Serum 1,5-anhydroglucitol is associated with diabetic retinopathy in Type 2 diabetes

AIMS

To determine whether there is a relationship between 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycaemia and glycaemic variability, and the presence of diabetic retinopathy and albuminuria in patients with Type 2 diabetes.

METHODS

Five hundred and sixty-seven patients with Type 2 diabetes (serum creatinine < 133 μmol/l), who were enrolled in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP), were cross-sectionally assessed by multivariate logistic regression analysis.

RESULTS

After controlling for age, sex, binary HbA(1c) levels, duration of diabetes, triglyceride, systolic blood pressure, smoking status, history of hypertension and dyslipidaemia, and the use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker medication, the odds ratios (95% CI) of diabetic retinopathy were 2.86 (1.12-7.25) for the first (lowest) quartile of 1,5-anhydroglucitol, 2.87 (1.25-6.61) for the second quartile and 0.88 (0.35-2.22) for the third quartile compared with the fourth quartile (P for trend = 0.010). Conversely, the associations between 1,5-anhydroglucitol and clinical albuminuria were non-significant after adjustment. Subjects with low 1,5-anhydroglucitol (< 10.0 μg/ml) were more likely to experience diabetic retinopathy than those with high 1,5-anhydroglucitol (≥ 10.0 μg/ml) under moderate glucose control (HbA(1c) < 8%, 64 mmol/mol) and there were no significant differences in the prevalence of diabetic retinopathy between the subgroup with HbA(1c) < 8% (64 mmol/mol) and low 1,5-anhydroglucitol and the subgroup with HbA(1c) ≥ 8% (64 mmol/mol).

CONCLUSIONS

1,5-Anhydroglucitol levels show close associations with diabetic retinopathy, especially among patients under moderate glucose control, but not with albuminuria. These results suggest that 1,5-anhydroglucitol might be a complementary marker for targeting higher risk group.

MR traceable delivery of p53 tumor suppressor gene by PEI-functionalized superparamagnetic iron oxide nanoparticles

Cancer gene therapy involves the replacement of missing or altered genes with healthy ones. In this paper, we have proposed tumor suppressor gene-carrying superparamagnetic iron oxide nanoparticles (SPIONs) for anti-cancer gene therapy. Thermally crosslinked SPIONs (TCL-SPIONs) were conjugated with branched polyethylenimine (PEI 1800 Da) by EDC-NHS chemistry for p53 plasmid DNA delivery. The morphology of the bPEI conjugated TCL-SPIONs (bPEI-TCL-SPION) and pDNA-loaded bPEI-TCL-SPION nanoparticles was measured using transmission electron microscopy (TEM). The particle sizes of the pDNA-loaded bPEI-TCL-SPION nanoparticles were also confirmed by dynamic light scattering, and ranged from 100 to 130 nm, depending on the molar charge ratio. The fluorescently labeled pDNA was complexed with bPEI-TCL-SPION and its intracellular internalization was investigated using confocal microscopy. The p53 plasmid-loaded bPEI-TCL-SPION nanoparticles achieved significantly higher p53 tumor suppressor gene expression and cellular viability compared to positive controls. The expressed wild-type p53 protein suppressed tumor cell proliferation as compared to the mutant control. When transgene expression of the p53 tumor suppressor gene was evaluated at the mRNA level and quantified using real-time PCR, the results were highly dependent on the molar charge ratio (N/P) as well as the cancer cell type. SPIONs internalized within cancer cells were tracked by magnetic resonance (MR) imaging. It was concluded that bPEI-TCL-SPION could be used as efficient gene delivery carriers that can be tracked by MR imaging.

Hybrid optical materials of plasmon-coupled CdSe/ZnS coreshells for photonic applications

A hybrid optical nanostructure of plasmon-coupled SQDs was developed for photonic applications. The coupling distances between the mono-layers of Au nanoparticles with a surface concentration of ~9.18 × 10^-4 nm^-2 and CdSe/ZnS SQDs with that of ~3.7 × 10^-3 nm^-2 were controlled by PMMA plasma etching. Time-resolved spectroscopy of plasmon-coupled SQDs revealed a strong shortening of the longest lifetime and ~9-fold PL enhancement. Polarization-resolved PL spectroscopy displayed linear polarization and depolarization at near- and far-field plasmon-coupling, respectively. The physical origin of PL enhancement could be attributable to both the large local field enhancement and the fast resonant energy transfer.

PGE2 promotes renal carcinoma cell invasion through activated RalA

Incidence of kidney cancer is on the rise, and a better understanding of molecular mechanisms involved in the cancer invasion and metastasis is required for the development of curative therapeutics. In this study, we report that the proinflammatory cytokine prostaglandin E2 (PGE2) induces the malignant SN12C, but not benign HK2 kidney cell invasion. The PGE2 increases SN12C cell invasion through a signal pathway that encompasses EP2 and EP4, Akt, small GTPase RalA and Ral·GTP inactivator RGC2. The results support the idea that targeted interference of EP2/EP4 signal to RalA·GTP may provide benefit to patients diagnosed with advanced kidney cancer.

Paradoxical response in HIV-negative patients with pleural tuberculosis: a retrospective multicentre study

OBJECTIVE

To evaluate the incidence, clinical characteristics and predicting factors for the development of paradoxical response in human immunodeficiency virus negative patients with isolated pleural tuberculosis (TB).

DESIGN

A multicentre, retrospective cohort study including 458 patients who were diagnosed and treated with isolated pleural TB between March 2005 and February 2010.

RESULTS

Paradoxical response developed in 72 patients (16%) with isolated pleural TB. The mean time to development of paradoxical response was 8.8 ± 6.4 weeks after initiation of anti-tuberculosis treatment. The main presentation of paradoxical response was aggravation of pre-existing pleural effusion in 58 patients (81%). However, the majority of the patients who developed paradoxical response had no associated symptoms (n = 49, 68%). In multiple logistic regression analysis, development of paradoxical response was independently associated with the proportion of eosinophils (adjusted OR 1.293, 95%CI 1.077-1.553) and protein concentrations (adjusted OR 0.590, 95%CI 0.397-0.878) in the pleural fluid at the time of diagnosis.

CONCLUSION

Paradoxical response developed in 16% of the patients approximately 2 months after initiation of anti-tuberculosis treatment, presenting with aggravation of pre-existing pleural effusion. Development of paradoxical response was associated with the proportion of eosinophils and protein concentrations in the pleural fluid at the time of diagnosis.

Pulmonary artery pressure in chronic obstructive pulmonary disease without resting hypoxaemia

BACKGROUND

Chronic obstructive pulmonary disease (COPD) can lead to pulmonary hypertension and cor pulmonale, which are predictors of mortality.

OBJECTIVE

To identify predictors of increased pulmonary artery pressure (PAP) in COPD patients without resting hypoxaemia, and to characterise COPD patients with increased PAP.

DESIGN

A study of 117 COPD patients from the Korean Obstructive Lung Disease (KOLD) cohort who had measurable tricuspid regurgitant flow under transthoracic Doppler echocardiography and no resting hypoxaemia.

RESULTS

The mean patient age was 67 years. Mean forced expiratory volume in 1 second (FEV(1)) was 47% predicted, mean haemoglobin (Hb) concentration was 145 g/l and mean systolic PAP (sPAP) was 33 mmHg. Multiple linear regression analysis showed that Hb was the only factor independently associated with sPAP (beta = -1.752, P = 0.005). Cluster analysis using FEV(1)% predicted, sPAP and Hb concentration as variables indicated three patient clusters: Cluster 1 (n = 36; mean FEV(1) 44% predicted, mean sPAP 39 mmHg, mean Hb 132 g/l), Cluster 2 (n = 45; FEV(1) 35% predicted, sPAP 31 mmHg, Hb 154 g/l), and Cluster 3 (n = 36; FEV(1) 65% predicted, sPAP 29 mmHg, Hb 148 g/l).

CONCLUSION

Elevated PAP was linked to low haemoglobin levels in COPD without resting hypoxaemia.

Detection of uncharged or feebly charged small molecules by field-effect transistor biosensors

This paper describes a new technique for the detection of uncharged or feebly charged small molecules (<400Da) using Si field-effect transistor (FET) biosensors that are signal-enhanced by gold nanoparticle (NP) charges under dry measurement conditions. NP charges are quickly induced by a chemical deposition (that is, Au deposition) and the indirect competitive immunogold assay, and strongly enhance the electrical signals of the FET biosensors. For the validation of signal enhancement of FET biosensors based on NP charges and detection of uncharged or feebly charged small molecules, mycotoxins (MTXs) of aflatoxin-B1 (AFB1), zearalenone (ZEN), and ochratoxin-A (OTA) were used as target molecules. According to our experimental results, the signal is 100 times more enhanced than the use of the existing solution FET biosensing techniques. Furthermore, this method enables the FET biosensor to quantitatively detect target molecules, regardless of the ionic strengths, isoelectric points (pI), or pHs of the measured sample solutions.

Synthesis and validation of cyanine-based dyes for DIGE

The application of difference gel electrophoresis (DIGE), in particular its most common "minimal labeling" variety, utilizes N-hydroxysuccinimide esters of Cy2, Cy3, and Cy5 dyes, which are commercially available. We describe methods for the efficient synthesis of all three dyes from relatively inexpensive and commercially available precursors in only a few steps and with relatively high yields. In model DIGE experiments, the newly synthesized dyes proved to be indistinguishable from commercially available ones and have been shown to be stable for years while stored under argon as dry solids or after being dissolved in N,N-dimethylformamide.

Different therapeutic responses in chronic obstructive pulmonary disease subgroups

SETTING

Eleven referring hospitals in South Korea.

OBJECTIVE

To compare therapeutic responses in chronic obstructive pulmonary disease (COPD) subgroups, classified by diffusing capacity of the lung for carbon monoxide (DL(CO)) and lung volume.

DESIGN

A total of 130 stable male COPD patients were classified into four subgroups according to baseline DL(CO) and residual volume/total lung capacity (RV/TLC) ratio. We compared therapeutic responses to short acting β(2)-agonist (SABA) and 3-month combined inhalation of long-acting β(2)-agonist (LABA) and corticosteroid among patients with these subgroups.

RESULTS

Among the 130 COPD patients, 41 (31.5%) had normal DL(CO) and RV/TLC, 28 (21.5%) low DL(CO) and normal RV/TLC, 31 (23.8%) normal DL(CO) and high RV/TLC, and 30 (23.1%) low DL(CO) and high RV/TLC. The normal DL(CO)/high RV/TLC subgroup showed a significantly larger flow response (changes in forced expiratory volume in 1 s) to salbutamol than the normal DL(CO)/RV/TLC subgroups, and a larger volume response (changes in forced vital capacity) than the two normal RV/TLC subgroups. The normal DL(CO)/high RV/TLC subgroup also showed significantly larger flow and volume response to 3-month combined inhalation of LABA and corticosteroid than the two normal RV/TLC subgroups.

CONCLUSION

COPD subgroups classified by DL(CO) and RV/TLC may have different pulmonary function responses to pharmacological treatment.

New experimental limits on non-Newtonian forces in the micrometer range

We report measurements of the short-range forces between two macroscopic gold-coated plates using a torsion pendulum. The force is measured for separations between 0.7 and 7 μm and is well described by a combination of the Casimir force, including the finite-temperature correction, and an electrostatic force due to patch potentials on the plate surfaces. We use our data to place constraints on the Yukawa-type "new" forces predicted by theories with extra dimensions. We establish a new best bound for force ranges 0.4-4 μm and, for forces mediated by gauge bosons propagating in (4+n) dimensions and coupling to the baryon number, extract a (4+n)-dimensional Planck scale lower limit of M(*)>70 TeV.

Evaluation of intraoperative brain natriuretic peptide as a predictor of 1-year mortality after liver transplantation

BACKGROUND

Although brain natriuretic peptide (BNP), a marker of cardiac dysfunction, has been known to predict postoperative mortality, little is known about the postoperative prognostic ability of BNP in liver transplantation (OLT) recipients. We aimed to determine whether intraoperative BNP level can predict 1-year all-cause mortality after OLT.

METHODS

We retrospectively investigated 525 OLT recipients. BNP and hemodynamic parameters were simultaneously measured 1 hour after induction of anesthesia. Cox regression analysis and receiver operating characteristic curve analysis were performed to determine clinical predictors and optimal cutoff values of post-OLT mortality.

RESULTS

The 1-year all-cause mortality rate was 9.7% (51/525). Median BNP concentration was significantly higher in nonsurvivors than in survivors (114 vs 56 pg/mL, P < .001). Significant factors in univariate Cox regression analysis were Child-Pugh score, model for end-stage liver disease (MELD) score, logBNP, hemoglobin, creatinine, heart rate, systolic pulmonary arterial pressure, and central venous pressure. In multivariate Cox regression analysis, independent predictors of posttransplant mortality were MELD score and logBNP. However, simultaneously measured hemodynamic parameters did not remain predictors. BNP levels greater than a cutoff of 136 pg/mL (specificity = 83.5%, negative predictive value = 93.6%) were associated with increased post-OLT mortality (log-rank test P < .001).

CONCLUSIONS

Intraoperative BNP level is an independent predictor of 1-year all-cause mortality after OLT with a high negative predictive value, suggesting that its measurement appears useful in identifying patients at low risk of post-OLT mortality.

Toxin detection by Si photosensitive biosensors with a new measurement scheme

We propose a new type of photosensitive biosensor with a CMOS compatible Si photodiode integrated circuit, for the high-sensitive detection of small mycotoxin molecules requiring competitive assay approach. In this work, a photodiode is connected to the gate of a field effect transistor (FET) so that the open circuit voltage (V(OC)) of the illuminated photodiode is transferred into the drain/source current (I(DS)) of the FET. The sensing scheme employs competitive binding of toxin molecules (within the sample solution) and toxin-BSA conjugates (immobilized on the photodiode surface) with Au-nanoparticle-labeled antibodies, followed by silver enhancement to generate opaque structures on the photodiode surface. By utilizing the non-linear dependence of the V(OC) on the light intensity, we can maintain a sufficiently high signal resolution at low toxin concentrations (with most of the incident light blocked) for the competitive assay. By monitoring the I(DS) of the FET whose gate is driven by the V(OC), quantitative detection of Aflatoxin B1 has been achieved in the range of 0-15ppb.

The hOGG1 mutant genotype is associated with prostate cancer susceptibility and aggressive clinicopathological characteristics in the Korean population

BACKGROUND

The gene encoding human 8-oxoguanine glycosylase 1 (hOGG1) is involved in DNA base excision repair from oxidatively damaged DNA. A case-control study was conducted to evaluate the correlation between the susceptibility and clinicopathological outcomes of prostate cancer (CaP) and hOGG1 genotype.

PATIENTS AND METHODS

Subjects were recruited from 266 CaP patients and 266 age-matched benign prostatic hyperplasia patients. The hOGG1 codon 326 genotype was determined by peptide nucleic acid-mediated PCR clamping and compared with Gleason score and tumor stage.

RESULTS

The Cys allele at codon 326 of hOGG1 was associated with an increased risk of CaP in comparison with the Ser allele (P = 0.005). Gleason scores of 8 or higher were observed more often in patients with the mutant genotypes Ser/Cys and Cys/Cys than in those with a wild-type genotype (P = 0.045), and the Cys/Cys homozygous genotype was associated with a significantly higher risk of metastatic disease in comparison with the Ser/Ser genotype (P = 0.017).

CONCLUSIONS

These results suggest that hOGG1 is associated with the susceptibility to CaP and its aggressive clinicopathological characteristics.

Clinical characteristics and outcomes of H1N1-associated pneumonia among adults in South Korea

BACKGROUND

Pneumonia has been reported to be the most life-threatening complication of influenza virus infection.

OBJECTIVE

to describe clinical characteristics and determine risk factors for death among patients with H1N1-associated pneumonia.

DESIGN

A retrospective cohort study included all adult patients diagnosed and treated with H1N1-associated pneumonia in 14 participating institutions between 1 May 2009 and 28 February 2010 in South Korea. Clinical outcomes were summarised and predictors for death evaluated through univariate and multivariate analysis.

RESULTS

A total of 269 adult patients with H1N1-associated pneumonia were diagnosed and treated. Hospital visits or admissions peaked in November 2009, coinciding with the peak in the 2009 H1N1 epidemic in South Korea. The patients' median age was 48 years; 143 were male. Most (n = 266, 98.9%) were admitted for treatment: 97 (36.1%) required intensive care and 28 (10.4%) needed mechanical ventilation. Despite the use of antiviral and antibacterial agents, 19 patients (7.1%) died. Risk factors predictive of death included presence of malignancy (aOR 12.0, 95%CI 2.8-51.5), and pneumonia severity index (PSI) score (aOR 1.03, 95%CI 1.01-1.04).

CONCLUSION

Deaths among adult patients with H1N1-associated pneumonia were not rare. Clinicians should be aware of the possibility of a poor prognosis among H1N1-associated pneumonia patients with underlying malignancy or high PSI score.

Thickness reduction effect in obtaining ultrafine-grained microstructure from oxygen-free copper using high-ratio differential speed rolling

This study has demonstrated a novel method of fabricating ultrafine-grained oxygen free copper sheets by applying high-ratio differential speed rolling (HRDSR) at room temperature that induces severe plastic deformation. Temperature rise of the sample due to friction and plastic deformation during deformation by HRDSR was significant such that beyond a thickness reduction > 65%, the grain refining efficiency was reduced. The proposed processing method holds great potential for continuous production of ultrafine-grained copper alloy sheets.

Three phenotypes of obstructive lung disease in the elderly

SETTING

Eleven referring hospitals in South Korea.

OBJECTIVE

To classify the phenotypes in elderly subjects with obstructive lung disease (OLD).

METHODS

We analysed 191 subjects aged ≥ 60 years with chronic respiratory symptoms and either obstructive spirometry or bronchial hyperresponsiveness. Factor analysis was performed using commonly measured variables and revealed four significant variables: 1) the ratio of inspiratory capacity to total lung capacity, 2) the total score on the St George's Respiratory Questionnaire, 3) the volume fraction of the lung less than 950 Hounsfield Unit at full inspiration on volumetric computed tomography and 4) post-bronchodilator forced expiratory volume in 1 second (FEV(1)) changes. We performed a cluster analysis on these four variables.

RESULTS

The mean age was 68.5 (± 5.2 SD) years and the mean post-bronchodilator FEV(1) was 52.4% (± 16.5) predicted. Three clusters with the following phenotypes were identified: Cluster 1 included subjects with moderate to severe airflow obstruction and bronchodilator reversibility; Cluster 2 subjects had moderate airflow obstruction without bronchodilator reversibility, and Cluster 3 subjects had severe airflow obstruction without bronchodilator reversibility.

CONCLUSIONS

We identified three phenotypes in elderly subjects with OLD. Follow-up studies are needed to explore the clinical significance of each phenotype.

Alendronate affects cartilage resorption by regulating vascular endothelial growth factor expression in rats

This study was performed to determine effects of alendronate on the tibial proximal epiphyseal cartilage undergoing endochondral ossification and the expression of vascular endothelial growth factor (VEGF) from the cartilage. Alendronate was injected subcutaneously every other day in postnatal Day 1 Sprague Dawley rats. The rats were sacrificed 3, 5, 7, and 10 days after the first injection. The effect of alendronate treatment for 10 days was demonstrated from the morphological change that the area of the secondary ossification center in the epiphysis was significantly smaller in the alendronate group than that in the control group (P < 0.05). Strong immunoreactivity to VEGF was observed in the hypertrophied chondrocytes and some proliferating chondrocytes in the epiphyseal cartilage at postnatal Day 5 and was decreased after the alendronate treatment for 5 days. Immunoreactivity was observed in not only hypertrophied cells but also the peripheral cartilaginous matrix adjacent to the vascular canals invading into the central portion of the cartilage at postnatal Day 7. This reactivity was also reduced considerably by the alendronate treatment for 7 days. The level of VEGF expression was reduced by the alendronate treatment at both the transcription and translation levels. However, the transcriptional level of the flt-1 and flk-1 receptors was relatively unaltered by the treatment. These results suggest that VEGF expression is required for vascular invasion into the developing cartilage and alendronate can affect its resorption by downregulating VEGF expression.

Association of COPD candidate genes with computed tomography emphysema and airway phenotypes in severe COPD

The principal determining factors influencing the development of the airway disease and emphysema components of chronic obstructive pulmonary disease (COPD) have not been clearly defined. Genetic variability in COPD patients might influence the varying degrees of involvement of airway disease and emphysema. Therefore, we investigated the genetic association of single nucleotide polymorphisms (SNPs) in COPD candidate genes for association with emphysema severity and airway wall thickness phenotypes. Polymorphisms in six candidate genes were analysed in 379 subjects of the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study with quantitative chest computed tomography (CT) data. Genetic association with per cent of lung area below -950 HU (LAA950), airway wall thickness, and derived square root wall area (SRWA) of 10-mm internal perimeter airways were investigated. Three SNPs in EPHX1, five SNPs in SERPINE2 and one SNP in GSTP1 were significantly associated with LAA950. Five SNPs in TGFB1, two SNPs in EPHX1, one SNP in SERPINE2 and two SNPs in ADRB2 were associated with airway wall phenotypes in NETT. In conclusion, several COPD candidate genes showed evidence for association with airway wall thickness and emphysema severity using CT in a severe COPD population. Further investigation will be required to replicate these genetic associations for emphysema and airway wall phenotypes.

Fabrication of anionic sulfate-functionalized nanoparticles as an immunosensor by protein immobilization

Anionic sulfate (SO(4)(-))-functionalized polystyrene (PS) nanoparticles were prepared by the thermal decomposition of potassium persulfate (KPS) in the presence of sodium tetraborate via emulsion polymerization. The presence of a SO(4)(-) group at a solid/liquid interface of a particle surface was confirmed by a zeta potential value of -40.6 mV as well as the shifting of S 2p spectra toward a lower-binding-energy region around 162.7 eV (2p(3/2)) and 164.4 eV (2p(1/2)) in X-ray photoelectron spectroscopy (XPS) analysis. The electrostatic attraction between positively charged antibodies of human immunoglobulin G (hIgG) and cardiac troponin I (cTnI) and negatively charged particle surfaces was accomplished. The atomic force microscopy (AFM) measurement and bicinchoninic acid (BCA) assay results show binding structure between hIgG and antibodies of hIgG (anti-hIgG) with a gradual increase in particle diameter to 152.6 nm (bare), 170.2 nm (hIgG), and 178.9 nm (hIgG/anti-hIgG). Surface coverage densities of 331.4 ng/cm(2) (hIgG) and 320.3 ng/cm(2) (cTnI) and the binding capacity of hIgG to HyLite-750-labeled Fab-specific anti-hIgG (approximately 81.2%) indicate that the majority of hIgG was immobilized with a Y-shaped orientation. The sandwich immunoassay results provide the evidence that the immunological activity of cTnI on the PS nanoparticle surface was retained because the binding activity of the cTnI-PS nanoparticle/cTnI (antigen)/detection cTnI-antibody reaction showed a 5-fold higher activity than that of the cTnI-PS nanoparticle/human serum albumin (HSA)/detection cTnI antibody used as a negative control.

Washoff behavior of in-sewer deposit in combined sewer system through artificial flushing experiment

In-sewer deposits in combined sewer systems (CSSs) are closely related with the behavior of first foul flush and combined sewer overflows. However, the research paying attention to the role of in-sewer deposits is quite rare, furthermore, their contributions for the washoff patterns of each pollutant including pathogenic microorganisms are almost never discussed so far. The artificial flushing experiment separating the washoff of in-sewer deposits from the inflow of surface pollutants was carried out to simulate the first foul flush in a CSS. The washoff behaviors of each pollutant including bacterial indicators and enteric viruses were investigated. Several morphological analyses for the concentration and load curves of each parameter were conducted and all patterns were classified according to their washoff characteristics and first foul flush patterns. The washoff behaviors of each pollutant and microorganism are different from each other and categorized into several groups according to their (i) time-series concentration and load curves and (ii) concentration vs. flow rate curves, respectively. The first foul flush patterns of each parameter were to be categorized into typical 3 groups; strong-, partial-, and no first foul flush group. The order of these groups signifies the strength of the first foul flush phenomena and the runoff priority as well.

Parasympathectomy induces morphological changes and alters gene-expression profiles in the rat submandibular gland

OBJECTIVE

The chorda-lingual (CL) nerve carries parasympathetic fibers to the hilum of the sublingual and submandibular glands (SMGs) and evokes the secretion of saliva. The effect of cutting the CL nerve on the biological processes in SMGs was investigated by examining the gene-expression profiles in the SMGs after a surgical parasympathectomy.

METHODS

At day 3 after the CL nerve cut, the changes in the SMGs at both the experimental cut and contralateral control sides were analysed by microarray and light microscopy. The expression levels of 6 selected genes were confirmed by real-time PCR, Western blot and immunofluorescence staining.

RESULTS

The wet weight of the parasympathectomised SMGs decreased significantly compared to that of the contralateral side (p<0.05). Histological analyses after the parasympathectomy showed a widened interacinar space as well as some atropic changes to the acini of the SMGs in the cut side. Microarray analysis revealed that twofold differential expression in mRNA expression in the parasympathectomized SMGs were detected in 88 genes (0.004%): 41 genes were overexpressed, 11 were underexpressed and 36 were unknown. Changes of the expression of 6 selected genes detected by Western blot and/or real-time PCR were consistent with the microarray data.

CONCLUSION

The important genes involved in biological processes for salivation were identified through a large-scale gene expression analysis.

Enhanced protein immobilization efficiency on a TiO2 surface modified with a hydroxyl functional group

An antibody immobilization was investigated using a self-assembled monolayer (SAM) over the highly refractive coatings with a SiO2, TiO2, or Si3N4 substrate. The immobilization was characterized by analyzing the hydrophilic properties of hydroxyl (OH) groups on surface coatings with contact angle (CA) measurements to enhance protein immobilization. The hydroxyl (OH) group was formed in greater amounts as the oxygen plasma exposure time was increased, which resulted in a large enhancement in antibody immobilization. It indicated that hydroxyl (OH) group formation is critical for developing a label-free optical transducer with a high sensitivity.

Effects of bisphosphonate on the endochondral bone formation of the mandibular condyle

The development of the mandibular condylar cartilage is important for the overall growth of the mandible. However, there have been a few researches into medical approaches aimed at controlling condylar growth. This study examined the effects of bisphosphonate on the growth of the condylar cartilage. Alendronate (3.5 mg/kg/week) was administered to postnatal day 1 SD rats for 7 and 10 days. The thickness of each chondrocyte layer and the level of MMP-9 expression were measured. The anteroposterior diameter of the developing condyle was unaffected by the alendronate treatment for 7 days (P > 0.05). The total thickness of the cartilage layers was also unaffected by the treatment for 7 days (P > 0.05). In particular, there was no change in the thickness of the perichondrium and reserve cell layer at the measured condylar regions (P > 0.05). However, the thickness of the proliferating cell layer was reduced significantly, whereas the thickness of hypertrophied cartilage layer was increased (P < 0.05). The number of chondroclasts engaged in hypertrophied cartilage resorption was reduced significantly by the alendronate treatment (P < 0.05). The level of MMP-9 expression was reduced at both the transcription and translation levels by the alendronate treatment for 7 and 10 days. These results indicate that alendronate (>3.5 mg/kg/week) inhibits the longitudinal growth of the mandibular condyle by inhibiting chondrocyte proliferation and the resorption of hypertrophied cartilage for ossification.

Measurement of the short-range attractive force between Ge plates using a torsion balance

We have measured the short-range attractive force between crystalline Ge plates, and found contributions from both the Casimir force and an electrical force possibly generated by surface patch potentials. Using a model of surface patch effects that generates an additional force due to a distance dependence of the apparent contact potential, the electrical force was parametrized using data at distances where the Casimir force is relatively small. Extrapolating this model, to provide a correction to the measured force at distances less than 5 microm, shows a residual force that is in agreement, within experimental uncertainty, with five models that have been used to calculate the Casimir force.

Expression of DCC in differentiating ameloblasts from developing tooth germs in rats

OBJECTIVE

This study examined the expression pattern of the Deleted-in-colorectal-carcinoma (DCC) gene in developing rat tooth germs.

METHODS

Rat pups at 4, 7 and 10 d postpartum were used in this study. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescent localization were used to determine the level of DCC expression during tooth development.

RESULTS

There was more than 2-fold higher level of DCC mRNA in the rat 2nd maxillary molar tooth germs on 10 d postpartum, which was the root stage, than in the rat 3rd maxillary molar tooth germ, which was at the cap/early bell development stage. In addition, the levels of DCC mRNA in the 2nd maxillary molar germs at 4, 7 and 10 d postpartum increased gradually according to tooth development. Interestingly, immunoreactivity against DCC was specifically detected in the differentiating ameloblasts. DCC was observed in the lateral and apical sides of the newly differentiating and secretory stage ameloblasts. Afterwards, DCC was localized only in the apical side of the maturation stage ameloblasts, not in the lateral side.

CONCLUSION

DCC is expressed in the differentiating ameloblasts, which suggests that this molecule plays a crucial role in amelogenesis.

Optical nonlinearities of Au nanoparticles and Au/Ag coreshells

Au nanoparticles exhibited both negative and positive nonlinear absorptions with ground-state plasmon bleaching and free-carrier absorption that could be origins of the saturable and reverse-saturable optical properties. Au/Ag coreshells displayed only positive nonlinear absorption and reverse-saturable optical properties as a function of excitation intensity at the edge of surface-plasmon resonance, which implies no ground-state plasmon bleaching and the existence of two-photon absorption.

Nonlinear optical properties of mushroom-shaped CdSe/CdS coreshells

The third-order nonlinear optical susceptibilities of mushroom-shaped CdSe/CdS coreshells as a function of concentration have been investigated using polarization- and concentration-resolved degenerate four-wave mixing in a resonant region. The effective third-order nonlinear optical susceptibilities, /chi(3)xxxx/ and /chi(3)xyyx/ of CdSe/CdS coreshells were estimated to be approximately 1.86 x 10(-21)-1.03 x 10(-20) m2/V2, and approximately 0.45 x 10(-21)-6.15 x 10(-21) m2/V2, respectively, for various concentrations of approximately 0.64 x 10(-3)-4.95 x 10(-3) mol/m3. The second hyperpolarizabilities, /<gammah>xxxx/ and /<gammah>xyyx/, of CdSe/CdS coreshells were extracted to be approximately 2.37 x 10(-41) m5/V2 and approximately 1.29 x 10(-41) m5/V2, respectively.

Effects of alendronate on a disintegrin and metalloproteinase with thrombospondin motifs expression in the developing epiphyseal cartilage in rats

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been reported to play a role in the degradation of aggrecan, a major component of cartilage. This study was performed to examine the effects of alendronate on the expression of ADAMTS in developing femoral epiphyseal cartilage. Primary cultured chondrocytes from this cartilage were treated with alendronate in vitro and postnatal day 1 rats were injected subcutaneously with alendronate (1 mg/kg) every second day in vivo. The number of cultured chondrocytes and their aggrecan mRNA levels were unaffected by the alendronate treatment at 10(-6) to 10(-4) M concentrations. The mRNA levels of ADAMTS-1, -2 and -9 in chondrocytes were also unaffected. However, the levels of ADAMTS-5 and -4 were reduced significantly by the same treatment. The thickness of the proliferating chondrocyte layers and the aggrecan mRNA levels in the epiphysis were unaffected by the alendronate treatment in vivo. However, the hypertrophied chondrocyte layers became significantly thicker, and the size of the secondary ossification centre was reduced significantly by the same treatment (P < 0.05). Both ADAMTS-4 and -5 mRNA expressions were also reduced significantly in vivo. The immunoreactivity against ADAMTS-4 was seen in hypertrophied chondrocytes and reduced significantly by the alendronate treatment. These results suggested that alendronate can inhibit the degradation of aggrecan in the articular cartilage by downregulating the expression of matrix enzymes such as ADAMTS-4 and -5.

Diurnal fluctuation of indicator microorganisms and intestinal viruses in combined sewer system

Combined sewer overflow (CSO) has been considered to be a source of pathogenic microorganisms for aquatic environment. For the effective control and treatment of CSOs, the microbial behavior in combined sewer system (CSS) needs to be investigated. In this study, whole-day extensive monitoring of indicator microorganisms and intestinal viruses in dry weather flow (DWF) was conducted at a small residential urban drainage area with CSS. All indicator bacteria represented similar diurnal variations in the two different monitoring campaigns; their concentrations gradually decreased to the minimum at the dawn (around 5 a.m.), increased sharply to the maximum around 7 to 8 a.m., and remained rather constant from noon to midnight. On the other hand, neither coliphages nor intestinal viruses showed any concentration peaks in the morning. The maximum/minimum load ratios ranged from 18 to 42 for total coliforms, fecal coliforms and E. coli, whereas those ratios for coliphages, enteroviruses and noroviruses G2 showed greater values than those for indicator bacteria. These results indicate that the diurnal variation patterns of bacterial and viral concentrations in DWF should be considered, which affect the discharge characteristics of each microorganism and the loads of bacteria and viruses in CSOs significantly vary with the overflow time as well.

Biomimetic approach to the formation of magnetic nanoparticle/silica core/shell structures

We report a mild method for constructing magnetic iron oxide nanoparticle (IONP)/silica core/shell hybrid structures by biomimetic silicification of silicic acids. 2-(Dimethylamino)ethyl methacrylate (DMAEMA) was grafted onto the surface of IONPs via surface-initiated, atom transfer radical polymerization, and then silica shells were subsequently formed by biomimetic polycondensation of silicic acids with poly(DMAEMA) as an organic template for the formation of silica structures. The resulting IONP/silica hybrids were characterized by Fourier-transform infrared spectroscopy and transmission electron microscopy.

Non-viral delivery of interleukin-2 and soluble Flk-1 inhibits metastatic and primary tumor growth in renal cell carcinoma

Treatments for renal cell carcinoma, while promising, are still limited by toxicity and cost. In the hopes of finding a novel compound or combination, we developed a plasmid containing the genes for interleukin-2 (IL-2) and soluble vascular endothelial growth factor receptor 2 (msFlk1). The plasmid, p2CMVIL2/msFlk1, demonstrated similar in vitro transgene expression of IL-2 or msFlk1 compared to their single-agent counterparts. Subcutaneous tumor growth was significantly inhibited in the p2CMVIL2/msFlk1 group when delivered locally by the non-viral water soluble polymer, WSLP and exhibited a 50% increase in survival over glucose and single-agent controls. In vivo experimentation demonstrated that WSLP/msFlk1 decreased microvessel density in pCMVmsFlk1 and p2CMVIL2/msFlk1 treated groups. Furthermore, tumor-infiltrating lymphocytes expressing CD45RO and CD68 were increased within the tumor microenvironment upon p2CMVIL2/msFlk1 treatment. To determine the effects of p2CMVIL2/msFlk1 in an experimental RENCA lung metastases model, therapeutic DNA was delivered systemically following complexation with the angiogenic endothelial-targeting polymer PEI-g-PEG-RGD. The p2CMVIL2/msFlk1 treatment significantly reduced metastases by 56% over single-agent therapy and increased survival proportions by 50% over all groups. Our work clearly demonstrates that non-viral delivery of p2CMVIL2/msFlk1 can inhibit RENCA growth in a synergistic manner and may represent a new treatment for renal carcinoma.

Expression of TGF-beta signaling proteins in normal placenta and gestational trophoblastic disease

The transforming growth factor beta (TGF-beta) is a vital regulator of placental development and functions. TGF-beta exerts several modulatory effects on trophoblast cells, such as inhibition of proliferation and invasiveness, and stimulation of differentiation by inducing multinucleated cell formation. In this study, we determine the expression patterns of TGF-beta signaling molecules in normal trophoblast, various hydatidiform mole types and choriocarcinoma. A total of 132 cases, including 51 normal placenta (20 first trimester, 11 second trimester, and 20 third trimester) and 81 gestational trophoblastic diseases (17 choriocarcinoma, and 64 hydatidiform moles: 39 complete, 6 partial, and 19 invasive) were immunohistochemically analyzed with anti-TGF beta1/2, TGF-beta receptor type I (TbetaRI), TbetaRII, Smad 2/3, and Smad 4 antibodies on paraffin blocks. In the case of normal placenta, maximal levels of all TGF-beta signaling molecules were observed in villous trophoblast in the first trimester, which decreased with gestational age. Expression of all the TGF-beta signaling proteins except Smad2/3, was significantly enhanced in various moles, relative to normal trophoblast. Moreover, TGF-beta signaling molecules were significantly downregulated in choriocarcinoma, compared to moles. In particular, TbetaRI and Smad2/3 levels were lower in choriocarcinoma than normal villous trophoblast (TbetaRI: p<0.025, Smad2/3: p<0.001). In conclusion, the TGF-beta signaling pathway plays an important role in the pathogenesis and progression of gestational trophoblastic disease, and may thus be employed as a potential therapeutic target and a diagnostic biomarker.

Characterization of the TSU-PR1 cell line by chromosome painting and flow cytometry

TSU-PR1 was originally reported as a prostatic carcinoma cell line derived from a lymph node metastasis. Recently, however, this cell line was reported to be derived from T24 bladder carcinoma cells, and thus further definition of its origin is needed. Conventional cytogenetic study of TSU-PR1 showed aneuploidy, ranging from 65 to 86 chromosome with a modal number of 80, and with 10 marker chromosomes, thus conventional cytogenetics cannot be used to determine which chromosomes or regions of chromosomes are critical in cancer development and progression of this cell line. The present study was conducted to characterize genetic changes of the cell line using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), and flow cytometry. CGH results showed that green-to-red fluorescence ratios were within the range of 0.85-1.15, except for a few chromosomes, which reflected near tetraploidy in TSU-PR1. Flow cytometric analysis of TSU-PR1 revealed a DNA index of 3.46n, which is close to the 3.48n calculated from a modal number of 80. The copy numbers of chromosomes 4, 6, 7, 17, and 20 determined by the DNA index and the CGH analyses were 2.85 +/- 0.09, 3.22 +/- 0.77, 3.01 +/- 0.26, 4.05 +/- 0.44, and 4.99 +/- 0.48, respectively. These numbers are also in accordance with the chromosome copy numbers determined with FISH: 2.98 +/- 0.23, 2.91 +/- 0.44, 2.74 +/- 0.44, 3.93 +/- 0.38, and 5.05 +/- 0.78 for chromosomes 4, 6, 7, 17, and 20, respectively (P > 0.05).

Biomimetic micropatterning of silica by surface-initiated polymerization and microcontact printing

Micropatterns of silica on a gold substrate were generated by a biomimetic approach, namely, the biosilicification of silicic acids. The procedure consists of three simple steps: pattern generation of a polymerization initiator, (BrC(CH(3))(2)COO(CH(2))(11)S)(2), by microcontact printing; surface-initiated, atom-transfer radical polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) from the patterned area; and polycondensation of silicic acids. The tertiary amine-containing polymer, pDMAEMA, aided in the spatially controlled polycondensation of silicic acids on surfaces in the presence of phosphate ions, and micropatterns of silica on a gold substrate were successfully generated in combination with the technique of microcontact printing. The procedure could be extended to the controlled fabrication of silica patterns with any size, shape, or thickness.

Practical syntheses of dyes for difference gel electrophoresis

The three dyes (two indocyanine and one benzoxazolium) useful in difference gel electrophoresis-methyl Cy5 1, propyl Cy3 2, and the benzoxazolium dye Cy2 3--and their NHS esters have been prepared by efficient routes in good overall yield from inexpensive precursors.

Varying Ti-6Al-4V surface roughness induces different early morphologic and molecular responses in MG63 osteoblast-like cells

Osteoblast response to Ti implants depends not only on the chemistry of the implant but also on the physical properties of the implant surface, such as microtopography and roughness. This study was undertaken to examine early changes in cell morphology and gene expression during the early phase of osteoblast interaction with titanium alloy (Ti-6Al-4V) surfaces of two different roughnesses. MG63 osteoblast-like cells were cultured for 2, 6, 24, and 72 h on smooth (Ra=0.18+/-0.03 microm) and rough (Ra=2.95+/-0.23 microm) Ti-6Al-4V surfaces. Changes in cell proliferation were assessed by measuring cell number after 72 h in culture. Morphological characteristics were observed by scanning electron microscopy after 2, 6, and 24 h of culture. Changes in gene expression for extracellular signal-regulated kinase 2 (Erk2), type I collagen (alpha2[I] collagen), phospholipase C-gamma2 (Plc-gamma2), and beta-actin were measured by RT-PCR after 6 and 24 h in culture. Cell number was significantly higher on the smooth surface. In scanning electron micrographs, cells on smooth Ti-6Al-4V were spherical and raised up from the surface after 2 h in culture. In contrast, cells on the rough surface adopted an irregular, elongated shape that spanned across pits in the surface. At 24 h, cells on the smooth surface had flattened, become elongate, and covered the surface. In contrast, cells on the rough surface appeared more differentiated in shape and the margins of the cells were irregular, with many processes extending out, following the contour of the surface. Of the genes examined, only Erk2 and beta-actin showed a change in expression with surface roughness. Both genes were upregulated (p<0.05) on the rough surface at 6 h. These results indicate that Ti-6Al-4V surface roughness affects osteoblast proliferation, morphology, and gene expression, and that these effects can be measured after periods as short as 2-6 h.

Biomimetic formation of silica thin films by surface-initiated polymerization of 2-(dimethylamino)ethyl methacrylate and silicic acid

Biosilicification in diatoms is achieved by specific interactions between silaffins, composed of polypeptides and long-chain polyamines, and silicic acid derivatives. The polycondensation of silicic acids is reported to be catalyzed by the long-chain polyamines that mainly contain tertiary N-methylpropyleneimine moieties. In this report, we utilized a tertiary amine-containing polymer, poly(2-(dimethylamino)ethyl methacrylate) (poly(DMAEMA)), as a surface-grafted, biomimetic counterpart of the long-chain polyamines in silaffins and demonstrated that the surface-initiated polycondensation of silicic acids, leading to the formation of silica thin films, proceeded smoothly on surfaces presenting poly(DMAEMA), where poly(DMAEMA) was grown from gold surfaces by surface-initiated, atom transfer radical polymerization. The formed silica film was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy.

Binding of aromatic isocyanides on gold nanoparticle surfaces investigated by surface-enhanced Raman scattering

The adsorption structure and binding of phenyl isocyanide (PNC), 2,6-dimethyl phenyl isocyanide (DMPNC), and benzyl isocyanide (BZI) on gold nanoparticle surfaces have been studied by means of surface-enhanced Raman scattering (SERS). PNC, DMPNC, and BZI have been found to adsorb on gold assuming a standing geometry with respect to the surfaces. The presence of the nu(CH) band in the SERS spectra denotes a vertical orientation of the phenyl ring of PNC, DMPNC, and BZI on Au. The lack of a substantial red shift and significant band broadening of the ring breathing modes implied that a direct ring pi orbital interaction with metal substrates should be quite low. For PNC, the band ascribed to the C-NC stretching vibration was found to almost disappear after adsorption on Au. On the other hand, the C-NC band remained quite strong for DMPNC after adsorption. This result suggests a rather bent angle of C-N[triple bond]C: for the nitrogen atom of the NC binding group on the surfaces, whereas a linear angle of C-N[triple bond]C: should be more favorable on gold surfaces due to an intramolecular steric hindrance of its two methyl groups. SERS of BZI on gold nanoparticles also supports a bent angle of :C[triple bond]N-CH2 for its nitrogen atom, suggesting a preference of sp3 (or sp2) hybridization for the nitrogen atom.

Pathogenesis of and immunity to a new influenza A (H5N1) virus isolated from duck meat

The outbreak of avian influenza H5N1 in Hong Kong in 1997 raised concerns about the potential for the H5 subtype to cause a human pandemic. In 2001 a new H5N1 virus, A/Duck Meat/Anyang/AVL-1/2001 (A/Dkmt), was isolated from imported duck meat in Korea. The pathogenesis of this virus was investigated in mice. A/Dkmt virus had low infectivity but was lethal for mice at high doses, and at lethal doses, the virus replicated in the brains of infected mice. A/Dkmt virus cross-reacted poorly with ferret antisera raised against human H5N1 viruses, but prior infection with A/Dkmt virus protected mice from death after secondary infection with human H5N1 virus.

Acceleration of DNA strand exchange by polycation comb-type copolymer

The accelerating effect of cationic substances on DNA strand exchange reaction between 20 bp DNA duplex and its complementary single strand was studied. A comb-type polycationic copolymer which is composed of poly (L-lysine) backbone and dextran graft chain (PLL-g-Dex) and known to stabilize triplex DNA expedites the strand exchange reaction under physiological relevant conditions. Electrostatically small excess of the copolymer increased DNA strand exchange rate by 300-fold while large excess of spermine or cethyltrimethylammonium bromide, cationic detergent known to promote markedly hybridization of complementary DNA strands, showed slight effect. It should be noted that the copolymer promotes the strand exchange reaction while it stabilizes double stranded DNA.

Polycation graft copolymers accelerating DNA strand exchange: involvement of ionic interaction

In the previous study (Chem. Eur. J., 7, 176 (2001)) we demonstrated that the comb-type polycationic copolymer (PLL-g-Dex) which is composed of poly (L-lysine) backbone and dextran graft chains expedited the DNA strand exchange reaction. In this study, fluorescence resonance energy transfer (FRET) was employed to explore the copolymer-mediated DNA strand exchange with higher time-resolution. To initiate strand exchange reaction the duplex prepared from 3'-fluorescein isothiocyanate (FITC)--and 5'-carboxytetramethylrhodamine(TAMRA)-labeled complementary DNAs was added to its non-labeled complementary single strand. DNA strand exchange was monitored by observing the recovery of the FITC quenching. More than 20,000 times increase in strand exchange rate at 37 degrees C by the copolymer was estimated. To investigate the accelerating mechanisms of the copolymer, the same reactions but at various ionic strenghts were studied. With increasing ionic strengths the strand exchange rate in the absence of the copolymer increased, suggesting that ionic repulsion among DNAs is unfavorable for the strand exchange to occur. Hence, alleviation of the electrostatic repulsion through interpolyelectrolyte complex formation is probably a role of the copolymer for accelerating the strand exchange reaction.

Effect of modified atmosphere packaging and irradiation in combination on content of nitrosamines in cooked pork sausage

The effect of modified atmosphere packaging and irradiation in combination on nitrosodimethylamine (NDMA) and nitrosopyrrolidine (NPYR) levels in pork sausage was studied. Emulsion-type cooked pork sausage was manufactured and packaged in aerobic, CO2 (100%), N2 (100%), and CO2/N2 (25%/75%) environments, respectively, and irradiated at 0, 5, 10, and 20 kGy with gamma irradiation. The nitrosamine contents were significantly reduced by irradiation, and the reduction of nitrosamines was more extensive with modified atmosphere packaging than with aerobic packaging. The correlation coefficient between irradiation dose and nitrosamine content indicated that irradiation can reduce the levels of nitrosamines. The combination of irradiation and modified atmosphere packaging is effective in enhancing the chemical safety of sausage by reducing nitrosamines, if present, as well as enhancing the microbial safety of cooked pork sausage.