Murine neutralizing antibody response and toxicity to synthetic peptides derived from E1 and E2 proteins of hepatitis C virus

Introduction

The highest estimated prevalence of HCV infection has been reported in Egypt, nearly 12% mostly type 4. Currently, a commercial vaccine to protect this high risk population as well as global HCV infected patients is not available.

Objectives

In the present study, we aim at: (1) examining the viral binding capacities of purified monospecific polyclonal murine antibodies raised against genetically conserved viral protein sequences, i.e. synthetic peptides derived from those sequences located within envelope proteins and (2) assessment of immunogenic properties and safety parameters of those peptides individually and in a vaccine format in mice.

Methods

Purified IgG Abs from immunized mice were used in immunocapture RT-PCR experiments to test viral neutralization by Abs raised against each of 4 peptides termed p35 (E1), p36 (E2), p37 (E2) and p38 (E2). Swiss mice were immunized with each of the 3 peptides (p35, p37 and p38) which generated neutralizing antibodies in immunocapture experiments. Antibody responses to corresponding peptides were determined using different routes of administration, different adjuvants, different doses and at different time points post-injection. To explore the dose range for future pharmacological studies, three doses namely 50 ng, 10 μg and 50 μg/25 gm mouse body weight were tested for biochemical and histopathological changes in several organs.

Results

Murine Abs against p35, p37 and p38 but not p36 showed HCV neutralization in immunocapture experiments. Subcutaneous injection of peptides elicited higher responses than i.m. and i.p. Immunization with Multiple Antigenic Peptide (MAP) form or coupled to Al PO4 elicited the highest Ab responses. Peptide doses of 50 ng/25 gm body weight or less were effective and safe, however dose assessment still requires further study. Histopathological changes were observed in animals that received doses ∼1000 times higher than the potential therapeutic dose.

Conclusion

Exploration of humoral immunogenicity, neutralization capacity and safety suggested that the peptides presented herein are candidate vaccine components for further preclinical assessment.     

Selective and validated spectrophotometric methods for the determination of nicorandil in pharmaceutical formulations

Two simple and sensitive validated spectrophotometric methods have been described for the assay of nicorandil in drug formulations. Method A is based on the reaction of the drug with phloroglucinol-sulfanilic acid reagent in sulfuric acid medium to give yellow-colored product, which absorbs maximally at 425 nm. Method B uses the oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with DL- 3,4 - dihydroxyphenylalanine (DL-dopa) in the presence of nicorandil as oxidant in sulfuric acid medium to form an intensely colored product having maximum absorbance at 530 nm. Beer's law is obeyed in the concentration range 2.5 to 50.0 and 1.0 to 15.0 microg mL(-1) with methods A and B, respectively. Both methods have been successfully applied for the analysis of drug in pharmaceutical formulations. The reliability and the performance of the proposed methods are established by point and interval hypothesis and through recovery studies. The experimental true bias of all samples is smaller than +/-2%.     

Bioactivation of food genotoxicants 5-hydroxymethylfurfural and furfuryl alcohol by sulfotransferases from human,mouse and rat: a comparative study

5-Hydroxymethylfurfural (HMF) and furfuryl alcohol (FFA) are moderately potent rodent carcinogens that are present in thermally processed foodstuffs. The carcinogenic effects were hypothesized to originate from sulfotransferase (SULT)-mediated bioactivation yielding DNA-reactive and mutagenic sulfate esters, a confirmed metabolic pathway of HMF and FFA in mice. It is known that orthologous SULT forms substantially differ in substrate specificity and tissue distribution. This could influence HMF- and FFA-induced carcinogenic effects. Here, we studied HMF and FFA sulfoconjugation by 30 individual SULT forms of humans, mice and rats. The catalytic efficiencies (k _cat/K _M) of HMF sulfoconjugation of human SULT1A1 (13.7 s^?1 M^?1), mouse Sult1a1 (15.8 s^?1 M^?1) and 1d1 (4.8 s^?1 M^?1) and rat Sult1a1 (5.3 s^?1 M^?1) were considerably higher than those of all other SULT forms investigated (≤0.73 s^?1 M^?1). FFA sulfoconjugation was monitored using adenosine as a nucleophilic scavenger for the reactive 2-sulfoxymethylfuran (t _1/2 = 20 s at 37 °C). The resulting adduct N ⁶-((furan-2-yl)methyl)-adenosine (N ⁶-MF-A) was quantified by isotope-dilution UPLC-MS/MS. The rates of N ⁶-MF-A formation showed that hSULT1A1 and its orthologues in mice and rats were also the most important contributors to FFA sulfoconjugation in each of the species. Taken together, the catalytic capacity of hSULT1A1 is comparable to that of mSult1a1 in mice, the species in which carcinogenic effects of HMF and FFA were detected. This is of primary concern due to the expression of hSULT1A1 in many different tissues.     

Ion-activated, Gelrite-based in situ ophthalmic gels of pefloxacin mesylate: comparison with conventional eye drops

The purpose of our work was to develop an ophthalmic delivery system of a flouroquinolone antibiotic, pefloxacin mesylate, based on the concept of ion-activated in situ gelation. Gelrite gellan gum, a novel ophthalmic vehicle, that gels in the presence of mono- or divalent-cations present in the lacrimal fluid, was used as the gelling agent. The developed formulation was compared with marketed eye drops in efficacy of treatment of bacterial conjunctivitis that was induced artificially in rabbits. The formulations were evaluated for rheological characteristics, in vitro release behavior, antimicrobial efficacy, and efficacy against bacterial conjunctivitis.We found that in situ gelling formulations passed the test for sterility. The formulations exhibited a first-order release pattern over 12 hr in in vitro release studies. The developed formulation was effective against selected micro-organisms in antimicrobial efficacy studies. The shelf lives of formulation was >2 years. The formulation demonstrated better therapeutic efficacy compared with standard eye drops because it improved the clinical parameters monitored for prolonged periods. The developed formulations can be considered as a viable alternative to conventional eye drops.     

Large Congenital Melanotic Nevi in an Extremity with Neurocutaneous Melanocytosis

Abstract:   A 14-day-old boy presented with a large congenital melanocytic nevus over his left thigh with approximately 17 satellite nevi distributed over the rest of his skin surface. Six weeks later, he developed generalized tonic–clonic seizures and additional satellite nevi became apparent ( n  > 20). A subsequent brain magnetic resonance imaging demonstrated right temporal T1 hyperintense signal abnormality. At 4 months of age the patient underwent a lumbar puncture that was normal without evidence of melanocytes or tumor. Nevertheless, a few days later he underwent resection of his right medial temporal lesion which demonstrated melanocytosis in the temporal lobe as well as melanocytosis in subependymal areas in other parts of the brain and ventricles, confirming the suspected diagnosis of neurocutaneous melanocytosis. Our case supports previous studies that conclude that the number of satellite nevi is a greater predictor of neurocutaneous melanocytosis than is the location of large congenital melanocytic nevus. In our case, cerebrospinal fluid studies were not reliable even in the face of florid neurocutaneous melanocytosis involving the leptomeninges and ventricles.     

Erectile Implants in Female-to-Male Transsexuals: Our Experience in 129 Patients

Background

The combination of a neourethra and erection prosthesis in a single neophallus in the female-to-male transsexual remains a challenge. No good data are available on this subject.

Objective

To report the outcome in 129 female-to-male transsexuals with a neophallus after the implantation of an erectile prosthesis.

Design, setting, and participants

From March 1996 until October 2007, 129 female-to-male transsexuals with a neophallus underwent the implantation of an erectile prosthesis. The mean follow-up was 30.2 mo (range: 0–132 mo).

Intervention

A Dynaflex prosthesis was implanted initially in 9 patients, a three-piece hydraulic device (AMS CX or AMS CXM) in 50 patients, and a CX Inhibizone, Ambicor, and Coloplast/Mentor prosthesis in 17, 47, and 6 patients, respectively.

Measurements

Data on outcome in these patients were retrospectively evaluated.

Results and limitations

Of 129 patients, 76 patients (58.9%) still have their original implant in place. Fifty-three patients (41.1%) needed to undergo either removal or revision of the prosthesis due to infection, erosion, dysfunction, or leak. Forty-one patients underwent a replacement of the prosthesis, nine needed a second revision, five needed a third revision, and one patient needed a fourth revision of prosthesis. Malposition of prosthesis was corrected by surgical repositioning so that removal or revision could be avoided. Of 185 prostheses used in 129 patients, 108 (58.4%) still remain in place, with a total infection rate of 11.9%, a total protrusion rate of 8.1%, a total prosthesis leak rate of 9.2%, a total dysfunction rate of 13%, and a total malposition rate of 14.6%.The period of follow-up in the more recent types of prostheses (Ambicor, Coloplast/Mentor) is much shorter; therefore, comparison with earlier types is difficult to make.

Conclusions

Despite high complication rates, implantation of a hydraulic erectile prosthesis remains the best option for achieving the possibility of sexual intercourse in female-to-male transsexuals.     

Modest abuse-related subjective effects of zolpidem in drug-naive volunteers

Recent case reports suggest that the short-acting benzodiazepine-like hypnotic, zolpidem, may have abuse potential among individuals who have no personal history of abusing drugs or alcohol, particularly at doses higher than those recommended for treating insomnia. This study recruited drug-naive volunteers to assess the subjective effects of multiple doses of zolpidem (0, 5, 10, or 20 mg) administered in a within-subject double-blind design. Participants (n=11) answered computerized questionnaires (Addiction Research Center Inventory, visual analog scales, and a hypothetical Drug versus Money Choice) to address the hypothesis that a supratherapeutic dose (20 mg) would increase ratings of abuse-related subjective effects, while lower therapeutic doses (5 and 10 mg) would not. Although participants rated some effects as negative at 10 and 20 mg, the highest dose engendered predominantly positive abuse-like effects such as 'High', 'Like', and 'Good Effects'. However, no dose of zolpidem was chosen over money ($0.35-$10) when participants made hypothetical choices between them. Results suggest that although individuals without a drug abuse history are not inclined to choose zolpidem when presented with an alternative reinforcer such as money, it may possess moderate abuse potential that limits its clinical utility.