Cellulose nanocrystal-reinforced keratin bioadsorbent for effective removal of dyes from aqueous solution

High-efficiency and recyclable three-dimensional bioadsorbents were prepared by incorporating cellulose nanocrystal (CNC) as reinforcements in keratin sponge matrix to remove dyes from aqueous solution. Adsorption performance of dyes by CNC-reinforced keratin bioadsorbent was improved significantly as a result of adding CNC as filler. Batch adsorption results showed that the adsorption capacities for Reactive Black 5 and Direct Red 80 by the bioadsorbent were 1201 and 1070mgg^-1, respectively. The isotherms and kinetics for adsorption of both dyes on bioadsorbent followed the Langmuir isotherm model and pseudo-second order model, respectively. Desorption and regeneration experiments showed that the removal efficiencies of the bioadsorbent for both dyes could remain above 80% at the fifth recycling cycles. Moreover, the bioadsorbent possessed excellent packed-bed column operation performance. Those results suggested that the adsorbent could be considered as a high-performance and promising candidate for dye wastewater treatment.

[2.2.1]-Bicyclic sultams as potent androgen receptor antagonists

This letter describes the discovery, synthesis, SAR, and biological activity of [2.2.1]-bicyclic sultams as potent antagonists of the androgen receptor. Optimization of the series led to the identification of compound 25, which displayed robust pharmacodynamic effects in rats after oral dosing.

Kinetic and equilibrium studies on the biosorption of reactive black 5 dye by Aspergillus foetidus

An isolated fungus, Aspergillus foetidus had the ability to decolourize growth unsupportive medium containing 100 mg L(-1) of reactive black 5 (RB5) dye with >99% efficiency at acidic pH (2-3). Pre-treatment of fungal biomass by autoclaving or exposure to 0.1M sodium hydroxide facilitated more efficient uptake of dye as compared to untreated fungal biomass. Pre-equilibrium biosorption of RB5 dye onto fungus under different temperatures followed pseudo-second-order kinetic model with high degree of correlation coefficients (R(2)>0.99). Biosorption isotherm data fitted better into Freundlich model for lower concentrations of dye probably suggesting the heterogeneous nature of sorption process. Based on the Langmuir isotherm plots the maximum biosorption capacity (Q(0)) value was calculated to be 106 mg g(-1) at 50 degrees C for fungal biomass pre-treated with 0.1M NaOH. Thermodynamic studies revealed that the biosorption process was favourable, spontaneous and endothermic in nature. Recovery of both adsorbate (dye) and adsorbent (fungal biomass) was possible using sodium hydroxide. Recovered fungal biomass could be recycled number of times following desorption of dye using 0.1M NaOH. Fungal biomass pre-treated with NaOH was efficient in decolourizing solution containing mixture of dyes as well as composite raw industrial effluent generated from leather, pharmaceutical and dye manufacturing company.

When is red urine not hematuria?: A case report

The definition of gross hematuria is "the presence of blood in the urine in sufficient quantity to be visible to the naked eye." Certainly red urine, especially after trauma, immediately sparks the concern for genitourinary trauma. However, we report the unique case of a 19-year-old male who presented with "gross hematuria" after a motorcycle accident that turned out not to be hematuria but rather urine discoloration caused by the liberal use of a topical sulfa ointment containing an azo dye obtained in Mexico. We discuss the differential diagnosis of pigmenturia due to drugs or food ingestion, which is sparsely reported in the literature, as well as the frequency of alternative treatments used by patients presenting to the Emergency Department and the impact that can have on their evaluation.

Accumulation of Acid Orange 7, Acid Red 18 and Reactive Black 5 by growing Schizophyllum commune

The effect of Acid Orange 7, Acid Red 18 and Reactive Black 5 on the growth and decolorization properties of Schizophyllum commune was studied with respect to the initial pH varying from 1 to 6 and initial dye concentration (10-100 mg/L). The optimum pH value was found to be 2 for both growth and color removal of these azo dyes. Increasing the concentration of azo dyes inhibited the growth of S. commune. It was observed that S. commune was capable of removing Acid Orange 7, Acid Red 18 and Reactive Black 5 with a maximum specific uptake capacity of 44.23, 127.53 and 180.17 (mg/g) respectively for an initial concentration of 100 mg/L of the dye. Higher decolorization was observed at lower concentrations for all the dyes. Finally it was found that the percentage decolorization was more in the case of Reactive Black 5 dye compared to the other two dyes used in the present investigation.

Unexpected relationship between plasma protein binding and the pharmacodynamics of 2-NAP, a CCK1-receptor antagonist

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT?: * Two chemically diverse CCK1 receptor antagonists have been shown clinically to inhibit CCK-evoked contraction of human gallbladder [2, 3]. These studies have not examined the relationship between plasma concentration and effect, the latter usually considered to be predictive from the free drug concentration [8]. * We wanted to examine our novel CCK1 receptor antagonist in this validated model and also to explore its PK-PD relationship.

WHAT THIS STUDY ADDS

* 2-NAP inhibited CCK-evoked human gallbladder contraction in vivo but at a plasma free concentration that was, in theory, too low to have achieved adequate CCK1 receptor occupancy. * The study serves as a caveat to the assumption that free plasma concentration can be used to predict pharmacological effect.

AIMS

To study the pharmacokinetics and pharmacodynamics of 2-NAP (2-naphthalenesulfonyl-L-aspartyl-(2-phenethyl)amide), a selective CCK1 receptor antagonist in healthy volunteers.

METHODS

2-NAP was given to 12 healthy male volunteers in an ascending dose, safety and PK phase 1a study by 1 h i.v. infusion (0.6-9.6 mg kg(-1) h(-1)). A further 12 healthy male volunteers received i.v. CCK-8S (6.25 pmol kg(-1) h(-1)) to produce gallbladder contraction, measured by ultrasound recordings of gallbladder volume, and the effect of concurrent i.v. 2-NAP administration was studied. Plasma protein binding in vitro and ex vivo was measured by ultrafiltration and by equilibrium dialysis.

RESULTS

2-NAP was generally well tolerated, displayed linear pharmacokinetics and a very high degree of plasma protein binding (99.9%). A 105 min i.v. CCK-8S infusion induced a reduction in gallbladder volume of 14.9 (+/-7.0) ml during placebo co-infusion and this was reduced to 2.4 (+/-5.9) ml when 2-NAP was co-infused with CCK-8S (P = 0.00024, paired t-test, mean change 12.5 ml; 95% CI For mean 7.4, 18.3 ml). This extent of inhibition was consistent with a 2-NAP total plasma concentration of 36 microm, but when protein binding corrections were made, the 'free concentration' of 2-NAP was only 0.04 microm, a value much less than the average equilibrium dissociation constant of 2-NAP for human CCK1 receptors ( approximately 0.7 microm).

CONCLUSIONS

The pharmacological effect of a drug is usually considered to be determined by its free concentration. However, the complete inhibition of CCK-8S-evoked gallbladder contraction by a free plasma concentration of 0.04 microm 2-NAP was much greater than would have been predicted from simple drug-receptor occupancy theory and cautions against the general use of free concentration of drug for predicting pharmacological effect.

Direct measurement of in-vivo vaginal microbicide levels of PRO 2000 achieved in a human safety study

OBJECTIVES

To directly measure the cervico-vaginal lavage (CVL) and plasma PRO 2000 concentrations achieved by vaginal dosing.

DESIGN

A sub-study of a prospective randomized, double-blind phase 1 trial of a candidate vaginal microbicide, PRO 2000 gel.

METHODS

Thirty-six sexually abstinent women self-administered 4% PRO 2000 gel, 0.5% PRO 2000 gel or placebo gel twice on day 0 and then once daily for a further 12 days.

RESULTS

There was no evidence of systemic absorption of PRO 2000. PRO 2000 concentrations in CVL exceeded 25 microg/ml in all women in both the 4 and 0.5% groups at 2 h post-first dose, and in 10 of 12 of the women in the 4% gel group compared with five of 12 of women in the 0.5% group at 12 h post-seventh dose. Single use of both 4 and 0.5% PRO 2000 gels was therefore associated with levels of PRO 2000 in CVL that would be capable of preventing HIV infection in vitro, although the 4% gel gave a greater margin of excess. Levels substantially in excess of the target concentration were present 12 h after repeated dosing in twice as many 4% gel recipients compared with 0.5% gel recipients.

CONCLUSIONS

Both PRO 2000 gel strengths provided satisfactory in-vivo HIV inhibitory concentrations. However, our observations show that higher concentrations of PRO 2000 are likely to provide a greater margin of potential efficacy in the context of sexual intercourse provided safety issues are equivalent for differing concentrations of the agent.

The non-nucleoside antiviral, BAY 38-4766, protects against cytomegalovirus (CMV) disease and mortality in immunocompromised guinea pigs

New antiviral drugs are needed for the treatment of cytomegalovirus (CMV) infections, particularly in immunocompromised patients. These studies evaluated the in vitro and in vivo activity of the non-nucleosidic CMV inhibitor, BAY 38-4766, against guinea pig cytomegalovirus (GPCMV). Plaque reduction assays indicated that BAY 38-4766 was active against GPCMV, with an IC(50) of 0.5muM. Yield reduction assays demonstrated an ED(90) and ED(99) of 0.4 and 0.6muM, respectively, of BAY 38-4766 against GPCMV. Guinea pigs tolerated oral administration of 50mg/kg/day of BAY 38-4766 without evidence of biochemical or hematologic toxicity. Plasma concentrations of BAY 38-4766 were high following oral dosing, with a mean peak level at 1-h post-dose of 26.7mg/ml (n=6; range, 17.8-35.4). Treatment with BAY 38-4766 reduced both viremia and DNAemia, as determined by a real-time PCR assay, following GPCMV infection of cyclophosphamide-immunosuppressed strain 2 guinea pigs (p<0.05, Mann-Whitney test). BAY 38-4766 also reduced mortality following lethal GPCMV challenge in immunosuppressed Hartley guinea pigs, from 83% (20/24) in placebo-treated guinea pigs, to 17% (4/24) in BAY 38-4766-treated animals (p<0.0001, Fisher's exact test). Mortality differences were accompanied by reduction in DNAemia in Hartley guinea pigs. Based upon its favorable safety, pharmacokinetic, and therapeutic profiles, BAY 38-4766 warrants further investigation in the GPCMV model.

Adsorptive stripping voltammetric behaviour of azomethine group in pyrimidine-containing drugs

The stripping voltammetric behaviour of buspirone hydrochloride (BUS) and piribedil (PIR), as models of pyrimidine-containing compounds, was studied using a hanging mercury drop electrode (HMDE). A sensitive adsorptive stripping voltammetric method for determination of such drugs is described. The voltammetric peaks were obtained at -1.23 and -1.22 V for BUS and PIR. respectively, which correspond to the reduction of the azomethine group of pyrimidine ring in Britton-Robinson buffer (pH 7). Factors such as pH of supporting electrolyte, accumulation potential and time and instrumental parameters were optimized. Calibration plots and regression data validation, accuracy, precision, limits of detection, limits of quantification, and other aspects of analytical merit are presented. The applicability of the method was evaluated through determination of BUS and PIR in tablet dosage forms. A preliminary study of the analysis of plasma samples, spiked with the investigated drug, after a simple extraction procedure is described.

Genotoxicity studies on the azo dye Direct Red 2 using the in vivo mouse bone marrow micronucleus test

The clastogenicity of the azo dye Direct Red 2 (DR2) has been investigated using the murine bone marrow micronucleus assay. A potent dose-dependent response was observed following oral gavage of DR2 up to 4 mg/kg, after which significant toxicity to the erythroid compartment was observed. The route of administration had a significant effect on the frequency of micronucleus formation: intraperitoneal injection was approximately two-fold less clastogenic than the equivalent dose delivered orally (p<0.05). The requirement for activation of DR2 by intestinal microflora was indicated by the fact that mice given acid-treated water prior to administration of DR2 showed a significant reduction (40%; p<0.001) in micronucleated polychromatic erythrocyte formation. The implications of these findings for the health and safety of occupationally exposed workers are discussed.

Inhibition of in vitro and in vivo HIV replication by a distamycin analogue that interferes with chemokine receptor function: a candidate for chemotherapeutic and microbicidal application

Select chemokine receptors act as coreceptors for HIV-1 entry into human cells and represent targets for antiviral therapy. In this report we describe a distamycin analogue, 2,2'-[4, 4'-[[aminocarbonyl]amino]bis[N,4'-di[pryrrole-2-carboxamide- 1, 1'-dimethyl]]-6,8-naphthalenedisulfonic acid]hexasodium salt (NSC 651016), that selectively inhibited chemokine binding to CCR5, CCR3, CCR1, and CXCR4, but not to CXCR2 or CCR2b, and blocked chemokine-induced calcium flux. Inhibition was not due to nonspecific charge interactions at the cell surface, but was based on a specific competition for the ligand receptor interaction sites since the inhibitory effect was specific for some but not all chemoattractant receptors. NSC 651016 inhibited in vitro replication of a wide range of HIV-1 isolates, as well as HIV-2 and SIV, and exhibited in vivo anti-HIV-1 activity in a murine model. In contrast, a distamycin analogue with similar structure and charge and the monomeric form of NSC 651016 demonstrated no inhibitory effects. These data demonstrate that molecules which interfere with HIV-1 entry into cells by targeting specific chemokine coreceptors can provide a viable approach to anti-HIV-1 therapy. NSC 651016 represents an attractive candidate for the chemotherapeutic treatment of HIV-1 infection and as a microbicide to prevent the sexual transmisssion of HIV-1. Moreover, NSC 651016 can serve as a template for medicinal chemical modifications leading to more effective antivirals.

Biotransformation of 1-naphthalenesulfonic acid by the green alga Scenedesmus obliquus

Under sulfate limitation, axenic batch cultures of the green alga Scenedesmus obliquus metabolized 1-naphthalenesulfonic acid and partially used the sulfonate as a source of sulfur. The main metabolite, 1-hydroxy-2-naphthalenesulfonic acid, which was not metabolized further in the algal culture, was formed by hydroxylation of the substrate in position 1 and by migration of the sulfonic acid group to position 2 of the naphthalene ring (NIH shift). A smaller amount of 1-naphthalenesulfonic acid was desulfonated. The resulting 1-naphthol was mostly transformed into 1-naphthyl beta-d-glucopyranoside.

Iontophoresis of reactive black 5 for pulsed dye laser sclerostomy

Ab interno pulsed dye laser sclerostomy uses a gonioscopic approach to form a limbal fistula for the treatment of glaucoma. This procedure requires a full thickness penetration of stain in sclera for adequate absorption of the visible light energy. Iontophoresis is a technique using an electrical current to noninvasively deliver Reactive Black 5 (RB5) stain into sclera. This project determined the stability of RB5 stain as well as the optimal parameters for iontophoresis (probe tip surface area, current, and duration) in a rabbit model. RB5 stain was stable over time (72 hr) as well as after exposure to extreme heat (120 degrees C), scleral constituents (namely collagen), high concentrations of oxidants (1.5% H2O2), and laser light energy. Ideal parameters for iontophoresis included a probe tip surface area between 0.1 and 0.7 mm2, a current of 0.5 mA, and a duration of 5 min. The maximum concentration of RB5 stain achieved in sclera was 0.15%. The threshold of ablation for RB5 using an energy of 250 mJ was 0.001%. Iontophoresis can effectively deliver RB5 stain into sclera and may be a viable adjunct to ab interno pulsed dye laser sclerostomy procedures in the eye.

Water-soluble metal naphthalocyanines--near-IR photosensitizers: cellular uptake, toxicity and photosensitizing properties in NHIK 3025 human cancer cells

Metal naphthalocyanine complexes (MNCSs) absorb light in the near-IR spectral region (760 nm) where tissue penetration is optimal and they have been proposed as agents for photodynamic therapy (PDT). Sulphonated derivatives of tris-(2,3-naphthalocyanato) bis-chloroaluminium(III) and zinc(II) with various degrees of sulphonation were prepared. Cellular uptake, aggregation in cellular environments, cytotoxicity and photosensitizing properties were studied. Three of the four dyes studied were taken up by cells to a satisfactory degree and were not cytotoxic at the concentration used (10 micrograms ml-1). The least sulphonated sample of zinc naphthalocyanine produced some phototoxic effects (LD50 = 1.12 J cm-2). All the other samples of sulphonated naphthalocyanine were found to be aggregated inside the NHIK 3025 cells, preventing any significant PDT effect.

Metabolic disposition of 14C-labelled carmoisine in the rat, mouse and guinea-pig

The absorption, metabolism and excretion of 14C-labelled carmoisine has been studied in the rat, mouse and guinea-pig. Following administration of a single oral dose of either 0.5 or 50 mg/kg body weight, substantially all of the dose was recovered in the excreta within 72 hr, mainly in the faeces. Although the urinary excretion of radioactivity was similar in the rat and the mouse, the proportion of the radioactivity found in the urine of the guinea-pig was significantly greater than that of the other species at both dose levels. Pretreating male rats with unlabelled colouring in the diet (0.05%, w/w) for 28 days prior to dosing with 14C-labelled colouring had no effect on the route of excretion or the time taken to eliminate the majority of the labelled dose. Following a single oral dose of 14C-labelled colouring to previously untreated rats, mice and guinea-pigs or to rats pretreated as above, no marked accumulation of radioactivity in any tissue was found. Pregnant rats eliminated a single oral dose of 14C-labelled colouring at a similar rate to non-pregnant females, and the concentration of radioactivity in the foetuses was similar to that in the other tissues. Naphthionic acid was the major urinary metabolite in all three species. In the rat and mouse, most of the remaining radioactivity co-chromatographed with 2-amino-1-naphthol-4-sulphonic acid (2-ANS), but in the guinea-pig radioactivity also co-chromatographed with 1,2-naphthoquinone-4-sulphonate (1,2-NQS). Only a trace amount of unchanged carmoisine was detected in the urine of the species examined. Naphthionic acid was also found in the faeces of all three species, but neither carmoisine, 2-ANS or 1,2-NQS was detected. At least five other radioactive metabolites were found in the faecal extracts of all three species, including a substantial amount of a compound with chromatographic properties similar to those of a trace metabolite in the urine. Two of the faecal metabolites were hydrolysed by beta-glucuronidase and sulphatase treatment. In studies on the absorption of carmoisine at concentrations of 50, 500 or 5000 ppm from isolated intestinal loops, no significant absorption was detected in the rat, mouse or guinea-pig.