Genetically engineered bacteriophages as novel nanomaterials: applications beyond antimicrobial agents

Bacteriophages, also known as phages, are viruses that replicate in bacteria and archaea. Phages were initially discovered as antimicrobial agents, and they have been used as therapeutic agents for bacterial infection in a process known as "phage therapy." Recently, phages have been investigated as functional nanomaterials in a variety of areas, as they can function not only as therapeutic agents but also as biosensors and tissue regenerative materials. Phages are nontoxic to humans, and they possess self-assembled nanostructures and functional properties. Additionally, phages can be easily genetically modified to display specific peptides or to screen for functional peptides via phage display. Here, we demonstrated the application of phage nanomaterials in the context of tissue engineering, sensing, and probing.

A colorimetric lateral flow immunoassay based on oriented antibody immobilization for sensitive detection of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The high human-to-human transmission and rapid evolution of SARS-CoV-2 have resulted in a worldwide pandemic. To contain SARS-CoV-2, it is essential to efficiently control the transmission of the virus through the early diagnosis of infected individuals, including asymptomatic people. Therefore, a rapid and accurate assay is vital for the early diagnosis of SARS-CoV-2 in suspected individuals. In this study, we developed a colorimetric lateral flow immunoassay (LFIA) in which a CBP31-BC linker was used to immobilize antibodies on a cellulose membrane in an oriented manner. The developed LFIA enabled sensitive detection of cultured SARS-CoV-2 in 15 min with a detection limit of 5 × 10⁴ copies/mL. The clinical performance of the LFIA for detecting SARS-CoV-2 was evaluated using 19 clinical samples validated by reverse transcription-polymerase chain reaction (RT-PCR). The LFIA detected all the positive and negative samples accurately, corresponding to 100% accuracy. Importantly, patient samples with low viral loads were accurately identified. Thus, the proposed method can provide a useful platform for rapid and accurate point-of-care testing of SARS-CoV-2 in infected individuals to efficiently control the COVID-19 pandemic.

Virus-like nanoparticles as a theranostic platform for cancer

Virus-like nanoparticles (VLPs) are natural polymer-based nanomaterials that mimic viral structures through the hierarchical assembly of viral coat proteins, while lacking viral genomes. VLPs have received enormous attention in a wide range of nanotechnology-based medical diagnostics and therapies, including cancer therapy, imaging, and theranostics. VLPs are biocompatible and biodegradable and have a uniform structure and controllable assembly. They can encapsulate a wide range of therapeutic and diagnostic agents, and can be genetically or chemically modified. These properties have led to sophisticated multifunctional theranostic platforms. This article reviews the current progress in developing and applying engineered VLPs for molecular imaging, drug delivery, and multifunctional theranostics in cancer research.

Glycan chip based on structure-switchable DNA linker for on-chip biosynthesis of cancer-associated complex glycans

On-chip glycan biosynthesis is an effective strategy for preparing useful complex glycan sources and for preparing glycan-involved applications simultaneously. However, current methods have some limitations when analyzing biosynthesized glycans and optimizing enzymatic reactions, which could result in undefined glycan structures on a surface, leading to unequal and unreliable results. In this work, a glycan chip is developed by introducing a pH-responsive i-motif DNA linker to control the immobilization and isolation of glycans on chip surfaces in a pH-dependent manner. On-chip enzymatic glycosylations are optimized for uniform biosynthesis of cancer-associated Globo H hexasaccharide and its related complex glycans through stepwise quantitative analyses of isolated products from the surface. Successful interaction analyses of the anti-Globo H antibody and MCF-7 breast cancer cells with on-chip biosynthesized Globo H-related glycans demonstrate the feasibility of the structure-switchable DNA linker-based glycan chip platform for on-chip complex glycan biosynthesis and glycan-involved applications.

Expression and purification of the full-length N-acetylgalactosaminyltransferase and galactosyltransferase from Campylobacter jejuni in Escherichia coli

The successful enzymatic synthesis of various ganglioside-related oligosaccharides requires many available glycan-processing enzymes. However, the number of available glycan-processing enzymes remains limited. In this study, the full-length CgtA43456 (β-(1→4)-N-acetylgalactosaminyltransferase) and CgtB11168 (β-(1→3)-galactosyltransferase) were successfully produced from Escherichia coli through the optimization of E. coli-preferable codon usage, selection of E. coli strain, and use of the molecular chaperone GroEL-GroES (GroEL/ES). The CgtA43456 enzyme was produced as a soluble form in E. coli C41(DE3) co-expressed with codon-optimized CgtA43456 and GroEL/ES. However, soluble CgtB11168 was well expressed in E. coli C41(DE3) with only the codon-optimized CgtB11168. Rather, when co-expressed with GroEL/ES, total production of CgtB11168 was reduced. Using immobilized-metal affinity chromatography, the CgtA43456 and CgtB11168 proteins were obtained with approximately 75-78 % purity. The purified CgtA43456 showed a specific activity of 21 mU/mg using UDP-N-acetylgalactosamine and GM3 trisaccharide as donor and acceptor, respectively. The purified CgtB11168 catalyzed the transfer of galactose from UDP-Gal to GM2 tetrasaccharide with a specific activity of 16 mU/mg. We propose that they could be used as catalysts for enzymatic synthesis of GM1 ganglioside-related oligosaccharides.

Determination of Ginsenosides (Ginseng Saponins) in Dry Root Powder from Panax ginseng, Panax quinquefolius, and Selected Commercial Products by Liquid Chromatography: Interlaboratory Study

Twelve collaborating laboratories assayed 4 products, namely, Panax ginseng, Panax quinquefolius, and 2 ginseng products, for 6 ginsenosides: Rb1, Rb2, Rc, Rd, Re, andRg1. Collaborators also received a negative control for the recovery study. Pure ginsenosides were provided as reference standards for the liquid chromatography (LC) analysis and the system suitability tests. The LC analyses were performed on the methanol extract using UV detection at 203 nm. For P. ginseng, individual ginsenosides were consistent in their means; repeatability standard deviations (RSDr)rangedfrom4.17to5.09% and reproducibility standard deviations (RSDR) ranged from 7.27 to 11.3%. For P. quinquefolius, the Rb1 and Rb2 ginsenosides were higher and lower in concentration than P. ginseng, with RSDr values of 3.44 and 6.60% and RSDR values of 5.91 and 12.6% respectively, and other analytes at intermediate precisions. For ginseng commercial products, RSDr values ranged from 3.39 to 8.12%, andRSDR values ranged from 7.65 to 16.5%. A recovery study was also conducted for 3 ginsenosides: Rg1, Re, andRb1. The average recoveries were 99.9, 96.2, and 92.3%, respectively. The method is not applicable for the determination of Rg1 and Re in ginseng product at levels <300 mg/kg.

Coexpression of CMP-sialic acid transporter reduces N-glycolylneuraminic acid levels of recombinant glycoproteins in Chinese hamster ovary cells

Recombinant glycoproteins expressed in Chinese hamster ovary (CHO) cells contain two forms of sialic acids; N-acetylneuraminic acid (Neu5Ac) as a major type and N-glycolylneuraminic acid (Neu5Gc) as a minor type. The Neu5Gc glycan moieties in therapeutic glycoproteins can elicit immune responses because they do not exist in human. In the present work, to reduce Neu5Gc levels of recombinant glycoproteins from CHO cell cultures, we coexpressed cytidine-5'-monophosphate-sialic acid transporter (CMP-SAT) that is an antiporter and transports cytosolic CMP-sialic acids (both forms) into Golgi lumen. When human erythropoietin was used as a target human glycoprotein, coexpression of CMP-SAT resulted in a significant decrease of Neu5Gc level by 41.4% and a notable increase of Neu5Ac level by 21.2%. This result could be reasonably explained by our hypothesis that the turnover rate of Neu5Ac to Neu5Gc catalyzed by CMP-Neu5Ac hydroxylase would be reduced through facilitated transportation of Neu5Ac into Golgi apparatus by coexpression of CMP-SAT. We confirmed the effects of CMP-SAT coexpression on the decrease of Neu5Gc level and the increase of Neu5Ac level using another glycoprotein human DNase I. Therefore, CMP-SAT coexpression might be an effective strategy to reduce the levels of undesired Neu5Gc in recombinant therapeutic glycoproteins from CHO cell cultures.

Systemic lupus erythematosus is a risk factor for cancer: a nationwide population-based study in Korea

OBJECTIVE

Specific differences in cancer risk have been observed between systemic lupus erythematosus patients and the general population. Although meta-analyses have estimated cancer incidence in systemic lupus erythematosus patients, results have been inconclusive. Hence, we aimed to assess malignancy risk in systemic lupus erythematosus patients, compared to the risk in the general population.

METHODS

Systemic lupus erythematosus patients ( n = 21,016; mean age 41.67 ± 13.14 years; female 90.22%) were selected from the Korean National Health Insurance Service database between 2008 and 2014. Age- and sex-matched controls were randomly sampled in a 5:1 ratio ( n = 105,080).

RESULTS

During the 7 years of follow up, malignancy was detected in 763 (3.63%) systemic lupus erythematosus patients and 2667 (2.54%) controls. Systemic lupus erythematosus patients had a higher risk of malignancy than controls (odds ratio 1.44; 95% confidence interval 1.327-1.559), after multivariate adjustment. Systemic lupus erythematosus patients had a higher odds ratio for developing cervical, thyroid, ovarian, and oral cancer, as well as lymphoma, leukemia, and multiple myeloma than controls. Based on subgroup analysis, male systemic lupus erythematosus patients and patients younger than 40 years showed the highest lymphoma risk.

CONCLUSIONS

Systemic lupus erythematosus might be an independent risk factor for cancer. Therefore, the importance of cancer screening programs should be emphasized in systemic lupus erythematosus patients. Our study is the first large nationwide cohort study for evaluating the risk of cancer in systemic lupus erythematosus patients.

Remifentanil vs. Lignocaine for Attenuating the Haemodynamic Response during Rapid Sequence Induction Using Propofol: Double-Blind Randomised Clinical Trial

This study was conducted to determine whether lignocaine or remifentanil effectively attenuate the response to endotracheal intubation during rapid sequence induction. Forty-eight patients were randomly divided into three groups: Group NS (n=16) received normal saline 0.1 ml/kg, Group L (n=16) received lignocaine 1.5 mg/kg, and Group R (n=16) received remifentanil 1 /μg/kg. Anaesthesia was induced with propofol 2 mg/kg after glycopyrrolate 0.2 mg IV. Each study drug was given intravenously over 30 seconds after loss of consciousness. Cricoid pressure was applied until intubation. Succinylcholine 1.0 mg/kg was administered to facilitate tracheal intubation. After intubation, the patient's lungs were ventilated with sevoflurane 1% and nitrous oxide 50% in oxygen. Mean arterial pressure and heart rate were recorded before induction, at loss of consciousness, immediately before laryngoscopy and every minute after intubation for 10 minutes. Mean arterial pressure fell following propofol in all groups. The maximum increase in mean arterial pressure in Group NS and Group L were 46% and 38% respectively above the baseline value one minute after intubation, whereas the mean arterial pressure in Group R increased only back to the baseline value. Heart rate in Group NS and Group L were increased by 27% and 33% above baseline value respectively one minute after intubation, while that in Group R was increased only to the baseline value. The results indicate that remifentanil 1 μg/kg, but not lignocaine 1.5 mg/kg, effectively attenuates the haemodynamic response to endotracheal intubation during rapid sequence induction using propofol.

On-chip biosynthesis of GM1 pentasaccharide-related complex glycans

A novel strategy for on-chip enzymatic glycosylation of complex glycans and direct analysis of glycan-related interactions is reported.

Survival outcome differences based on treatments used and knowledge of the primary tumour site for patients with cancer of unknown and known primary in Ontario

Introduction

Patients with cancer of unknown primary (cup) have pathologically confirmed metastatic tumours with unidentifiable primary tumours. Currently, very little is known about the relationship between the treatment of patients with cup and their survival outcomes. Thus, we compared oncologic treatment and survival outcomes for patients in Ontario with cup against those for a cohort of patients with metastatic cancer of known primary site.

Methods

Using the Ontario Cancer Registry and the Same-Day Surgery and Discharge Abstract databases maintained by the Canadian Institute for Health Information, we identified all Ontario patients diagnosed with metastatic cancer between 1 January 2000 and 31 December 2005. Ontario Health Insurance Plan treatment records were linked to identify codes for surgery, chemotherapy, or therapeutic radiation related to oncology. Multivariable Cox regression models were constructed, adjusting for histology, age, sex, and comorbidities.

Results

In 45,347 patients (96.3%), the primary tumour site was identifiable, and in 1743 patients (3.7%), cup was diagnosed. Among the main tumour sites, cup ranked as the 6th largest. The mean Charlson score was significantly higher (p < 0.0001) in patients with cup (1.88) than in those with a known primary (1.42). Overall median survival was 1.9 months for patients with cup compared with 11.9 months for all patients with a known-primary cancer. Receipt of treatment was more likely for patients with a known primary site (n= 35,012, 77.2%) than for those with cup (n = 891, 51.1%). Among patients with a known primary site, median survival was significantly higher for treated than for untreated patients (19.0 months vs. 2.2 months, p < 0.0001). Among patients with cup, median survival was also higher for treated than for untreated patients (3.6 months vs. 1.1 months, p < 0.0001).

Conclusions

In Ontario, patients with cup experience significantly lower survival than do patients with metastatic cancer of a known primary site. Treatment is associated with significantly increased survival both for patients with cup and for those with metastatic cancer of a known primary site.

Systemic lupus erythematosus is a risk factor for cardiovascular disease: a nationwide, population-based study in Korea

OBJECTIVE

To investigate the incidence and clinical significance of cardiovascular disease in systemic lupus erythematosus patients.

METHODS

We included systemic lupus erythematosus patients ( n = 18,575) without previous cardiovascular disease and age- and sex-matched individuals without systemic lupus erythematosus (controls; n = 92,875) from the Korean National Health Insurance Service database (2008-2014). Both cohorts were followed up for incident cardiovascular disease and death until 2015.

RESULTS

During follow up, myocardial infarction occurred in 203 systemic lupus erythematosus patients and 325 controls (incidence rate: 1.76 and 0.56 per 1000 person-years, respectively), stroke occurred in 289 patients and 403 controls (incidence rate: 2.51 and 0.70 per 1000 person-years, respectively), heart failure occurred in 358 patients and 354 controls (incidence rate 3.11 and 0.61 per 1000 person-years, respectively), and death occurred in 744 patients and 948 controls (incidence rate 6.54 and 1.64 per 1000 person-years, respectively). Patients with systemic lupus erythematosus had higher risks for myocardial infarction (hazard ratio: 2.74, 95% confidence interval: 2.28-3.37), stroke (hazard ratio: 3.31, 95% confidence interval: 2.84-3.86), heart failure (hazard ratio: 4.60, 95% confidence interval: 3.96-5.35), and cardiac death (hazard ratio: 3.98, 95% confidence interval: 3.61-4.39).

CONCLUSIONS

Here, systemic lupus erythematosus was an independent risk factor for cardiovascular disease, thus cardiac assessment and management are critical in systemic lupus erythematosus patients.

Gemigliptin, a novel dipeptidyl peptidase-IV inhibitor, exerts a synergistic cytotoxicity with the histone deacetylase inhibitor PXD101 in thyroid carcinoma cells

PURPOSE

The influence of the dipeptidyl peptidase-IV inhibitor gemigliptin alone or in combination with the histone deacetylase inhibitor PXD101 on survival of thyroid carcinoma cells was investigated.

METHODS

SW1736, TPC-1, 8505C and BCPAP human thyroid carcinoma cells were used. To assess cell survival, cell viability, the percentage of viable cells and dead cells, cytotoxic activity, ATP levels and FACS analysis were measured. To validate the impact of gemigliptin combined with PXD101, the interactions were estimated by obtaining combination index in cells treated with two agents.

RESULTS

In cells treated with gemigliptin or PXD101, cell viability, the percentage of viable cells and ATP levels were reduced, and the percentage of dead cells and cytotoxic activity were elevated. In cells treated with both gemigliptin and PXD101, compared with PXD101 alone, cell death was augmented, and all of the combination index values were lower than 1.0, suggesting the synergism between gemigliptin and PXD101. The percentage of apoptotic cells, and the protein levels of Bcl2 and cleaved poly (ADP-ribose) polymerase were elevated, and the protein levels of xIAP and survivin were reduced. The protein levels of phospho-Akt and phospho-AMPK were elevated, and cell migration was reduced.

CONCLUSIONS

Our results demonstrate that gemigliptin induces cytotoxicity in thyroid carcinoma cells. Moreover, gemigliptin has a synergistic activity with PXD101 in the induction of cell death through involvement of Bcl2 family proteins, xIAP and survivin as well as mediation of Akt and AMPK in thyroid carcinoma cells.

Two-dimensional plasmonic grating for increased quantum efficiency in midwave infrared nBn detectors with thin absorbers

We demonstrate a strategy for increasing the operating temperatures of nBn midwave infrared (MWIR) focal plane arrays, based on the use of two-dimensional plasmonic gratings to enhance the quantum efficiency (QE) of structures with very thin absorbers. Reducing the absorber volume correspondingly reduces the dark current in a diffusion-limited photodiode, while light trapping mediated by the plasmonic grating increases the net absorbance to maintain high QE. The plasmonically enhanced nBn MWIR sensors with absorber thicknesses of only 0.5 μm exhibit peak internal QEs as high as 57%, which enables a 5-fold reduction in dark current. Numerical simulations indicate the potential for further improvement.

Perisomatic changes in h-channels regulate depressive behaviors following chronic unpredictable stress

Chronic stress can be a precipitating factor in the onset of depression. Lentiviral-mediated knockdown of HCN1 protein expression and reduction of functional I_h produce antidepressant behavior. However, whether h-channels are altered in an animal model of depression is not known. We found that perisomatic HCN1 protein expression and I_h-sensitive physiological measurements were significantly increased in dorsal but not in ventral CA1 region/neurons following chronic unpredictable stress (CUS), a widely accepted model for major depressive disorder. Cell-attached patch clamp recordings confirmed that perisomatic I_h was increased in dorsal CA1 neurons following CUS. Furthermore, when dorsal CA1 I_h was reduced by shRNA-HCN1, the CUS-induced behavioral deficits were prevented. Finally, rats infused in the dorsal CA1 region with thapsigargin, an irreversible inhibitor of the SERCA pump, exhibited anxiogenic-like behaviors and increased I_h, similar to that observed following CUS. Our results suggest that CUS, but not acute stress, leads to an increase in perisomatic I_h in dorsal CA1 neurons and that HCN channels represent a potential target for the treatment of major depressive disorder.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.

Diatom-Inspired Silica Nanostructure Coatings with Controllable Microroughness Using an Engineered Mussel Protein Glue to Accelerate Bone Growth on Titanium-Based Implants

Silica nanoparticles (SiNPs) have been utilized to construct bioactive nanostructures comprising surface topographic features and bioactivity that enhances the activity of bone cells onto titanium-based implants. However, there have been no previous attempts to create microrough surfaces based on SiNP nanostructures even though microroughness is established as a characteristic that provides beneficial effects in improving the biomechanical interlocking of titanium implants. Herein, a protein-based SiNP coating is proposed as an osteopromotive surface functionalization approach to create microroughness on titanium implant surfaces. A bioengineered recombinant mussel adhesive protein fused with a silica-precipitating R5 peptide (R5-MAP) enables direct control of the microroughness of the surface through the multilayer assembly of SiNP nanostructures under mild conditions. The assembled SiNP nanostructure significantly enhances the in vitro osteogenic cellular behaviors of preosteoblasts in a roughness-dependent manner and promotes the in vivo bone tissue formation on a titanium implant within a calvarial defect site. Thus, the R5-MAP-based SiNP nanostructure assembly could be practically applied to accelerate bone-tissue growth to improve the stability and prolong the lifetime of medical implantable devices.

Increase in resting heart rate over 2 years predicts incidence of diabetes: A 10-year prospective study

OBJECTIVE

The association between resting heart rate (RHR) and the development of diabetes has yet to be fully elucidated, and the relationship between changes in RHR and incidence of diabetes also remains unclear. Our study aimed to investigate the association between changes in RHR over 2 years and the risk of diabetes.

METHODS

A total of 7416 adults without diabetes were included. All had participated in the Korean Genome and Epidemiology Study, a community-based, 10-year prospective study in which RHR was measured at baseline and 2 years later. Incident diabetes was defined as fasting blood glucose ≥126mg/dL, 2-h post-load glucose ≥200mg/dL during a 75-g oral glucose tolerance test or current use of diabetes medication. The relative risk of diabetes associated with the 2-year change in RHR was calculated using Cox models.

RESULTS

During the 10-year follow-up, 1444 (19.5%) developed diabetes. Compared with RHR increases <5 beats per minute (bpm) over 2 years, increases >10bpm were significantly associated with development of diabetes (adjusted hazard ratio: 1.31, 95% confidence interval: 1.06-1.60), even after adjusting for glycometabolic parameters and baseline RHR. This significant association was attenuated in people who exercised regularly (P=0.650), but remained significant in those not doing any regular exercise (P=0.010).

CONCLUSION

An increase in RHR over a 2-year follow-up period is significantly associated with a risk of diabetes, independently of baseline RHR and glycometabolic parameters. Further investigations into ways to control RHR as a potential preventative measure against the development of diabetes are now needed.

Distribution of bisphenol A in the neuroendocrine organs of female rats

The distribution of 14C-bisphenol A (BPA) in plasma and neuroendocrine organs was determined in Fischer 344 female rats following three oral doses (0.1, 10 or 100 mg/kg). Plasma and tissue maximum concentrations (Cmax) were reached within 15-30 min of dosing. Plasma areas-under-the-curve (AUC) ranged from 0.06 to 53.9 mg-h/mL. The AUCs of the pituitary gland and uterus/gonads were 16-21% higher than that of plasma. The AUCs of hypothalamus and the rest of the brain were 43.7% and 77% of the plasma AUCs, respectively. In the brain tissue, the exposure increased linearly with the oral dose, as the dose was increased from 0.1 to 10 and 100 mg/kg; the exposure in the brain relative to the plasma increased by factors of 1, 1.19 and 1.24. This indicates that the brain barrier systems do not limit the access of the lipophilic BPA to the brain. The increases of the uterus/gonads relative to the plasma were 1, 1.07 and 1.04. Tissue partitioning was also examined in vitro by the uptake of 14C-BPA. The BPA tissue/blood partition coefficients were as follows: heart, 7.5; liver, 6.1; kidney, 6.4; fat, 3.6; muscle, 2.6; breast, 3.6; ovaries, 9.1; uterus, 5.9; stomach, 5.1; and small intestine, 6.7. The tissue/cerebrospinal fluid partition coefficients were as follows: pituitary gland, 12.8; brain stem, 6.1; cerebellum, 6.4; hippocampus, 7.1; hypothalamus, 6.1; frontal cortex, 4.9; and caudate nucleus, 6.8.

Interband cascade lasers with long lifetimes

Narrow-ridge interband cascade lasers were subjected to accelerated aging. The aging curves were statistically evaluated by a log-normal distribution of the failure time, and by the mixed effects of the degradation parameters. Based on 10,000 h of output power trend data for lasers operating at 90°C and the maximum cw power, an unexpectedly long lifetime is predicted. The projected lifetimes range from about 500,000 h (57 years) for the linear degradation model to 183,000 h (21 years) for the exponential one.

Generation of Charged Nanoparticles During Thermal Evaporation of Silver at Atmospheric Pressure

The generation of charged silver nanoparticles in the gas phase during thermal evaporation of silver at atmospheric pressure was confirmed by the nano-differential mobility analyzer (DMA). Effects of the evaporation temperature, the nitrogen gas flow rate and the amount of silver to be evaporated on the size distribution of charged nanoparticles (CNPs) were examined. Both positively and negatively-charged nanoparticles were generated under all processing conditions adopted in this study. The deposition behavior of CNPs was affected by the gas flow, which is affected by the temperature gradient in the reactor and by the applied electric bias. The electric bias, which not only enhanced the film growth rate but also produced a much denser film surface, turned out to be an important process parameter under the condition where an appreciable amount of CNPs is generated.

Gain and loss as a function of current density and temperature in interband cascade lasers

We characterize the internal efficiency, internal loss, and optical gain versus current density in 7-stage interband cascade lasers operating at λ=3.1 and 3.45 μm using a cavity-length study of the external differential quantum efficiency (EDQE) and threshold current density at temperatures between 300 and 345 K. We find that the pronounced efficiency droop of the EDQE at high current densities is primarily due to an increase in the internal loss rather than a reduction in the internal efficiency. On the other hand, if the current density J is fixed, the temperature variation of the EDQE at that J is due primarily to a decrease of the internal efficiency. The gain versus current density is fit well by a logarithmic relationship, although the magnitude of the experimental gain is >20% below the theoretical estimate.

Mid-infrared multi-mode absorption spectroscopy using interband cascade lasers for multi-species sensing

An interband cascade laser (ICL) operating at 3.7 μm has been used to perform multimode absorption spectroscopy, MUMAS, at scan rates up to 10 kHz. Line widths of individual modes in the range 10-80 MHz were derived from isolated lines in the MUMAS signatures of HCl. MUMAS data for methane covering a spectral range of 30 nm yielded a detection level of 30 μbar·m for 1 s measurement time at 100 Hz. Simultaneous detection of methane, acetylene, and formaldehyde in a gas mixture containing all three species is reported.

Rg3-enriched Korean Red Ginseng improves vascular function in spontaneously hypertensive rats

Background

Panax ginseng has distinct and impressive health benefits, such as improved blood pressure and immune system functioning. Rg3-enriched Korean Red Ginseng (REKRG) isolated from Korean Red Ginseng contains a high percentage of Rg3.

Methods

In this study, we examined the effects of REKRG on endothelial cell nitric oxide synthase (eNOS) activation and adhesion molecules in endothelial cells and vascular function in rats.

Results

REKRG dose-dependently increased eNOS phosphorylation and nitric oxide (NO) production in endothelial cells. In addition, REKRG markedly inhibited the tumor necrosis factor-α (TNF-α)-mediated induction of intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expressions in endothelial cells. REKRG improved endothelium-dependent vasorelaxation in the Wistar-Kyoto (WKY) rat and spontaneously hypertensive rats (SHRs) compared with controls. Furthermore, REKRG treatment for 6 weeks increased serum NO levels and reduced the mean aortic intima-media thickness compared with controls.

Conclusion

Taken together, these results suggest that REKRG increased vascular function and improved immune system functioning. Therefore, REKRG is a very useful food for preventing or improving various cardiovascular diseases.

Antifeedants against Acusta despesta from the Japanese Cedar, Cryptomeria japonica

During our studies on the components in Japanese cedar, Cryptomeria japonica, we found that the crude methanol extract of C. japonica showed intense antifeeding activity against one snail species, Acusta despesta, which is well-known as a pest of many vegetables and crops.

The active components in the extract were separated into the hexane and ethyl acetate soluble fractions. From the active ethyl acetate soluble fraction, two norlignans, sequirin-C and agatharesinol, were isolated and identified as the active compounds. Both compounds inhibited feeding behavior of A. despesta at 30 μg/cm2 and 40 μg/cm2 concentrations, respectively, when applied by an eggplant leaf or filter paper containing 20 μl of 5% sucrose solution.

Expression of heat shock protein 90 in the kidneys of diabetic db/db mice

OBJECTIVE

To identify novel genes regulated in diabetic nephropathy.

MATERIALS AND METHODS

Total RNA from the renal cortex of db/+ and db/db mice was isolated and DNA microarrays specific for diabetes signaling pathways were used for expression profiling. Expression of mRNA and protein was determined by RT-PCR and western blotting. The terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling (TUNEL) assay and immunohistochemical staining were assessed in renal cortex of db/db mice.

RESULTS

Microarray data revealed that 7 genes show up- or down-regulated pattern and diabetic mice specifically decreased heat shock protein (Hsp) 90α expression of genes compared to control mice (diabetic mice 0.68 vs. control mice 1 relative density). Expression of Hsp90α mRNA and Hsp90 protein was significantly decreased in the renal cortex of diabetic mice. However, Hsp70 mRNA and protein expression was not changed. Apoptosis was increased in glomeruli of diabetic mice due to increased expression of cleaved caspase-3 and Bax.

CONCLUSIONS

Our results suggest that Hsp 90 expression was decreased in diabetic glomeruli and decreased Hsp90 expression may mediate podocyte apoptosis in type 2 diabetic kidneys.

Akt inhibition enhances the cytotoxic effect of apigenin in combination with PLX4032 in anaplastic thyroid carcinoma cells harboring BRAFV600E

Aim of the present study was to evaluate the effect of apigenin in combination with BRAFV600E inhibitor PLX4032 on cell survival, and to investigate the influence of Akt inhibition on the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E. In 8505C and FRO cells harboring BRAFV600E, after treatment of apigenin and PLX4032, the cell viability decreased, and the percentage of dead cells increased in a time- and concentration-dependent manner, respectively. In apigenin- and PLX4032- treated cells, compared with apigenin alone-treated cells, the cell viability was lessened, and the percentage of dead cells was multiplied. In the addition of PLX4032 to apigenin, compared with the treatment of apigenin alone, the protein levels of cleaved PARP-1 and cleaved caspase-3 were elevated, and phospho-ERK protein levels were reduced, and the protein levels of total ERK, c-Myc, BRAF, phospho-Akt, phospho-p70S6K and phospho-4EBP1 were not varied. Compared with the treatment of PLX4032 alone, phosphop70S6K protein levels were reduced, and the other protein levels were not altered. Phospho-ERK protein levels were reduced only in 8505C cells. Under the co-treatment of apigenin and PLX4032, administration of the PI3K inhibitor wortmannin further decreased the cell viability, and increased the percentage of dead cells. In conclusion, our results suggest that PLX4032 augments apigenin-induced cytotoxicity in ATC cells harboring BRAFV600E. Moreover, Akt suppression potentiates the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E.

Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV

OBJECTIVES

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

METHODS

Cross-sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007-209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

RESULTS

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78-0.98, and aOR = 0.7 and 95% CI = 0.60-0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81-0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49-1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18-1.68).

CONCLUSIONS

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.

(Micro)spectroscopic analyses of particle size dependence on arsenic distribution and speciation in mine wastes

The chemical speciation and distribution of potentially toxic metal(loid)s in mine wastes is critical to assessing the risks posed by these wastes and predicting the potential bioavailability of the metal(loid)s present. Of additional potential importance is the role of particle size in the fate, transport, and toxicity of contaminated mining materials. Spectroscopic analyses of size-separated mine tailings and adjacent background samples from the Randsburg Historic Mining District, California were conducted to quantify the speciation and distribution of arsenic (As) as a function of particle size. Micro-X-ray fluorescence (μXRF) mapping of separate size fractions was used to identify multiple populations of particles with different As:Fe ratios, indicating a variety of distinct arsenic-bearing species. Bulk extended X-ray absorption fine structure (EXAFS) spectroscopy identified phases including arseniosiderite, Ca2Fe3(3+)(AsO4)3O3·3H2O, and As(V) sorbed to iron hydroxides (ferrihydrite, goethite), confirming a strong statistical correlation between arsenic and iron observed in both μXRF studies and bulk chemical analyses. Differences in As speciation between the mine tailings and background samples also suggest that weathering of crystalline As-bearing phases in tailings leads to sorption of dissolved arsenic to iron hydroxides in nontailings background material.

Inhibition of p21 and Akt potentiates SU6656-induced caspase-independent cell death in FRO anaplastic thyroid carcinoma cells

SU6656 is a small-molecule indolinone that selectively inhibits Src family kinase and induces death of cancer cells. The aim of the present study was to investigate the influence of SU6656 on cell survival and to assess the role of p21 and PI3K/Akt signaling in cell survival resulting from SU6656 treatment in anaplastic thyroid carcinoma (ATC) cells. When 8505C, CAL62, and FRO ATC cells were treated with SU6656, the viability of 8505C and CAL62 ATC cells decreased only after treatment with SU6656 at a dosage of 100 μM for 72 h, while the viability of FRO ATC cells decreased after treatment with SU6656 in a concentration- and time-dependent manner. Cell viability was not changed by pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk. Phospho-Src protein levels were reduced, and p21 protein levels were elevated. Phospho-ERK1/2 protein levels were multiplied without alteration of total ERK1/2, total Akt, and phospho-Akt protein levels. Regarding FRO ATC cells, the decrement of cell viability, the increment of cleaved PARP-1 protein levels, and the decrement of phospho-Src protein levels were shown in p21 siRNA- or LY294002-pretreated cells compared to SU6656-treated control cells. ERK1/2 siRNA transfection did not affect cell viability and protein levels of cleaved PARP-1, p21, and Akt. In conclusion, these results suggest that SU6656 induces caspase-independent death of FRO ATC cells by overcoming the resistance mechanism involving p21 and Akt. Suppression of p21 and Akt enhances the cytotoxic effect of SU6656 in FRO ATC cells.

A retrospective study of clinical outcomes of α-blocker or finasteride monotherapy followed by combination therapy: determination of the period of combination therapy of α-blocker and finasteride

AIMS

We investigated outcomes after discontinuing alpha-blockers or finasteride in patients who initially received combination therapy and compared differences by duration of combination therapy.

METHODS

Patients with international prostate symptom score ≥ 8, serum prostatic-specific antigen (PSA) < 4 ng/ml, prostate volume > 25 cm(3) and combination therapy of alpha-blockers and finasteride for more than 6 months were classified into three groups. Group 1 continued combination therapy; group 2, alpha-blockers monotherapy; and group 3, finasteride monotherapy. All parameters were evaluated before and after changing to monotherapy. Patients who received combination therapy for 6-9 months and those who received combination therapy for longer were comparatively analysed.

RESULTS

Mean age of the 106 patients was 66.9 ± 7.8 years. No significant differences in baseline symptom scores, PSA or prostate volume were found. Following combination therapy, symptom scores, and quality of life (QoL) decreased for all groups. Group 1 maintained decreased PSA and prostate volume, and improved uroflowmetric profiles. No differences in uroflowmetric parameters were found after 6 months. Group 2 maintained improved symptoms, QoL and uroflowmetric profiles, although PSA and prostate volume returned to baseline. Group 3 maintained lowered PSA and prostate volume, whereas Qmax returned to baseline. QoL scores showed no change. Patients who received combination therapy for ≥9 months improved more in symptoms and QoL than those who received shorter combination therapy.

CONCLUSIONS

Discontinuation of alpha-blockers or finasteride after combination therapy for ≥ 6 months maintained improvements in symptoms. The appropriate period of combination therapy was ≥ 9 months.

CCAAT/Enhancer-binding protein-homologous protein sensitizes to SU5416 by modulating p21 and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma cells

SU5416, vascular endothelial cell growth factor receptor inhibitor, suppresses hypoxia-induced angiogenesis, growth, proliferation, and metastasis in cancer cells. CCAAT/enhancer-binding protein-homologous protein (CHOP) has pivotal roles in regulation of growth and survival. In the present study, we evaluated the effects of SU5416 on cell survival, p21, and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma (ATC) cells. Moreover, we investigated the roles of CHOP in cell survival under condition of SU5416 treatment in FRO ATC cells. After SU5416 treatment, cell viability, PARP-1, and caspase-3 protein levels were not changed. p53 and p27 protein levels decreased while p21 protein levels increased. Phospho-Akt protein levels were not altered. In SU5416-treated situation, cell viability was not different before and after administration of either p21 siRNA or LY294002 whereas it was lessened after co-administration of p21 siRNA and LY294002. Compared to SU5416 treatment alone, cell viability was reduced with CHOP plasmid but it was unchanged with CHOP siRNA. PARP-1 and caspase-3 protein levels with CHOP plasmid were elevated whereas the protein levels with CHOP siRNA were similar. While CHOP plasmid transfection diminished p21 and phospho-Akt protein levels, CHOP siRNA transfection did not alter the protein levels. In conclusion, these results suggest that CHOP may sensitize FRO ATC cells to SU5416 thereby inhibiting cell survival by modulating p21 and PI3K/Akt signal pathway. Furthermore, these findings imply that CHOP may be a possible candidate as the chemosensitizing factor for induction of cytotoxicity in ATC cells exposed to SU5416.

Factors of compliance in patients with hypercholesterolemia using rosuvastatin in primary care

BACKGROUND

In order to evaluate the factors of compliance with a lipid lowering therapy, a prospective observational study of patients with hypercholesterolemia using rosuvastatin was carried out.

METHODS

A total of 2,607 patients who were newly prescribed rosuvastatin were enrolled from 32 family physicians in Korea from March 2009 to December 2009. Of them, 301 patients were excluded due to incomplete data or follow-up compliance data. The patients were regularly observed to ascertain the compliance associated with rosuvastatin at intervals of 12 and 24 weeks. We collected risk factors for the compliance using a structured questionnaire. The criteria for evaluating compliance are to measure clinic attendance, to assess the continuity of therapy, and to calculate the percentage of doses taken.

RESULTS

Among a total of 2,306 patients, the degree of compliance was 54.1%. According to logistic regression analysis, the factors for compliance with the lipid lowering drug included old age (odds ratio [OR], 2.68; 95% confidence interval [CI], 2.09 to 3.45), frequent exercise (OR, 1.76; 95% CI, 1.43 to 2.18), previous statin therapy (OR, 4.02; 95% CI, 3.22 to 5.01), hypertension (OR, 1.80; 95% CI, 1.48 to 2.19), diabetes mellitus (OR, 2.20; 95% CI, 1.69 to 2.87), concomitant medication (OR, 2.28; 95% CI, 1.88 to 2.77), and high coronary heart disease (CHD) risk category (OR, 1.82; 95% CI, 1.39 to 2.38). The compliance decreased with high low density lipoprotein cholesterol levels (OR, 0.20; 95% CI, 0.16 to 0.26).

CONCLUSION

The compliance of patients using rosuvastatin was 54.1% in primary care. The factors related to higher compliance were old age, regular exercise, previous statin therapy, concomitant medication, presence of hypertension or diabetes, and higher CHD risk level.

Functional interaction analysis of GM1-related carbohydrates and Vibrio cholerae toxins using carbohydrate microarray

The development of analytical tools is important for understanding the infection mechanisms of pathogenic bacteria or viruses. In the present work, a functional carbohydrate microarray combined with a fluorescence immunoassay was developed to analyze the interactions of Vibrio cholerae toxin (ctx) proteins and GM1-related carbohydrates. Ctx proteins were loaded onto the surface-immobilized GM1 pentasaccharide and six related carbohydrates, and their binding affinities were detected immunologically. The analysis of the ctx-carbohydrate interactions revealed that the intrinsic selectivity of ctx was GM1 pentasaccharide ≫ GM2 tetrasaccharide > asialo GM1 tetrasaccharide ≥ GM3trisaccharide, indicating that a two-finger grip formation and the terminal monosaccharides play important roles in the ctx-GM1 interaction. In addition, whole cholera toxin (ctxAB(5)) had a stricter substrate specificity and a stronger binding affinity than only the cholera toxin B subunit (ctxB). On the basis of the quantitative analysis, the carbohydrate microarray showed the sensitivity of detection of the ctxAB(5)-GM1 interaction with a limit-of-detection (LOD) of 2 ng mL(-1) (23 pM), which is comparable to other reported high sensitivity assay tools. In addition, the carbohydrate microarray successfully detected the actual toxin directly secreted from V. cholerae, without showing cross-reactivity to other bacteria. Collectively, these results demonstrate that the functional carbohydrate microarray is suitable for analyzing toxin protein-carbohydrate interactions and can be applied as a biosensor for toxin detection.

Diagnostic efficacy of gadoxetic acid-enhanced MRI for the detection and characterisation of liver metastases: comparison with multidetector-row CT

OBJECTIVES

We compared the diagnostic performance of gadoxetic acid-enhanced MRI and 16-slice multidetector CT (MDCT) with respect to their abilities to detect hepatic metastases and differentiate hepatic metastases from hepatic cysts and haemangiomas.

METHODS

67 patients with 110 liver metastases (size 0.3-2.5 cm), 33 haemangiomas (size 0.5-1.5 cm) and 17 cysts (size 0.3-1.0 cm) underwent 4-phase MDCT and gadoxetic acid-enhanced MRI, including early dynamic phases, post-contrast T(2) weighted turbo spin echo sequences and 20 min hepatocyte-selective phases. Two observers independently analysed each image in random order. Sensitivity and diagnostic accuracy for lesion detection and differentiation for MDCT and gadoxetic acid-enhanced MRI were calculated using receiver operating characteristic analysis.

RESULTS

For both observers, the Az values of gadoxetic acid-enhanced MRI (mean, 0.982 and 0.981) were significantly higher than the Az values of MDCT (mean, 0.839 and 0.892) (p<0.05) for the detection of metastases and for the differentiation of metastases from haemangiomas and cysts. Sensitivities of gadoxetic acid-enhanced MRI with regard to the detection and characterisation of liver metastases (mean, 96.9% and 96.0%) were significantly higher than those of MDCT (mean, 78.7% and 75.0%) (p<0.05).

CONCLUSION

Gadoxetic acid-enhanced MRI showed higher diagnostic accuracy and sensitivity than did MDCT for the detection of hepatic metastases and for the differentiation between hepatic metastases and hepatic haemangiomas or cysts.