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Biomedical subjects

Michele Trotta

Publications and source records attributed to Michele Trotta.

11 recordsLinked to original sources
PubMed2005

Multiplex PCR method for use in real-time PCR for identification of fish fillets from grouper (Epinephelus and Mycteroperca species) and common substitute species.

Mitochondrial 16S rRNA sequences from morphological validated grouper (Epinephelus aeneus, E. caninus, E. costae, and E. marginatus; Mycteroperca fusca and M. rubra), Nile perch (Lates niloticus), and wreck fish (Polyprion americanus) were used to develop an analytical system for group diagnosis based on two alternative Polymerase Chain Reaction (PCR) approaches. The first includes conventional multiplex PCR in which electrophoretic migration of different sizes of bands allowed identification of the fish species. The second approach, involving real-time PCR, produced a single amplicon from each species that showed different Tm values allowing the fish groups to be directly identified. Real-time PCR allows the quick differential diagnosis of the three groups of species and high-throughput screening of multiple samples. Neither PCR system cross-reacted with DNA samples from 41 common marketed fish species, thus conforming to standards for species validation. The use of these two PCR-based methods makes it now possible to discriminate grouper from substitute fish species.

Animals↗
PubMed2005

Chemical modification of chitosan under high-intensity ultrasound.

Chitosan (CTS), a biocompatible, biodegradable, non-toxic polymer, dissolves in water only if pH is lowered under 6.5, when a substantial fraction of the amino groups is protonated. Its range of application has been much extended by partially depolymerising it or converting it to water-soluble derivatives. Working under high-intensity ultrasound at 17.8-18.5 kHz, using either a simple horn or a cup horn, we achieved a controlled depolymerization of CTS, also prepared in high yields several derivatives that can be useful intermediates for further chemical modification, as well as several water-soluble derivatives that lend themselves to a host of industrial applications. Compared to conventional methods, all these reactions went to completion in considerably shorter times at lower temperatures.

Chitosan↗
PubMed2005

Mitochondrial cytochrome b DNA sequence variations: an approach to fish species identification in processed fish products.

The identification of fish species in food products is problematic because morphological features of the fish are partially or completely lost during processing. It is important to determine fish origin because of the increasing international seafood trade and because European Community Regulation 104/2000 requires that the products be labeled correctly. Sequence analysis of PCR products from a conserved region of the cytochrome b gene was used to identity fish species belonging to the families Gadidae and Merluccidae in 18 different processed fish products. This method allowed the identification of fish species in all samples. Fish in all of the examined products belonged to these two families, with the exception of one sample of smoked baccalà (salt cod), which was not included in the Gadidae cluster.

Animals↗
PubMed2004

Deformable liposomes for dermal administration of methotrexate.

Deformable liposomes were prepared to investigate the effectiveness of dermal administration of methotrexate (MTX). The phospholipids used to prepare the liposomes were soybean lecithin (PC) or hydrogenated lecithin (HPC) and dipotassium glycyrrhizinate (KG) as surfactant. The lipid/KG ratio (w/w) was 2:1 and 4:1. Liposomes size, entrapment efficiency and MTX release through dialysis membrane were determined and the interaction between MTX and liposomes was investigated using differential scanning calorimetry. The MTX amount permeated through pig skin were three- to four-fold higher using liposomes containing KG compared to those from water solution or normal liposomes. No significant differences were observed between PC-KG liposomes and HPC-KG liposomes. At the end of the skin permeation assay using deformable liposomes, up to 50% of the administered dose was found in the skin. This capability depends on the self-regulating carrier deformability. These results suggest that liposomes containing KG may be of value for the topical administration of MTX in the treatment of psoriasis.

Administration, Cutaneous↗
PubMed2004

Hydrophilic microspheres from water-in-oil emulsions by the water diffusion technique.

PURPOSE: In this study, we developed and evaluated a novel method to produce insulin-loaded hydrophilic microspheres allowing high encapsulation efficiency and the preservation of peptide stability during particle processing. The preparation method used the diffusion of water by an excess of solvent starting from a water-in-solvent emulsion. METHODS: The water dispersed phase containing albumin or lactose, or albumin-lactose in different weight ratios, and insulin was emulsified in water-saturated triacetin with and without emulsifiers, producing a water-in-triacetin emulsion. An excess of triacetin was added to the emulsion so that water could be extracted into the continuous phase, allowing the insulin-loaded microsphere precipitation. Insulin stability within the microspheres after processing was evaluated by reverse-phase and size-exclusion high-performance liquid chromatography. RESULTS: The water diffusion extraction process provided spherical microparticles of albumin or albumin-lactose. The mean diameter of the microspheres prepared with or without emulsifiers ranged from 2 to 10 microm, and the encapsulation efficiency of insulin was between 60% and 75%, respectively. The analysis of microsphere content after processing showed that insulin did not undergo any chemical modification within microspheres. The use of lactose alone led to the formation of highly viscous droplets that coalesced during the purification step. CONCLUSIONS: The water extraction procedures successfully produced insulin-loaded hydrophilic microspheres allowing the preservation of peptide stability. The type of excipient and the size of the disperse phase of the primary w/o emulsion were crucial determinants of microsphere characteristics.

Albumins↗
PubMed2004

Atypical CD30+ cutaneous lymphoid proliferation in a patient with tuberculosis infection.

We describe the case of a 65-year-old woman affected by a diffuse lymphadenopathy consistent with tuberculous infection who developed a papular eruption on the head and neck region. Histopathologic examination of one papule showed an atypical CD30+ lymphoid infiltrate, which initially was cause of concern for the pathologists but was eventually regarded as reactive in nature. The case reported herein enlarges the spectrum of inflammatory infiltrates in which atypical CD30+ cells may be found. Since the reactive atypical CD30+ cells are morphologically similar to those cells observed in CD30+ lymphoproliferative disorders, including lymphomatoid papulosis, complete clinical history and laboratory findings are necessary to make the final and correct diagnosis. Although the pathogenetic relevance of the presence of CD30+ cells within the cutaneous infiltrate of patients with systemic tuberculosis remains to be determined, our findings support the hypothesis that the cytokine profile associated with tuberculosis may not be strictly TH1-like, and that a TH1-like to TH2-like switch may also occur.

Aged↗
PubMed2003

Preparation of solid lipid nanoparticles by a solvent emulsification-diffusion technique.

A preparation method for nanoparticles based on the emulsification of a butyl lactate or benzyl alcohol solution of a solid lipid in an aqueous solution of different emulsifiers, followed by dilution of the emulsion with water, was used to prepare glyceryl monostearate nanodispersions with narrow size distribution. To increase the lipid load the process was conducted at 47+/-2 degrees C and in order to reach submicron size a high-shear homogenizer was used. Particle size of the solid lipid nanoparticles (SLN) was affected by using different emulsifiers and different lipid loads. By using lecithin and taurodeoxycholic acid sodium salt, on increasing the GMS percentage from 2.5 to 10% an increase of the mean diameter from 205 to 695 nm and from 320 to 368nm was observed for the SLN prepared using benzyl alcohol and butyl lactate, respectively. Transmission electron micrographs of SLN reveal nanospheres with a smooth surface.

Diffusion↗
PubMed2003

Preparation of griseofulvin nanoparticles from water-dilutable microemulsions.

Nanoparticles of griseofulvin, a model drug with poor solubility and low bioavailability, were prepared from water dilutable microemulsions by the solvent diffusion technique. Solvent-in-water microemulsion formulations containing water, butyl lactate, lecithin, taurodeoxycholate sodium salt (TDC) or dipotassium glycyrrhizinate (KG), 1,2-propanediol or ethanol were used. The formation of macroscopically homogeneous, stable, fluid, optically transparent, isotropic solutions (microemulsions) was investigated by constructing pseudo-ternary phase diagrams. In the presence of TDC or KG, microemulsion systems that remained transparent on water dilution could be obtained. The displacement of butyl lactate, with an excess of water, from the internal phase of the microemulsions containing the drug into the external phase, lead to successful fabrication of drug nanosuspensions. Nanoparticle size was dependent on microemulsion composition: using KG, griseofulvin nanoparticles below 100 nm with low polydispersity and an increased dissolution rate were obtained.

Antifungal Agents↗
PubMed2003

Influence of ion pairing on topical delivery of retinoic acid from microemulsions.

The purpose of the present study was to determinate the significance of ion pairing on the topical permeation of retinoic acid (R.A) using microemulsions as delivery vehicles. Phenylalanine methyl ester, phenylalanine ethylester, histidine methyl ester, tryptophan methyl ester and valine methyl ester were used as counter ions. Results of diffusion studies through polydimethylsiloxane membrane (PDMS) indicate that retinoic acid permeation from ethanol-pH 6.4 buffer mixture significantly increased in the presence of counter ions. A linear relationship was found between apparent partition coefficients and permeation coefficients. The highest values were with valine methyl ester and phenylalanine ethyl ester. In order to develop alternative formulations for topical administration of R.A, microemulsions were evaluated as delivery vehicles. Oil-in-water (O/W) and water-in-oil (W/O) microemulsion formulations were prepared using water, isopropyl myristate, lecithin, caprylyl-capryl glucoside and ethanol or 1,2 hexanediol. Experiments with PDMS membranes showed decreasing permeabilities of R.A from microemulsions in the presence of counter ions. This was related to the increased lipophilicity and different vehicle membrane affinity of the ion pairs The ability of the systems to deliver R.A through the skin was evaluated in vitro using pig-skin. R.A permeabilities were much lower with microemulsions than with solution, while a large increase in R.A skin deposition was observed only from O/W microemulsions in the presence of counter ions. The depth of skin accumulation was below 100 microm after 24 h application. The results suggest that O/W microemulsions containing a counter ion can be used to optimise drug targeting without a concomitant increase in systemic absorption.

Administration, Topical↗
PubMed2002

Stability of drug-carrier emulsions containing phosphatidylcholine mixtures.

Lipid emulsion particles containing 10% of medium chain triglycerides were prepared using 2% w/w of a mixture 1:1 w/w of purified soya phosphatidylcholine and 2-hexanoyl phosphatidylcholine as emulsifier mixture, for use as drug carriers. The mean droplet sizes of emulsions, prepared using an Ultra Turrax or a high-pressure homogenizer, were about 288 and 158 nm, respectively, compared with 380 and 268 nm for emulsions containing lecithin, or 325 and 240 nm for those containing 6-phosphatidylcholine. The stability of the emulsions, determined by monitoring the decrease of a lipophilic marker at a specified level within the emulsion, and observing coalescence over time, was also greatly increased using the emulsifier mixture. The emulsion stability did not notably change in the presence of a model destabilizing drug, indomethacin. The use of a second hydrophilic surfactant to adjust the packing properties of the lecithin at the oil-water interface provided an increase in the stability of lipid emulsions, and this may be of importance in the formulation of drug delivery systems.

Drug Carriers↗