed from 2 to 9 years. The 5-year survival rate was 100% (Kaplan-Meir method).

CONCLUSIONS

The prognosis of the SBTs is favorable. SBTs with exophytic growth are often associated with peritoneum implants.

The Crohn's disease-associated bacterial protein I2 is a novel enteric t cell superantigen

An aberrant T cell response to enteric bacteria is important in inflammatory bowel disease. However, the identity of relevant microbial antigens is unknown. Here, we report the presence of I2, a Crohn's disease-associated microbial gene, in the murine intestine. The I2 protein induced a proliferative and IL-10 response by CD4(+) T cells from unimmunized mice. The I2 response was dependent on MHC class II-mediated recognition but did not require antigen processing. Selective activation was observed for the TCR-Vbeta5 subpopulation. These findings indicate that the I2 protein is a new class of T cell superantigen and suggest that colonization by the I2 microorganism in susceptible hosts may provide a superantigenic stimulus pertinent to Crohn's disease pathogenesis.

Use of artificial neural network in the prediction of algal blooms

A model to quantify the interactions between abiotic factors and algal genera in Lake Kasumigaura, Japan was developed using artificial neural network technology. Results showed that the timing and magnitude of algal blooms of Microcystis, Phormidium and Synedra in Lake Kasumigaura could be successfully predicted. As for the newly occurring dominant Oscillatoria, results were not satisfactory. The evaluation of the importance of factors showed that Microcystis, Phormidium, Oscillatoria and Synedra were alkalophilic. The algal proliferation for Microcystis, Oscillatoria and Synedra decrease due to the increase in total nitrogen, while the growth of Phormidium is enhanced with more nitrogen. In addition, the algal density is affected by zooplankton grazing but with the exception of Phormidium due to it being poor food source. Algal responses to the orthogonal combinations of the external environmental factors, chemical oxygen demand, pH, total nitrogen and total phosphorus at three levels were modeled. Various combinations of environmental factors enhance the proliferation of some algae while other combinations inhibit bloom formation.

Vascular Injury Induces Posttranscriptional Regulation of the Id3 Gene

Abstract —The molecular mechanisms that regulate the proliferation of smooth muscle cells (SMCs) of the vasculature in response to injury are poorly understood. Members of the inhibitor of DNA binding (Id) class of helix-loop-helix transcription factors are known to regulate the growth of a variety of cell types; however, the expression of the various Id genes in SMCs and in vascular lesions has not been examined. In the present study, the yeast 2-hybrid system was used to clone Id genes from a cultured rat aortic SMC library. By use of ubiquitous E proteins as bait, Id3 and a novel isoform of Id3 (Id3a) were cloned. Id3a is the product of alternative splicing of the Id3 gene, resulting in inclusion of a 115-bp “coding intron,” which encodes a unique 29–amino acid carboxyl terminus for the Id3a protein. Unlike Id3, Id3a mRNA was not detected in the normal rat carotid artery. However, after balloon injury, Id3a was abundantly expressed throughout the neointimal layer. In addition, mRNA of the human homologue of Id3a (Id3L) was detected in human carotid atherosclerotic plaques. Adenovirus-mediated overexpression of these Id3 isoforms in cultured rat aortic SMCs revealed that infection of SMCs with an adenovirus overexpressing Id3a (in contrast to Id3) resulted in a significant decrease in cell number versus AdLacZ-infected cells. DNA fragmentation analysis suggested that this decrease in SMC viability was due to increased apoptotic activity in cells infected with adenovirus overexpressing Id3a. These results provide evidence that alternative splicing of the Id3 gene may represent an important mechanism by which neointimal SMC growth is attenuated during vascular lesion formation.

Making an Oriental equivalent of the yeast cytosolic aldehyde dehydrogenase as well as making one with positive cooperativity in coenzyme binding by mutations of glutamate 492 and arginine 480

Yeast has at least three partially characterized aldehyde dehydrogenases. Previous studies by gene disrupted in our laboratory revealed that the Saccharomyces cerevisiae cytosol ALDH1 played an important role in ethanol metabolism as did the class 2 mitochondrial enzyme. To date, few mutagenesis studies have been performed with the yeast enzymes. An important human variant of ALDH is one found in Asian People. In it, the glutamate at position 487 is replaced by a lysine. This glutamate interacts with an arginine (475) that is located in the subunit that makes up the dimer pair in the tetrameric enzyme. Sequence alignment shows that these two residues are located at positions 492 and 480, respectively, in the yeast class 1 enzyme which shares just 45% sequence identity with the human enzymes. Mutating glutamate 492 to lysine produced an enzyme with altered kinetic properties when compared to the wild-type glutamate-enzyme. The K(m) for NADP of E492K increased to nearly 3600 microM compare to 40 microM for wild-type enzyme. The specific activity decreased more than 10-fold with respect to the recombinant wild-type yeast enzyme. Moreover, substituting a glutamine for a glutamate was not detrimental in that the E492Q had wild-type-like K(m) for NADP and V(max). These properties were similar to the changes found with the human class 2 E487K mutant form. Further, mutating arginine 480 to glutamine produced an enzyme that exhibited positive cooperativity in NADP binding. The K(m) for NADP increased 11-fold with a Hill coefficient of 1.6. The NADP-dependent activity of R480Q mutant was 60% of wild-type enzyme. Again, these results are very similar to what we recently showed to occur with the human enzyme [Biochemistry 39 (2000) 5295-5302]. These findings show that the even though the glutamate and arginine residues are not conserved, similar changes occur in both the human and the yeast enzyme when either is mutated.

Subunit communication in tetrameric class 2 human liver aldehyde dehydrogenase as the basis for half-of-the-site reactivity and the dominance of the oriental subunit in a heterotetramer

Data has been published showing that in heterotetrameric liver mitochondrial aldehyde dehydrogenase composed of the active (E487) and the inactive Oriental-variant (K487) subunit, the Oriental variant was dominant and caused the inactivation of the E487 subunit. The published structures of the enzyme showed that the glutamate at position 487 is salt bonded to an arginine (475) in a different subunit. Arg475 was mutated to a glutamine to test for its importance in causing the Oriental variant to be an enzyme with a high Km for NAD and a low specific activity. Unexpectedly, the R475Q mutant exhibited positive cooperativity in NAD binding with a Hill coefficient of 2. Individual heterotetramers composed of subunits of E487 and K487 were produced by making changes to two residues on the surface of the enzyme and then co-expressing both cDNAs in E. coli. The E(3)K form had essentially 50% the activity of the E(4) homotetrameric form while EK(3) had essentially the same properties as did the homotetrameric K(4) Oriental variant. This showed that in a dimer pair composed of one K- and one E- subunit the K-subunit became dominant and caused the inactivation of its E-partner. Further, pre-steady state burst data and steady state kinetic data make it appear that there was one functioning active subunit in each of the dimer pairs that made up the tetrameric enzyme. Thus, the half-of-the-site reactivity is a result of having one functioning and one non-functioning subunit in each dimer pair. The actual structural basis for this is still not understood, but could be related to the E487-R475 inter-dimer salt bond.

[The status of protein P16 and P53 in the surgical margins of laryngeal carcinoma and the association with local recurrence]

OBJECTIVE

To assess the status of P53 and P16 of surgical margins in laryngeal carcinoma and the association with the local recurrence following surgical treatment

METHODS

The status of P53 and P16 of surgical margins in laryngeal carcinoma was studied using immunohistochemistry (IHC) staining method in 100 cases of laryngeal carcinoma. Fifty-two of them had recurrent tumors while 48 cases were free of local recurrence after 5-year follow up. The original tumor sites and T stages, which bear important influence over the risk of local recurrence, were strictly matched between the two groups, and the ages and preoperative doses of radiation were also considered.

RESULTS

The percentage of local recurrence was 85% in these patients who showed positive staining for P53 and simultaneous negative staining for P16 in both the cancer tissues and the surgical margins. No association was found between the expression of P53 and P16 and the clinical types or T stages.

CONCLUSION

The status of P53 and P16 in combination demonstrated by IHC technique in surgical margins of laryngeal carcinoma may predict the possibility of local recurrence.

Alveolar epithelial cell chemokine expression triggered by antigen-specific cytolytic CD8(+) T cell recognition

CD8(+) T lymphocyte responses are a critical arm of the immune response to respiratory virus infection and may play a role in the pathogenesis of interstitial lung disease. We have shown that CD8(+) T cells induce significant lung injury in the absence of virus infection by adoptive transfer into mice with alveolar expression of a viral transgene. The injury is characterized by the parenchymal infiltration of host cells, primarily macrophages, which correlates with physiologic deficits in transgenic animals. CD8(+) T cell-mediated lung injury can occur in the absence of perforin and Fas expression as long as TNF-alpha is available. Here, we show that the effect of TNF-alpha expressed by CD8(+) T cells is mediated not exclusively by cytotoxicity, but also through the activation of alveolar target cells and their expression of inflammatory mediators. CD8(+) T cell recognition of alveolar cells in vitro triggered monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) expression in the targets, which was mediated by TNF-alpha. Antigen-dependent alveolar MCP-1 expression was observed in vivo as early as 3 hours after CD8(+) T cell transfer and depended upon TNF-R1 expression in transgenic recipients. MCP-1 neutralization significantly reduced parenchymal infiltration after T cell transfer. We conclude that alveolar epithelial cells actively participate in the inflammation and lung injury associated with CD8(+) T cell recognition of alveolar antigens.

[Study on fluorimetry of aluminum quaternary complex and analytical application]

This study was conducted to seek an easy-to-do method for determination of aluminum in biological and food samples. The fluorescent reaction of aluminum forming quaternary complex with fluoride, Ferron and CTMAB in the buffer solution of ammonium acetate (at pH 6.0) was investigated. The conditions of the reaction and the pretreatment of samples were optimized. In addition, the aluminum contents of hair and food samples was detected. A good linear relationship between fluorescence intensity and aluminum concentrations from 0.002 microgram/ml to 0.20 microgram/ml was observed. The detection limit was 1.0 x 10(-3) micrograms/ml. The spiked recoveries were in the range of 88.66%-112.61% with relative standard deviation varying from 1.87% to 2.56%. This method has characters of good sensitivity, selectivity and the ability against interference, it can be of wide application.

[Tracheal transplantation]

OBJECTIVE

To treat long tracheal cancer by tracheal transplantation.

METHODS

In March 17, 1999, a patient received a total laryngeal resection and a resection of 8 cm upper and middle trachea, which was replaced by a 6 cm long trachea of another donor. The donor trachea was dipped first in preservation liquid A for sterilization for 24 hours, then in preservation liquid B for over 48 hours for destructing MHC. Pedunculated greater omentum and pedunculated greater pectoral musculus supplied the blood for the donor trachea. One side of the donor was anastomosed with the lower trachea, and the other with the neck skin.

RESULTS

The patient survived 300 days after operation. The auto tracheal membrane covered the donor surface; auto- and xeno trachea was well anastomose. The new trachea grew very well.

CONCLUSION

Trachea transplantation is possible the best method to treat long tracheal disease if the transplantable trachea is less 5 cm.

Identification of a novel bacterial sequence associated with Crohn's disease

BACKGROUND & AIMS

Enteric microorganisms are implicated in the pathogenesis of Crohn's disease (CD), but no clear bacterial or viral species has been identified. In this study, representational difference analysis (RDA) was used to isolate DNA segments preferentially abundant in lamina propria mononuclear cells of lesional mucosa vs. adjacent uninvolved mucosa.

METHODS

Two RDA-derived microbial sequences were isolated (I1 and I2) and identified as novel homologues of the ptxR and tetR bacterial transcription-factor families.

RESULTS

Quantitative competitive polymerase chain reaction of paraffin-embedded intestinal specimens from 212 patients showed that I2 DNA was present in many CD colonic lesions (43%), but was infrequent in other colonic specimens (9% of ulcerative colitis lesions and 5% of non-inflammatory bowel disease diseases; P<0.0001). I2 was prevalent in ileal specimens, regardless of disease status (43%-54%). Enzyme-linked immunosorbent assay analysis of 150 individuals with an I2 glutathione-S-transferase fusion protein showed frequent immunoglobulin A seroreactivity in CD (54% of patients), but infrequent seroreactivity in patients with ulcerative colitis, other inflammatory enteric diseases, or normals (10%, 19%, and 4%, respectively; P<0.001 to 0.00001).

CONCLUSIONS

These findings relate CD to a novel lesion-localized and immunologically associated bacterial sequence, suggesting that the microorganism expressing the I2 gene product may be related to CD pathogenesis.

Cooperativity in nicotinamide adenine dinucleotide binding induced by mutations of arginine 475 located at the subunit interface in the human liver mitochondrial class 2 aldehyde dehydrogenase

The low-activity Oriental variant of human mitochondrial aldehyde dehydrogenase possesses a lysine rather than a glutamate at residue 487 in the 500 amino acid homotetrameric enzyme. The glutamate at position 487 formed two salt bonds, one to an arginine at position 264 in the same subunit and the other to arginine 475 in a different subunit [Steinmetz, C. G., Xie, P.-G.,Weiner, H., and Hurley, T. D. (1997) Structure 5, 2487-2505]. Mutating arginine 264 to glutamine produced a recombinantly expressed enzyme with nativelike properties; in contrast, mutating arginine 475 to glutamine produced an enzyme that exhibited positive cooperativity in NAD binding. The K(M) for NAD increased 23-fold with a Hill coefficient of 1.8. The binding of both NAD and NADH was affected by the mutation at position 475. Restoring the salt bonds between residues 487 and either or both 264 and 475 did not restore nativelike properties to the Oriental variant. Further, the R475Q mutant was thermally less stable than the native enzyme, Oriental variant, or other mutants. The presence of NAD restored nativelike stability to the mutant. It is concluded that movement of arginine 475 disrupted salt bonds between it and residues other than the one at 487, which caused the apo-R475Q mutant to have properties typical of an enzyme that exhibits positive cooperativity in substrate binding. Breaking the salt bond between glutamate 487 in the Oriental variant and the two arginine residues cannot be the only reason that this enzyme has altered catalytic properties.

Colonic bacteria express an ulcerative colitis pANCA-related protein epitope

Bacteria are a suspected pathogenic factor in inflammatory bowel disease, but the identity of the relevant microbial species remains unresolved. The pANCA autoantibody is associated with most cases of ulcerative colitis (UC) and hence reflects an immune response associated with the disease process. This study addresses the hypothesis that pANCA identifies an antigen(s) expressed by bacteria resident in the human colonic mucosa. Libraries of colonic bacteria were generated using aerobic and anaerobic microbiologic culture conditions, and bacterial pools and clonal isolates were evaluated for cross-reactive antigens by immunoblot analysis using the pANCA monoclonal antibody Fab 5-3. Two major species of proteins immunoreactive to pANCA monoclonal antibodies were detected in bacteria from the anaerobic libraries. Colony isolates of the expressing bacteria were identified as Bacteroides caccae and Escherichia coli. Isolation and partial sequencing of the B. caccae antigen identified a 100-kDa protein without database homologous sequences. The E. coli protein was biochemically and genetically identified as the outer membrane porin OmpC. Enzyme-linked immunosorbent assay with human sera demonstrated elevated immunoglobulin G anti-OmpC in UC patients compared to healthy controls. These findings demonstrate that a pANCA monoclonal antibody detects a recurrent protein epitope expressed by colonic bacteria and implicates colonic bacterial proteins as a target of the disease-associated immune response.

Global regulatory mutations in csrA and rpoS cause severe central carbon stress in Escherichia coli in the presence of acetate

The csrA gene encodes a small RNA-binding protein, which acts as a global regulator in Escherichia coli and other bacteria (T. Romeo, Mol. Microbiol. 29:1321-1330, 1998). Its key regulatory role in central carbon metabolism, both as an activator of glycolysis and as a potent repressor of glycogen biosynthesis and gluconeogenesis, prompted us to examine the involvement of csrA in acetate metabolism and the tricarboxylic acid (TCA) cycle. We found that growth of csrA rpoS mutant strains was very poor on acetate as a sole carbon source. Surprisingly, growth also was inhibited specifically by the addition of modest amounts of acetate to rich media (e.g., tryptone broth). Cultures grown in the presence of >/=25 mM acetate consisted substantially of glycogen biosynthesis (glg) mutants, which were no longer inhibited by acetate. Several classes of glg mutations were mapped to known and novel loci. Several hypotheses were examined to provide further insight into the effects of acetate on growth and metabolism in these strains. We determined that csrA positively regulates acs (acetyl-coenzyme A synthetase; Acs) expression and isocitrate lyase activity without affecting key TCA cycle enzymes or phosphotransacetylase. TCA cycle intermediates or pyruvate, but not glucose, galactose, or glycerol, restored growth and prevented the glg mutations in the presence of acetate. Furthermore, amino acid uptake was inhibited by acetate specifically in the csrA rpoS strain. We conclude that central carbon flux imbalance, inhibition of amino acid uptake, and a deficiency in acetate metabolism apparently are combined to cause metabolic stress by depleting the TCA cycle.

Characterization of an E-box-dependent cis element in the smooth muscle alpha-actin promoter

Identification of the regulators of smooth muscle specific gene expression is critical for understanding smooth muscle cell (SMC) differentiation and the alterations in SMC phenotype seen in vascular diseases. Previous studies have identified that a 2-bp mutation in a conserved cis-acting element (TGTTTATC) in the promoter of the chicken smooth muscle (SM) alpha-actin gene abolished nuclear factor binding and decreased transcriptional activity of a 271-bp SM alpha-actin promoter fragment when transfected into rat aortic SMC. However, the promoter region containing this conserved sequence has negative cis regulatory activity when studied in homologous systems. The goal of the present studies was to further characterize the transcriptional activity of the rat SM alpha-actin promoter region between -224 and -236 that is conserved across mammals. DNAse I analysis and electrophoretic mobility shift assays demonstrated that SMC nuclear proteins bound an extended sequence (TGTTTATCCCCATAA). Transient transfection experiments of wild-type and mutant rat SM alpha-actin promoter-luciferase constructs into rat aortic SMC revealed that promoter activity was enhanced by mutations of specific nucleotides in the TGTTTATCCCCA region. Interestingly, the TGTTTATCCCCA element in the rat SM alpha-actin promoter is centered between 2 canonical E-boxes. Mutations of the flanking E-boxes abolished the enhancement in promoter activity seen with mutation of the TGTTTATCCCCA element alone. Thus studies provide evidence for a regulatory cassette in the rat SM alpha-actin promoter that regulates gene expression via combinatorial interactions between 2 E-boxes and a newly described TGTTTATCCCCA element.

[Macro, micro and ultrastructural observations of pituitary, adrenal, pancreas and spleen in experimental brain death]

The purpose of this study is to observe the macro, micro and ultrastructural changes of the pituitary, adrenal, pancreas and spleen in the experimental primary brain death. The results showed: 1. acinar zymogen granule of pancreas decreased, karyopyknosis of islet cells formed. 2. dilation and blood stasis of spleen sinus happened 3. adrenocortical karyopyknosis formed, mitochondrial crista vanish. 4. Pituitary karyopyknosis and cytolysis developed. 5. there was correlation between the extent of lesions and time after brain death.

SAA-only HDL formed during the acute phase response in apoA-I+/+ and apoA-I-/- mice

Serum amyloid A (SAA) is an acute phase protein of unknown function that is involved in systemic amyloidosis and may also be involved in atherogenesis. The precise role of SAA in these processes has not been established. SAA circulates in plasma bound to high density lipoprotein-3 (HDL3). The pathway for the production of SAA-containing HDL is not known. To test whether apolipoprotein (apo)A-I-HDL is required in the production of SAA-HDL, we analyzed the lipopolysaccharide (LPS)-induced changes in apoA-I+/+ and apoA-I-/- mice. In apoA-I+/+ mice, after injection of LPS, remodeling of HDL occurred: total cholesterol increased and apoA-I decreased slightly and shifted to lighter density. Dense (density of HDL3) but large (size of HDL2 ) SAA-containing particles were formed. Upon fast phase liquid chromatography fractionation of plasma, >90% of SAA eluted with HDL that was enriched in cholesterol and phospholipid and shifted "leftward" to larger particles. Non-denaturing immunoprecipitation with anti-mouse apoA-I precipitated all of the apoA-I but not all of the SAA, confirming the presence of SAA-HDL devoid of apoA-I. In the apoA-I-/- mice, which normally have very low plasma lipid levels, LPS injection resulted in significantly increased total and HDL cholesterol. Greater than 90% of the SAA was lipid associated and was found on dense but large, spherical HDL particles essentially devoid of other apolipoproteins.We conclude that serum amyloid A (SAA) is able to sequester lipid, forming dense but large HDL particles with or without apoA-I or other apolipoproteins. The capacity to isolate lipoprotein particles containing SAA as the predominant or only apolipoprotein provides an important system to further explore the biological function of SAA.

[Biological characteristics and damaging regularities of grubs endangering the growth of Ophiopogen japonicus (Thunb.) Ker-Gawl]

OBJECTIVE

To provide a scientific basis for prevention and control of the damage done to Ophiopogen japonicus by grubs.

METHOD

Conducting laboratory observation along with field investigation.

RESULT

The grubs endangering the growth of O. japonicus are mainly Hoplosternus incanus, Holotrichina paraullela and Anomala corpulenta, H. incanus takes two years to make a generation and overwinters in the form of second or third-instar larvae. H. parallela and A. corpulenta generate yearly and overwinter in the form of third-instar larvae. The extent of the damage done to O. japonicus by grubs is related to such factors as the number of sequential cropping years, the model of intercropping and the type of soil.

CONCLUSION

Prevention and control of the pest grub should be based primarily on proper agricultural (cultivating) measures.

[Clinical application of 2 mm micro-thoracoscopic surgery]

OBJECTIVE

To determine the clinical safety and efficacy of micro-thoracoscopic surgery.

METHOD

From July 1996 to July 1997, video-assisted thoracoscopic surgery was performed in 47 patients by using 2 mm microthoracoscope. There were 36 males and 11 females. Their age ranged from 40 to 75 years with a mean age of 56.7 years. Surgical procedures included bullectomy (16 patients), wedge resection (3), lung cancer staging (4), lobectomy (2), exploration (15), and resection of mediastinal tumor (2), esophagectomy (1) and repair of pneumothorax (4). Local anesthesia was employed in 18 patients and general anesthesia with double lumen endotracheal tube in 29.

RESULT

There were no operative mortality and postoperative complications.

CONCLUSION

2 mm micro-thoracoscopic surgery could be used in the management of a variety of thoracic conditions. It may be of significant value for diagnostic and therapeutic purposes, but the further study for this new technique is required to determine its safety and efficacy.

[Thoracoscopic lung reduction surgery for emphysema]

OBJECTIVE

To study the surgical treatment of emphysema.

METHOD

Five patients with severe diffused pulmonary emphysema underwent surgical bilateral lung volume reduction by video-assisted thoracoscopy. All patients were male and their age ranged from 60 to 71 years (mean 64.3 years). Before surgery, 5 patients required supplement oxygen with exertion and one oxygen supplement at rest. Preoperative and postoperative assessments included standard pulmonary function studies, chest CT scan and quantitative nuclear lung perfusion and ventilation scan. Wedge resection was performed were in 3 patients, simple plication in 1, and combined wedge resection and plication in 1. There were no early or late mortality and no requirement for immediate postoperative ventilatory assistance.

RESULT

Follow-up ranged from 10 to 12 months. After surgery the mean forced expiratory volume in 1 second (FEV(1)) was significantly increased from 0.46 L to 1.13 L (P < 0.001) and the mean forced vital capacity (FVC) was markedly improved from 1.74 L to 2.93 L (P < 0.001). Pulmonary compliance was significantly improved and resistance of airway decreased (P < 0.001). The mean distance during 6-min walk test increased from 10 m to 400 m in 4 patients.

CONCLUSION

Thoracoscopic bilateral lung volume reduction is an effective and safe technique for patients with severe emphysema. It can relieve dyspnea and improve in excise tolerance and quality of life.

Effects of biliary tract pressure on dynamics of the Oddi's sphincter and its nerve mechanism

In order to explore the effect of biliary tract pressure on Oddi's sphincter and the mechanism of development of high pressure of biliary tract during acute obstructive and suppurative cholangitis (AOSC), house rabbits were used to establish model of high biliary pressure in acute biliary duct caecus. It was observed that when the pressure of the acute biliary tract was increased to 8 kPa, the electric activity of Oddi's sphincter was obviously enhanced, the pressure of Oddioes sphincter increased remarkably (P < 0.05), and even constant spasm appeared with accompanying increase of discharge frequency of the right greater splanchnic nerves (P < 0.05) and progressive decrease of mean arterial pressure. However, when lidocaine of 0.6% was used to block the right celiac plexus, no above-mentioned reaction happened when the biliary tract pressure was increased again. The results indicated that the acute biliary tract obstruction might induce the contraction or spasm of Oddi's sphincter and bring about a vicious cycle. Its mechanism is related to splanchnic nerves reflection and it is one of important factors in the development of AOSC course.

[A study on three dimensional modeling of human body in man-machine system simulation]

Modeling of the human body is a basic problem in human-machine system simulation. In this study a B-spline surface model of the human body was established. In the modeling, human body is split into several segments and each segment is a cubic B-spline surface. A blend surface was used to link two jointed segments. It is easy to simulate the motion of the human body by using the algorithm of axial deformation.

The RNA molecule CsrB binds to the global regulatory protein CsrA and antagonizes its activity in Escherichia coli

The RNA-binding protein CsrA (carbon storage regulator) is a new kind of global regulator, which facilitates specific mRNA decay. A recombinant CsrA protein containing a metal-binding affinity tag (CsrA-H6) was purified to homogeneity and authenticated by N-terminal sequencing, matrix-assisted laser desorption/ionization time of flight mass spectrometry, and other studies. This protein was entirely contained within a globular complex of approximately 18 CsrA-H6 subunits and a single approximately 350-nucleotide RNA, CsrB. cDNA cloning and nucleotide sequencing revealed that the csrB gene is located downstream from syd in the 64-min region of the Escherichia coli K-12 genome and contains no open reading frames. The purified CsrA-CsrB ribonucleoprotein complex was active in regulating glg (glycogen biosynthesis) gene expression in vitro, as was the RNA-free form of the CsrA protein. Overexpression of csrB enhanced glycogen accumulation in E. coli, a stationary phase process that is repressed by CsrA. Thus, CsrB RNA is a second component of the Csr system, which binds to CsrA and antagonizes its effects on gene expression. A model for regulatory interactions in Csr is presented, which also explains previous observations on the homologous system in Erwinia carotovora. A highly repeated nucleotide sequence located within predicted stem-loops and other single-stranded regions of CsrB, CAGGA(U/A/C)G, is a plausible CsrA-binding element.

[Clinical application of a modified small posterolateral thoracotomy in general thoracic surgery]

To assess the application of a modified thoracotomy approach in general thoracic operation. 311 general thoracic operations were performed using a modified small posterolateral thoracotomy surgical procedures included lobectomy plus lymph nodes dissection in 186, pneumonectomy in 23, esophagectomy for esophageal cancer in 23. The modified method of thoracotomy had following advantages: (1) reduce postoperative morbidity; (2) reduce bleeding and bank blood transfusion; (3) shorter operating time. This study suggested that the modified small posterolateral thoracotomy have some advantages than standard approach. It should be used in some selected thoracic operations.

[Detection of nicotine in prehistorical skeletal remains of South China]

Human remains from excavation sites in southern China, dated from 100 to 10,000 years, were investigated for nicotine. The nicotine concentrations were measured by radioimmunoassay. Consequently, the values measured represent the sum of nicotine and its metabolites. Positive results were observed in 25.9% (mean values of all samples). The concentrations ranged from 11.8 to 474.2 ng/g sample. From the excavation sites with the highest number of individuals, Chongtong (18 individuals) were 38.9%, and from the site Leigund (21 individuals) were 28.6% from the samples nicotine positive. The highest level with 474.2 ng/g nicotine was found in a sample dated 100 years. It is possible, that this individual was smoker. In addition the samples were investigated also by gas chromatography/mass spectrometry. The GC/MS indicated the presence of nicotine and its primary metabolite, cotinine. The presence of cotinine points out the assumption that nicotine was used antemortem. The detection of unchanged nicotine indicates that nicotine remained present in bones up centuries.

[230 cases of video-assisted thoracoscopic surgery]

We performed video-assisted thoracoscopic surgery (VATS) in 230 cases. As traditional technique is used in VATS, the operetive cost is lower, and more and more patients may accept VATS.

Microcomputer system for automatic identification of the Cryptococcus neoformans and its clinical application

In this study, microcomputer image processing and pattern recognition technology, and the knowledge of morphology and optical characteristics of Cryptococcus neoformans were used for identification of Cryptococcus neoformans. Four groups of mice were lethally infected with standard strain, Wuhan strain, American B-2643 strain and Var. Shanghainesis of the Cryptococcus neoformans. The samples collected included mice brain, lung, kidney, liver, small intestine tissue and were observed under a light microscope. More than 600 images of the fungus were input into a microcomputer. A system of computer for automatic identification of the Cryptococcus neoformans was developed. The technique involved image preprocessing, image segmenting, coding of line-length on the edge, curve fitting, extracting of image feature, building of image library and feature data bank etc.. And then, 768 images of the clinical samples and other fungus samples whose morphological features tend to be confused with Cryptococcus neoformans were input into microcomputer and subjected to automatic identification. The Cryptococcus neoformans was accurately identified within 15 min, and the consistency rate with results of routine culture was 98%.

Modelling and Analysis of Pulse Electrochemical Machining (PECM)

A small interelectrode gap in Electrochemical Machining (ECM) results in improved dimensional accuracy control and simplified tool design. However, using a small gap with conventional ECM equipment adversely affects the electrolyte flow or mass transport conditions in the gap, leading to process instability. The most remarkable breakthrough in this regard is the development of ECM using pulsed current. Pulse Electrochemical Machining (PECM) involves the application of a voltage pulse at high current density in the anodic dissolution process. PECM allows for more precise monitoring and control of machining parameters than ECM using continuous current. Small interelectrode gap, low electrolyte flow rate, gap state recovery during the pulse-off times and improved anodic dissolution efficiency features encountered in PECM lead to improved workpiece precision and surface finish when compared with ECM using continuous current. This paper presents mathematical models for the PECM process which take into consideration the nonsteady physical phenomena in the gap between the electrodes, including the conjugate fields of electrolyte flow velocities, pressure, temperature, gas concentrations, current densities and anodic material removal rates. The principles underlying higher dimensional accuracy and simpler tool design attainable with optimum pulse parameters are also discussed. Experimental studies indicate the validity of the proposed PECM models.