Emerging therapies for gout.

Over the past decade much has been learned about the mechanisms of crystal-induced inflammation and renal excretion of uric acid, which has led to more specific targeting of gout therapies and a more potent approach to future management of gout. This article outlines agents being developed for more aggressive lowering of urate and more specific anti-inflammatory activity. The emerging urate-lowering therapies include lesinurad, arhalofenate, ulodesine, and levotofisopam. Novel gout-specific anti-inflammatories include the interleukin-1β inhibitors anakinra, canakinumab, and rilonacept, the melanocortins, and caspase inhibitors. The historic shortcomings of current gout treatment may, in part, be overcome by these novel approaches.

Downregulation of endotoxin-induced uveitis by intravitreal injection of vasoactive intestinal Peptide encapsulated in liposomes.

PURPOSE: To reestablish the immunosuppressive microenvironment of the eye, disrupted by ocular inflammation during endotoxin-induced uveitis (EIU), by means of intravitreal injection of vasoactive intestinal peptide (VIP) in saline or encapsulated in liposomes, to increase its bioavailability and efficiency. METHODS: EIU was induced in Lewis rats by subcutaneous injection of lipopolysaccharide (LPS). Simultaneously, animals were intravitreally injected with saline, saline/VIP, VIP-loaded liposomes (VIP-Lip), or unloaded liposomes. EIU severity and cellular infiltration were assessed by clinical examination and specific immunostaining. VIP concentration was determined in ocular fluids by ELISA. Ocular expression of inflammatory cytokine and chemokine mRNAs was detected by semiquantitative RT-PCR. Biodistribution of rhodamine-conjugated liposomes (Rh-Lip) was analyzed by immunohistochemistry in eyes and regional cervical lymph nodes (LNs). RESULTS: Twenty-four hours after intravitreal injection of VIP-Lip, VIP concentration in ocular fluids was 15 times higher than after saline/VIP injection. At that time, EIU clinical severity, ocular infiltrating polymorphonuclear leukocytes (PMNs), and, to a lesser extent, ED1(+) macrophages, as well as inflammatory cytokine and chemokine mRNA expression, were significantly reduced in VIP-Lip-injected rats compared with rats injected with saline/VIP, unloaded liposomes, or saline. Rh-Lip was distributed in vitreous, ciliary body, conjunctiva, retina, and sclera. It was internalized by macrophages and PMNs, and VIP colocalized with liposomes at least up to 14 days after injection. In cervical LNs, resident macrophages internalized VIP-Rh-Lip, and some adjacent lymphocytes showed VIP expression. CONCLUSIONS: VIP was efficient at reducing EIU only when formulated in liposomes, which enhanced its immunosuppressive effect and controlled its delivery to all tissues affected by or involved in ocular inflammation.

Ribavirin Concentrations Do Not Predict Sustained Virological Response in HIV/HCV-Coinfected Patients Treated with Ribavirin and Pegylated Interferon in the Swiss HIV Cohort Study.

BACKGROUND: Ribavirin (RBV) is an essential component of most current hepatitis C (HCV) treatment regimens and still standard of care in the combination with pegylated interferon (pegIFN) to treat chronic HCV in resource limited settings. Study results in HIV/HCV-coinfected patients are contradicting as to whether RBV concentration correlates with sustained virological response (SVR). METHODS: We included 262 HCV treatment naïve HIV/HCV-coinfected Swiss HIV Cohort Study (SHCS) participants treated with RBV and pegIFN between 01.01.2001-01.01.2010, 134 with HCV genotype (GT) 1/4, and 128 with GT 2/3 infections. RBV levels were measured retrospectively in stored plasma samples obtained between HCV treatment week 4 and end of therapy. Uni- and multivariable logistic regression analyses were used to evaluate the association between RBV concentration and SVR in GT 1/4 and GT 2/3 infections. The analyses were repeated stratified by treatment phase (week 4-12, 13-24, >24) and IL28B genotype (CC versus CT/TT). RESULTS: SVR rates were 35.1% in GT 1/4 and 70.3% in GT 2/3 infections. Overall, median RBV concentration was 2.0 mg/L in GT 1/4, and 1.9 mg/L in GT 2/3, and did not change significantly across treatment phases. Patients with SVR had similar RBV concentrations compared to patients without SVR in both HCV genotype groups. SVR was not associated with RBV levels ≥2.0 mg/L (GT 1/4, OR 1.19 [0.5-2.86]; GT 2/3, 1.94 [0.78-4.80]) and ≥2.5 mg/L (GT 1/4, 1.56 [0.64-3.84]; GT 2/3 2.72 [0.85-8.73]), regardless of treatment phase, and IL28B genotype. CONCLUSION: In HIV/HCV-coinfected patients treated with pegIFN/RBV, therapeutic drug monitoring of RBV concentrations does not enhance the chance of HCV cure, regardless of HCV genotype, treatment phase and IL28B genotype.

A Lead-In with Silibinin Prior to Triple-Therapy Translates into Favorable Treatment Outcomes in Difficult-To-Treat HIV/Hepatitis C Coinfected Patients.

BACKGROUND: The efficacy of first-generation protease inhibitor based triple-therapy against hepatitis C virus (HCV) infection is limited in HIV/HCV-coinfected patients with advanced liver fibrosis and non-response to previous peginterferon-ribavirin. These patients have a low chance of achieving a sustained virologic response (SVR) using first generation triple-therapy, with a success rate of only 20%. We investigated the efficacy and safety of lead-in therapy with intravenous silibinin followed by triple-therapy in this difficult-to-treat patient group. METHODOLOGY: Inclusion criteria were HIV/HCV coinfection with advanced liver fibrosis and documented previous treatment failure on peginterferon-ribavirin. The intervention was a lead-in therapy with intravenous silibinin 20 mg/kg/day for 14 days, followed by triple-therapy (peginterferon-ribavirin and telaprevir) for 12 weeks, and peginterferon-ribavirin alone for 36 weeks. Outcome measurements were HCV-RNA after silibinin lead-in and during triple-therapy, SVR data at week 12, and safety and tolerability of silibinin. RESULTS: We examined sixteen HIV/HCV-coinfected patients with previous peginterferon-ribavirin failure, of whom 14 had a fibrosis grade METAVIR ≥F3. All were on successful antiretroviral therapy. Median (IQR) HCV-RNA decline after silibinin therapy was 2.65 (2.1-2.8) log10 copies/mL. Fifteen of sixteen patients (94%) had undetectable HCV RNA at weeks 4 and 12, eleven patients (69%) showed end-of-treatment response (i.e., undetectable HCV-RNA at week 48), and ten patients (63%) reached SVR at week 12 (SVR 12). Six of the sixteen patients (37%) did not reach SVR 12: One patient had rapid virologic response (RVR) (i.e., undetectable HCV-RNA at week 4) but stopped treatment at week 8 due to major depression. Five patients had RVR, but experienced viral breakthroughs at week 21, 22, 25, or 32, or a relapse at week 52. The HIV RNA remained below the limit of detection in all patients during the complete treatment period. No serious adverse events and no significant drug-drug interactions were associated with silibinin. CONCLUSION: A lead-in with silibinin before triple-therapy was safe and highly effective in difficult-to-treat HIV/HCV coinfected patients, with a pronounced HCV-RNA decline during the lead-in phase, which translates into 63% SVR. An add-on of intravenous silibinin to standard of care HCV treatment is worth further exploration in selected difficult-to-treat patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT01816490.

Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves

Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.

The influence of water on the glucose affinity of hexokinase

In the present thesis, the role of hydration during the glucose induced conformational change of hexokinase is investigated. This is accomplished by applying the osmotic stress technique. The osmotic stress technique is founded on varying of the activity of water in a system in order to determine ifs effects. This is accomplished by adding inert solute molecules that are excluded from the system under study. The solute molecules used within the present investigation are Polyethylene glycols (PEGs). PEGs aid in the removal of water from hexokinase by exerting osmotic pressure. The osmotic pressures of the PEG solutions are also measured with both vapour pressure osmometry and secondary osmometry with phospholipids. An interesting discovery is made in that the osmotic pressures of PEG and co-solute solutions are non-additive. This indicates that PEG concentrates co-solutes in solution by making a certain proportion of the water inaccessible. Glucose binding was measured fluorometrically and the glucose equilibrium dissociation constant (GEDC) of hexokinase is measured in solutions containing the different MW PEGs. Changes in the sensitivity of the glucose affinity with osmotic pressure allows the calculation of the change in the numbers of polymer-inaccessible water molecules upon the binding of glucose to hexokinase ~Nw. It was determined the ~Nw decreases with increases in osmotic pressure in the presence of all MW PEGs. ~Nw decreases from values between 45-290 water molecules at low pressure to approximately 15 at high pressure. There is also a molecular weight dependence observed. There are large decreases in ~Nw with osmotic pressure in the presence of PEGs above MW 1000. However, below MW 1500 changes in ~Nw with osmotic pressure are relatively small. These findings are interpreted with respect to two possible mechanisms involving changes in the conformation of hexokinase u~der osmotic pressure and the access of the PEG molecules to water surrounding hexokinase.

Evaluation of water properties in HEA–HEMA hydrogels swollen in aqueous-PEG solutions using thermoanalytical techniques

Hydrogels are polymeric materials used in many pharmaceutical and biomedical applications due to their ability to form 3D hydrophilic polymeric networks, which can absorb large amounts of water. In the present work, polyethylene glycols (PEG) were introduced into the hydrogel liquid phase in order to improve the mechanical properties of hydrogels composed of 2-hydroxyethylacrylate and 2-hydroxyethylmethacrylate (HEA–HEMA) synthesized with different co-monomer compositions and equilibrated in water or in 20 % water–PEG 400 and 600 solutions. The thermoanalytical techniques [differential scanning calorimetry (DSC) and thermogravimetry (TG)] were used to evaluate the amount and properties of free and bound water in HEA–HEMA hydrogels. The internal structure and the mechanical properties of hydrogels were studied using scanning electron microscopy and friability assay. TG “loss-on-drying” experiments were applied to study the water-retention properties of hydrogels, whereas the combination of TG and DSC allowed estimating the total amount of freezable and non-freezing water in hydrogels. The results show that the addition of viscous co-solvent (PEG) to the liquid medium results in significant improvement of the mechanical properties of HEA–HEMA hydrogels and also slightly retards the water loss from the hydrogels. A redistribution of free and bound water in the hydrogels equilibrated in mixed solutions containing 20 vol% of PEGs takes place.

Antimicrobial effect of intracanal substances

In some situations, endodontic infections do not respond to therapeutic protocol. In these cases, it is suggested the administration of an alternative intracanal medication that presents a wide spectrum of action and has an in-depth effect on the root canal system. The purpose of this study was to assess the antimicrobial action of ciprofloxacin, metronidazole and polyethylene glycol and natrosol vehicles with different associations and concentrations. The minimum inhibitory concentration (MIC) was determined by using the agar dilution method. The culture media (Muller-Hinton agar) were prepared containing antimicrobial agents at multiple two-fold dilutions of 0.25 to 16 mu g/mL, and with the vehicles at the concentrations of 50, 45, 40, 35, 30 and 25%. Twenty-three microbial strains were selected for the study. Metronidazole was not capable of eliminating any of the tested microorganisms. The association of ciprofloxacin with metronidazole resulted in a reduction of the MIC. The vehicle polyethylene glycol inhibited the growth of 100% of the tested strains, while natrosol inhibited 18% of the strains. Ciprofloxacin formulations with polyethylene glycol presented better effects than those of formulations to which metronidazole was added. It was possible to conclude that ciprofloxacin presented antimicrobial action against all tested bacteria] strains, and its association with metronidazole was synergic. The vehicle polyethylene glycol showed antimicrobial effect and the ciprofloxacin/polyethylene glycol association was the most effective combination for reducing the tested bacteria and yeasts.

Triton X-100 solubilized bone matrix-induced alkaline phosphatase

1. 1. Solubilized and membrane-bound alkaline phosphatase showed Michaelis-Menten behavior in a wide range of different substrate concentrations. 2. 2. Membrane-bound alkaline phosphatase has a molecular weight of 130,000 and its minimum active configuration comprises two identical subunits of about 65,000. 3. 3. The two forms of the enzyme behave similarly with respect to NaCl, urea and guanidine HCl. 4. 4. Catalytic groups have pK values of about 8.5 and 9.7 for both membrane-bound and solubilized enzyme. © 1987.

Increased oxygen radical and high-dietary-carbohydrate pancreatic damage.

These data suggest that an improved understanding of the relationship between high dietary carbohydrate and the rate of lipid peroxidation may give some insight into possible treatment modalities for pancreatic damages and may shed light on molecular mechanisms underlying certain pathological processes. High dietary carbohydrate lesions are age related and induced alterations on ceruloplasmin, phospholipids, total proteins, copper and zinc serum levels. Significantly increased serum and pancreatic amylase, and lipoperoxide determinations were observed in 20 month old rats. Cu-Zn superoxide dismutase was decreased in these animals. Daily injection of Cu-Zn superoxide dismutase conjugated with polyethylene glycol (SOD-PEG) prevented the serum and pancreatic changes, indicating that superoxide radical is an important intermediate to high dietary carbohydrate lesion.

Study of Hybrid Silica-Polyethyleneglycol Xerogels by Eu3+ Luminescence Spectroscopy

Good optical quality Eu3+-doped silica-polyethyleneglycol hybrids were prepared by the sol-gel process. Thermomechanical analysis showed an increase of the glass transition temperature, due to the stiffness of the polymeric network, as the amount of Eu3+ increased. Europium luminescent properties were used to study structural evolution during the sol-gel transition. For lower doping concentrations dried gels present statistical distributions of Eu3+, typical of an amorphous environment, while for higher concentrations a crystalline-like environment of Eu3+ was observed. A broad emission band was observed in the visible part of the electromagnetic spectrum and assigned to the intrinsic emission from the hybrid polymeric network.

Full-color phosphors from amine-functionalized crosslinked hybrids lacking metal activator ions

Sol-gel derived hybrids that contain OCH2CH2 (polyethylene glycol, PEG) repeat units grafted onto a siliceous backbone by urea, -NHC(=O)NH-, or urethane, -NHC(=O)O-, bridges have been prepared. It is demonstrated that the white light PL of these materials results from an unusual convolution of a longer lived emission that originates in the NH groups of the urea/urethane bridges with shorter lived electron-hole recombinations occurring in the nanometer-sized siliceous domains. The PL efficiencies reported here (maximum quantum yields at room temperature of ≈ 0.20 ± 0.02 at a 400 nm excitation wavelength) are in the same range as those for tetramethoxysilane-formic acid, and APTES-acetic acid, sol-gel derived phosphors. The high quantum yields combined with the possibility of tuning the emission to colors across the chromaticity diagram present a wide range of potential applications for these hybrid materials.