Latent Toehold-Mediated DNA Circuits Based on a Bulge-Loop Structure for Leakage Reduction and Its Application to Signal-Amplifying DNA Logic Gates

DNA circuits based on successive toehold-mediated DNA displacement reactions, particularly entropy-driven DNA circuit (EDC) systems, have attracted considerable attention as powerful enzyme-free tools for dynamic DNA nanotechnology. However, background leakage (noise signal) often occurs when the circuit is executed nonspecifically, even in the absence of the appropriate catalyst DNA (input). This study designed and developed a new latent toehold-mediated DNA circuit (LDC) system that relies on a bulge-loop structure as a latent toehold toward leakage reduction. Furthermore, the number (size) of nucleotides (nt) in the bulge-loop is found to play a significant role in the performance (i.e., leakage, signal, and kinetics) of LDC systems. In fact, the signal rate for the LDC systems increased as the number of nt in the bulge-loop increased from 4 to 8, whereas the leakage rate of the LDC systems with bulge-loops of 7 nt or less was low, but the leakage rate of the LDC system with a bulge-loop of 8 nt increased significantly. Note that the LDC system with the optimal bulge-loop (7 nt) was capable of not only reducing the leakage but also accelerating the circuit speed without any signal loss, unlike methods of reducing the leakage by reducing the signal reported previously for the conventional EDC systems. These facts indicate that the 7 nt bulge-loop acts as a "latent" toehold for the DNA circuit system. By using the amplification function of output signals with an accelerated circuit and reduced leakage, our LDC system with a 7 nt bulge-loop could be applied directly and successfully to signal-amplifying DNA logic gates such as OR and AND gates, and thus, sufficient output signals could be obtained even with a small amount of input. These findings reveal that our LDC systems with a bulge-loop structure can replace the conventional EDC system and have enormous potential in the field of DNA nanotechnology.

Acceleration of DNA Hybridization Chain Reactions on 3D Nanointerfaces of Magnetic Particles and Their Direct Application in the Enzyme-Free Amplified Detection of microRNA

Accelerated DNA hybridization chain reactions (HCRs) using DNA origami as a scaffold have received considerable attention in dynamic DNA nanotechnology. However, tailor-made designs are essential for DNA origami scaffolds, hampering the practical application of accelerated HCRs. Here, we constructed the semilocalized HCR and localized HCR systems using magnetic beads (MBs) as a simple scaffold to explore them for the enzyme-free miR-21 detection. The semilocalized HCR system relied on free diffusing one hairpin DNA and MBs immobilized with another hairpin DNA, and the localized HCR system relied on MBs coimmobilized with two hairpin DNAs. We demonstrated that the DNA density on MBs plays a critical role in HCR kinetics and limit of detection (LOD). Among semilocalized HCR systems, MBs with a medium DNA density showed a faster HCR and lower LOD (10 pM) than the diffusive (conventional) HCR system (LOD: 86 pM). In contrast, the HCR further accelerated for the localized HCR systems as the DNA density increased. The localized HCR system with the highest DNA density showed the fastest HCR and the lowest LOD (533 fM). These findings are of great importance for the rational design of accelerated HCRs using simple scaffolds for practical applications.

Simple Single-Legged DNA Walkers at Diffusion-Limited Nanointerfaces of Gold Nanoparticles Driven by a DNA Circuit Mechanism

We designed and prepared a single-legged DNA walker that relies on the creation of a simple diffusion-limited nanointerface on a gold nanoparticle (DNA/PEG⁽⁺⁾-GNP) track co-modified with fluorescence-labeled hairpin DNA and poly(ethylene glycol) (PEG) containing a positively charged amino group at one end. The movement of our single-legged DNA walker is driven by an enzyme-free DNA circuit mechanism through cascading toehold mediated DNA displacement reactions (TMDRs) using fuel hairpin DNAs. The acceleration of TMDRs was observed for the DNA/PEG⁽⁺⁾-GNP track through electrostatic interaction between the positively charged track and negatively charged DNAs, resulting in the acceleration of the DNA circuit and amplification of the fluorescence signal. Furthermore, the DNA/PEG⁽⁺⁾-GNP track allowed autonomous and persistent movement of a walker DNA strand on the same GNP track, because the intraparticle DNA circuit occurred preferentially by preventing diffusion of the negatively charged free walker DNA strand from near the positively charged tracks into solution through electrostatic interaction. Based on comparative study of kinetics of TMDRs and DNA walking behaviors, it is to be noted that the DNA/PEG⁽⁺⁾-GNP track showed the fastest DNA circuit reaction (walking rate) and the largest number of steps taken by the walker DNA strand compared to other GNP tracks with varying nanointerfaces that differ in terms of their type of charges (no and negative charges), density of positive charges, and number of hairpin DNAs per GNP track. These facts reveal that the positive charges on the GNP track play an important role in the acceleration of the DNA circuit, as well as the successful walking motion of the single-legged DNA strand. By using the fluorescence signal amplification functions, our single-legged DNA walker could be applied directly and successfully to enzyme-free miRNA-detection systems. The miRNA-detection system provided higher discrimination of other mismatched miRNAs and higher sensitivity (the lowest LOD: 4.0 pM) when compared to other miRNA-detection systems based on other GNP tracks without positive charges. Unlike existing single-legged DNA walkers, our single-legged DNA walkers do not require complex processes, such as immobilization of the walker DNA strand on the tracks and precise adjustment of the sequence of walker DNA. Therefore, our strategy, based on the creation of diffusion-limited nanointerfaces, has enormous potential for the applications of single-legged DNA walkers to biosensors, bioimaging, and computing.

Dynamically Programmed Switchable DNA Hydrogels Based on a DNA Circuit Mechanism

Biological stimuli-responsive DNA hydrogels have attracted much attention in the field of medical engineering owing to their unique phase transitions from gel to sol through cleavage of DNA cross-linking points in response to specific biomolecular inputs. In this paper, a new class of biological stimuli-responsive DNA hydrogels with a dynamically programmed DNA system that relies on a DNA circuit system through cascading toehold-mediated DNA displacement reactions is constructed, allowing the catalytic cleavage of cross-linking points and main chains in response to an appropriate DNA input. The dynamically programmed DNA hydrogels exhibit a significant sharp phase transition from gel to sol in comparison to another DNA hydrogel showing noncatalytic cleavage of cross-linking points due to synchronization of the catalytic cleavage of cross-linking points and the main chains. Further, the sol-gel phase transitions of the DNA hydrogels in response to the DNA input are easily tunable by changing the cross-linking density. Additionally, with a structure-switching aptamer, DNA hydrogels encapsulating PEGylated gold nanoparticles can be used as enzyme-free signal amplifiers for the colorimetric detection of adenosine 5'-triphosphate (ATP); this detection system provides simplicity and higher sensitivity (limit of detection: 5.6 × 10^-6 m at 30 min) compared to other DNA hydrogel-based ATP detection systems.

Comparative Study of DNA Circuit System-Based Proportional and Exponential Amplification Strategies for Enzyme-Free and Rapid Detection of miRNA at Room Temperature

Because circulating microRNAs (miRNAs) have been recognized as a new class of blood-based biomarkers for various diseases, a significant challenge has been the development of point-of-care testing (POCT) systems based on detection of circulating miRNAs directly from serum. A promising approach to POCT systems is considered to be the development of enzyme-free and isothermal detection systems. Here, two types of DNA circuit system based on proportional and exponential amplification strategies were constructed using double-stranded DNA-modified magnetic beads (dsDNA-MBs) and their performances for detection of miRNA were studied comparatively. Both proportional and exponential amplification DNA circuit systems enabled the detection of target miRNA (miR-141) at room temperature without the need for additional enzymes because miR-141 acted as a catalyst for successive toehold-mediated DNA displacement reactions. A significant increase in the noise fluorescence signal was observed for the exponential amplification DNA circuit system because of the leakage (undesired DNA displacement reaction) revealed by the kinetic study on each DNA displacement reaction. Nevertheless, the exponential amplification DNA circuit system showed a lower limit of detection (LOD: 46 pM) and shorter assay time (15 min) compared to those of the proportional amplification DNA circuit system (LOD: 103 pM at 180 min). It is most likely that the exponential amplification DNA circuit system enabled amplification of both the signals and target miR-141, whereas the proportional amplification DNA circuit system enabled amplification of the signals alone. In addition, the exponential amplification DNA circuit system was able to discriminate between mismatched base sequences in miR-200 family members and specifically detect miR-141 even in the presence of serum. These findings are important for the rational design for POCT systems.

An Efficient Particle-Based DNA Circuit System: Catalytic Disassembly of DNA/PEG-Modified Gold Nanoparticle-Magnetic Bead Composites for Colorimetric Detection of miRNA

An efficient particle-based DNA circuit system for a new colorimetric miRNA assay is designed and devised based on a catalytic disassembly strategy through a target miRNA-triggered DNA circuit mechanism. The new particle-based DNA circuit system shows a rapid color change as well as significant improvement of sensitivity without need for other enzymes or instruments.

Resveratrol directly targets DDX5 resulting in suppression of the mTORC1 pathway in prostate cancer

Resveratrol has various attractive bioactivities, such as prevention of cancer, neurodegenerative disorders, and obesity-related diseases. Therefore, identifying its direct binding proteins is expected to discover druggable targets. Sirtuin 1 and phosphodiesterases have so far been found as the direct molecular targets of resveratrol. We herein identified 11 novel resveratrol-binding proteins, including the DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5, also known as p68), using resveratrol-immobilized beads. Treatment with resveratrol induced degradation of DDX5 in prostate cancer cells. Depletion of DDX5 caused apoptosis by inhibiting mammalian target of rapamycin complex 1 (mTORC1) signaling. Moreover, knockdown of DDX5 attenuated the inhibitory activities of resveratrol against mTORC1 signaling and cancer cell growth. These data show that resveratrol directly targets DDX5 and induces cancer cell death by inhibiting the mTORC1 pathway.

Changes in the Small Intestine of a Cat Associated with Barium Sulphate Following Contrast Radiography

A 7-year-old neutered male domestic short-haired cat that had undergone contrast radiography of the bowel with barium sulphate after acute episodes of vomiting 2 months previously, was presented with chronic vomiting, anorexia and weight loss. Abdominal radiography and ultrasonography revealed residual contrast enhancement and an obstruction of the small intestine. A contracted and stenosed ileum and distal jejunum were identified by exploratory laparotomy and surgically resected; subsequently, the clinical signs resolved. Histopathological examination of the ileum revealed mucosal ulceration with severe submucosal granulation tissue formation associated with scattered foreign crystalline material. Energy-dispersive X-ray spectroscopy revealed that the crystals contained barium sulphate. This is the first report in animals of the rare complication of barium sulphate incorporation into the gastrointestinal mucosa after contrast radiography.

Pioglitazone treatment and cardiovascular event and death in subjects with type 2 diabetes without established cardiovascular disease (JDDM 36)

AIMS

The protective association of pioglitazone with cardiovascular events and death was investigated over 6-years in large-scale type 2 diabetic subjects without established cardiovascular disease in a primary care setting.

METHODS

A six-year observational cohort study including 2864 subjects with type 2 diabetes without established cardiovascular disease was performed. The primary endpoint was a composite of first occurrence of cardiovascular disease or death. The effect of pioglitazone use at a baseline year with a Cox proportional hazard model and the time-dependent use in each one-year examination interval with a pooled logistic regression model were analyzed.

RESULTS

Baseline use of pioglitazone (n=493) did not show a statistically protective effect on the primary endpoint (n=175), although it tended to reduce the risk (adjusted hazard ratio 0.67 [95% CI: 0.43-1.05]). However, pooled logistic regression analysis indicated a significant protective association of pioglitazone with the primary endpoint (0.58 [0.38 to 0.87] and cardiovascular disease (0.54 [0.33-0.88]), independent of concurrent levels of blood glucose, blood pressure, lipids, albuminuria, and renal function. In particular, this protective association was observed in those with diabetic nephropathy regardless of the daily dose of pioglitazone. Among a total of 898 subjects who took pioglitazone during the period, 43% experienced a discontinuation at least once; however, serious adverse effects were rare.

CONCLUSIONS

This observational study indicated a protective association of pioglitazone with cardiovascular disease and death in type 2 diabetic subjects without established vascular disease, particularly those with nephropathy.

Development of a compact label-free small molecule measurement system using a periodically nanostructured sensor substrate

Compact label-free small molecule measurement system with visible light.

Kinetic study of DNA hybridization on DNA-modified gold nanoparticles with engineered nano-interfaces

We report a systematic study of DNA hybridization kinetics on GNPs with probe DNA and different molecular weight PEGs, and protruding structure of probe DNA from the PEG layer is the key factors for DNA hybridization on GNPs.

Revisit to diffraction anomalous fine structure

The diffraction anomalous fine structure (DAFS) method that is a spectroscopic analysis combined with resonant X-ray diffraction enables the determination of the valence state and local structure of a selected element at a specific crystalline site and/or phase. This method has been improved by using a polycrystalline sample, channel-cut monochromator optics with an undulator synchrotron radiation source, an area detector and direct determination of resonant terms with a logarithmic dispersion relation. This study makes the DAFS method more convenient and saves a large amount of measurement time in comparison with the conventional DAFS method with a single crystal. The improved DAFS method has been applied to some model samples, Ni foil and Fe3O4 powder, to demonstrate the validity of the measurement and the analysis of the present DAFS method.

Ultrasensitive detection of DNA and RNA based on enzyme-free click chemical ligation chain reaction on dispersed gold nanoparticles

An ultrasensitive colorimetric DNA and RNA assay using a combination of enzyme-free click chemical ligation chain reaction (CCLCR) on dispersed gold nanoparticles (GNPs) and a magnetic separation process has been developed. The click chemical ligation between an azide-containing probe DNA-modified GNP and a dibenzocyclooctyne-containing probe biotinyl DNA occurred through hybridization with target DNA (RNA) to form the biotinyl-ligated GNPs (ligated products). Eventually, both the biotinyl-ligated GNPs and target DNA (RNA) were amplified exponentially using thermal cycling. After separation of the biotinyl-ligated GNPs using streptavidin-modified magnetic beads, the change in intensity of the surface plasmon band at 525 nm in the supernatants was observed by UV/vis measurement and was also evident visually. The CCLCR assay provides ultrasensitive detection (50 zM: several copies) of target DNA that is comparable to PCR-based approaches. Note that target RNA could also be detected with similar sensitivity without the need for reverse transcription to the corresponding cDNA. The amplification efficiency of the CCLCR assay was as high as 82% due to the pseudohomogeneous reaction behavior of CCLCR on dispersed GNPs. In addition, the CCLCR assay was able to discriminate differences in single-base mismatches and to specifically detect target DNA and target RNA from the cell lysate.

Enzyme-free fluorescent-amplified aptasensors based on target-responsive DNA strand displacement via toehold-mediated click chemical ligation

A new target-responsive DNA strand displacement system via toehold-mediated click chemical ligation was designed and prepared for enzyme-free fluorescent-amplified aptasensors. The aptasensors significantly amplified fluorescent signals in response to targets based on target recycling processes.

Persistent elevated C-reactive protein after treatment is an independent marker of a poor prognosis in patients with hepatocellular carcinoma

PURPOSE

The pretreatment C-reactive protein (CRP) level is reported to be a prognostic indicator in patients with hepatocellular carcinoma (HCC).

METHODS

We investigated the prognostic implications of the changes in the CRP level after initial treatment in patients with HCC. We prospectively evaluated a cohort of 150 patients with newly diagnosed HCC. The patients were categorized into three groups: group 1 (n = 120) with pre- and post-treatment CRP <1.0 mg/dl, group 2 (n = 5) with pre-treatment CRP ≥1.0 mg/dl and post-treatment CRP <1.0 mg/dl, and group 3 (n = 25) with pre- and post-treatment CRP ≥1.0 mg/dl.

RESULTS

The 1- and 3-year overall survival rates were 92.3 and 82.9 % for group 1, 80.0 and 53.3 % for group 2, and 58.8 and 4.2 % for group 3. The overall survival rate for group 3 was significantly lower than that for group 1 (P < 0.0001), or group 2 (P = 0.003). No significant difference was found between groups 1 and 2 (P = 0.627). A multi-variate analysis showed that albumin level (P = 0.049), the CRP group (P < 0.0001), and the Cancer of the Liver Italian Program (CLIP) score (P < 0.0001) were independently associated with the overall survival.

CONCLUSIONS

A persistently elevated CRP level after initial treatment is an independent marker of a poor prognosis, and normalization of the CRP level after initial treatment is associated with a better outcome in patients with HCC.

Comparison of the prognostic value of inflammation-based prognostic scores in patients with hepatocellular carcinoma

Background:

Inflammation-based prognostic scores including the Glasgow Prognostic Score (GPS), neutrophil to lymphocyte ratio (NLR), and Prognostic Nutritional Index (PNI) are associated with survival in patients with hepatocellular carcinoma (HCC). The aim of this study was to investigate the prognostic value of these inflammation-based prognostic scores in patients with HCC.

Methods:

In total, 150 patients with newly diagnosed HCC were prospectively evaluated. Patients were divided according to the GPS, modified GPS, NLR, platelet to lymphocyte ratio (PLR), Prognostic Index (PI), and PNI. The area under the receiver operating characteristics curve (AUC) was calculated to compare the predictive ability of each of the scoring systems. A univariate and multivariate analysis were performed to identify the clinicopathological variables associated with overall survival.

Results:

The GPS consistently had a higher AUC value at 6 months (0.768), 12 months (0.787), and 24 months (0.758) in comparison with other inflammation-based prognostic scores. A multivariate analysis showed that the GPS was independently associated with overall survival.

Conclusion:

This study demonstrates that the GPS, an inflammation-based prognostic score, is an independent marker of poor prognosis in patients with HCC and is superior to the other inflammation-based prognostic scores in terms of prognostic ability.

Chronic kidney disease categories and renal-cardiovascular outcomes in type 2 diabetes without prevalent cardiovascular disease: a prospective cohort study (JDDM25)

AIMS/HYPOTHESIS

In type 2 diabetic patients at low risk for cardiovascular disease (CVD), the relationship between the clinical course of nephropathy by stage of chronic kidney disease (CKD) and onset of CVD remains unclear. Clarification of this relationship is important for clinical decision-making for both low- and high-risk diabetic patients.

METHODS

This 4 year prospective study enrolled 2,954 type 2 diabetic patients with no prevalent CVD, and serum creatinine <176.8 μmol/l. The risk for CVD onset (non-fatal and fatal CVD and stroke, and peripheral arterial disease) was assessed according to CKD stage categorised by urinary albumin-to-creatinine ratio (ACR; mg/mmol) and estimated GFR (eGFR; ml min(-1) 1.73 m(-2)). Association of progression from 'no CKD' stage (ACR <3.5 mg/mmol and eGFR ≥ 90 ml min(-1) 1.73 m(-2)) with risk for CVD onset was also evaluated.

RESULTS

During follow-up (median 3.8 years), 89 CVD events occurred. Compared with patients with 'no CKD' as reference, those with ACR ≥ 35.0 mg/mmol with co-existing eGFR 60-89 ml min(-1) 1.73 m(-2) or <60 ml min(-1) 1.73 m(-2) showed increased risk for CVD onset, whereas those with eGFR ≥ 90 ml min(-1) 1.73 m(-2) did not. Those with ACR <3.5 mg/mmol and eGFR <60 ml min(-1) 1.73 m(-2) did not show any increased risk. Among patients with 'no CKD' stage at baseline, those who progressed to ACR ≥ 3.5 mg/mmol during follow-up showed an increased risk compared with those who did not, whereas those who progressed to eGFR <90 ml min(-1) 1.73 m(-2) did not have increased risk.

CONCLUSIONS/INTERPRETATION

The risk for CVD was associated with progression of albuminuria stage rather than eGFR stage in type 2 diabetic patients at relatively low risk for CVD.

Effect of high-sensitivity C-reactive protein on the development of diabetes as demonstrated by pooled logistic-regression analysis of annual health-screening information from male Japanese workers

AIM

The aim of this study was to determine the relationship between the development of diabetes mellitus and high-sensitivity C-reactive protein (HsCRP) adjusted for various potential confounders.

METHODS

This 5-year prospective cohort study was conducted at a Japanese steel factory and involved male workers who had received annual health screenings between 2005 and 2010. The 7392 male participants were aged 19-75 years. The study endpoint, the development of diabetes mellitus, was defined as HbA(1c) greater or equal to 6.5% or the use of antidiabetic medication. The association between variables was investigated using pooled logistic regression adjusted for various covariates such as age, baseline body mass index (BMI) and increase in BMI from baseline, blood biochemistry, job schedule and job-related stress.

RESULTS

The incidence rate of diabetes development per 1000 person-years was 13.9. Multivariate analysis showed a significant relationship between the development of diabetes and elevated levels of baseline HsCRP and increases in levels from baseline. The Odds ratios for a 2.9-fold (±1 geometric standard deviation) increase in baseline HsCRP and increase in HsCRP level from baseline were 1.18 [95% confidence interval (CI): 1.03-1.34; P=0.018] and 1.21 (95% CI: 1.03-1.41; P=0.018), respectively.

CONCLUSION

The present study has indicated that HsCRP is an independent predictor for the development of diabetes in men, together with various confounders such as BMI, type of job schedule and job-related stress.

Observational 6-Month Open-Label Study of Japanese Type 2 Diabetes Patients Switching from NPH Insulin to Insulin Detemir in Basal—Bolus Regimen: 23rd Article of the Japan Diabetes Clinical Data Management Study Group (JDDM23)

OBJECTIVE: Glycaemic control is critical to prevent diabetic complications and mortality. This 6-month, open-label, observational study assessed the efficacy and safety of switching Japanese patients with type 2 diabetes from neutral protamine Hagedorn (NPH) insulin to insulin detemir. METHODS: Patients with type 2 diabetes ( n = 126) receiving basal—bolus insulin therapy with NPH insulin plus rapid-acting insulin analogues were recruited. NPH insulin was replaced with insulin detemir for 6 months. Glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), daily glucose levels and hypoglycaemia were monitored. Nocturnal quality of life was assessed by insulin therapy related quality of life at night questionnaire. RESULTS: HbA1c, FPG and body weight were all significantly reduced after treatment with insulin detemir for 6 months, without increasing severe hypoglycaemia. Insulin dose increased significantly over the same time. There were significant improvements in overall nocturnal quality of life, as well as well-being. CONCLUSIONS: Treatment with insulin detemir for 6 months resulted in substantial benefits, including reduced HbA1c, FPG and body weight, and improvements in nocturnal quality of life, without increasing hypoglycaemia.

Active hexose correlated compound inhibits the expression of proinflammatory biomarker iNOS in hepatocytes

BACKGROUND/AIMS

Excess production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated as proinflammatory biomarker in liver injury. The application of active hexose correlated compound (AHCC) as a functional food in complementary and alternative medicine has increased. The possibility that AHCC might inhibit iNOS induction was investigated as a potential liver-protective effect.

METHODS

Hepatocytes were isolated from rats by collagenase perfusion and cultured. Primary cultured hepatocytes were treated with interleukin-1β in the presence or absence of AHCC-sugar fraction (AHCC-SF).

RESULTS AND CONCLUSION

AHCC-SF inhibited the production of NO and reduced expressions of iNOS mRNA and its protein. AHCC-SF had no effects on either IκB degradation or nuclear factor-κB (NF-κB) activation. In contrast, AHCC-SF inhibited the upregulation of type I interleukin-1 receptor (IL-1RI) through the inhibition of Akt phosphorylation. Transfection experiments with iNOS promoter-luciferase constructs revealed that AHCC-SF reduced the levels of iNOS mRNA at both promoter transactivation and mRNA stabilization steps. AHCC-SF inhibited the expression of iNOS gene antisense transcript, which is involved in iNOS mRNA stabilization. These findings demonstrate that AHCC-SF suppresses iNOS gene expression through a IκB/NF-κB-independent but Akt/IL-1RI-dependent pathway, resulting in the reduction of NO production. AHCC-SF may have therapeutic potential for various liver injuries.

Serum Amyloid a Low-Density Lipoprotein Levels and Smoking Status in Obese Japanese Patients

Serum amyloid A low-density lipoprotein (SAA-LDL) is formed by an oxidative interaction and is considered to be a new marker related to oxidative modification of LDL. As the effect of smoking on oxidized LDL is of concern, this study investigated the association between SAA-LDL and smoking status. A total of 578 Japanese obese outpatients (mean ± SD age 50.5 ± 14.3 years) were studied. Smoking status was examined via a self-reported questionnaire. Cardiometabolic variables, including high-sensitivity C-reactive protein (hsCRP), were analysed in addition to SAA-LDL. There was an increasing trend in SAA-LDL levels from non- to ex- to current smokers, and significantly higher SAA-LDL levels were observed in current smokers versus non-smokers (median SAA-LDL level 36 μg/ml versus 28 μg/ml, respectively). This significant difference was reduced after adjusting for multiple confounders, including lipid levels. Smoking may be associated with increased levels of SAA-LDL in an obese Japanese population, but further studies are needed.

Low incidence of cardiovascular events in Japanese patients with Type 2 diabetes in primary care settings: a prospective cohort study (JDDM 20)

AIMS

To investigate whether a reduced incidence of cardiovascular disease in Type 2 diabetes can be achieved in a newly recruited cohort following the recently advanced concept of multifactorial treatment and followed in primary care settings as compared with earlier cohorts.

METHODS

A prospective study was performed in primary care settings at multiple clinics nationwide in the Japan Diabetes Clinical Data Management (JDDM) study group. Subjects were 2984 patients with Type 2 diabetes without prevalent cardiovascular disease. The main outcome measure was the first event of non-fatal or fatal coronary heart disease, ischaemic stroke or peripheral artery disease, and the incidence was compared with other representative cohorts.

RESULTS

There were 90 cardiovascular events over 10,827 person-years of follow-up with a dropout rate of 6%. The incidences (per 1000 person-years, 95% confidence interval) of composite, coronary heart disease, ischaemic stroke and peripheral artery disease in the JDDM study were 8.3 (6.6-10.0), 4.4 (3.2-5.6), 3.1 (2.1-4.2), and 0.7 (0.2-1.2), respectively. Each incidence was lowest in the JDDM study compared with other cohorts (P < 0.01 vs. each cohort). In the JDDM study, significant variables predictive of the occurrence of a cardiovascular event were age, duration of diabetes, HbA(1c), HDL cholesterol and urinary albumin.

CONCLUSION

The novel finding of low cardiovascular disease occurrence in this study may be conferred by the feasibility at primary care settings for providing patients with Type 2 diabetes with favourable control of blood glucose, blood pressure and lipids, coupled with unique ethnicity/country factors.

Systemic delivery of siRNA to tumors using a lipid nanoparticle containing a tumor-specific cleavable PEG-lipid

Previously, we developed a multifunctional envelope-type nano device (MEND) for efficient delivery of nucleic acids. For tumor delivery of a MEND, PEGylation is a useful method, which confers a longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. To overcome this, we developed a PEG-peptide-DOPE (PPD) that is cleaved in a matrix metalloproteinase (MMP)-rich environment. In this study, we report on the systemic delivery of siRNA to tumors by employing a MEND that is modified with PPD (PPD-MEND). An in vitro study revealed that PPD modification accelerated both cellular uptake and endosomal escape, compared to a conventional PEG modified MEND. To balance both systemic stability and efficient activity, PPD-MEND was further co-modified with PEG-DSPE. As a result, the systemic administration of the optimized PPD-MEND resulted in an approximately 70% silencing activity in tumors, compared to non-treatment. Finally, a safety evaluation showed that the PPD-MEND showed no hepatotoxicity and innate immune stimulation. Furthermore, in a DNA microarray analysis in liver and spleen tissue, less gene alternation was found for the PPD-MEND compared to that for the PEG-unmodified MEND due to less accumulation in liver and spleen.