Modulation of Wnt/β-catenin Signaling Attenuates Periapical Bone Lesions

Wnt/β-catenin signaling plays an important role in bone biology. The present study investigated the involvement of Wnt/β-catenin signaling in rat periapical bone destruction and whether lithium chloride (LiCl), a glycogen synthase kinase-3β (GSK-3β) inhibitor, promotes bone restoration. Rat bone marrow mesenchymal cells (BMMSCs) treated with Porphyromonas gingivalis lipopolysaccharide ( Pg LPS) showed decreased osteogenic potential through inhibited Wnt/β-catenin signaling as quantified by Western blot, immunofluorescence, and luciferase reporter assay. Transient Wnt3a treatment in vitro partially restored mineralization and Runx2/Osx and osteocalcin expression in cultures with Pg LPS-induced osteogenic arrest. Prolonged Wnt3a treatment impaired osteogenic commitment. X-ray microtomography showed dramatically enhanced periapical bone formation in rats gavage-fed with LiCl for 2 wks, while continuous LiCl treatment for 4 wks impaired periapical bone healing. LiCl treatment also increased GSK-3β phosphorylation and osteocalcin expression in periapical tissue. Collectively, these results indicate that Wnt/β-catenin has dichotomous functions in bone homeostasis. Modulation of this signaling pathway by LiCl may be a potential therapeutic option for bone destruction in endodontic disease.

All-oral therapy with nucleotide inhibitors sofosbuvir and GS-0938 for 14 days in treatment-naive genotype 1 hepatitis C (nuclear)

Sofosbuvir and GS-0938 are distinct nucleotide analogues with activity against hepatitis C virus (HCV) in vitro. We evaluated the antiviral activity and safety of sofosbuvir and GS-0938 alone and in combination in HCV genotype 1 patients. In this double-blind study, 40 treatment-naïve patients were randomly assigned to 4 treatment cohorts: (i) GS-0938 for 14 days, (ii) GS-0938 for 7 days followed by GS-0938 plus sofosbuvir for 7 days, (iii) sofosbuvir for 7 days followed by GS-0938 plus sofosbuvir for 7 days and (iv) GS-0938 plus sofosbuvir for 14 days. In each arm, 8 patients received active drug and 2 placebo. After 7 days of dosing, patients in all 4 dose groups experienced substantial reductions in HCV RNA, with median declines (Q1, Q3) of -4.50 (-4.66, -4.24) in Cohort 1, -4.55 (-4.97, -4.13) in Cohort 2, -4.65 (-4.78, -4.17) in Cohort 3 and -4.43 (-4.81, -4.13) in Cohort 4; patients receiving placebo had essentially no change in HCV RNA (+0.07 log(10) IU/mL). Seven days after the end of treatment, the proportions of patients with HCV RNA <15 IU/mL were 4 (50%), 8 (100%), 7 (88%) and 5 (63%) for Cohorts 1-4, respectively, vs 0 for placebo. No viral breakthrough or resistance mutations were observed. No serious adverse events or Grade 3 or 4 adverse events were reported. Sofosbuvir and GS-0938-alone and in combination--were well tolerated and led to substantial reductions in viral load. Sofosbuvir is undergoing further investigation as a possible backbone of an all-oral regimen for chronic HCV.

Caveolin-1 deficiency protects against mesangial matrix expansion in a mouse model of type 1 diabetic nephropathy

AIMS/HYPOTHESIS

Glomerular matrix protein accumulation, mediated largely by resident mesangial cells (MCs), is central to the pathogenesis of diabetic nephropathy. We previously showed that caveolin (CAV)-1/caveolae mediate matrix upregulation by MCs in response to high glucose and TGFβ, two important pathogenic mediators of diabetic glomerular sclerosis. Here, we evaluated the in vivo role of CAV-1/caveolae in the development of diabetic nephropathy.

METHODS

Diabetes was induced in Cav1-knockout (KO) mice and their wild-type (WT) counterparts by streptozotocin injection. After 10 months, kidneys were evaluated for the development of nephropathy, including glomerular sclerosis and upregulation of matrix proteins. Parallel experiments assessing glucose-induced matrix upregulation were carried out in MCs isolated from KO mice.

RESULTS

KO diabetic mice developed hyperglycaemia and renal hypertrophy, but were protected from developing albuminuria and glomerular sclerosis compared with WT mice. KO mice were significantly protected from the upregulation of glomerular collagen I, fibronectin, connective tissue growth factor (CTGF) and TGFβ. In vitro, glucose induced collagen I A1 promoter activation and collagen I, fibronectin and CTGF protein upregulation in WT but not KO MCs. Re-expression of Cav1 in KO cells restored this response.

CONCLUSIONS/INTERPRETATION

Cav1 deletion rendered significant protection from glomerular matrix accumulation and albuminuria in a mouse model of type 1 diabetes. These studies provide a foundation for the development of renal-targeted interference with CAV-1/caveolae as a novel approach to the treatment of diabetic nephropathy.

Proteomic analysis of nuclei dissected from fixed rat brain tissue using expression microdissection

Expression microdissection (xMD) is a high-throughput, operator-independent technology that enables the procurement of specific cell populations from tissue specimens. In this method, histological sections are first stained for cellular markers via either chemical or immuno-guided methods, placed in close contact with an ethylene vinyl acetate (EVA) film, and exposed to a light source. The focal, transient heating of the stained cells or subcellular structures melts the EVA film selectively to the targets for procurement. In this report, we introduce a custom-designed flashcube system that permits consistent and reproducible microdissection of nuclei across an FFPE rat brain tissue section in milliseconds. In addition, we present a method to efficiently recover and combine captured proteins from multiple xMD films. Both light and scanning electron microscopy demonstrated captured nuclear structures. Shotgun proteomic analysis of the samples showed a significant enrichment in nuclear localized proteins, with an average 25% of recovered proteins localized to the nucleus, versus 15% for whole tissue controls (p < 0.001). Targeted mass spectrometry using multiple reaction monitoring (MRM) showed more impressive data, with a 3-fold enrichment in histones, and a concurrent depletion of proteins localized to the cytoplasm, cytoskeleton, and mitochondria. These data demonstrate that the flashcube-xMD technology is applicable to the proteomic study of a broad range of targets in molecular pathology.

RGD-conjugated iron oxide magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia

The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic iron oxide nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin α(v)β₃ targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic iron oxide. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy.

Comparative performance of four equations estimating glomerular filtration rate in adult Chinese diabetics

BACKGROUND

The Cockcroft-Gault equation, abbreviated Modification of Diet in Renal Disease (MDRD) equation, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and improved abbreviated MDRD equation were used to evaluate renal function in diabetic patients. However, little is known regarding their applicability and precision in Chinese diabetic patients.

AIM

To compare the accuracy of four methods evaluating Chinese diabetic patients' renal function.

MATERIALS AND METHODS

This study included 329 Chinese diabetic patients. Standard GFR (sGFR) was measured via ⁹⁹mTc-DTPA dynamic renal imaging. Estimated GFR (eGFR) was calculated by four equations separately. Applicability of these four equations in Chinese diabetic patients was determined by correlation studies, agreement test, and receiver operating characteristic (ROC) curves.

RESULTS

For Chinese diabetic patients, four methods assessing eGFR correlated well with sGFR. Overall, eGFR calculated via improved abbreviated MDRD had less bias and greater accuracy than the other algorithms estimating GFR (p ≤ 0.01). For patients with sGFR ≥ 60 ml/min/1.73 m², all four equations significantly underestimated actual GFR, with the improved abbreviated MDRD equation best approximating actual GFR (p ≤ 0.01). Conversely, in patients with sGFR<60 ml/min/1.73 m², all four equations overestimated actual GFR; GFR(improved MDRD) was relatively the most accurate (p ≤ 0.01).

CONCLUSIONS

While all four equations were inaccurate, the improved abbreviated MDRD equation best diagnosed and stratified renal failure in Chinese diabetic patients.

Inhibiting periapical lesions through AAV-RNAi silencing of cathepsin K

Dental caries, one of the most prevalent infectious diseases worldwide, affects approximately 80% of children and the majority of adults. Dental caries may result in endodontic disease, leading to dental pulp necrosis, periapical inflammation and bone resorption, severe pain, and tooth loss. Periapical inflammation may also increase inflammation in other parts of the body. Although many studies have attempted to develop therapies for this disease, there is still an urgent need for effective treatments. In this study, we applied a novel gene therapeutic approach using recombinant adeno-associated virus (AAV)-mediated RNAi knockdown of Cathepsin K (Ctsk) gene expression, to target osteoclasts and periapical bone resorption in a mouse model. We found that AAV-sh-Cathepsin K (AAV-sh-Ctsk) impaired osteoclast function in vivo and furthermore reduced bacterial infection-stimulated bone resorption by 88%. Reduced periapical lesion size was accompanied by decreases in mononuclear leukocyte infiltration and inflammatory cytokine expression. Our study shows that AAV-RNAi silencing of Cathepsin K in periapical tissues can significantly reduce endodontic disease development, bone destruction, and inflammation in the periapical lesion. This is the first demonstration that AAV-mediated RNAi knockdown gene therapy may significantly reduce the severity of endodontic disease.

The influencing factor of in vitro fertilization and embryonic transfer in the domestic fowl (Gallus domesticus)

This study was conducted to explore the influencing factors of ova in vitro fertilization (IVF) and transfer of the fertilized ova into the oviduct of recipient hens. The efficiency of fertilization was compared using three aspects: (i) the different time of ova collection and transfer, (ii) egg-laying period of recipient hen; and (iii) semen volume. The following results are observed: 72%, 40% and 0% of ova were found in ovarian sac in 30∼40 min, 50∼60 min and more than 90 min post-oviposition, respectively; 20%, 18%, 14% and 5.8% of ova were fertilized with 0.1, 0.2, 0.5 and 1.0 ml semen, respectively; and 33% and 100% of healthy chickens were hatched from fertile ova with 0.1 and 0.5 ml of semen, respectively. All oocytes obtained from ovary and mid-oviduct were unfertilized. Embryos were transferred into recipient hens 30 min ± 10 min post-oviposition, and 70% of shelled eggs were produced. There were no eggs produced in the other transfer times. This demonstrated that live chicken can be obtained by IVF of ova collected shortly after oviposition. It was important that the ovum was transferred into the oviduct infundibulum of recipient hens immediately or shortly after oviposition.

A phase I dose-escalation study of aflibercept administered in combination with pemetrexed and cisplatin in patients with advanced solid tumours

Background:

To evaluate the safety, pharmacokinetics (PKs), and pharmacodynamics of aflibercept, and to identify the recommended phase II dose (RP2D) of aflibercept in combination with pemetrexed and cisplatin.

Methods:

Aflibercept was administered at escalating doses of 2, 4, or 6 mg kg⁻¹ in combination with fixed doses of pemetrexed (500 mg m⁻²) plus cisplatin (75 mg m⁻²) every 3 weeks. Blood samples were collected for PK analyses. Serum antiaflibercept antibodies were quantified to assess their impact on systemic aflibercept concentrations.

Results:

Eighteen patients were enrolled. One patient dosed at 4 mg kg⁻¹ experienced grade 3 hypophosphatemia (dose-limiting toxicity; DLT), which prompted a cohort expansion. No further DLTs were observed in the 4 mg kg⁻¹ cohort or the 6 mg kg⁻¹ dose cohort. Most common adverse events (AEs) of all grades included (%): fatigue (89), anaemia (89), nausea (83), hyponatremia (78), and neutropenia (72). Grade ⩾3 AEs consistent with anti-vascular endothelial growth factor therapy included (%): hypertension (22), pulmonary embolism (11), and deep vein thrombosis (6). Five patients (28%) experienced mild neurocognitive disturbance. No episodes of reversible posterior leukoencephalopathy syndrome (RPLS) were noted.

Conclusion:

The results of this phase I study allowed further evaluation of the combination of aflibercept with pemetrexed and cisplatin in a phase II study. The RP2D of aflibercept was 6 mg kg⁻¹, to be administered intravenously every 3 weeks in combination with pemetrexed and cisplatin.

Wegener's granulomatosis with pulmonary fungal infection: a case report and brief review

Wegener's granulomatosis (WG) is an autoimmune, necrotizing granulomatous disease of unknown aetiology that affects small and medium blood vessels, and is usually recurrent. Infection is the most frequent cause of death in patients with WG. A case of WG with pulmonary fungal infection in a 50-year-old man is reported. The patient was hospitalized following a 2-month history of haemoptysis and a 1-month history of intermittent fever. Examination and pathology results confirmed a diagnosis of WG with associated pulmonary fungal infection. The patient's condition was complicated by a septic pneumothorax and sinus formation after lung biopsy, and preexisting diabetes and hypertension, which worsened rapidly due to his critical condition. He was treated with glucocorticoids and cyclophosphamide therapy with the goal of controlling these complications, and had no recurrence within the 4-year follow-up period. This case demonstrated the utility of combined glucocorticoid and cyclophosphamide therapy for the treatment of infection in WG.

Direct observation of the proliferation of ferroelectric loop domains and vortex-antivortex pairs

We discovered stripe patterns of trimerization-ferroelectric domains in hexagonal REMnO(3) (RE=Ho,···,Lu) crystals (grown below ferroelectric transition temperatures (T(c)), reaching up to 1435 °C), in contrast with the vortex patterns in YMnO(3). These stripe patterns roughen with the appearance of numerous loop domains through thermal annealing just below T(c), but the stripe domain patterns turn to vortex-antivortex domain patterns through a freezing process when crystals cross T(c) even though the phase transition appears to not be Kosterlitz-Thouless-type. The experimental systematics are compared with the results of our six-state clock model simulation and also the Kibble-Zurek mechanism for trapped topological defects.

Stent-assisted coiling of intracranial bifurcation aneurysms leads to immediate and delayed intracranial vascular angle remodeling

BACKGROUND AND PURPOSE

Wide-neck bifurcating aneurysms are increasingly treated with intracranial stent-assisted coiling by using shape-memory alloy microstents. We sought to investigate the short- and long-term effects of intracranial stent implantation on the geometry and angular conformation of the stent-coiled vascular bifurcation.

MATERIALS AND METHODS

Thirty patients underwent stent-mediated coiling for 31 bifurcation aneurysms by using 31 self-expanding Neuroform (n = 14) and Enterprise (n = 17) stents (17 women; mean age, 56 years). The angle (δ) between the stented mother and daughter vessels at the bifurcation was measured by using multiplanar imaging of reconstructed rotational conventional angiography volumes and was compared by using matched-pair statistics. Neuroform and Enterprise longitudinal stent stiffness was measured in vitro at an increasing bending angle θ (θ = 180°-δ).

RESULTS

Stent deployment increased the bifurcation angle δ from 101.5° to 119.8° postprocedurally and to 137.3° (P < .0001) at latest follow-up, resulting in effective straightening; the angular remodeling was greater in distal-versus-proximal arteries (anterior cerebral > MCA > BA > ICA), inversely proportional to mother-vessel diameter and proportional to pretreatment bending angle θ. At follow-up, angle δ continued to significantly expand, with remodeling being greater in the early period (1-6 versus >7 months) and more pronounced with the longitudinally stiffer closed-cell Enterprise compared with the open-cell Neuroform stent.

CONCLUSIONS

Stent placement across bifurcation aneurysms leads to a significant biphasic angular remodeling related to stent type and vessel caliber, altering morphology to mimic sidewall lesions, a phenomenon needing consideration during procedural planning. Future work is needed to uncover the hemodynamic implications of this structural change and any possible effect on aneurysm-recurrence rates.

High glucose-induced RhoA activation requires caveolae and PKCβ1-mediated ROS generation

Glomerular matrix accumulation is a hallmark of diabetic nephropathy. We previously showed that RhoA activation by high glucose in mesangial cells (MC) leads to matrix upregulation (Peng F, Wu D, Gao B, Ingram AJ, Zhang B, Chorneyko K, McKenzie R, Krepinsky JC. Diabetes 57: 1683-1692, 2008). Here, we study the mechanism whereby RhoA is activated. In primary rat MC, RhoA activation required glucose entry and metabolism. Broad PKC inhibitors (PMA, bisindolylmaleimide, Gö6976), as well as specific PKCβ blockade with an inhibitor and small interfering RNA (siRNA), prevented RhoA activation by glucose. PKCβ inhibition also abrogated reactive oxygen species (ROS) generation by glucose. The ROS scavenger N-acetylcysteine (NAC) or NADPH oxidase inhibitors apocynin and DPI prevented glucose-induced RhoA activation. RhoA and some PKC isoforms localize to caveolae. Chemical disruption of these microdomains prevented RhoA and PKCβ1 activation by glucose. In caveolin-1 knockout cells, glucose did not induce RhoA and PKCβ1 activation; these responses were rescued by caveolin-1 reexpression. Furthermore, glucose-induced ROS generation was significantly attenuated by chemical disruption of caveolae and in knockout cells. Downstream of RhoA signaling, activator protein-1 (AP-1) activation was also inhibited by disrupting caveolae, was absent in caveolin-1 knockout MC and rescued by caveolin-1 reexpression. Finally, transforming growth factor (TGF)-β1 upregulation, mediated by AP-1, was prevented by RhoA signaling inhibition and by disruption or absence of caveolae. In conclusion, RhoA activation by glucose is dependent on PKCβ1-induced ROS generation, most likely through NADPH oxidase. The activation of PKCβ1 and its downstream effects, including upregulation of TGF-β1, requires caveolae. These microdomains are thus important mediators of the profibrogenic process associated with diabetic nephropathy.

Laser-locked, continuously tunable high resolution cavity ring-down spectrometer

A continuous-wave cavity ring-down spectrometer with sub-MHz precision has been built using the sideband of a frequency stabilized laser as the tunable light source. The sideband is produced by passing the carrier laser beam through an electro-optic modulator (EOM) and then selected by a short etalon on resonance. The carrier laser frequency is locked to a longitude mode of a thermo-stabilized Fabry-Perot interferometer (FPI) with a long-term absolute frequency stability of 0.2 MHz (5 × 10(-10)). Broad and precise spectral scanning is accomplished, respectively, by selecting a different longitudinal mode of the FPI and by tuning the radio-frequency driving the EOM. The air broadened water absorption line at 12,321 cm(-1) was studied to test the performance of the spectrometer.

Fabrication of silver tips for scanning tunneling microscope induced luminescence

We describe a reliable fabrication procedure of silver tips for scanning tunneling microscope (STM) induced luminescence experiments. The tip was first etched electrochemically to yield a sharp cone shape using selected electrolyte solutions and then sputter cleaned in ultrahigh vacuum to remove surface oxidation. The tip status, in particular the tip induced plasmon mode and its emission intensity, can be further tuned through field emission and voltage pulse. The quality of silver tips thus fabricated not only offers atomically resolved STM imaging, but more importantly, also allows us to perform challenging "color" photon mapping with emission spectra taken at each pixel simultaneously during the STM scan under relatively small tunnel currents and relatively short exposure time.

In situ transmission electron microscopy imaging of grain growth in a platinum nanobridge induced by electric current annealing

We report an in situ transmission electron microscopy (TEM) imaging of grain growth in a Pt nanobridge induced by a high electric current density. The change in morphology at the nanoscale was recorded in real time together with the electrical characterization of the Pt nanobridge. We find a drop in the differential resistance as the voltage across the bridge is increased; TEM inspection shows that this coincides with thermally induced grain growth, indicating that a reduction of grain boundary scattering is the cause of the resistance decrease.