Stemmed DNA nanostructure for the selective delivery of therapeutics.

DNA has emerged as a biocompatible biomaterial that may be considered for various applications. Here, we report tumor cell-specific aptamer-modified DNA nanostructures for the specific recognition and delivery of therapeutic chemicals to cancer cells. Protein tyrosine kinase (PTK)7-specific DNA aptamer sequences were linked to 15 consecutive guanines. The resulting aptamer-modified product, AptG15, self-assembled into a Y-shaped structure. The presence of a G-quadruplex at AptG15 was confirmed by circular dichroism and Raman spectroscopy. The utility of AptG15 as a nanocarrier of therapeutics was tested by loading the photosensitizer, methylene blue (MB), to the G-quadruplex as a model drug. The generated MB-loaded AptG15 (MB/AptG15) showed specific and enhanced uptake to CCRF-CEM cells, which overexpress PTK7, compared with Ramos cells, which lack PTK7, or CCRF-CEM cells treated with a PTK7-specific siRNA. The therapeutic activity of MB/AptG15 was tested by triggering its photodynamic effects. Upon 660 nm light irradiation, MB/AptG15 showed greater reactive oxygen species generation and anticancer activity in PTK7-overexpressing cells compared to cells treated with MB alone, those treated with AptG15, and other comparison groups. AptG15 stemmed DNA nanostructures have significant potential for the cell-type-specific delivery of therapeutics, and possibly for the molecular imaging of target cells.

Immune-camouflaged graphene oxide nanosheets for negative regulation of phagocytosis by macrophages.

Signal regulatory protein alpha (SIRPα) is highly expressed in macrophages of the reticuloendothelial system and in tumor-associated macrophages, whereas tumor cells express the surface membrane protein, CD47, which interacts with SIRPα to negatively regulate phagocytosis. In this study, we modified the surfaces of graphene oxide (GO) nanosheets with a CD47-like SIRPα-binding peptide (SP). The presence of SP on GO nanosheets reduced the macrophage uptake to a greater extent than the PEGylation of such nanosheets. This reduced uptake was found to be mediated by the activation of Src homology region 2 domain-containing phosphatase 1 (SHP-1) and the downstream inhibition of myosin assembly, which is necessary for phagosome formation. Unlike SP-coated GO nanosheets, PEGylated GO nanosheets did not affect myosin assembly or phagocytosis. After in vivo systemic administration, the clearance of SP-coated GO nanosheets was slower than that of PEGylated GO nanosheets, and this difference increased with repeated administration. Finally, SP-coated GO nanosheets showed a higher distribution to tumor tissues than PEGylated GO nanosheets or a physical mixture of SP and GO nanosheets. Our findings indicate that immune-camouflaged GO nanosheets with natural CD47-like SIRPα-binding molecules can reduce the nonspecific loss of such nanosheets through macrophage uptake, thereby enhancing their blood circulation and tumor delivery after multiple injections.

Clinical outcomes in Asian elderly kidney transplant recipients: a multicenter cohort study.

BACKGROUND: The kidney transplantation rate in elderly patients is increasing rapidly. However, the clinical outcomes of kidney transplantation in elderly patients have not yet been thoroughly evaluated. METHODS: This multicenter cohort study included adult kidney transplant recipients (KTRs) admitted to five major tertiary hospitals in Korea between 1997 and 2012. A total of 3,565 adult participants were enrolled. Patient survival, allograft survival, and biopsy-proven acute rejection (BPAR) of 242 elderly recipients (≥ 60 years) were assessed and compared with those of a younger population. RESULTS: Patients were divided into five groups according to age at time of transplantation. The proportion of elderly patients was 6.7 % (mean age, 63.1 ± 2.7 years; n = 242). The numbers of male patients (69.4%), those with diabetes mellitus history (36.3%), and those with pretransplantation ischemic heart disease history (17.7%) were significantly higher in the elderly group than in the younger age groups. Elderly patients were more likely to receive a cadaveric kidney, and overall mortality rates were significantly higher in the elderly patients (1-year survival 93.3%, 5-year survival 91.3%). However, death-censored allograft survival rate and BPAR were not affected by patient age (P = .104 and .501, respectively). Among the elderly, BPAR and female donors were independent risk factors for allograft loss. CONCLUSION: The overall survival rate of the elderly KTRs was significantly lower than that of younger KTRs. However, the death-censored allograft survival rate did not differ between groups. Kidney transplantation should not be stagnated especially in elderly patients with end-stage renal disease.

Effect of estradiol on the expression of renal sodium transporters in rats.

BACKGROUND: Although estradiol has been thought to perform an important role in blood pressure regulation, the effects of estradiol on the expression of renal sodium transporters are not fully understood. METHODS: Female Sprague-Dawley rats were treated with 17ß-estradiol or vehicle for 10 days after ovariectomy, and after both ovariectomy and adrenalectomy to eliminate the effect of aldosterone. RESULTS: In the ovariectomized (OVX) rats, estradiol decreased the abundance of the Na-K-2Cl cotransporter (NKCC2) (31.5% of control (OVX), p < 0.01), Na-Cl cotransporter (NCC) proteins (40.5% of control (OVX), p < 0.01) and α- and γ-subunits of the epithelial sodium channel (ENaC) (44.7% and 11.0% of control (OVX), p < 0.01). Estradiol also reduced plasma aldosterone levels (OVX + 17ß-estradiol vs. OVX, 116.3 ± 44.4 vs. 184.2 ± 33.4 pmol/l, p < 0.05) and systolic blood pressure (OVX + 17ß-estradiol vs. OVX, 115 ± 4 vs. 132 ± 2 mmHg, p < 0.05). In rats having undergone adrenalectomy and ovariectomy, estradiol did not reduce systolic blood pressure, or the expression of sodium transporters. CONCLUSION: Estradiol decreased systolic blood pressure, plasma aldosterone levels, and the expression of renal sodium transporters. After aldosterone was eliminated, estradiol did not affect blood pressure or the expression of sodium transporters, which indicates that the effect of estradiol on the renal sodium transporters is at least partly influenced by aldosterone.

A comparison of outcomes between concurrent chemoradiotherapy and radiotherapy alone in cancer of the uterine cervix: a single institutional experience.

PURPOSE: To compare failure patterns and evaluate prognostic factors related to survival rates after concurrent chemoradiotherapy (CCRT) or radiotherapy (RT) alone in cervical cancer. MATERIALS AND METHODS: From January 1996 to December 2006, 218 patients with cervical cancer (FIGO Stage IB2 - III) treated with CCRT or RT alone as primary treatments were included, retrospectively. One-hundred eight patients were treated with CCRT and 110 with RT alone. RESULTS: There was no significant difference in failure patterns between the treatment groups, but distant metastasis was the predominant pattern in both groups. The frequent metastatic sites were supraclavicular lymph node, lung, and brain. Treatment group, diabetes, and FIGO Stage were found to be significant for overall survival (OS) and disease-free survival (DFS), and initial hemoglobin level for DFS. CONCLUSION: Distant metastasis is the predominant failure pattern and diabetes is one of the independent prognostic factors to survival rates in this study.

The effects of oral iron supplementation on the progression of anemia and renal dysfunction in patients with chronic kidney disease.

AIMS: Oral iron traditionally has been administered to patients with chronic kidney disease (CKD). However, there are limited data on the effect of oral iron in CKD patients. Here, we evaluate the effects of oral iron therapy on renal anemia and progression of renal disease in CKD patients. METHODS: Anemic patients with nondialytic CKD who were naive to erythropoiesis-stimulating agents (ESAs) were recruited for the prospective observational study. The participants were classified into oral iron or control group, and they were asked to keep their treatment status for 1 year. The primary outcomes were change in Hb and estimated glomerular filtration rate (eGFR). RESULTS: A total of 182 participants were enrolled and 138 completed a 12-month follow-up. No change in Hb level was observed during the follow-up period in the iron group, whereas a significant decrease in Hb was observed in the control group. Oral iron supplementation was effective, especially in patients with eGFR < 30 ml/min/1.73 m2. The changes in eGFR did not differ between the two groups. The incidences of drug-related adverse events were equivalent in two groups. CONCLUSIONS: Oral iron supplementation might attenuate the progression of anemia in nondialytic CKD patients without ESAs and not impact kidney function.

Pancreatic adenocarcinoma upregulated factor promotes metastasis by regulating TLR/CXCR4 activation.

Pancreatic adenocarcinoma upregulated factor (PAUF) is overproduced in certain types of cancer. However, little is known of the tumorigenic function of PAUF. In this study, we report the X-ray crystal structure of PAUF and reveal that PAUF is a mammalian lectin normally found in plant lectins. We also identify PAUF as an endogenous ligand of Toll-like receptor 2 (TLR2) and TLR4 by screening extracellular domain receptor pools. We further confirmed the specificity of the PAUF-TLR2 interaction. PAUF induces extracellular signal-regulated kinase (ERK) phosphorylation and activates the IKK-ß-mediated TPL2/MEK/ERK signaling pathway through TLR2. In agreement with the result of TLR2-mediated ERK activation by PAUF, PAUF induces increased expression of the protumorigenic cytokines RANTES and MIF in THP-1 cells. However, PAUF does not fully activate Iκ-B-α signaling pathways in THP-1 cells, and fails to translocate the p65 subunit of the nuclear factor-κB (NF-κB) complex into the nucleus, resulting in no NF-κB activation. Surprisingly, we found that PAUF also associated with the CXC chemokine receptor (CXCR4)-TLR2 complex and inhibited CXCR4-dependent, TLR2-mediated NF-κB activation. Together, these findings suggest that the new cancer-associated ligand, PAUF, may activate TLR-mediated ERK signaling to produce the protumorigenic cytokines, but inhibits TLR-mediated NF-κB signaling, thereby facilitating tumor growth and escape from innate immune surveillance.

Wastewater screening method for evaluating applicability of zero-valent iron to industrial wastewater.

This study presents a screening protocol to evaluate the applicability of the ZVI pretreatment to various industrial wastewaters of which major constituents are not identified. The screening protocol consisted of a sequential analysis of UV-vis spectrophotometry, high-performance liquid chromatograph (HPLC), and bioassay. The UV-vis and HPLC analyses represented the potential reductive transformation of unknown constituents in wastewater by the ZVI. The UV-vis and HPLC results were quantified using principal component analysis (PCA) and Euclidian distance (ED). The short-term bioassay was used to assess the increased biodegradability of wastewater constituents after ZVI treatment. The screening protocol was applied to seven different types of real industrial wastewaters. After identifying one wastewater as the best candidate for the ZVI treatment, the benefit of ZVI pretreatment was verified through continuous operation of an integrated iron-sequencing batch reactor (SBR) resulting in the increased organic removal efficiency compared to the control. The iron pretreatment was suggested as an economical option to modify some costly physico-chemical processes in the existing wastewater treatment facility. The screening protocol could be used as a robust strategy to estimate the applicability of ZVI pretreatment to a certain wastewater with unknown composition.

5,7-dihydroxy-3,4,6-trimethoxyflavone inhibits the inflammatory effects induced by Bacteroides fragilis enterotoxin via dissociating the complex of heat shock protein 90 and I kappaB alpha and I kappaB kinase-gamma in intestinal epithelial cell culture.

Enterotoxin produced by enterotoxigenic Bacteroides fragilis (BFT) has been associated with mucosal inflammation and diarrhoeal diseases. In this study, the anti-inflammatory molecular mechanism of 5,7-dihydroxy-3,4,6-trimethoxyflavone (eupatilin) was characterized in an HT-29 intestinal epithelial cell line stimulated with BFT. Pre-treatment of HT-29 cells with eupatilin decreased the production significantly of both interleukin (IL)-8 and prostaglandin E(2) induced by BFT in a dose-dependent manner. BFT-activated nuclear factor-kappaB (NF-kappaB) signals in HT-29 cells and pretreatment with eupatilin suppressed NF-kappaB activation that resulted in the significant inhibition of IL-8 and cyclo-oxygenase-2 expression. BFT-induced phosphorylation of both I kappaB alpha and I kappaB kinase (IKK) signals was prevented in eupatilin-pretreated HT-29 cells. Transfection of siRNA for IKK-alpha and IKK-beta decreased the production of IL-8 and prostaglandin E(2); however, the transfection of IKK-beta siRNA showed a more significant reduction of BFT-induced I kappaB alpha phosphorylation compared with that of IKK-alpha siRNA. In addition, herbimycin A, a specific inhibitor of heat shock protein 90 (Hsp90), decreased the BFT-induced activation of IKK and NF-kappaB, suggesting that Hsp90 is associated with a pathway of IKK-NF-kappaB-IL-8/cyclo-oxygenase-2 gene signalling. Furthermore, eupatilin dissociated the complex between Hsp90 and IKK-gamma in BFT-stimulated HT-29 cells. These results suggest that eupatilin can suppress the NF-kappaB signalling pathway by targeting the Hsp90-IKK-gamma complex in intestinal epithelial cells and may attenuate BFT-induced inflammatory responses.

Zero-valent iron pretreatment for detoxifying iodine in liquid crystal display (LCD) manufacturing wastewater.

This study investigated reductive transformation of iodine by zero-valent iron (ZVI), and the subsequent detoxification of iodine-laden wastewater. ZVI completely reduced aqueous iodine to non-toxic iodide. Respirometric bioassay illustrated that the presence of iodine increase the lag phase before the onset of oxygen consumption. The length of lag phase was proportional to increasing iodine dosage. The reduction products of iodine by ZVI did not exhibit any inhibitory effect on the biodegradation. The cumulative biological oxidation associated with iodine toxicity was closely fitted to Gompertz model. When iodine-laden wastewater was continuously fed to a bench-scale activated sludge unit, chemical oxygen demand (COD) removal efficiencies decreased from above 90% to below 80% along with a marked decrease in biomass concentration. On the other hand, the COD removal efficiency and biomass concentration remained constant in the integrated ZVI-activated sludge system. Respirometric bioassay with real iodine-laden LCD manufacturing wastewater demonstrated that ZVI was effective for detoxifying iodine and consequently enhancing biodegradability of wastewater. This result suggested that ZVI pretreatment may be a feasible option for the removal of iodine in LCD processing wastewater, instead of more costly processes such as adsorption and chemical oxidation, which are commonly in the iodine-laden LCD wastewater treatment facility.

Korea Superconducting Tokamak Advanced Research vacuum and gas puffing system.

A piezoelectric valve, which has a flow rate of about 463 mbar l/s, has been installed to fuel the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The valve flow rate is in situ calibrated by analyzing the pressure rise curve while fueling the vessel at a constant rate. The calibration method and results are presented. In addition to the flow rate, other vacuum system parameters, such as the pumping speed and the vessel volume, were experimentally obtained. Based on these measurements, a KSTAR vacuum system simulator was developed to calculate the valve drive signal to obtain a programmed pressure trace. An arbitrarily shaped pressure trace was successfully controlled in KSTAR with this hardware and software system.

Association between the clara cell secretory protein (CC16) G38A polymorphism and the progression of IgA nephropathy.

AIMS: Clara cell secretory protein (CC16) is a protein with anti-inflammatory and immunomodulatory properties. Moreover, both CC16 gene knockout and antisense-transgenic mouse models developed glomerulonephritis resembling IgA nephropathy (IgAN). In the present study, we evaluated the influence of the G38A polymorphism in the CC16 gene exon 1 on the development and progression of IgAN. METHODS: Korean patients with biopsy-proven IgAN (n=267) with a minimal follow-up of 4 years (mean +/- SD 103.8 +/- 52.6 months) were recruited. Healthy normal subjects (n=315) were included as controls. The G38A polymorphism was determined using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: GG, GA and AA genotype frequencies were 36.3, 50.2 and 13.5% in IgAN patients, respectively, and 34.3, 50.2 and 15.5% in controls (chi2 = 0.596, p = 0.742). The G allele frequency was 0.614 in IgAN patients and 0.594 in controls (chi2 = 0.429, p = 0.512). Moreover, the GG genotype frequencies were 40.4% in patients showing stable disease course and 26.6% in those with progressive disease (chi2 = 4.029, p = 0.045). Patients with the GG genotype showed a better outcome by Kaplan-Meier analysis in terms of renal survival (p = 0.043). The CC16 polymorphism remained an independent risk factor for progression after multivariate analysis (Cox regression model, HR for CC16 AA genotype: 2.34, 95% CI 1.19-4.64, p = 0.014). CONCLUSION: Our results suggest that CC 16 gene G38A polymorphism is not associated with the development of IgAN, but that it is an important marker of progression in IgAN.

NF-kappa B activation pathway is essential for the chemokine expression in intestinal epithelial cells stimulated with Clostridium difficile toxin A.

Intestinal epithelial cells are known to upregulate the expression of several chemokines in response to stimulation with bacterial toxin. However, the cellular mechanisms of Clostridium difficile toxin A-induced mucosal inflammation have not yet been fully elucidated. In this study, we investigated whether nuclear factor-kappa B (NF-kappaB) could regulate chemokine expression in intestinal epithelial cells. Toxin A increased the levels of NF-kappaB complexes containing p65/p50 heterodimers and p65/p65 homodimers. Concurrently, toxin A decreased the levels of IkappaBalpha. Toxin A stimulation also increased the signals of phosphorylated IkappaB kinase (IKK)alpha/beta and NF-kappaB-inducing kinase (NIK). In the toxin A-stimulated HT-29 cells, the suppression of IKK or NIK inhibited the upregulation of downstream target genes of NF-kappaB such as IL-8 and monocyte-chemotactic protein (MCP)-1 and similarly, inhibition of NF-kappaB also downregulated the expression of IL-8, growth-related oncogene-alpha, and MCP-1. These results suggest that NF-kappaB signalling events may be involved in the inflammatory responses to toxin A produced by toxigenic C. difficile.

Induction of proinflammatory mediators requires activation of the TRAF, NIK, IKK and NF-kappaB signal transduction pathway in astrocytes infected with Escherichia coli.

Escherichia coli is associated with inflammation in the brain. To investigate whether astrocytes are involved in E. coil-induced inflammation, we assessed the levels of expression of proinflammatory mediators produced by E. coli-infected astrocytes. E. coli infection in primary human astrocytes and cell lines increased expression of the CXC chemokine IL-8/GRO-alpha, the CC chemokine MCP-1, TNF-alpha, and iNOS. E. coli infection activated p65/p50 heterodimeric NF-kappaB and concurrently decreased the signals of IkappaBalpha. Blocking the NF-kappaB signals by IkappaBalpha-superrepressor-containing retrovirus or antisense p50 oligonucleotide transfection resulted in down-regulation of expression of the proinflammatory mediators. Furthermore, superrepressors of IkappaBalpha, IkappaB kinase (IKK) or NF-kappaB inducing kinase (NIK) inhibited the up-regulated expression of the downstream target genes of NF-kappaB such as IL-8 and MCP-1, and superrepressors of TNF receptor-associated factor (TRAF)2 and TRAF5 also inhibited expression of the E. coli-induced target genes of NF-kappaB. These results indicate that proinflammatory mediators such as the CXC chemokine IL-8/GRO-alpha, the CC chemokine MCP-1, TNF-alpha, and iNOS can be expressed in E. coli-infected astrocytes via an NF-kappaB pathway, suggesting that these mediators may contribute to inflammation in the brain, including infiltration of inflammatory cells.

Escherichia coli up-regulates proinflammatory cytokine expression in granulocyte/macrophage lineages of CD34 stem cells via p50 homodimeric NF-kappaB.

Umbilical cord blood has emerged as an alternative source of haematopoietic CD34+ cells for allogeneic stem cell transplantation. Although bacteraemia induced by Escherichia coli is considered one of the complications of transplantation, expression of proinflammatory cytokines is poorly understood. In this study, we report the altered expression of proinflammatory cytokines in CD34+ cells and their in vitro cultured cells following E. coli infection. CD34+ stem cells and their cultured cells up-regulated expression of proinflammatory cytokines such as interleukin (IL)-1alpha, IL-6, IL-8 and tumour necrosis factor (TNF)-alpha after infection with E. coli. Expression of the proinflammatory cytokines was generated mainly by the granulocyte-macrophage lineages. E. coli infection activated the signals of p50/p50 nuclear factor-kappaB (NF-kappaB) homodimers and IkappaB kinase. Furthermore, inhibition of NF-kappaB activation lowered the up-regulated expression of the proinflammatory cytokines. These results suggest that CD34+ cells and their cultured cells infected with E. coli induce the expression of proinflammatory cytokines via the NF-kappaB pathway.

Enhanced immunogenicity of human papillomavirus 16 L1 genetic vaccines fused to an ER-targeting secretory signal peptide and RANTES.

To increase the potency of human papillomavirus (HPV) DNA vaccines, we constructed a series of HPV16 L1 vaccines genetically fused with a secretion signal and/or immune cell-recruiting RANTES. The DNA vaccines encoding secretory HPV L1 were constructed by inserting HPV L1 gene into a vector with an ER-targeting secretory signal sequence. The expression plasmid encoding secretory HPV L1 (pER/L1) was fused with cDNA of RANTES, generating pER/L1/R. For comparison, HPV L1 genes were cloned into pVAX1 vector with no signal sequence (pL1), and further linked to the N-terminus (pL1/R) or C-terminus of RANTES (pR/L1). The secretion of L1 proteins was observed in the pER/L1, pER/L1/R, and pR/L1-transfected cells, except the pL1/R-transfected group. Cytoplasmic localization of L1 protein was observed in the cells transfected with pL1/R, but not with pER/L1/R at 48 h after transfection. In mice, RANTES-fused vaccines more effectively elicited the levels of HPV16 L1-specific IgG and IgG2a antibodies than pL1. Of RANTES-fused vaccines, pER/L1/R encoding the secreted fusion protein induced the highest humoral and CD8(+) T-cell-stimulating responses. These results suggest that the immunogenicity of HPV L1 DNA vaccines could be enhanced by genetic fusion to a chemokine and secretory signal peptide sequences.

Polyethylenimine-mediated cellular uptake, nucleus trafficking and expression of cytokine plasmid DNA.

Although polyethylenimine (PEI) has been widely used as a nonviral vector, there is little mechanistic understanding on PEI-mediated delivery. Here, we studied whether the expression of murine interleukin-2 (mIL-2) plasmids could be improved by complexation with PEI at various N/P ratios, and whether the cellular uptake, nuclear translocation, and retention of plasmids could be affected by the N/P ratios. Compared with the naked mIL-2, PEI/mIL-2 complexes showed at least two orders of magnitude higher expression at Raw264 cells in the N/P ratio-dependent manner. PEI-mediated cellular uptake and nuclear trafficking of plasmids, quantitated by competitive polymerase chain reaction, also depended on the N/P ratios showing the highest cell and nuclear levels of plasmids at 10/1. The higher cellular levels of plasmid DNA after PEI-mediated delivery were also observed in other cell lines. Unlike naked plasmids, PEI/mIL-2 complexes (N/P ratios >/=4/1) showed prolonged cellular and nuclear retention of mIL-2 plasmids. The nuclear translocation and higher cellular level of plasmids given in PEI complexes were similarly observed by fluorescence microscopy. Moreover, PEI/mIL-2 complexes revealed high stability against DNase I, partly explaining the prolonged subcellular retention. These results indicate that the expression of plasmid mIL-2 might be highly enhanced by complexation with PEI and that such increased expression could be attributed by the higher cellular uptake, nuclear translocation and prolonged retention.

Nuclear factor-kappa B activation pathway in intestinal epithelial cells is a major regulator of chemokine gene expression and neutrophil migration induced by Bacteroides fragilis enterotoxin.

Although intestinal epithelial cells are known to up-regulate the expression of several chemokine genes in response to the stimulation with B. fragilis enterotoxin (BFT), there has been little understanding on the cellular mechanisms of BFT-induced mucosal inflammation. To test whether nuclear transcriptional factor-kappa B (NF-kappaB) is involved in the process, we stimulated intestinal epithelial cells with BFT, and evaluated the signalling NF-kappaB pathways. BFT increased signals of NF-kappaB in HT-29 and T84 epithelial cell lines as well as primary human colon epithelial cells. NF-kappaB molecules activated by BFT stimulation were composed of p65 and p50 heterodimers. In contrast, BFT decreased the signals of IkappaBalpha and IkappaB epsilon, as assessed by immunoblot. Super-repressors of IkappaBalpha, IkappaB kinase (IKK)beta, and NF-kappaB inducing kinase (NIK) inhibited an up-regulated transcription of downstream target gene (CXCL8) of NF-kappaB. Moreover, blocking the activation of NF-kappaB by MG-132 or antisense p50 oligonucleotide transfection resulted in down-regulated expression of chemokines such as CXCL1, CXCL8, and CCL2 in BFT-stimulated HT-29 cells. In addition, NF-kappaB inhibition suppressed the BFT-induced neutrophil transepithelial migration in T84 cells. These results indicate that NF-kappaB can be a central regulator of chemokine gene expression in BFT-stimulated intestinal epithelial cells and may be an important regulator of neutrophil migration.

Gene amplification and expression of the DNA repair enzyme, N-methylpurine-DNA glycosylase (MPG) in HPV-infected cervical neoplasias.

BACKGROUND: Lethal and mutagenic damages of DNA is caused by a variety of agents including viruses. It is known that HPV is one of the major causes of cervical carcinogenesis and that cells eliminate DNA lesions with DNA repair enzymes. However, the role of N-methylpurine-DNA glycosylase (MPG) is not known in the development of cervical cancer. MATERIALS AND METHODS: Multiplex polymerase chain reaction (PCR) was used for the detection and typing of HPV in the biopsy. Gene amplification of MPG was measured by a PCR-based assay. The mRNA levels of MPG were determined by reverse transcription-PCR using hypoxanthine-guanine phosphoribosyl transferase as the reference gene. An immunohistochemical technique was used to examine the distribution of MPG in the tissues. RESULTS: Of 68 Korean cervical neoplasia patients, 86.8% showed HPV infection. High-risk HPV 16/18 were the most prevalent but positive only in 47.3% of the invasive cancer patients. Gene amplification of MPG was significantly increased in high-risk HPV-infected tissues as compared to low-risk HPV-infected and normal tissues (p < 0.05). The mRNA levels of MPG were higher in HPV-infected invasive carcinoma than normal cervical tissues. Immunohistochemical staining revealed that the intracellular expression and distribution (localization) of MPG altered in the cervical neoplasia. Interestingly, MPG expression in CIN III and invasive carcinoma (IC) was much higher than normal and CIN I. Granular positivity of MPG was notable in the perinuclear regions of the cytoplasm in HPV-infected invasive cancer. CONCLUSION: This is the first report on MPG expression in cervical neoplasia. Our results indicate that the gene amplification and expression of MPG were increased in high-risk HPV-infected cervical neoplasias and the intracellular distribution of MPG protein was altered, suggesting a role of MPG in carcinogenesis.

Effects of presurgical and post-surgical irradiation on the healing process of Medpor in dogs.

The purpose of this study was to determine the effect of irradiation on the healing process and the effect on the contact surface of Medpor and bone. Eighteen dogs were studied. The animals were divided into three groups. Six non-irradiated dogs served as controls (Group 1). Twelve dogs irradiated on the left femur, before and after implantation of Medpor, were studied. The dogs were euthanized 4 and 8 weeks after Medpor was implanted in presurgical irradiation subgroup animals (Group 2) and after the completion of irradiation in post-surgical irradiation subgroup animals (Group 3). Light microscopic and scanning electron microscopic examinations were performed. The appearance of osteoblasts and bone matrix formation were remarkably late and manifest slight reactions in post-surgical irradiation group compared to the control group presenting the osteoblasts at 4 weeks, and those osteoblasts were not visible in presurgical irradiation group in both the 4-week and 8-week observation. We concluded that the bone remodeling was delayed in the irradiated bone, especially in the presurgical group.