The JAK2/STAT3 and mitochondrial pathways are essential for quercetin nanoliposome-induced C6 glioma cell death

The formulation of quercetin nanoliposomes (QUE-NLs) has been shown to enhance QUE antitumor activity in C6 glioma cells. At high concentrations, QUE-NLs induce necrotic cell death. In this study, we probed the molecular mechanisms of QUE-NL-induced C6 glioma cell death and examined whether QUE-NL-induced programmed cell death involved Bcl-2 family and mitochondrial pathway through STAT3 signal transduction pathway. Downregulation of Bcl-2 and the overexpression of Bax by QUE-NL supported the involvement of Bcl-2 family proteins upstream of C6 glioma cell death. In addition, the activation of JAK2 and STAT3 were altered following exposure to QUE-NLs in C6 glioma cells, suggesting that QUE-NLs downregulated Bcl-2 mRNAs expression and enhanced the expression of mitochondrial mRNAs through STAT3-mediated signaling pathways either via direct or indirect mechanisms. There are several components such as ROS, mitochondrial, and Bcl-2 family shared by the necrotic and apoptotic pathways. Our studies indicate that the signaling cross point of the mitochondrial pathway and the JAK2/STAT3 signaling pathway in C6 glioma cell death is modulated by QUE-NLs. In conclusion, regulation of JAK2/STAT3 and ROS-mediated mitochondrial pathway agonists alone or in combination with treatment by QUE-NLs could be a more effective method of treating chemical-resistant glioma.

Depth profiling of PLGA copolymer in a novel biomedical bilayer using confocal Raman spectroscopy

Confocal Raman spectroscopy was undertaken to identify separate layers of PLGA and gentamicin sulfate (GS) coatings on a titanium alloy substrate for a novel drug-delivery system. Additionally, it was found that it was possible to measure the layer thickness and uniformity of the PLGA accurately by detecting intensity and wavelength changes in the vibrational bands of the copolymer bonds. Further analysis of the materials was done using FIB, SEM/EDX, and profilometry; these techniques were used to confirm the findings of the Raman data. It was determined that the substrate was extremely rough and therefore the coating was not uniform in thickness but the materials were uniformly dispersed. Most importantly, two distinct GS and PLGA layers were present.

A randomized, double-blind, placebo-controlled phase II study of eculizumab in patients with refractory generalized myasthenia gravis

INTRODUCTION

Complement activation at the neuromuscular junction is a primary cause of acetylcholine receptor loss and failure of neuromuscular transmission in myasthenia gravis (MG). Eculizumab, a humanized monoclonal antibody, blocks the formation of terminal complement complex by specifically preventing the enzymatic cleavage of complement 5 (C5).

METHODS

This study was a randomized, double-blind, placebo-controlled, crossover trial involving 14 patients with severe, refractory generalized MG (gMG).

RESULTS

Six of 7 patients treated with eculizumab for 16 weeks (86%) achieved the primary endpoint of a 3-point reduction in the quantitative myasthenia gravis (QMG) score. Examining both treatment periods, the overall change in mean QMG total score was significantly different between eculizumab and placebo (P = 0.0144). After assessing data obtained from all visits, the overall change in mean QMG total score from baseline was found to be significantly different between eculizumab and placebo (P < 0.0001). Eculizumab was well tolerated.

CONCLUSION

The data suggest that eculizumab may have a role in treating severe, refractory MG.

Dietary supplementation with Lactobacillus fermentum I5007 improves the anti-oxidative activity of weanling piglets challenged with diquat

AIMS

To determine the effects of Lactobacillus fermentum I5007 on the redox state of piglets oxidatively stressed with diquat.

METHODS AND RESULTS

Twenty-four, 28-day-old barrows were used in a 2 × 2 factorial design experiment with the main effects being Lact. fermentum supplementation and diquat challenge. Half of the pigs (n = 12) were orally administered with 20 ml of a solution containing 10(8 ) CFU ml(-1) of Lact. fermentum each morning of the 21-day trial, while the remainder received saline. On day 8, these two groups were further subdivided so that half of the pigs in each group (n = 6) were intraperitoneally injected with 10 mg kg(-1) BW diquat, while the remainder received saline. The diquat-injected pigs had significantly poorer performance and increased levels of plasma cortisol, adrenaline, carbonyl and malondialdehyde. Lactobacillus fermentum supplementation significantly increased superoxide dismutase and glutathione and increased the ability to inhibit superoxide anion production in liver and muscle.

CONCLUSIONS

Lactobacillus fermentum improved the anti-oxidative defence system and alleviated damage caused by diquat.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactobacillus fermentum has the potential to alleviate oxidative stress and improve weaning pig performance.

Frequency and risk factors of non-retinopathy ocular conditions in people with diabetes: the Singapore Malay Eye Study

AIM

To investigate the frequency and risk factors of non-retinopathy ocular conditions in persons with diabetes.

METHODS

A population-based cross-sectional study of 3176 Malay persons aged between 40 and 79 years in Singapore was conducted. Cataract, glaucoma, refractive errors, age-related macular degeneration, dry eye, epiretinal membrane, ocular hypertension and retinal conditions were assessed based on standardized interviews, clinical examinations and laboratory investigations.

RESULTS

A total of 768 participants (24.2%) had diabetes. People with diabetes were more likely to have cortical cataract (52.1 vs. 37.3%, P < 0.001), ocular hypertension (10.9 vs. 7.4%, P = 0.002) and epiretinal membrane (17.2 vs. 10.1%, P < 0.001) compared with those without diabetes. The odds of having cortical cataract (odds ratio 1.63, 95% CI 1.20-2.20) and epiretinal membrane (among those with previous cataract surgery: odds ratio 1.63, 95% CI 1.20-2.20) were significantly higher in people with diabetes compared with those without. The population attributable risks for cortical cataract and epiretinal membrane because of diabetes were 8.7 and 9.0%, respectively. In persons with diabetes, hypertension and high cholesterol were the major risk factors associated with non-retinopathy eye complications such as ocular hypertension (odds ratio 1.18, 95% CI 1.04-1.33) and retinal emboli (odds ratio 1.99, 95% CI 1.05-3.80).

CONCLUSION

Our results allow clinicians to better inform patients with diabetes that they are more likely to have cortical cataract and epiretinal membranes (those with previous cataract surgery) in addition to diabetic retinopathy. Two modifiable risk factors-blood pressure and cholesterol associated with ocular hypertension and retinal emboli, respectively-are also risk factors for non-retinopathy ocular conditions in persons with diabetes.

Regional and voxel-wise comparisons of blood flow measurements between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and arterial spin labeling (ASL) in brain tumors

The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF.

Novel versus traditional risk markers for diabetic retinopathy

AIMS/HYPOTHESIS

To explore the relative contribution of novel and traditional risk markers for diabetic retinopathy (DR).

METHODS

A clinic-based study of 224 diabetic patients (85 type 1, 139 type 2) from a diabetes clinic was performed. DR was graded from fundus photographs according to the Airlie House Classification system and classified as absent or present (at least ETDRS level 14). Novel risk markers assessed included serum apolipoprotein (Apo) AI and B, skin microvascular responses to acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) iontophoresis, flicker-light-induced retinal vasodilation and retinal vascular tortuosity. Relative contribution was determined by semi-partial correlation coefficient generated from a logistic regression model containing all traditional and novel risk markers simultaneously.

RESULTS

There were 144 (64.3%) participants with DR. Of the novel markers, ApoAI, flicker-light-induced vasodilation and retinal arteriolar tortuosity were significantly associated with DR, independently of traditional measures (all p < 0.03). Diabetes duration contributed most (51%) to the risk of DR, followed by ApoAI (16%), systolic blood pressure (13%), retinal arteriolar tortuosity (8%) and flicker-light-induced venular and arteriolar dilation (3% and 0.5%, respectively).

CONCLUSIONS/INTERPRETATION

ApoAI and retinal arteriolar tortuosity made considerable contributions to DR risk, independently of traditional risk markers. Findings from this study suggest that serum ApoAI and retinal arteriolar tortuosity may be novel and independent risk markers of DR.

Review of key findings from the Singapore Malay Eye Study (SiMES-1)

INTRODUCTION

This study highlights the key epidemiological findings from the Singapore Malay Eye Study (SiMES-1).

METHODS

SiMES-1 was a cross-sectional, population-based epidemiological study on eye diseases. It was performed on 3,280 randomly selected Malay adults living in the south-western part of Singapore. All study participants underwent various validated questionnaires and detailed eye examinations. A review of all papers published from SiMES-1 was performed.

RESULTS

A total of 24.6% of the study population had myopia, while 35.3% had hyperopia and 39.4% had astigmatism. 20.4% of the population had under-corrected refractive error. 1,338 (45.7%) participants were diagnosed to have cataracts in at least one eye. 8.6% of the study population had undergone cataract surgery in either eye, while 4.7% had bilateral cataract surgery. 150 (4.6%) participants were diagnosed to have glaucoma, of which primary open angle glaucoma was the most common type (3.2% of the study population), followed by secondary glaucoma (0.8%) and primary angle closure glaucoma (0.2%). Pterygium was diagnosed in 508 out of 3,266 study participants, giving a prevalence rate of 15.6%. The presence of diabetic retinopathy was observed in 421 (12.9%) out of 3,265 study participants. 183 (5.6%) study participants had some degree of age-related macular degeneration (AMD), of which 23 (0.7%) were classified as having late AMD.

CONCLUSION

This paper provides a summary of the prevalence of common eye diseases among the Singaporean adult Malay population and provides data useful for public health education and disease prevention.

Low divergence photonic nanojets from Si3N4 microdisks

High intensity sub-wavelength spots and low divergence nanojets are observed in a system of Si3N4 microdisks illuminated from the side with laser light of wavelengths 488 nm, 532 nm and 633 nm. The disks are of height 400 nm with diameters ranging from 1μm to 10μm. Light scattered from the disk and substrate is observed by imaging from above. In free space light is focused inside the disks and a sub wavelength spot is observed, whereas in water the refractive index contrast is such that photonic nanojets are formed. The angular distribution of the intensity compares well to the analytical solution for the case of an infinite cylinder. Two distinct cases of scattering pattern are observed with even and odd numbers of lobes. Finally when the disks are illuminated with a focused Gaussian beam perpendicular to the substrate an extremely low divergence beam is observed. This beam has a divergence angle over 10 times smaller than a focused Gaussian in free space with the same waist.

Long-term follow-up of patients treated with neoadjuvant chemotherapy and radiotherapy for large, extremity soft tissue sarcomas

BACKGROUND

Patients with large, high-grade, extremity soft tissue sarcomas (STS) are at significant risk for distant recurrence and death. A regimen of preoperative chemotherapy consisting of mesna, Adriamycin (doxorubicin), ifosfamide, and dacarbazine (MAID), interdigitated with radiotherapy (RT) and followed by resection and postoperative chemotherapy with or without RT, has demonstrated high rates of local and distant control. We report the long-term follow-up data on 48 patients treated with this regimen compared to an historical matched-control patient population.

METHODS

Adult patients with high-grade extremity STS ≥ 8 cm were treated with 3 cycles of preoperative chemotherapy combined with 44 Gy of RT followed by surgery. Three cycles of postoperative MAID were planned. For patients with positive surgical margins, 16 Gy of RT was delivered postoperatively.

RESULTS

Patients received the MAID/RT regimen from 1989 through 1999. After a median follow-up of 9.3 years in surviving patients in the MAID group and 13.2 years in surviving patients in the control group, the 7-year disease-specific and overall survival rates were 81% and 50% (P = .004) and 79% and 45% (P = .003) for the MAID and control patients, respectively. Five of 11 patients in the MAID group and 7 of 25 control patients died of sarcoma ≥5 years after treatment. One patient in the MAID group developed a fatal myelodysplasia at 53 months.

CONCLUSIONS

For patients with high-risk, extremity STS, the significant survival benefits conferred by an intense regimen of neoadjuvant chemoradiotherapy and surgery are sustained even with long-term follow-up.

Photoinduced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on silicone hydrogels for reducing protein adsorption

The biomimetic synthetic methacrylate monomer containing a phosphorylcholine group, 2-methacryloyloxyethyl phosphorylcholine (MPC), has been widely used to improve the surface property of biomaterials. In the current report, both hydrophilic and antifouling surfaces were prepared on silicone hydrogels with MPC grafted by UV-induced free radical polymerization. The MPC-grafted silicone hydrogels were characterized by graft yield and static water contact angle (SCA) measurements. According to the results, the graft yield reached a maximum at 5 min of UV exposure time and 8 wt% MPC concentration. The modified silicone hydrogels possessed hydrophilic surfaces with the lowest water contact angle of 20º. The oxygen permeability of the MPC-grafted silicone hydrogels was as high as the unmodified silicone hydrogel. The mechanical property of silicone hydrogels was maintained at about 95% of the tensile strength and elastic modulus after the MPC grafting. The results of the in vitro single protein adsorption on the MPC-grafted silicone hydrogels were in agreement with the SCA measurements. The smaller the water contact angle, the greater was the protein repelling ability. The MPC-grafted silicone hydrogel is expected to be a novel biomaterial which possesses excellent surface hydrophilicity, antifouling property, oxygen permeability and mechanical property.

The relationship between aortic stiffness and changes in retinal microvessels among Asian ischemic stroke patients

Large-artery stiffness is a risk factor for stroke, including cerebral small-vessel disease. Retinal microvascular changes are thought to mirror those in cerebral microvessels. We investigated the relationship between aortic stiffness and retinal microvascular changes in Asian ischemic stroke patients. We studied 145 acute ischemic stroke patients in Singapore who had aortic stiffness measurements using carotid-femoral pulse wave velocity (cPWV). Retinal photographs were assessed for retinal microvessel caliber and qualitative signs of focal arteriolar narrowing, arteriovenous nicking and enhanced arteriolar light reflex. Aortic stiffening was associated with retinal arteriolar changes. Retinal arteriolar caliber decreased with increasing cPWV (r=-0.207, P=0.014). After adjusting for age, gender, hypertension, diabetes, mean arterial pressure and small-vessel stroke subtype, patients within the highest cPWV quartile were more likely to have generalized retinal arteriolar narrowing defined as lowest caliber tertile (odds ratio (OR) 6.84, 95% confidence interval (CI) 1.45-32.30), focal arteriolar narrowing (OR 13.85, CI 1.82-105.67), arteriovenous nicking (OR 5.08, CI 1.12-23.00) and enhanced arteriolar light reflex (OR 3.83, CI 0.89-16.48), compared with those within the lowest quartile. In ischemic stroke patients, aortic stiffening is associated with retinal arteriolar luminal narrowing as well as features of retinal arteriolosclerosis.

Pharyngoesophageal stricture after treatment for head and neck cancer

BACKGROUND

The purpose of this study was to report the risk of pharyngoesophageal stricture after treatment for head and neck cancer.

METHODS

Human studies on radiation therapy with or without chemotherapy for head and neck cancer published in peer-reviewed journals with assessment of pharyngoesophageal stricture with barium swallow or endoscopy were included.

RESULTS

A total of 4727 patients from 26 studies treated between 1989 and 2008 were eligible for analysis. The reported overall risk of stricture was 7.2%. The risks of pharyngoesophageal stricture in both conventional and intensity-modulated radiation therapy (IMRT) studies were 5.7% and 16.7%, respectively (p < .001). Use of concurrent (p < .001) and taxane (p = .01) chemotherapy was associated with the IMRT technique. Prospective studies reported a 3.3-fold increased risk of stricture compared with that of retrospective studies (odds ratio: 3.3; 95% confidence interval: 2.3-4.8; p < .001).

CONCLUSIONS

Pharyngoesophageal stricture after IMRT and chemotherapy treatment for head and neck cancer is not uncommon. Videofluoroscopic swallow study should be performed prospectively to evaluate swallowing function.

Retinal vascular tortuosity in persons with diabetes and diabetic retinopathy

AIM/HYPOTHESIS

The aim of this hypothesis was to examine the association of retinal vessel tortuosity with diabetes and diabetic retinopathy (DR).

METHODS

A clinic-based study of 327 participants (224 with diabetes and 103 non-diabetic controls) aged ≥ 18 years. DR was graded from fundus photographs according to the modified Airlie House Classification system and categorised into mild non-proliferative DR (NPDR), moderate NPDR and vision-threatening DR (VTDR). Retinal vessel tortuosity was measured from disc-centred retinal photographs. Measurements were taken, using a semi-automated computer program by a single grader, of arterioles and venules within 0.5 to 2 disc diameters away from the optic disc.

RESULTS

There were 114 (44%) participants with DR. In the multivariate analysis, retinal arteriolar and venular tortuosity were increased in participants with diabetes without DR (mean difference 12.4 × 10(-5) and 13.3 × 10(-5), respectively; both p < 0.05) and in those with DR (mean difference 15.4 × 10(-5) and 15.0 × 10(-5), respectively; both p < 0.01) compared with non-diabetic participants. Among participants with diabetes, increased arteriolar tortuosity was significantly associated with mild NPDR (OR 1.53, 95% CI 1.03-2.05, per SD increase in arteriolar tortuosity) and moderate NPDR (OR 1.67, 95% CI 1.10-2.55) but not VTDR (OR 0.91, 95% CI 0.54-1.54). No association with DR was found for venular tortuosity.

CONCLUSIONS/INTERPRETATION

Persons with diabetes had more tortuous retinal vasculature than persons without diabetes. In persons with diabetes, increased arteriolar tortuosity was associated with mild and moderate stages of DR. This suggests that retinal vascular tortuosity might be an early indicator of microvascular damage in diabetes; thus, further investigation is indicated.

Celecoxib and acetylbritannilactone interact synergistically to suppress breast cancer cell growth via COX-2-dependent and -independent mechanisms

The use of celecoxib is associated with a significant decrease in breast cancer risk. However, the long-term use of high-dose celecoxib might be limited owing to cardiovascular side effects. In this study, we found that acetylbritannilactone (ABL), extract from a Chinese medicinal herb, could reduce celecoxib dose and potentiate the growth-inhibitory effect in breast cancer cells. ABL enhanced the apoptotic effect of celecoxib in COX-2-expressing cells, but had little effect in COX-2-negative cells. The apoptosis induced by the combination treatment disappeared when COX-2 was knocked down, whereas the lack of apoptotic effects in COX-2-negative cells was reversed after COX-2 transfection. However, the combination treatment induced a G(0)/G(1) phase arrest independent of whether or not the cells expressed COX-2. The G(0)/G(1) arrest was attributed to a decreased expression of cyclinD1, cyclinE, CDK2 and CDK6, especially the upregulation of p21. In addition, inhibition of Akt and p38 signaling pathways was required by the synergism, as the constitutively active Akt and p38 protected cells against apoptosis and cell cycle arrest induced by the combination treatment. In vivo, administration of celecoxib and ABL were more effective than the individual agents against xenograft tumor growth. Thus, our data suggested that the combinatorial approach of celecoxib and ABL might be helpful for breast cancer treatment.

Fusion of multiscale wavelet-based fractal analysis on retina image for stroke prediction

In this paper, we present a novel method of analyzing retinal vasculature using Fourier Fractal Dimension to extract the complexity of the retinal vasculature enhanced at different wavelet scales. Logistic regression was used as a fusion method to model the classifier for 5-year stroke prediction. The efficacy of this technique has been tested using standard pattern recognition performance evaluation, Receivers Operating Characteristics (ROC) analysis and medical prediction statistics, odds ratio. Stroke prediction model was developed using the proposed system.

Soybean-derived beta-conglycinin affects proteome expression in pig intestinal cells in vivo and in vitro

It is well known that β-conglycinin, a soybean allergen, induces allergies and causes intestinal damage in fetuses and neonates. However, the underlying mechanisms responsible for the adverse effects of β-conglycinin remain elusive. In particular, it is unknown whether or not this dietary substance causes direct damage affecting the proliferation and integrity of intestinal cells. This study evaluated the effect of different concentrations of β-conglycinin (0 to 1,500 µg/mL) and the duration of culture (48 or 72 h) on the proliferation and proteome of porcine intestinal epithelial cells. Eight individually housed piglets (10 d old; initial BW, 3.79 ± 0.07 kg) were randomly divided into 2 groups (n = 4) and challenged with or without β-conglycinin via oral administration d 10 through 28. After the last administration of β-conglycinin or PBS, piglets were killed and jejuna mucosal samples were collected for proteomic analysis. Supplementing β-conglycinin to either culture medium or weanling pigs increased (P < 0.05) the expression of proteins related to apoptosis, stress, and inflammation, but decreased (P < 0.05) the expression of proteins related to cytoskeleton and nucleus replication in intestinal cells. Further analysis confirmed an increase in caspase-3 expression in the cells exposed to β-conglycinin in vivo and in vitro. Collectively, these novel results indicate that β-conglycinin directly induces intestinal damage by depressing intestinal-cell growth, damaging the cytoskeleton, and causing apoptosis in the piglet intestine.

Two-dimensional nanosheets produced by liquid exfoliation of layered materials

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS(2), WS(2), MoSe(2), MoTe(2), TaSe(2), NbSe(2), NiTe(2), BN, and Bi(2)Te(3) can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS(2) and MoS(2) effectively reinforce polymers, whereas WS(2)/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.