Wetting-driven structure ordering of a copolymer/homopolymer/nanoparticle mixture in the presence of a modulated potential

We investigate pattern formation on a solid substrate of a diblock copolymer-homopolymer mixture containing doping wettable nanoparticles with a preferential attraction for one component of the copolymers, using a three-order-parameter model. The presence of doping nanoparticles under the surface-interaction modulation breaks the isotropy in the process of microphase-separation and macrophase-separation. This leads to the formation of orientational microphase and macrophase structures due to the interplay between the phase separation and wetting particle ordering under a modulated potential at the late stage. Simulations suggest that the microphase morphology and macrophase morphology can be changed through adjustment of the wetting strength, the amplitude as well as the period of the modulated potential. It provides some important insights for changing microphase and macrophase structures in polymer blends by wetting-driven spinodal decomposition.

Frequent occurrence of UVB-induced sister chromatid exchanges in telomere regions and its implication to telomere maintenance

Sister chromatid exchanges (SCEs) are symmetrical exchanges between newly replicated chromatids and their sisters. While homologous recombination may be one of the principal mechanisms responsible for SCEs, the full details of their molecular basis and biological significance remain to be elucidated. Following exposure to ultraviolet light B (UVB), mitomycin C (MMC) and cisplatin, we analyzed the location of SCEs on metaphase chromosomes in Chinese hamster CHO cells. The frequency of SCEs increased over the spontaneous level in proportion to the agent's dose. UVB-induced SCEs occurred frequently in telomere regions, as cisplatin-induced SCEs did, differing from MMC-induced ones. The remarkable difference of intrachromosomal distribution among the three mutagens may be attributed to the specificity of induced DNA lesions and structures of different chromosome regions. Telomeric DNA at the end of chromosomes is composed of multiple copies of a repeated motif, 5'-TTAGGG-3' in mammalian cells. Telomeric repeats may be potential targets for UVB and cisplatin, which mainly form pyrimidine dimers and intrastrand d(GpG) cross-links, respectively, resulting in SCE formation. UVB irradiation shortened telomeres and augmented the telomerase activity. The possible implications of the frequent occurrence of SCEs in telomere regions are discussed in connection with the maintenance of telomere integrity.

Acetylenic TACE inhibitors. Part 1. SAR of the acyclic sulfonamide hydroxamates

The SAR of a series of potent sulfonamide hydroxamate TACE inhibitors, all bearing a butynyloxy P1' group, was explored. In particular, compound 5j has excellent in vitro potency against isolated TACE enzyme and in cells, good selectivity over MMP-1 and MMP-9, and oral activity in an in vivo model of TNF-alpha production and a collagen-induced arthritis model.

Functional improvement by electro-acupuncture after transient middle cerebral artery occlusion in rats

Functional recovery by the application of electro-acupuncture (EA) on different acupoints was investigated using a transient middle cerebral artery occlusion (MCAO) model in rat. Acupoints were Baihui (D20) plus Renzhong (D26) (MCAO + D group), and Hanyan (G4), Xuanlu (G5), Xuanli (G6), plus Qubin (G7) (MCAP + G group). Animals with EA treatment showed significant functional improvements from 12 days after the reperfusion against those without EA treatment. Among EA treated groups, MCAO + G showed a more significant recovery than MCAO + D. Infarct volume revealed the significant reduction in the EA treated groups especially in MCAO + G at 30 days. Immunohistochemical study showed a remarkable induction of vascular endothelial growth factor (VEGF) in astrocytes of the peri-infarct area at 30 days, more in EA treated groups than in groups treated with MCAO alone. These results suggest that the acupoints applied in this study are effective for the functional recovery, and an enhanced expression of VEGF may play a certain role in recovery process after stroke.

Synthesis and SAR of bicyclic heteroaryl hydroxamic acid MMP and TACE inhibitors

Potent and selective bicyclic heteroaryl hydroxamic acid MMP and TACE inhibitors were synthesized by a novel convergent route. Selectivity and efficacy versus MMPs and TACE could be controlled by appropriate substitution on the scaffolds and by variation of the P1' group. Select compounds were found to be effective in in vivo models of arthritis.

Protection against ischemic brain damage by GDNF affecting cell survival and death signals

Neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) on cell survival and death signals were investigated after 90 min of transient middle cerebral artery occlusion (MCAO) in rats. Immunoreactivities of phosphorylated Akt (p-Akt), cleaved caspase-9 (c-cas9), and -3 (c-cas3) increased after the reperfusion in the penumbra in vehicle group with peaks at 3 h, 8 h, and 1 day, respectively. Topical application of GDNF (6.8 micrograms/9 microliters) on brain surface potentiated and prolonged p-Akt activation, but suppressed activation of the caspases, and reduced the number of terminal deoxynucleotidyl transferase-mediated dUDP-biotin in situ nick labeling (TUNEL) positive cells. These results suggest that GDNF plays a protective role against ischemic injury by controlling the balance between Akt pathway and caspase cascades.

An integrated treatability protocol for biotreatment/bioremediation of toxic pollutants generated by chemical industries

To optimize the efficiency of bioremediation, treatability studies are needed to understand the fate of pollutants and environmental conditions under which microorganism growth is promoted and efficient degradation of these pollutants result. This article presents a recommended procedure which may achieve these goals. Results and treatability comparisons for candidate compounds including carbon tetrachloride (CT), methyl-tert-butyl-ether (MTBE) and hexachlorobutadiene (HCBD) are presented and discussed. Culture redox potential (ORP) which is an indicator or free electron activity of a system appeared to have a significant impact on CT biodegradation. Optimum biodegradation of CT by Pseudomonas cepacia was observed between -100 and -200mv. Under the optimum environmental conditions established during the batch-scale biotransformation study, 98 to 99.9% of CT and 70% of MTBE introduced into the continuous fixed-biofilm reactor were degraded. The biphasic model simulating biodegradation of CT and MTBE provided an excellent correlation in the fixed-biofilm study and was simple to apply as compared with other models.

Targeting of post-ischemic cerebral endothelium in rat by liposomes bearing polyethylene glycol-coupled transferrin

To achieve an efficient delivery targeting to post-ischemic cerebral vascular endothelium, PEG-liposome conjugated with transferrin (Tf) (Tf-PEG-liposome) was intravenously administered to the rats after 90 min of transient middle cerebral occlusion. The expression of Tf receptor (TfR) in the cerebral endothelium increased with a peak at 1 day after the reperfusion and returned to the control level by 6 days. The Tf-PEG fluorescence was marginally detectable in sham control brain, but remarkably increased with a peak at 2 days, showing about 70% of TfR positive vascular endothelium double-labeled with Tf-PEG. These results indicate that the Tf-PEG-liposome could be utilized as an efficient drug delivery tool to the brain after stroke.

A preliminary study on coastal water quality monitoring and modeling

The overall objective of this study was to assess the impact of individual rainfall events on Lake Pontchartrain water quality and risk to swimmers. Indicator organisms in lake water under dry weather conditions, in storm water runoff (prior to dilution with lake water), and in the outfall plume within the lake following storm events were monitored and quantified. Results indicated that drainage canals constitute a significant microbial loading to lake waters. Significant reductions of indicator microbes are observed in the water column following two to three days after storm pumping events into the lake. A mathematical model incorporating advection, dispersion, and bacterial die-off gives fairly good prediction on E. coli, enterococcoi, and fecal coliform titers. The somewhat under estimation by model suggests re-suspension of sediment and re-introduction of the indicator organisms that attached to the sediment back into the water column. Future direction of model development should include the mechanism of re-suspension and survival of indicator organisms in sediment.

Activation of cell-survival signal Akt by GDNF in normal rat brain

Glial cell line-derived neurotrophic factor (GDNF) activates protein kinase Akt/PKB by phosphorylation (p-Akt) which plays key roles in cell survival. In the current study, we investigated a temporal expression of p-Akt by immunohistochemical analysis after a topical application of GDNF to normal cerebral hemisphere of rats. Although p-Akt immunoreactivity was weakly present in the sham control neural cells, GDNF application greatly enhanced it at 3 h, which lasted until 1 day. These results indicate that p-Akt is expressed in neuronal cells under physiological conditions, and that topical application of GDNF greatly enhanced the phosphorylation of Akt in normal rat brain.

Enhanced phosphorylation of PTEN in rat brain after transient middle cerebral artery occlusion

A phosphatase PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a tumor suppressor gene that suppresses cell growth, inhibits cell migration, and induces apoptosis. Phosphorylated form of PTEN (p-PTEN) is a key survival factor relating PI3K-Akt pathway and their downstream effectors. A spatiotemporal profiles of PTEN and p-PTEN expression were immunohistochemically examined after 90 min of transient middle cerebral artery occlusion in rats. In the ischemic core, PTEN progressively decreased by 3 days, whereas a rapid but transient increase of p-PTEN was found with a peak at 1 h after the reperfusion. In contrast, in the ischemic penumbra, PTEN showed a minor change and a gradual but sustained p-PTEN expression was observed in the ischemic penumbra with a peak at 12 h. In addition, the balance of population among strongly, moderately, and weakly stained cells was different between the ischemic core and penumbra at their peak time points. These results suggest an important role of p-PTEN for cell survival after ischemia as an upstream regulator for PI3K-Akt.

Enhanced expression of phospho-Akt by electro-acupuncture in normal rat brain

Electro-acupuncture (EA) is an effective curative method for various diseases in oriental medicine. To investigate a detailed molecular mechanism of EA stimulation, an induction of phospho-Akt (p-Akt) was examined in normal adult rat brain after 60 min of EA with acupoints of Baihui (D20) and Renzhong (D26). In the sham control brain, strong neuronal p-Akt expression was found in ventral posterolateral thalamic nucleus (VPL) and medial habenular nuclei (MHb), but moderate to weak in cortex, caudate, CA1 sector and dentate gyrus of hippocampus, and ventral posteromedial thalamic nucleus. EA stimulation generally enhanced and sustained p-Akt expression for at least 24 h especially in the regions listed above, except VPL and MHb where no apparent change was found. Western blot analysis of p-Akt confirmed the enhanced signal intensity after EA at 8 and 24 h. These results suggest that the EA on D20 and D26 acupoints activates the survival Akt signal pathway, which may be maintaining the neural functions such as cell survival and memory formation in normal brain.

Viral latency--the papillomavirus model

To investigate the prevalence and the natural history of human papillomavirus infections, we monitored HPV DNA shedding as a consequence of immunosuppression, with the expectation that latent viral infections would reactivate and become detectable. The study populations consisted of women who were in end-stage renal failure, those who ultimately received kidney transplantations, and those who had HIV/AIDS with various degrees of immune depression at entry. For each woman, cervico-vaginal lavage to sample viral shedding from the lower genital tract was performed at approximately six month intervals, and the cohorts have been followed since 1996. Nested polymerase chain reaction amplification of papillomavirus DNA using novel pairs of primers was followed by diagnostic restriction endonuclease cleavage or by DNA sequencing. This strategy is particularly capable of identifying single and multiple infections and determining the genotypes of any viruses present. Of the 225 women in the HIV cohort, 177 (79%) were HPV-positive and 111 (49%) shed from two up to eight different HPV types over the course of the survey. Thirty-five different mucosotropic HPV types, virtually all that have ever been described worldwide, were isolated from these 225 women, and nine additional new (provisional) types were discovered. As is always the case, HPV-6 was very common. However, all the other frequently detected HPV types (45, 52, 53, 54, 58, 74) were more prevalent than the types typically reported forthe general population (HPV-11, 16, 18, 31, 33, 35). Notably, the 14 members of the A3 phylogenetic subgroup (HPV-61, 62, 72, 81, 83, 84, and all the new types) were by far the most frequently observed viral types in the AIDS cohort. The HPV prevalence in the cohorts of kidney transplantation candidates and recipients was only slightly lower than that in the AIDS cohort. We conclude that HPV infections are extraordinarily common and are normally held in a sub-clinical state by functional immune systems, but can be reactivated by immunosuppressive conditions. The question of how so many distinct types persist in the human population and can be repeatedly isolated from specimens collected around the world raises complex issues concerning the nature of viral transmission, reproduction, shedding, and mutational drift. These molecular epidemiological observations signal the likelihood that HPV is part of the commensal microflora of human epithelia. Their prevalence elicits a caution that latent HPV DNA may be present in primary human epithelial tissues.

Anthranilate sulfonamide hydroxamate TACE inhibitors. Part 2: SAR of the acetylenic P1' group

The SAR of a series of potent sulfonamide hydroxamate TACE inhibitors bearing novel acetylenic P1' groups was explored. In particular, compound 4t bearing a butynyloxy P1' moiety has excellent in vitro potency against isolated TACE enzyme and in cells, good selectivity over MMP-1 and oral activity in an in vivo model of TNF-alpha production.

The discovery of anthranilic acid-based MMP inhibitors. Part 3: incorporation of basic amines

Anthranilic acid derivatives bearing basic amines were prepared and evaluated in vitro and in vivo as inhibitors of MMP-1, MMP-9, MMP-13, and TACE. Piperazine 4u has been identified as a potent, selective, orally active inhibitor of MMP-9 and MMP-13.

Study of laser vas deferens occlusion

The objective of this study was to determine threshold levels for high-power laser output Nd:YAG laser photocoagulation and to determine the possible reversibility of laser vas occlusion. The study included vas deferens of 220 rabbits and 20 samples of men in vitro, applying the Nd:YAG laser instrument, doing vasopuncture by a catheter needle, guiding the fiber into the vas, and performing the irradiation occlusion experiment to determine effective threshold value of photocoagulation. The effect and safety of occlusion were followed-up over a year, and reopening a experiment was done in 60 occluded nodes of rabbits. The postoperative sperm disappearance rate was 100%, and reopening rate was 72.7% without obvious complications. High-power lasers may be used as photocoagulation, and its merits are reliable, effective, and rapid recovery. The vas threshold lesion value of rabbits and men in vitro are 50 W/0.5 s, 45 W/1 s, respectively, and irradiation depth reached the middle-ring muscularis.

[Study on the adsorption of collagen onto surfaces with imaging ellipsometry]

The adsorption of collagen onto hydrophilic and hydrophobic surfaces was studied with imaging ellipsometry in different pH, adsorption time, ion strength and BSA existence. The results showed that there was more collagen adsorbed onto hydrophobic surfaces than onto hydrophilic surfaces. The maximum collagen adsorption was observed at pH 7.2. The existence of BSA affected the adsorption of collagen onto hydrophobic surfaces more than that onto hydrophilic surfaces.

The discovery of anthranilic acid-based MMP inhibitors. Part 2: SAR of the 5-position and P1(1) groups

A novel series of anthranilic acid-based inhibitors of MMP-1, MMP-9, MMP-13, and TACE was prepared and evaluated. Selective inhibitors of MMP-9, MMP-13, and TACE were identified, including the potent, orally active MMP-13 inhibitor 4p.

A comprehensive view of regulation of gene expression by double-stranded RNA-mediated cell signaling

Double-stranded (ds) RNA, a common component of virus-infected cells, is a potent inducer of the type I interferon and other cellular genes. For identifying the full repertoire of human dsRNA-regulated genes, a cDNA microarray hybridization screening was conducted using mRNA from dsRNA-treated GRE cells. Because these cells lack all type I interferon genes, the possibility of gene induction by autocrine actions of interferon was eliminated. Our screen identified 175 dsRNA-stimulated genes (DSG) and 95 dsRNA-repressed genes. A subset of the DSGs was also induced by different inflammatory cytokines and viruses demonstrating interconnections among disparate signaling pathways. Functionally, the DSGs encode proteins involved in signaling, apoptosis, RNA synthesis, protein synthesis and processing, cell metabolism, transport, and structure. Induction of such a diverse family of genes by dsRNA has major implications in host-virus interactions and in the use of RNA(i) technology for functional ablation of specific genes.

Inhibition of neointimal formation in porcine coronary artery by a Ras mutant

BACKGROUND

Therapeutic approaches to reduce the neointimal formation caused by balloon injury have been focused mainly on experimental models of restenosis in the rat carotid artery. However, restenosis in rat carotid artery may not replicate the coronary arterial responses to injury in larger animals and humans.

METHODS

In this study, we used pig coronary arteries as an animal model to evaluate the preventive effects of a virus-mediated dominant negative mutant RasN17 on balloon injury-induced restenosis. The viral particles were delivered to the balloon-injured coronary arteries via a dispatch catheter to keep the virus in a confined arterial segment for 10 min to reach optimal transfection. Six weeks after balloon injury, the pigs were sacrificed and the left anterior descending arteries were isolated for histological analysis.

RESULTS

Neointima formation was prominent in the group receiving balloon injury as compared with the uninjured controls. A remodeling process with migration of collagen was also found in the injured coronary arteries. The application of AdRasN17 led to a 56% decrease in neointima formation and a 75% increase in lumen size, as compared with the balloon-injured vessels treated with AdLacZ control.

CONCLUSIONS

These results suggest that AdRasN17 is an effective therapeutic gene in preventing balloon injury-induced neointimal formation in pig coronary arteries.

Esters of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinones with melphalan as multifunctional anticancer agents

Eight esters of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinone with melphalan were prepared and tested for their antitumor activity (S-180) and cytotoxicity. 2-[1-[4-(p-Bis(2-chloroethyl)-aminophenyl)-butanoyloxy]methyl]-1,4-dihydroxy-9,10-anthraquinone and 2-[1-[4-(p-bis(2-chloroethyl)-aminophenyl)-butanoyloxy]ethyl]-1,4-dihydroxy-9,10-anthraquinone showed remarkable antitumor activity (T/C, 265 and 272%).

[Using self-assembled monolayers to understand the interactions of surfaces with cells]

It is important to understand the interactions of surfaces with cells. Self-assembled monolayers formed on the adsorption of long-chain alkanethiols to the surface of gold or alkylsilanes to hydroxylated surfaces and their patterned surfaces permit of understanding and controlling over the surface-cell interactions at the molecular scale. The present paper reviewed the latest research in using patterned self-assembled monolayers to understand surface-cell interactions.

Angiosarcoma of the scalp: absence of vascular endothelial cadherin in primary and metastatic lesions

A 73-year-old man with angiosarcoma of the scalp died about 1 year after disease onset, despite systemic and topical administration of recombinant interleukin-2. Histopathology showed typical changes of endothelial cells with very sparse lymphocytic infiltration into the tumour. An autopsy revealed that the primary site penetrated cranial bone and invaded vertically into the subarachnoid space. Multiple metastases to lung, chest wall, vertebrae and ribs were also found. On immunofluorescence staining, the expression of vascular endothelial cadherin, which is present in normal endothelium, was absent from both primary and metastatic sites. This may have promoted local invasion and metastasis.

Heteroaryl and cycloalkyl sulfonamide hydroxamic acid inhibitors of matrix metalloproteinases

Heteroaryl and cycloalkyl sulfonamide-hydroxamic acid MMP inhibitors were investigated. Of these, the pyridyl analogue 2 is the most potent and selective inhibitor of MMP-9 and MMP-13 in vitro.

The discovery of anthranilic acid-based MMP inhibitors. Part 1: SAR of the 3-position

A novel series of anthranilic acid-based inhibitors of MMP-1, MMP-9, and MMP-13 was prepared and evaluated both in vitro and in vivo. The most potent compound, 6e, has in vivo activity in a rat sponge-wrapped cartilage model.

Effects of active and negative mutants of Ras on rat arterial neointima formation

BACKGROUND

Ras protein is a key signal transducer in the cause of cell proliferation. We studied the effects of active and negative mutants of the Ras gene on arterial neointimal formation in rats, with the aim of elucidating the molecular mechanisms regulating restenosis following percutaneous transluminal coronary angioplasty.

MATERIALS AND METHODS

AdRasV12 and AdRasN17, the recombinant adenoviruses containing a constitutively active mutant and a dominant negative mutant of Ras, respectively, were used to determine whether Ras is necessary and sufficient to modulate the smooth muscle cell proliferation and neointima formation. Following balloon injury, rat common carotid arteries were treated in their distal half with AdRasV12, AdRasN17, or AdLacZ, with the proximal half used as uninfected control.

RESULTS

In rat arteries subjected to balloon injury, either uninfected or treated with AdLacZ, there were pronounced SMC proliferation and neointima formation. These changes were markedly augmented by AdRasV12 and reduced by AdRasN17.

CONCLUSION

Ras is necessary and sufficient for SMC proliferation and neointima formation and may play a critical role in restenosis following balloon angioplasty.

Biomechanical regulation of matrix metalloproteinase-9 in cultured chondrocytes

Abnormal mechanical loading of joints may induce degeneration of articular cartilage. Shear stress is one mode of mechanical loading that may regulate chondrocyte metabolism. We investigated the mechanism by which shear stress induces the gene encoding matrix metalloproteinase-9, a mediator of the progressive degradation of articular cartilage in osteoarthritis. In vitro experiments using passaged rabbit chondrocytes in monolayer culture subjected to a shear stress of 16 dyn/cm2 (1.6 Pa) in a flow channel showed increased expression of the matrix metalloproteinase-9 gene. The induction of matrix metalloproteinase-9 appeared to depend on a region in the 5' promoter of the gene that contains a 12-0-tetradecanoylphorbol 13-acetate-responsive element. Transfection experiments using a construct containing a luciferase reporter driven by a 12-0-tetradecanoylphorbol 13-acetate-responsive element indicated that shear stress activated a 12-0-tetradecanoylphorbol 13-acetate-responsive element-mediated transcription in chondrocytes. Similar experiments showed that shear stress induced a matrix metalloproteinase-9 promoter construct (matrix metalloproteinase-9-luciferase). Shear stress activated c-Jun NH2-terminal kinase, extracellular signal-regulated kinase, and p38. Transfection of matrix metalloproteinase-9-luciferase together with the dominant negative mutant of c-Jun NH2-terminal kinase, but not with that of extracellular signal-regulated kinase or p38, attenuated the shear-induced matrix metalloproteinase-9 promoter activity. In addition, transfection of constructs encoding dominant negative mutants of Ras, Rac, and Cdc42 attenuated the induction of c-Jun transcriptional activity by shear stress. Thus. shear stimulation of chondrocytes stimulates Ras, Rac, and Cdc42, which subsequently activate c-Jun NH2-terminal kinase to induce a 12-0-tetradecanoylphorbol 13-acetate-responsive element-mediated expression of matrix metalloproteinase-9.

[Imaging ellipsometry in biomolecule research]

Imaging Ellipsometry is an optical surface-sensitive method for the investigation of various aspects of biomolecules adsorbing mainly at reflecting metal surfaces and silicon surface. It has advantages of high sensitivity to layer-thickness, big area of view, high sampling speed, and high lateral resolution. It can be used for studying adsorption kinetics of biomolecules and detecting complex layer of antigen-antibody when antibody (or antigen) combined with antigen (or antibody) coated on solid surfaces. Compared with other solid phase methods such as enzyme linked immunosorbent assay, immunofluorescence and radioimmunoassay, imaging ellipsometry has the advantage of not involving any labelling of reactants and it is a relatively inexpensive method and easy to handle. Compared with traditional ellipsometer, imaging ellipsometry shows an advantage of distinguishing both affinity and non-specific binding in different area on the surfaces.

Chemical cleaving method of relief microstructure formation on dichromated gelatin

A chemical cleaving method to improve the resolution of relief modulation in dichromated gelatin is presented. The process (which uses hydroxylamine) yields higher relief resolution and better profile fidelity than a process that uses the enzyme trypsin because it has many fewer cleaving sites. Experiments prove that relief modulation can produce a resolution of as much as 500 lines/mm. With a projection exposure system, a microprism array with a 30-mum-wide, 0.8-mum-high cell is fabricated by this method. A method for forming a continuous relief on dichromated gelatin is also discussed.

The hinge of the human papillomavirus type 11 E2 protein contains major determinants for nuclear localization and nuclear matrix association

The E2 protein of papillomaviruses is a site-specific DNA binding nuclear protein. It functions as the primary replication origin recognition protein and assists in the assembly of the preinitiation complex. It also helps regulate transcription from the native viral promoter. The E2 protein consists of an amino-terminal (N) trans-acting domain, a central hinge (H) domain, and a carboxyl-terminal (C) protein dimerization and DNA binding domain. The hinge is highly divergent among papillomaviruses, and little is known about its functions. We fused the enhanced green fluorescent protein (GFP) with the full-length human papillomavirus type 11 (HPV-11) E2 protein and showed that the resultant fusion, called gfpE2, maintained transcription and replication functions of the wild-type protein and formed similar subnuclear foci. Using a series of GFP fusion proteins, we showed that the hinge conferred strong nuclear localization, whereas the N or C domain was present in both cytoplasm and nucleus. Biochemical fractionation demonstrated that the N domain and hinge, but not the C domain, independently associated with the nuclear matrix. Mutational analyses showed that a cluster of basic amino acid residues, which is conserved among many mucosotropic papillomaviruses, was required for efficient nuclear localization and nuclear matrix association. This mutation no longer repressed the HPV-11 upstream regulatory region-controlled reporter expression. However, a very small fraction of this mutant colocalized with E1 in the nucleus, perhaps by a piggyback mechanism, and was able to support transient replication. We propose that the hinge is critical for the diverse regulatory functions of the HPV-11 E2 protein during mRNA transcription and viral DNA replication.

HeLa cells are phenotypically limiting in cyclin E/CDK2 for efficient human papillomavirus DNA replication

Human papillomaviral (HPV) origin-containing plasmids replicate efficiently in human 293 cells or cell extracts in the presence of HPV origin-recognition protein E2 and replication initiation protein E1, whereas cervical carcinoma-derived, HPV-18-positive HeLa cells or cell extracts support HPV DNA replication poorly. We recently showed that HPV-11 E1 interacts with cyclin/cyclin-dependent kinase (cdk) complexes through an RXL motif and is a substrate for these kinases. E1 mutations in this motif or in candidate cdk phosphorylation sites are impaired in replication, suggesting a role for cdks in HPV replication. We now demonstrate that one limiting activity in HeLa cells is cyclin E/CDK2. Purified cyclin E/CDK2 or cyclin E/CDK3 complex, but not other cdks, partially complemented HeLa cell extracts. Cyclin E/CDK2 expression vectors also enhanced transient HPV replication in HeLa cells. HeLa cell-derived HPV-18 E1 protein is truncated at the carboxyl terminus but can associate with cyclin E/CDK2. This truncated E1 was replication-incompetent and inhibited cell-free HPV replication. These results indicate that HeLa cells are phenotypically limiting in cyclin E/CDK2 for efficient HPV replication, most likely due to sequestration by the endogenous, defective HPV-18 E1 protein. Further analyses of the regulation of HPV E1 and HPV replication by cyclin E may shed light on the roles of cyclin E/CDK2 in cellular DNA replication.

[Dynamic changes in hepatic myofibroblast of rabbits with Schistosoma japonicum]

OBJECTIVE

To observe the dynamic changes in hepatic myofibroblasts during the formation of schistosomal hepatic fibrosis and to investigate the pathogenesis of hepatic fibrosis.

METHODS

Each rabbit was infected with 80 +/- 1 S japonicum. Liver biopsies were done at different time point after infection and the samples were embedded with paraffin and stained with HE and picric acid-sirius red. The dynamic changes in the areas of granuloma were observed, and the extent of liver fibrosis and the expression of alpha-SMA positive cells were semiquantitated. At the 16th week after infection, the rabbits with S. japonicum were received IFN-gamma after treatment of praziquantel and contrasted with the saline group.

RESULTS

The granuloma appeared at the 6th week after infection and its areas reached the biggest at the 8th week. Then the granuloma shrinked gradually, but the extent of liver fibrosis aggravated progressively. The alpha-SMA positive cells were observed at the 4th week after infection and their number enhanced gradually. The extent of liver and the expression of alpha-SMA positive cells were significantly different between each treated group, and the IFN-gamma treated group showed the best result.

CONCLUSION

The myofibroblasts play an essential role in the formation and development of schistosomal hepatic fibrosis.

Molecular cloning and sequence analysis of cDNA encoding haemorrhagic toxin acutolysin A from Agkistrodon acutus

By means of reverse transcription polymerase chain reaction, a full-length cDNA of 1632 bp is amplified from the snake venom gland total RNA of Agkistrodon acutus. Analysis of the nucleotide sequence indicates that the amplified cDNA contains a complete open reading frame encoding 413 amino acid residues including signal peptide sequence, zymogen sequence and proteinase domain. The zymogen sequence contains PKMCGVT motif which is highly conserved in almost all venom metalloproteinases. The metalloproteinase domain contains the conserved signature zinc-binding motif HEXXHXXGXXH in the catalytic region. The predicted amino acid sequence of the metalloproteinase domain is identical to the crystallographic sequence of acutolysin A and also shares high homology with other class I snake venom haemorrhagic toxins.

[Diagnosis and surgical treatment of idiopathic slow transit constipation]

OBJECTIVE

To investigate the pathogenesis, the diagnostic criteria, and the therapeutic method of idiopathic slow transit constipation.

METHODS

History recording, bowel transit, anorectal dynamic, electromyography of the pelvic floor and defecography were performed before subtotal or total colectomy for severe constipation resistant to conservative treatment.

RESULTS

The natural stool frequency was decreased and the time of bowel transit was delayed. The rectal sensation and the ability to reflect inhibition of the pelvic floor when attempting to defecate were damaged significantly compared with normal controls. pathological findings showed that the argyrophilic neurons in the myentenic and submucous plexus reduced quantitatively. All the patients were followed up for an average of 32.2 months. Satisfactory functional outcome was obtained in 91.8% of the patients receiving the operation.

CONCLUSIONS

The severe damage colon transit function is due to the impairement of the myentenic and submucous plexus of the colon. It causes vary. The diagnosis of the disease is dependent on the typical clinic features and the bowel transit test. The symptoms of constipation could be relieved effectively by removal of the pathologic colon.

[Experience of endoscopic sinus operation on 74 cases]

OBJECTIVE

To improve the curative effect of endoscopic sinus operation.

METHOD

The clinical data of nasal cavity and nasal sinus via endoscopic sinus operation on 74 cases (115 sides) were in summary. Of those 74 cases, 65 were followed-up over six mothes.

RESULT

It showed that 44 cases were cured, 18 were improved, 3 were ineffective. The effective rate was 95.4%. The disappearance rate of four symptons-nasal obstruction, headache, purulent nasal discharge and loss of smelling was 95.2%, 92%, 66.7% and 42.5%, respectively. The serious operative complication was absent.

CONCLUSION

It helped to raise thd effect of anesthetization to apply nasal cavity surface anesthesia, nerve block anesthesia. Paying attention to the distinguish of dissection label can help to decrease the occurance of the serious complication of the sinus ethmoidal operation. The operation which was alternatively conducted between endoscope and cavascope, according to the operation requirement, can be carried out more thoroughly and more safely. Cleaning the operation cavity after operation can promote healing.

Transforming growth factor beta regulates clusterin gene expression via modulation of transcription factor c-Fos

Transforming growth factor-beta (TGFbeta) induces gene expression of the glycoprotein clusterin in a variety of cell types via a consensus AP-1 binding site. Here, we demonstrate, by supershift analysis, that JunB, JunD, Fra1, Fra2, and c-Fos bound to AP-1 but that prior treatment of the cells with TGFbeta reduced dramatically c-Fos binding, suggesting that c-Fos might be playing a negative regulatory role in clusterin gene expression. Transient cotransfection assays in mink lung epithelial (CCL64) cells, using a human c-Fos expressing plasmid together with a clusterin promoter/reporter construct or the artificial TGFbeta-inducible reporter construct 3TPLux, revealed that c-Fos was indeed repressive for TGFbeta-induced promoter transactivation. Further, we demonstrate that in stable c-Fos-overexpressing cell lines, TGFbeta induction of endogenous clusterin mRNA, as well as clusterin promoter transactivation are blocked. Co-transfection with c-Fos deletion constructs revealed that the C-terminal region, including the homologue box 2 motif and the extreme C-terminal serine phosphorylation sites (Ser362 and Ser374) are required for repression of clusterin and 3TPLux transactivation. TGFbeta treatment of CCL64 cells resulted in the induction of c-Fos mRNA but caused no alternation in total c-Fos protein levels. The results suggest that the c-Fos represses clusterin gene expression, maintaining a low basal level in the absence of TGFbeta, and that TGFbeta, presumably through its effects on c-Fos protein synthesis and/or stability, abrogates the repression of c-Fos, thereby resulting in gene expression.

A study of the diagnostic location of pulpitis

OBJECTIVE

To demonstrate the involvement of the root pulp in pulpitis, which may help in selecting a desirable therapy.

METHODS

Symptoms of 158 cases of caries-caused pulpitis were recorded and histologic diagnosis was made. The location of lesions was determined, and contributive rates and diagnostic indices were developed on the basis of the characteristics of various symptoms.

RESULTS

Computer analysis provided the following contributive rates in terms of symptoms: pain upon probing of the tooth (14.72%), duration of spontaneous pain of the diseased tooth (13.07%), intensified pain by cold stimulation (8.25%), and intensified pain by cold test during treatment (4.05%). The exact diagnostic rate was 76% on the basis of the above four contributive rates to demonstrate the involvement of the root of the tooth, while the dentist could only make a correct diagnosis 56.72% of the time.

CONCLUSION

The four symptoms with the highest contributive rates improved the diagnostic rate of location, while other symptoms were excluded because of their uncertain contributive rates. As a result, the process of obtaining information was simplified. The tables of diagnostic indices are of value in clinical application as they are easy to learn and understand.

[A clinical study on vaccine of Mycobacterium vaccae in treating pulmonary tuberculosis]

OBJECTIVE

To study the effect of vaccine of Mycobacterium vaccae on cell-mediated immunity and on treating patients with pulmonary tuberculosis.

METHODS

Seventy cases of pulmonary tuberculosis with smear positive and initial treatment were classified randomly into group I (35 cases) and group II (35 cases), receiving 2HRZS/4HR and 2HRZS/4HR plus vaccine of Mycobacterium vaccae regimens respectively. Thirty-one multi-drug resistant pulmonary tuberculosis cases were classified into group III, receiving 4 - 6 sensitive antituberculous drugs and vaccine of Mycobacterium vaccae. Improvement of clinical symptoms, resolution of pulmonary lesions, negative conversion of sputum and changes of immunological functions were observed.

RESULTS

No significant difference in improvement of symptoms was found in group I and group II (P > 0.05), and the improvement rate of clinical symptoms in group III was found more than 50%. X-ray resolution rates in 4th month were 83% and 89%, and cavity reducing rates 40% and 50% respectively in group I and group II, and no significant differences were found (P > 0.05). X-ray resolution rate was 29%, cavity reducing rate 7% and no deteriorated case was found in group III. Sputum negative conversion rates in 1st, 2nd, 3rd and 4th month were 23%, 51%, 83% and 97% respectively in group I, while 31%, 77%, 89% and 100% in group II, and 3%, 16%, 29% and 32% in group III. Significant difference was found between group I and group II in sputum negative conversion rate in 2nd month after treatment (P < 0.05). After treatment, values of lymphocyte transformation test (LTT), CD(3), CD(4) and CD(4)/CD(8) of the above 3 groups were all higher than that before the treatment (P < 0.05), level of tumor necrosis factor decreased in group II and IL-2, IL-6 increased in group III.

CONCLUSIONS

Vaccine of Mycobacterium vaccae is a good immunotherapy preparation, which promotes sputum negative conversion and activation of cell-mediated immunity.

Interaction of DNA-binding proteins with the 5'-flanking region of a cytokinin-responsive cucumber hydroxypyruvate reductase gene

Transcription of the cucumber hpr-A gene is responsive to cytokinin and light. To investigate the molecular basis for transcriptional regulation by cytokinin, we have identified DNA sequences and proteins that may be involved in the regulation of hpr-A gene expression. Transient expression assays in etiolated cucumber cotyledons indicate that the 315 bp fragment (-382 to -67) contains sequences necessary for cytokinin responsiveness of the luciferase reporter gene. Band shift assays detected cytokinin-enhanced and -reduced protein binding sites in a 97 bp fragment (-382 to -285) upstream of the hpr-A gene. DNase I footprinting identified two protein-protected sites, a 15 bp sequence, 5'-AAATGACGAAAATGC-3', that contains an as-1 TGACG motif found in other plant promoters, and a 13 bp sequence, 5'-AAGATTGATTGAG-3', of unknown function. Two-dimensional band shift analysis of the cytokinin-responsive DNA protein complex revealed the presence of six DNA protein interactions. Band shift assays showed that cytokinin and light have different effects on the interaction of nuclear proteins to the 97 bp fragment of the hpr-A gene. These data suggest that cytokinin and light do not share identical signal transduction pathways in regulating hpr-A gene expression.

[The osteoinductivity and the dose-effect relationship with implantation of reconstituted bone xenograft: experimental study]

OBJECTIVE

To observe osteoinductivity and the dose-effect relationship with administration of reconstituted bone xenograft (RBX).

METHOD

A posterior thigh muscle pouch model with RBX transplantation was established in BALB/C mice. Samples were treated at regular postoperative intervals for radiologic, histomorphologic and ALP examinations.

RESULT

(1) In the groups that had been implanted with RBX, the osteoinductivity was positively correlated with the bBMP contents in RBX (r = 0.7204, P < 0.01), showing a dose-dependent relationship; (2) satisfactory osteogenesis was noted in the RBX I group, whereas no substantial bone formation was seen in the group implanted with bBMP alone apart from some evidence of osteogenic effect; (3) the alkaline phosphatase activity attained its peak on the 7th day postoperatively and kept still higher to the 42nd day.

CONCLUSION

RBX is a highly osteoinductive grafting material with the treated homologous cancellous bone being a good slow-delivery carrier which can enhance the osteoinductive capacity of bBMP.

[Effects of l-stepholidine on the peripheral vascular dopamine DA1 and DA2 receptor subtypes]

The effects of l-stepholidine(l-SPD) on peripheral vascular dopamine DA1 and DA2 receptors were studied using isolated vascular rings in rabbits. It was shown that (1) l-SPD(0.1-10 mumol.L-1) shifted the dose-response curves to the right in a nonparallel fashion and decreased the maximal response (Emax) of both the fenoldopam(FODA, a selective DA1 agonist)-induced and the propyl-buty-dopamine(PBDA, a selective DA2 agonist)-induced vasorelaxation showing a non-competitive antagonistic action. The pD2 values of l-SPD for FODA in the renal, pulmonary and mesenteric arteries were 5.43, 5.48 and 5.58, respectively. The pD2 values for PBDA in the mesenteric and femoral arteries were 5.35 and 5.89, respectively. The potencies of its antagonistic action were comparable to SCH23390, a selective DA1 antagonist, and to domperidone, a selective DA2 antagonist. (2) l-SPD(0.1-100 mumol.L-1) per se was also found to induce slight but dose-related vasorelaxations in the renal and pulmonary arteries displaying its DA1 agonistic activity. Its pD2 values were 4.98 and 5.02, respectively. However, its Emax were considerably smaller than that of FODA. These results suggest that l-SPD is a mixed peripheral DA1 and DA2 receptor antagonists and weak DA1 receptor agonist with pharmacological property of dual action.

Selective inhibition of cell proliferation and BCR-ABL phosphorylation in acute lymphoblastic leukemia cells expressing Mr 190,000 BCR-ABL protein by a tyrosine kinase inhibitor (CGP-57148)

The excessive proliferation of the myeloid marrow compartment in Philadelphia chromosome (Ph)-positive acute and chronic leukemias has been largely attributed to a hyperactive and autonomously acting hybrid tyrosine kinase BCR-ABL, a product of the fusion between the second exon of the c-ABL proto-oncogene and 5' portions of the BCR gene on chromosome 22. This specific molecular event, amenable to attack with specifically designed inhibitors, has recently been successfully influenced by the drug CGP-57148 in mammalian cells transfected with full-length BCR-ABL gene and expressing full-length p210Bcr-Abl protein, as well as in primary human leukemic cells expressing p210Bcr-Abl fusion protein. In view of the heterogeneity of BCR-ABL transcripts associated with various phenotypes, we investigated the effect of CGP-57148 on p190Bcr-Abl- and p210Bcr-Abl-expressing, patient-derived cell lines and primary intact blast cells. In particular, we were interested in whether the variations in molecular events and/or the phenotype of Ph-positive cells would affect their susceptibility to the specific tyrosine kinase inhibitor CGP-57148. We have demonstrated that the sensitivity of human cells with lymphoblastic immunophenotype expressing p190Bcr-Abl protein is comparable to that for leukemic myeloid cells expressing p210Bcr-Abl protein. After documenting profound and phenotype-independent suppression of both autophosphorylation and cell growth, we explored the importance of time and dose of exposure on the manifestation and stability of the induced events. Although there were variations between target cells, in vitro exposure for 24-48 h induced extensive and apparently irreversible apoptosis in BCR-ABL-expressing but not other normal or BCR-ABL-negative leukemic cells. These findings support the potential use of CGP-57148 to purge Ph-positive cells from autologous bone marrow in vitro. Another important finding was the comparable suppressive effect of temporary CGP-57148 exposure on both clonogenic KBM-5 cells and the whole cell population. Exposure time and dose appeared to be important variables among various cell types. Moreover, effective doses appeared uniformly harmless to cells lacking BCR-ABL protein functioning as tyrosine kinase. Thus, the continuous exposure of target cells, at least during the initial period of 24-48 h, may prove to be an important variable in the design of in vitro and in vivo therapy using tyrosine kinase inhibitors.