Surgical treatment of recurring preauricular sinus: supra-auricular approach

Congenital preauricular sinus is a malformation of the preauricular soft tissues with an incidence ranging between 0.1 and 0.9% in Europe and the United States. It presents a high risk of recurrence when treated by a standard surgical technique (simple sinectomy), the incidence of which is reported to be between 19% and 40%. The supra-auricular approach, proposed by Prasad et al. in 1990, is easier to perform and presents a lower recurrence risk. Personal experience is presented in the treatment of congenital preauricular sinus with the supra-auricular approach as first choice or in the case of recurrence following previous standard surgery. This report includes a short review of the literature in order not only to focus on the supra-auricular approach and check the efficacy as far as concerns reduction of recurrence risk but also to contribute to a more widespread use of this method.

Structural and functional characterization of the porcine proline–rich antifungal peptide SP-B isolated from salivary gland granules

A 1905-Da cationic proline-rich peptide, named SP-B, was recently isolated by our group as the main component of salivary gland granules, and its primary sequence fully characterized by means of automated Edman sequencing and LC-MS/MS tools. In the present study SP-B is shown to possess antifungal activity when challenged with strains of Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus, while only negligible antibacterial activity was detected. Furthermore, SP-B was found to be non-cytotoxic when tested on fibroblast cell lines. To obtain information regarding its structure affinity, capillary electrophoresis (CE), circular dichroism (CD) and attenuated total reflection (ATR)-FT/IR experiments were performed. CE revealed a pH dependence of the hydrodynamic radial dimensions both in aqueous and 2,2,2-trifluoroethanol solutions. CD and ATR-FT/IR measurements confirmed the structure-pH relationship, revealing a secondary structure composed of mixed proportions of polyproline-II, unordered and turn motifs, the last being more evident in the zwitterionic form of the peptide. From these findings SP-B peptide could be classified as a new member of the proline-rich antimicrobial peptide family.

Impedance spectroscopy of solutions at physiological glucose concentrations

Impedance spectroscopy has been proposed as possible approach for non-invasive glycaemia monitoring. However, few quantitative data are reported about impedance variations related to glucose concentration variations, especially below the MHz band. Furthermore, it is not clear whether glucose directly affects the impedance parameters or only indirectly by inducing biochemical phenomena. We investigated the impedance variations in glucose-water, glucose-sodium chloride, and glucose-blood samples, for increasing glucose values (up to 300 mg/dl). In all the frequency range (0.1-10(7) Hz) glucose-water samples showed impedance modulus increases for increasing glucose values (up to 135%). In blood and sodium chloride samples the impedance modulus showed only slight variations (2% and 1.4%), but again in wide frequency ranges. Therefore: i) glucose directly affects the impedance parameters of solutions; ii) effects are more relevant at frequencies below the MHz band; iii) the influence on the impedance is decreased in high conductivity solutions, but still clearly present.

In vitro candidacidal activity of a synthetic killer decapeptide (KP) against Candida albicans cells adhered to resin acrylic discs

BACKGROUND

Oral Candida spp., and C. albicans in particular, are considered as important aetiological agents in the pathogenesis of denture-induced stomatitis. Several studies have reported that C. albicans is able to easily adhere to different medical devices, such as vascular and urinary catheters or acrylic denture surfaces, and that adhesion is a fundamental step in the initial pathogenic process of colonization and further possible infection. Recently, a synthetic decapeptide (KP) derived from the sequence of a single-chain recombinant anti-idiotypic antibody, acting as a functional internal image of a microbicidal, broad spectrum yeast killer toxin, has been reported to kill in vitro C. albicans cells and to exert a therapeutic activity against experimental mucosal and systemic candidiasis.

METHODS

The aim of this study was to evaluate, through a CFU assay, the candidacidal activity of KP on sanded acrylic resin discs, previously colonized by C. albicans cells.

RESULTS AND CONCLUSIONS

At 100 microg/ml KP showed over 90% of killing activity on C. albicans cells adhered to resin discs, when compared with a scramble peptide used as control. The results of this study suggest a potential effect of KP on C. albicans cells adhered on the surface of resin materials, such as prosthetic dentures.

Matrices containing NaCMC and HPMC

The aim of the present study is an investigation of the swelling behaviour of matrix systems containing a mixture of hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) with a model soluble drug to find the correlation between the morphological behaviour and the drug release performance. The swelling study was conducted on tablets containing only the drug and the two polymers mixture (MB) and on reference tablets containing each polymer and the same drug, at three different pHs. MB matrices show a similar swelling trend at pH 4.5 and 6.8, while they have different behaviour in acidic fluid. At pH 1 the gel layer formed by NaCMC is characterized by a rigid structure of a partially chemically crosslinked hydrogel while HPMC and MB matrices form a physical not crosslinked gel. At pH 4.5 and 6.8, all the systems show the typical morphological behaviour of a swellable matrix in which the macromolecular chains in the gel network are held together by weak bondings (physical gel). In these buffers, MB systems maintain a constant drug release rate coupling diffusion and erosion mechanism: the gel and infiltrated layers thicknesses are maintained constant and a zero-order release kinetics can be achieved.

Matrices containing NaCMC and HPMC 1. Dissolution performance characterization

In this study hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were used as polymeric carriers to improve controlled release performances of matrix tablets containing a soluble drug. The drug release behaviour of the systems containing these two polymers mixture and each material separately was investigated. To evaluate the effect of the dissolution medium pH, on the drug release performance, release tests were conducted at pH 1, 4.5 and 6.8. In vitro release studies demonstrated that the mixture of the two cellulose derivatives enables a better control of the drug release profiles at pH 4.5 and at 6.8 both in term of rate and mechanism. Texture analysis on the swollen tablets helps to understand drug release kinetic and mechanism. In fact, the results obtained confirm that a gel, which is characterized by high strength and consistence is less susceptible to erosion and chains disentanglement and the drug release mechanism is mainly governed by diffusion. On the contrary, gels, which show a low strength and texture, have low resistance to the fluid erosion action and the release of the active molecule is manly due to polymer relaxation and chains disentanglement moving the drug delivery kinetic towards an erosion/relaxation mechanism.

Influenza vaccination in patients on long-term anticoagulant therapy

The study evaluates the risk/benefit of influenza vaccination in patients on stable long-term oral anticoagulant therapy (OAT). One hundred and four consecutive patients with indication for influenza vaccination were randomized to receive one dose of 2004/2005 influenza vaccine followed by placebo after 6 weeks, or vice versa, in a cross-over blinded trial. All patients were tested for anticoagulation levels and for hemagglutination inhibiting antibody titres against the influenza vaccine antigens. The highly protective antibody titres induced by influenza vaccination and the absence of statistically relevant interactions between vaccination and OAT suggest that influenza vaccination can be used safely and successfully in elderly patients on OAT.

In vitro antifungal susceptibility to six antifungal agents of 229 Candida isolates from patients with diabetes mellitus

The most common antifungal drugs in current clinical use for the treatment of oral candidosis are polyenes and azoles, mainly used topically. Poor glycaemic control in association with other local factors, such as the presence of oral dental prostheses, salivary pH, salivary flow rate and tobacco habits, may lead to the development of oral candidosis. Topical antifungal agents are frequently used to prevent the development of candidal infections in patients with poor metabolic control, particularly in the elderly wearing dentures. The aim of this study was to assess the antifungal susceptibility of Candida isolates to six antifungal agents using a commercially available kit, Fungitest. The isolated were collected from patients affected by diabetes mellitus from two different geographic localities (London, UK, and Parma, Italy) and from a group of healthy non-diabetic subjects. No differences in antifungal susceptibility to the six agents tested were observed between Candida isolates from diabetic and non-diabetic subjects. However, differences were observed between the two geographically different diabetes mellitus populations. Oral yeast isolates from diabetes mellitus patients in the UK more often displayed resistance or intermediate resistance to fluconazole (P=0.02), miconazole (P<0.0001), and ketoconazole (P=0.01) than did isolates from diabetes mellitus patients in Italy. In addition, more C. albicans isolates were found in diabetic and non-diabetic subjects that were susceptible to fluconazole (P=0.0008 and P=0.01, respectively) than non-albicans isolates. The difference in the antifungal resistance of isolates from the two populations of diabetes mellitus patients may be related to differences in the therapeutic management of candidal infections between the two centres.

Successful treatment with rFVIIa of spontaneous intracerebral hemorrhage in a patient with mechanical prosthetic heart valves

Intracerebral hemorrhage (ICH) is associated with high mortality in patients on oral anticoagulant treatment. The normalization of hemostatic balance usually requires slow-acting or risky treatments, such as vitamin K, fresh frozen plasma or prothrombin complex concentrates, which have narrow therapeutic windows particularly in cardiopathic patients like those with mechanical heart valves. Recombinant activated factor VII (rFVIIa) seems useful in patients with normal or pathologic coagulation who have an ICH. We report of a patient on acenocumarol for mitro-aortic valve replacement, referred for headache and found at computerized tomography scanning to have a parietal hemorrhage with ventricular invasion. International normalized ratio was 3.22. The patient was treated with vitamin K and with a bolus of 80 mug/kg of rFVIIa, with correction of the international normalized ratio within 15 min. Sequential computerized tomographies showed progressive reduction of the hematoma and normalization of ventricular spaces and the patient fully recovered. No valvular dysfunctions or cardiac thrombi were found at sequential echocardiograms. Neurological examination at 3 months follow-up visit was completely normal. To our knowledge, this is the first report of the safe and successful use of rFVIIa to treat ICH in a patient on oral anticoagulants for prosthetic heart valves.

In vitro activity of a monoclonal killer anti-idiotypic antibody and a synthetic killer peptide against oral isolates of Candida spp. differently susceptible to conventional antifungals

BACKGROUND/AIMS

A monoclonal killer anti-idiotypic antibody (mAbK10) and a synthetic killer peptide, acting as internal images of a microbicidal, wide-spectrum yeast killer toxin (KT) have been recently shown to express candidacidal in vitro and an in vivo therapeutic activity against experimental mucosal and systemic candidosis models caused by a reference strain of Candida albicans (10S).

MATERIAL AND METHODS

The in vitro candidacidal activity of mAbK10 and synthetic killer peptide was compared using a colony forming unit assay against a large number of isolates of different Candida spp., obtained from oral saliva of adult diabetic (type 1 and 2) and nondiabetic subjects from Parma (Italy) and London (UK).

RESULTS

Both the KT-mimics exerted a strong dose-dependent candidacidal activity, probably mediated by the interaction with beta-glucan KT receptors on target yeast cells, against all the tested strains, regardless of their species and pattern of resistance to conventional antifungal agents.

CONCLUSIONS

These observations open new perspectives in the design and production of candidacidal compounds whose mechanism reflects that exerted in nature by killer yeasts.

Protective Antifungal Yeast Killer Toxin-Like Antibodies

After several years of controversy, antibodies (Abs) are now believed to play an important role in the protection against fungal infections. Among them, recent data are strongly supporting the relevance of protective yeast killer toxin-like Abs ("antibiobodies", KT-Abs), which are able to exert a direct microbicidal activity by mimicking a killer toxin (PaKT) and its interaction with cell wall receptors on susceptible cells essentially constituted by beta-glucans. This review will focus on the implications of the yeast killer phenomenon, and, particularly, the occurrence and antimicrobial activity of protective antifungal KT-Abs, such as those produced during the course of experimental and natural infections caused by PaKT-sensitive microorganisms or produced by idiotypic vaccination with a PaKT-neutralizing mAb. The strong therapeutic activity exerted against different experimental mucosal and systemic mycoses by monoclonal and recombinant microbicidal KT-Abs (either in their soluble forms or expressed on human commensal bacteria) as well as by a synthetic killer peptide (KP, an antibody fragment engineered from the sequence of a recombinant KT-Ab) will be discussed. The surprisingly wide antimicrobial spectrum of activity against eukaryotic and prokaryotic pathogenic agents, such as fungi, bacteria and protozoa, of these Abs and Ab-derived molecules suggests new potential strategies for transdisease anti-infective prevention and therapy.

Preparation and evaluation of release characteristics of 3TabGum, a novel chewing device

A new chewing gum device in the form of a three layers tablet (3TabGum) has been developed. The new drug delivery system is obtained, at room temperature, by direct compression using conventional pharmaceutical equipment. Basically, the resulting chewing gum tablets comprise a gum core combined with two protective antiadherent external layers, which prevent gum adhesion to the punches of the tableting machine. Drug release from a dosage form is the critical step in drug absorption and bioavailability, thus an experimental protocol has been designed to evaluate the efficiency of this kind of therapeutic system by verifying its capability to release the drug dose and by assessing the delivery rate. Simple diffusion into the medium causes the release of only a small percentage of the drug contained in the medicated chewing gum, while the delivery of the major part of the dose occurs during mastication. The results obtained in this study suggest that water soluble drugs are freely and easily released by chewing gums, while for actives characterized by reduced water solubility the release rate depends on the chewing time although all the drugs tested are completely released after a reasonable mastication time.

Engineered killer mimotopes: new synthetic peptides for antimicrobial therapy

This review deals with a novel approach to produce synthetic antibiotic peptides (killer mimotopes), similar to those described for the conversion of epitopes into peptide mimotopes, allowing their use as surrogate vaccines. Synthetic peptides pertaining to the complementary determining regions (CDRs) of a recombinant antiidiotypic antibody (PaKTscFv), which mimic the wide spectrum of microbicidal activity of a killer toxin produced by the yeast Pichia anomala (PaKT), have proven to act as structural or functional mimotopes of PaKT. This activity appeared to be mediated by interaction with specific cell wall killer toxin receptors (KTRs), mainly constituted by beta glucans. Killer mimotopes have shown in vitro an impressive microbicidal activity against Candida albicans. They were adopted as a model of PaKT- and PaKTscFv-susceptible microorganisms. Optimization through alanine scanning led to the generation of an engineered decapeptide (KP) of a CDR-L1 pertaining antibody fragment with an enhanced in vitro microbicidal activity. It had a potent therapeutic effect against experimental vaginal and systemic candidiasis in normal and immunodeficient mice caused by flucanozole susceptible and resistant yeast isolates. KP exerted a microbicidal activity in vitro against multidrug-resistant eukaryotic and prokaryotic pathogenic microorganisms, which was neutralized by interaction with laminarin (beta 1,3-glucan). To our knowledge, KP represents the prototype of an engineered peptide fragment derived from a microbicidal recombinant antiidiotypic antibody. It is capable of exerting antimicrobial activity in vitro and a therapeutic effect in vivo presumably acting through interaction with the beta glucan KTR component in the cell walls of pathogenic microorganisms.

Stresses in Polyethylene Liners in a Semiconstrained Ankle Prosthesis

A finite element model of a semiconstrained ankle implant with the tibia and fibula was constructed so that the stresses in the polyethylene liner could be computed. Two different widths of talar components were studied and proximal boundary conditions were computed from an inverse process providing a load of five times body weight appropriately distributed across the osseous structures. von Mises stresses indicated small regions of localized yielding and contact stresses that were similar to those in acetabular cup liners. A wider talar component with 36% more surface area reduced contact stress and von Mises stresses at the center of the polyethylene component by 17%.

The VEPSY UPDATED Project: clinical rationale and technical approach

More than 10 years ago, Tart (1990) described virtual reality (VR) as a technological model of consciousness offering intriguing possibilities for developing diagnostic, inductive, psychotherapeutic, and training techniques that can extend and supplement current ones. To exploit and understand this potential is the overall goal of the "Telemedicine and Portable Virtual Environment in Clinical Psychology"--VEPSY UPDATED--a European Community-funded research project (IST-2000-25323, www.cybertherapy.info). Particularly, its specific goal is the development of different PC-based virtual reality modules to be used in clinical assessment and treatment of social phobia, panic disorders, male sexual disorders, obesity, and eating disorders. The paper describes the clinical and technical rationale behind the clinical applications developed by the project. Moreover, the paper focuses its analysis on the possible role of VR in clinical psychology and how it can be used for therapeutic change.

Repeated treatment with the synthetic cannabinoid WIN 55,212-2 reduces both hyperalgesia and production of pronociceptive mediators in a rat model of neuropathic pain

The antinociceptive properties of cannabinoids in persistent pain are not fully elucidated. We investigated the effect of repeated treatment with the synthetic cannabinoid receptor agonist WIN 55,212-2 on the neuropathic pain induced in rats by chronic constriction of the sciatic nerve. WIN 55,212-2 administered daily throughout the development of neuropathy reversed the hyperalgesia, at a dose (0.1 mg x kg(-1), s.c.) that had no effect on the nociceptive responses of either paw contralateral to the sciatic ligation or of animals subjected to sham surgery. At 14 days after injury, the levels of mediators known to be involved in neuropathic pain, such as prostaglandin E2, NO and the neuronal NOS, were increased. Repeated treatment with WIN 55,212-2 abolished these increases. In the light of the current clinical need for neuropathic pain treatments, these findings indicate that cannabinoid agonists, at doses devoid of psychoactive effects, could constitute important compounds for the development of new analgesics.