C–S bond induced ultrafine SnS2 dot/porous g-C3N4 sheet 0D/2D heterojunction: synthesis and photocatalytic mechanism investigation

A C–S bond induced novel ultrafine SnS₂ dot/porous g-C₃N₄ sheet 0D/2D heterojunction for enhanced carrier separation and photocatalytic activities was developed.

Multiple active components, synergistically driven cobalt and nitrogen Co-doped porous carbon as high-performance oxygen reduction electrocatalyst

Economical g-C₃N₄derived Co,N dual-doped porous carbon with multiple active components shows high-performance oxygen reduction electrocatalytic activity.

[Cerebral infarction in a patient with primary Sjogren's syndrome: a case report and literature review]

Sjogren's syndrome (SS) is a chronic autoimmune disorder characterized by lymphocytes infiltration in the exocrine glands. Central nervous system complications of primary SS are not rare, but ischemic stroke has been rarely reported. Here we report a 43-year-old female with a two-year history of primary SS, presenting with sudden cerebral infarction. Her primary SS was diagnosed on the basis of clinical features, high levels of serum anti-SSA and anti-SSB antibodies, salivary gland secretion evaluation and positive sublingual gland biopsy results. Magnetic resonance imaging revealed infarct lesions in the parietal and occipital lobes, as well as in the left basal ganglia. Magnetic resonance angiography showed a remarkable stenosis in the left middle cerebral artery. Other differential diagnoses were ruled out. Corticosteroid and immunosuppressor, together with anti-platelet and statin were effective, and the patient recovered quickly without sequelae. Based on these findings, vasculitis due to primary SS should be considered among the causes of stroke. The literature was reviewed and the relationship between primary SS and cerebral infarction explored. The pathogenesis of ischemic stroke in primary SS is still unknown and warrants further studies.

Aluminium foil as a single-use substrate for MALDI-MS fingerprinting of different melanoma cell lines

Herein, we present the intact cell matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the fingerprinting of human melanoma cancer cell lines grown on aluminium foil.

Electronic and magnetic properties of epitaxial perovskite SrCrO₃(0 0 1)

We have investigated the intrinsic properties of SrCrO3 epitaxial thin films synthesized by molecular beam epitaxy. We find compelling evidence that SrCrO3 is a correlated metal. X-ray photoemission valence band and O K-edge x-ray absorption spectra indicate a strongly hybridized Cr3d-O2p state crossing the Fermi level, leading to metallic behavior. Comparison between valence band spectra near the Fermi level and the densities of states calculated using density functional theory (DFT) suggests the presence of coherent and incoherent states and points to strong electron correlation effects. The magnetic susceptibility can be described by Pauli paramagnetism at temperatures above 100 K, but reveals antiferromagnetic behavior at lower temperatures, possibly resulting from orbital ordering.

Profiling of small RNAs involved in plant-pathogen interactions

Small RNA (sRNA)-mediated gene silencing is an important gene expression regulatory mechanism conserved in eukaryotes. Such sRNAs, first discovered in plants, are involved in diverse biological processes. In plants, sRNAs participate in many growth and developmental processes, such as embryo development, seed germination, flowering, hormone synthesis and distribution, and nutrient assimilation. However, the significance of sRNA in shaping the relationship between plants and their symbiotic microbes or pathogens has been underestimated. Recent progress in profiling sRNA, especially advances in next-generation sequencing technology, has revealed its extensive and complicated involvement in interactions between plants and viruses, bacteria, and fungi. In this review, we will summarize recent findings regarding sRNA in plant-pathogen interactions.

Identification and characterization of the novel Col10a1 regulatory mechanism during chondrocyte hypertrophic differentiation

The majority of human skeleton develops through the endochondral pathway, in which cartilage-forming chondrocytes proliferate and enlarge into hypertrophic chondrocytes that eventually undergo apoptosis and are replaced by bone. Although at a terminal differentiation stage, hypertrophic chondrocytes have been implicated as the principal engine of bone growth. Abnormal chondrocyte hypertrophy has been seen in many skeletal dysplasia and osteoarthritis. Meanwhile, as a specific marker of hypertrophic chondrocytes, the type X collagen gene (COL10A1) is also critical for endochondral bone formation, as mutation and altered COL10A1 expression are often accompanied by abnormal chondrocyte hypertrophy in many skeletal diseases. However, how the type X collagen gene is regulated during chondrocyte hypertrophy has not been fully elucidated. We have recently demonstrated that Runx2 interaction with a 150-bp mouse Col10a1 cis-enhancer is required but not sufficient for its hypertrophic chondrocyte-specific reporter expression in transgenic mice, suggesting requirement of additional Col10a1 regulators. In this study, we report in silico sequence analysis of this 150-bp enhancer and identification of its multiple binding factors, including AP1, MEF2, NFAT, Runx1 and TBX5. Using this enhancer as bait, we performed yeast one-hybrid assay and identified multiple candidate Col10a1-interacting genes, including cyclooxygenase 1 (Cox-1) and Cox-2. We have also performed mass spectrometry analysis and detected EF1-alpha, Fus, GdF7 and Runx3 as components of the specific complex formed by the cis-enhancer and nuclear extracts from hypertrophic MCT (mouse chondrocytes immortalized with large T antigen) cells that express Col10a1 abundantly. Notably, some of the candidate genes are differentially expressed in hypertrophic MCT cells and have been associated with chondrocyte hypertrophy and Runx2, an indispensible Col10a1 regulator. Intriguingly, we detected high-level Cox-2 expression in hypertrophic MCT cells. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays confirmed the interaction between Cox-2 and Col10a1 cis-enhancer, supporting its role as a candidate Col10a1 regulator. Together, our data support a Cox-2-containing, Runx2-centered Col10a1 regulatory mechanism, during chondrocyte hypertrophic differentiation.

Effects of surface defects on two-dimensional electron gas at NdAlO3/SrTiO3 interface

Density functional theory calculations of NdAlO₃/SrTiO₃ heterostructure show that two-dimensional electron gas (2-DEG) is produced at the interface with a built-in potential of ~0.3 eV per unit cell. The effects of surface defects on the phase stability and electric field of 2-DEG have been investigated. It is found that oxygen vacancy is easily to form on the NdAlO₃(001) surface, with a low threshold displacement energy and a low formation energy. This point defect results in surface reconstruction and the formation of a zigzag -Al-O-Al- chain, which quenches the built-in potential and enhances the carrier density significantly. These results will provide fundamental insights into understanding how surface defects influence the electronic behavior of 2-DEG and tuning their electronic properties through surface modification.

Silencing of Jagged1 inhibits cell growth and invasion in colorectal cancer

Dysregulated Notch signaling has a critical role in the tumorigenesis. Jagged1, a Notch ligand, is overexpressed in various human cancers. Recent studies revealed the involvement of Jagged1 in colorectal cancer (CRC) development. These basic studies provide a promising potential for inhibition of the Notch pathway for the treatment of CRC. Herein, we aimed to investigate the consequences of targeting Jagged1 using shRNA on CRC both in vitro and in vivo to test their potential to inhibit this key element for CRC treatment. We found that downregulation of Jagged1 with lentiviral Jagged1-shRNA resulted in decreased colon cancer cell viability in vitro, most likely mediated through reduced cell proliferation. Importantly, Jagged1 knockdown induced G₀/G₁ phase cell cycle arrest, with reduced Cyclin D1, Cyclin E and c-Myc expression. Silencing of Jagged1 reduced the migration and invasive capacity of the colon cancer cells in vitro. Furthermore, colon cancer cells with knockdown of Jagged1 had much slower growth rate than control cells in a xenograft mouse model in vivo, with a marked downregulation of cell proliferation markers (PCNA, Ki-67, and c-Myc) and metastasis markers (MMP-2 and MMP-9). These findings rationalize a mechanistic approach to CRC treatment based on Jagged1-targeted therapeutic development.

Water decoction of coptidis rhizoma prevents oxidative damage in erythrocytes of mice

Coptidis Rhizoma (Coptis chinensis) has been reported to have antioxidative effect on hemolysis of erythrocytes induced by acetylphenylhydrazine in mice and rats. However, the ability of Coptidis Rhizoma to protect structure and function of erythrocytes membrane and morphology of erythrocytes against oxidative damage remains unknown. In this study, we undertook a characterization of antioxidative activity in erythrocytes membrane of Coptidis Rhizoma using an in vivo model of acetylphenylhydrazine-induced mice together with in vitro studies with 2,2-azo-bis (2-amidinopropane) dihydrochloride-induced erythrocytes for further morphology characterization. Acetylphenylhydrazine-induced mice were treated intragastrically with Coptidis Rhizoma at doses of 0.3, 0.6, and 1.2 g/kg per day for 3 days and at the dose of 0.6 and 1.2 g/kg it showed that there was an increasing trend in membranes cytoskeletal proteins of band I-IV, especially a significant upregulation in band II. Significant increase in phosphatidylserine and phosphatidylcholine content at the dose of 1.2 g/kg Coptidis Rhizoma was obsereved. At all doses of Coptidis Rhizoma, the declined membrane fluidity of acetylphenylhydrazine-induced mice was significantly increased. In addition, at the dose of 1.2 g/kg Coptidis Rhizoma treatment showed a significant increase in Ca²⁺/Mg²⁺-ATPase activity and there was an increasing trend in the activity of Na⁺/K⁺-ATPase. In vitro, Coptidis Rhizoma protected erythrocytes from 2,2-azo-bis (2-amidinopropane) dihydrochloride-induced hemolysis in a dose-dependent manner at concentrations of 0.25-1.5 mg/ml, and also significantly inhibited the 2,2-azo-bis (2-amidinopropane) dihydrochloride-induced morphological alterations in mice erythrocytes. These results demonstrate that Coptidis Rhizoma is capable of protecting erythrocytes against oxidative damage probably by acting as an antioxidant and maintaining membrane integrity.

Aspirin and aspirin-like drugs induce HLA-DR expression in HT29 colon cancer cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) decrease the incidence of colon cancer. The underexpression of HLA antigens during colon cancer development is suspected to be a mechanism by which malignant cells escape immune surveillance. We examined whether NSAIDs affect the expression of HLA-DR in HT29 human colon adenocarcinoma cells, which do not express HLA-DR. Aspirin, indomethacin and sulindac induced several-fold the expression of HLA-DR in these cells in a concentration- and time-dependent manner. Aspirin increased HLA-DR alpha steady-state mRNA levels and HLA-DR alpha gene transcription rate. These findings raise the possibility that such a mechanism may be operative in vivo.

Partial longitudinal resection of the anorectum and sphincter for very low rectal adenocarcinoma: a surgical approach to avoid permanent colostomy

AIM

Abdominoperineal resection has been the standard procedure for low rectal cancer. The present study details a new technique, partial longitudinal resection of the anorectum and sphincter, and assesses the oncological and functional outcomes.

METHOD

Between January 2004 and April 2008, 12 patients underwent partial longitudinal resection of the anorectum and sphincter for low rectal cancer. All patients underwent a diverting ileostomy and received biofeedback training before stoma closure. Functional results were assessed by vector manometry, Wexner constipation score and Wexner incontinence score. The quality of life (QoL) was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).

RESULTS

There was no postoperative mortality and a R0 curative resection was confirmed in every case. Morbidity included anastomotic leakage in three patients, one of whom underwent reoperation, and stenosis in 11, which was successfully managed with dilatation. The patient who underwent reoperation was not included in the functional analysis. The 11 successful patients received biofeedback training for 1-4 months, and underwent ileostomy closure 6-12 months after surgery. No patient had severe faecal incontinence after stoma closure. The EORTC QLQ-C30 global health status and QoL scores at 12 months after stoma closure were 50.4 ± 24.3, similar to preoperation scores of 52.3 ± 25.6 (P = 0.927), and not significantly different to scores for the healthy control population of 63.4 ± 23.5 (P = 0.539). No patients developed local recurrence during the median observation period (35.5 months). One patient had distant metastases at 24 months, and underwent resection of the left liver.

CONCLUSION

Curability and acceptable anal function can be obtained by partial longitudinal resection of the anorectum and sphincter in patients with very low rectal cancers. This technique is recommended as an alternative to abdominoperineal resection in patients with external sphincter muscle invasion or tumours located below the dentate line.

Band alignment, built-in potential, and the absence of conductivity at the LaCrO3/SrTiO3(001) heterojunction

Core-level and valence-band x-ray photoemission spectra measured for molecular-beam-epitaxy-grown LaCrO(3)/SrTiO(3)(001) yield band offsets and potential gradients within the LaCrO(3) sufficient to trigger an electronic reconstruction to alleviate the polarity mismatch. Yet, the interface is insulating. Based on first principles calculations, we attribute this unexpected result to interfacial cation mixing combined with charge redistribution within CrO(2) layers, enabled by low-lying d states within LaCrO(3), which suppresses an electronic reconstruction.

Synthesis of one-dimensional TiO2/V2O5 branched heterostructures and their visible light photocatalytic activity towards Rhodamine B

We present the synthesis and visible-light-induced catalytic activity of one-dimensional (1D) TiO(2)/V(2)O(5) branched heterostructures. The 1D TiO(2)/V(2)O(5) heterostructures were prepared by RF reactive magnetron sputtering of V(2)O(5) onto electrospun TiO(2) nanofibers. Then, the samples were annealed at 300 °C for 2 h in air ambient to form the 1D TiO(2)/V(2)O(5) branched heterostructures. The photodecomposition rate of Rhodamine B (RhB) by the 1D TiO(2)/V(2)O(5) branched heterostructures under visible light was much faster than that of pure TiO(2) nanofibers, revealing that the visible-light-induced catalytic activity of the 1D TiO(2)/V(2)O(5) branched heterostructures was greatly improved. The enhancement of the photocatalytic activity of the 1D TiO(2)/V(2)O(5) branched heterostructures can be ascribed to the coupling with a small bandgap semiconductor material V(2)O(5), where the absorption range is extended, the photogenerated electrons and holes are highly separated and the surface charge carrier transfer rate is promoted.

PET-CT scan is a valuable modality in the diagnosis of fibrolamellar hepatocellular carcinoma: a case report and a summary of recent literature

We report a case of liver cancer with features consistent with fibrolamellar hepatocellular carcinoma (FLHCC) detected by PET-CT scan. A 20-year-old female with a large liver tumor was diagnosed with 'malignant hepatic tumor' 2 years earlier and received five courses of transhepatic arterial chemoembolization (TACE) before she presented to our hospital with abdominal distension and mild pain at the right upper quadrant. Ultrasound and CT scan showed a large tumor in the right lobe of the liver. Contrast CT scan and (18)F-FDG PET-CT showed metastatic lesions in multiple organs. The imaging diagnosis was confirmed by an ultrasound-guided fine needle biopsy of the hepatic lesion which showed features of FLHCC. Immunohistochemical staining showed a marked increase in the expressions of Hepar, CD99, MIB1, proliferating cell nuclear antigen (PCNA), Fibronectin, E-cadherin and CK7. The recent knowledge on the FLHCC and the possible applications of PET-CT were discussed.

Extension of imaging depth in two-photon fluorescence microscopy using a long-wavelength high-pulse-energy femtosecond laser source

We experimentally demonstrate, for the first time to the best of our knowledge, two-photon fluorescence imaging with a femtosecond optical parametric amplifier. In particular, we systematically compare the imaging depths of two-photon fluorescence microscopes based on three different excitation sources, including a femtosecond oscillator, a femtosecond regenerative amplifier and the optical parametric amplifier. The results show that the optical parametric amplifier can greatly extend the penetration depth by approximately 227% as compared with that obtained with the femtosecond oscillator due to effective suppression of scattering at longer wavelength and enhanced excitation efficiency enabled by higher pulse energy.

Thermodynamic instability at the stoichiometric LaAlO3/SrTiO3(001) interface

Stoichiometric epitaxial LaAlO(3) grown on TiO(2)-terminated SrTiO(3)(001) by off-axis pulsed laser deposition is shown to exhibit strong cation intermixing. This result is corroborated by classical and quantum mechanical calculations of the relative stabilities of abrupt and intermixed interface configurations. The valence band offset was measured to be 0.16 ± 0.10 eV, and this value cannot be accounted for theoretically without including intermixing in the physical description of the interface.

Mass transport of alkali metal with pulses in a surface reaction

It is shown that the pulses which develop in the NO+H2 reaction on an alkali promoted Rh(110) surface reaction can transport alkali metal. This leads to the accumulation of a substantial alkali-metal concentration in the collision area of pulse trains. Realistic simulations revealed that the effect is due to the strong energetic interactions of the alkali metal with coadsorbates, i.e., the attractive interaction with coadsorbed oxygen and the effectively repulsive interaction with coadsorbed nitrogen.

Anisotropic dewetting on stretched elastomeric substrates

We study the instability of a very thin liquid film resting on a uniformly stretched soft elastomeric substrate driven by van der Waals forces. A linear stability analysis shows that the critical fluctuation wavelength in the tensile direction is larger than those in the other directions. The magnitudes of the critical wavelengths are adjustable in the sense that they depend on the principal stretch of the substrate. For example, when the principal stretch of the substrate varies from 1.0 (unstretched) to 3.0, the range of the critical wavelength in the tensile direction increases by 7.0% while that normal to the tensile direction decreases by 8.7%. Therefore, the phenomenon may find potential applications in creating tunable topographically patterned surfaces with nano- to microscale features.

Enhancement of surface activity in CO oxidation on Pt(110) through spatiotemporal laser actuation

We explore the effect of spatiotemporally varying substrate temperature profiles on the dynamics and the resulting reaction rate enhancement of the catalytic oxidation of CO on Pt(110). The catalytic surface is "addressed" by a focused laser beam whose motion is computer controlled. The averaged reaction rate is observed to undergo a characteristic maximum as a function of the speed of this moving laser spot. Experiments as well as modeling are used to explore and rationalize the existence of such an optimal laser speed.

Field emission properties of N-doped capped single-walled carbon nanotubes: A first-principles density-functional study

The geometrical structures and field emission properties of pristine and N-doped capped (5,5) single-walled carbon nanotubes have been investigated using first-principles density-functional theory. The structures of N-doped carbon nanotubes are stable under field emission conditions. The calculated work function of N-doped carbon nanotube decreases drastically when compared with pristine carbon nanotube, which means the enhancement of field emission properties. The ionization potentials of N-doped carbon nanotubes are also reduced significantly. The authors analyze the field emission mechanism in terms of energy gap between the lowest unoccupied molecular orbital and the highest occupied molecular orbital, Mulliken charge population, and local density of states. Due to the doping of nitrogen atom, the local density of states at the Fermi level increases dramatically and donor states can be observed above the Fermi level. The authors' results suggest that the field emission properties of carbon nanotubes can be enhanced by the doping of nitrogen atom, which are consistent with the experimental results.

Potent antitumor efficacy of XAF1 delivered by conditionally replicative adenovirus vector via caspase-independent apoptosis

XAF1 is a newly identified tumor-suppressor gene that can antagonize XIAP and sensitize cells to other cell death triggers. In this study, we utilized ZD55, a conditionally replicative adenovirus (CRAd) similar to ONYX-015 as the vector to transfer XAF1 into the tumor cells to evaluate its antitumor efficacy in vitro and in vivo. Potent and specific cytopathic effect (CPE) was observed upon infection with ZD55-XAF1 in tumor cell lines. Importantly, ZD55-XAF1 exhibited a superior suppression of tumor growth in an animal model of colorectal carcinoma in nude mice compared with Ad-XAF1 (E1-deleted replication-defective viral) and ONYX-015. Complete eradication of the established tumors was observed in four of eight mice. Our data also showed that infection with ZD55-XAF1 resulted in caspase-independent apoptosis. Although caspase-3, poly(ADP-ribose) polymerase were mildly activated in response to ZD55-XAF1 infection, pretreatment with pan-caspase inhibitor hardly influence its apoptosis-inducing activity. In summary, our study strongly suggested that ZD55-XAF1 could serve as an effective gene-virotherapy strategy and has highly potential against human cancers.

Guiding chemical pulses through geometry: Y junctions

We study computationally and experimentally the propagation of chemical pulses in complex geometries. The reaction of interest, CO oxidation, takes place on single crystal Pt(110) surfaces that are microlithographically patterned; they are also addressable through a focused laser beam, manipulated through galvanometer mirrors, capable of locally altering the crystal temperature and thus affecting pulse propagation. We focus on sudden changes in the domain shape (corners in a Y-junction geometry) that can affect the pulse dynamics; we also show how brief, localized temperature perturbations can be used to control reactive pulse propagation. The computational results are corroborated through experimental studies in which the pulses are visualized using reflection anisotropy microscopy.

Geometry-induced pulse instability in microdesigned catalysts: the effect of boundary curvature

We explore the effect of boundary curvature on the instability of reactive pulses in the catalytic oxidation of on microdesigned Pt catalysts. Using ring-shaped domains of various radii, we find that the pulses disappear (decollate from the inert boundary) at a turning point bifurcation, and we trace this boundary in both physical and geometrical parameter space. These computations corroborate experimental observations of pulse decollation.

Long-term results of functional hemispherectomy for intractable seizures

OBJECTIVE

From May 1989 to April 1997, functional hemispherectomy was performed in 8 cases of intractable seizures. We retrospectively analyzed our experience to evaluate the seizure control and complications of this surgical technique.

METHODS

Following Dr. Rasmussen's model of functional hemispherectomy or performing a modification of this operation, we removed the sensorimotor cortex and temporal lobe associated with disconnection of the remaining portions of the frontal lobe and parieto-occipital lobe.

RESULTS

All the patients were followed up for 3-11 years (mean 6.7 years). Satisfactory seizure control was obtained in all the cases. Life quality improved and patients worked or studied well after the operations. No cases of superficial cerebral hemosiderosis were found.

CONCLUSION

Modified functional hemispherectomy may allow the patients to lead more independent lives by leading to a cessation or reduced frequency of seizures.

Papillomavirus pseudovirus: a novel vaccine to induce mucosal and systemic cytotoxic T-lymphocyte responses

Intestinal mucosa is a portal for many infectious pathogens. Systemic immunization, in general, does not induce a cytotoxic T-lymphocyte (CTL) response at the mucosal surface. Because papillomavirus (PV) naturally infects mucosa and skin, we determined whether PV pseudovirus, i.e., PV-like particles in which unrelated DNA plasmids are packaged, could generate specific mucosal immunity. We found that the pseudovirus that encoded the lymphocytic choriomeningitis virus gp33 epitope induced a stronger CTL response than a DNA vaccine (plasmid) encoding the same epitope given systemically. The virus-like particles that were used to make the pseudoviruses provided an adjuvant effect for induction of CTLs by the DNA vaccine. The PV pseudovirus pseudoinfected mucosal and systemic lymphoid tissues when administered orally. Oral immunization with the pseudovirus encoding human PV type 16 mutant E7 induced mucosal and systemic CTL responses. In comparison, a DNA vaccine encoding E7, when given orally, did not induce a CTL response in intestinal mucosal lymphoid tissue. Further, oral immunization with the human PV pseudovirus encoding E7 protected mice against mucosal challenge with an E7-expressing bovine PV pseudovirus. Thus, PV pseudovirus can be used as a novel vaccine to induce mucosal and systemic CTL responses.

Hepatitis B virus X protein increases expression of p21(Cip-1/WAF1/MDA6) and p27(Kip-1) in primary mouse hepatocytes, leading to reduced cell cycle progression

Previously, we have linked prolonged intense mitogen-activated protein kinase (MAP kinase; MAPK) signaling in hepatocytes to increased expression of p21(Cip-1/WAF1/MDA6) (p21) and p16(INK4a) (p16), that leads to a p21-dependent growth arrest. In this study, we investigated the impact of hepatitis B virus X protein (pX) expression on MAPK-modulated cell cycle progression in primary mouse hepatocytes. In hepatocytes, expression of pX enhanced protein levels of p21 and p27, but not of p16. The elevated levels of p21 and p27 correlated with reduced DNA synthesis in wild-type (+/+) hepatocytes and with a weak stimulation of DNA synthesis in p21 null (-/-) cells. Antisense p27 messenger RNA (mRNA) (p27as) increased DNA synthesis in +/+ and p21 -/- cells, and pX blunted this effect in +/+ cells. In p21 -/- cells, however, p27as permitted pX to further stimulate DNA synthesis. These data argue that a reduced ability to enhance expression of both p21 and p27 is required to fully reveal the growth-potentiating properties of pX. This finding also implies that depending on the functional status of the p21 and p27 genes, expression of pX can have 2 very different effects on hepatocyte proliferation. Prolonged intense MAPK signaling reduced DNA synthesis in +/+ cells and enhanced DNA synthesis in p21 -/- cells. The enhancement of DNA synthesis in p21 -/- cells was blocked by pX, and the effect of pX was abrogated by p27as. Furthermore in p21 -/- cells, overexpression of p16 blocked MAPK-stimulated DNA synthesis, and this effect was partially reversed by p27as. These data argue that p27 can also cooperatively interact with p16 to inhibit DNA synthesis in hepatocytes. Collectively, our findings show that reduced expression of p16, p21, and p27, which can occur during hepatocellular carcinoma, enhances the ability of MAPK signaling and pX to cause proliferation in hepatocytes. Thus loss of cyclin kinase inhibitor function may play an important role in the process of tumor progression after chronic hepatitis B virus infection.

MAPK dependence of DNA damage repair: ionizing radiation and the induction of expression of the DNA repair genes XRCC1 and ERCC1 in DU145 human prostate carcinoma cells in a MEK1/2 dependent fashion

PURPOSE

To examine the role of mitogen-activated protein kinase (MAPK) signalling on the induction by ionizing radiation of the nucleotide excision repair gene (ERCC1), the X-ray cross-complementing group 1 protein (XRCC1) and the repair of radiation-induced DNA damage.

MATERIALS AND METHODS

The expression of ERCC1 and XRCC1 was examined in DU145 human prostate cancer cells following exposure to ionizing radiation. We characterized the MAPK dependence of this expression through RT-PCR analysis, Western analysis, transcription inhibition and measurement of the activation of each promoter. Pre-exposure with the specific MEK1/2 inhibitor PD980059 (10 microM) was used to blunt radiation induction of MAPK without suppressing basal levels of MAPK activity. In addition, we examined the MAPK dependence of DNA damage repair by measuring radiation-induced micronucleus formation and the removal of and nicking activity associated with AP sites.

RESULTS

Irradiation caused a time-dependent, MAPK-dependent increase in the protein levels of both ERCC1 and XRCC1. For each gene product, the protein level increase followed an increase in mRNA, which also was MAPK-dependent. Radiation also enhanced the activities of the ERCC1 and XRCC1 promoters in an MAPK-dependent fashion. Inhibition of transcription by DRB abolished the radiation-induced increase of ERCC1 and XRCC1 proteins. Inhibition of radiation-induced MAPK also diminished the ability of DU145 cells to remove AP sites and increased the number of cells displaying micronuclei following radiation exposure.

CONCLUSIONS

These findings demonstrate a role for radiation-induced MAPK signalling in the regulation of DNA repair enzyme levels and DNA repair. Radiation-induced protein expression of ERCC1 and XRCC1 appears to require de novo transcription. These data suggest a significant role for MAPK signalling in the early response to DNA damage caused by ionizing radiation.

[Clindamycin soluble suppository-production and its efficacy in treating bacterial vaginosis]

OBJECTIVE

To make the soluble suppository of clindamycin which is an effective drug for treatment of Bacterial vaginosis and to treat patients in clinical trials.

METHODS

Outpatients who had vaginal infections from Sept. 1998 to Jan. 1999 were investigated. The diagnoses of bacterial vaginosis were made according to Amsel's criteria and 80 patients were included in this study. They were divided into two groups to be treated respectively by metronidanole suppository and clindamycin suppository which were made by our hospital pharmacy.

RESULTS

The cure rate of metronidanole was 87.5% and that of clindamycin 90.3%; No significant difference was noted between the two groups(P > 0.05). The new clindamycin suppository was not irritant and it was easy to dissolve in vagina. There was no discontinued treatment because of side-effect.

CONCLUSION

The clindamycin suppository does not irritate the mucosa of vagina, it is an efficacious remedy for bacterial vaginosis.