2,901 research outputs found

    Synthesis and characterization of P(MMA-AA) copolymers for targeted oral drug delivery

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    This paper describes the development of pH-sensitive poly(methyl methacrylate-acrylic acid) copolymers for the enteric coating of pharmaceutical products for oral administration. To obtain the dissolution at the desired pH level, different pH-sensitive polymers are available on the market. Usually, for each desired dissolution pH, an ad hoc polymer is designed. Thus, different dissolution pH values could ask for completely different polymers. Instead, the materials proposed in this work are copolymers of the same two monomers, and the different dissolution pH was obtained by changing the volume fraction of the hydrophobic methyl methacrylate monomer to the hydrophilic acrylic acid monomer. Increasing the volumetric percentage of methyl methacrylate causes the polymer to dissolve at increasing pH, until the dissolution does not take place at all, and it is replaced by a slow swelling phenomenon. The copolymers obtained were characterized by differential scanning calorimetry, in order to evaluate their glass transition temperature, and these latter were related to %MMA. The molecular weights of the pure polymers (PAA, PMMA) were measured by intrinsic viscosity, to further validate the glass transition temperatures observed. The dissolution of the copolymers was carefully tested in buffer solutions for a dense set of pH values. A linear relationship between dissolution pH and volumetric percentage of methyl methacrylate was obtained from these measurements. As a result, for any physiological compartment, the copolymer which dissolves at the pH of interest can be easily synthesized. doi:10.1007/s00289-009-0040-

    Soil Remediation Assessment by Detection of Reactive Oxygen Species in Lizard Testis: An Electron Spin Resonance (ESR) Approach

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    Recent developments in applied research have led to implement novel operative protocols for life-based restoration of contaminated soils, including new monitoring approach. Here, we report the measurements of reactive oxygen species (ROS) content in lizard testis performed in the framework of the project Life Ecoremed. The ROS levels detected by electron spın resonance (ESR) spectroscopy using the spin-trapping technique were analyzed and validated using measurements of total soluble antioxidant capacity and the poly(ADP-ribose) polymerase enzymatic activity, which detect the gonadal antioxidant defense and DNA repair, respectively. The investigations on soil biosentinel Podarcis sicula reproductive health gave significant evidence that the ROS level in the testis well correlates with alteration of the antioxidant capacity. In specimens coming from polluted sites, before remediation, a significant increase of ROS content was detected respect to that found in specimens from an unpolluted site. Thereafter, an evident decrease of the ROS levels, corresponding to high levels of total soluble antioxidant capacity and low repair of DNA integrity, has been detected after remediation. Thus, the data relative to all the polluted sites examined support the testis of Podarcis sicula as an elective tissue for an innovative and reliable screening method, based on ESR analysis of ROS, in the soil remediation assessment

    Chlamydia psittaci in ocular adnexa MALT lymphoma: a possible role in lymphomagenesis and a different geographical distribution

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    Ocular adnexa MALT-lymphomas represent approximatively 5-15% of all extranodal lymphomas. Almost 75% of OAMLs are localized in orbital fat, while 25% of cases involves conjunctive. MALT-lymphomas often recognize specific environmental factors responsible of lymphoma development and progression. In particular as Helicobacter pylori in gastric MALT lymphomas, other bacterial infections have been recognized related to MALT lymphomas in specific site. Recently Chlamydia psittaci has been identified in Ocular Adnexa MALT lymphomas, with variable frequence dependently from geographic areas. Thus bacterial infection is responsible of clonal selection on induced MALT with subsequent lymphoma development. Moreover Chlamydia psittaci could promote chromosomal aberration either through genetic instability as a consequence of induced proliferation and probably through DNA oxidative damage. The most common translocation described in MALT lymphomas affects NF-kB pathway with a substantial antiapoptotic effect. Several therapeutic approaches are now available, but the use of antibiotic-therapy in specific cases, although with conflicting results, could improve the treatment of ocular adnexa MALT lymphomas. In this review we analyse the most relevant features of Ocular adnexa MALT lymphomas, underlining specific biological characteristics mainly related to the potential role of Chlamydia psittaci in lymphomagenesis

    Complete Resolution of Retroperitoneal Lymphangioma with a Single Trial of OK-432 in an Infant

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    Retroperitoneal lymphangioma is extremely rare. Although these neoplasms are benign, they can grow progressively with subsequent compression and infiltration of the adjacent structures. Surgical excision is demanding when the lesion surrounds vital structures and it is generally fraught with a high recurrence and morbidity rate. We report the case of a huge retroperitoneal lymphangioma in a newborn treated successfully with intracystic injection of OK-432

    Malocclusion and rhinitis in children: an easy-going relationship or a yet to be resolved paradox? A systematic literature revision

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    Objective: The relation between nasal flow and malocclusion represents a practical concern to pediatricians, otorhinolaryngologists, orthodontists, allergists and speech therapists. If naso-respiratory function may influence craniofacial growth is still debated. Chronic mouth-breathing is reported to be associated also with a characteristic pattern of dental occlusion. On the other hand, also malocclusion may reduce nasal air flows promoting nasal obstruction. Hereby, the aim of this review was to describe the relationship between rhinitis and malocclusion in children. Methods: An electronic search was conducted using online database including Pubmed, Web of Science, Google Scholar and Embase. All studies published through to January 30, 2017 investigating the prevalence of malocclusion in children and adolescents (aged 0-20 years) affected by rhinitis and the prevalence of rhinitis in children with malocclusion were included. The protocol was registered at PROSPERO - International prospective register of systematic reviews under CRD42016053619. Results: Ten studies with 2733 patients were included in the analysis. The prevalence of malocclusion in children with rhinitis was specified in four of the studies ranging from as high as 78.2% to as low as 3%. Two out of the studies reported the prevalence of rhinitis in children with malocclusion with a rate ranging from 59.2 to 76.4%. Conclusion: The results of this review underline the importance of the diagnosis and treatment of the nasal obstruction at an early age to prevent an altered facial growth, but the data currently available on this topic do not allow to establish a possible causal relationship between rhinitis and malocclusion

    Inside the Phenomenological Aspects of Wet Granulation: Role of Process Parameters

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    Granulation is a size-enlargement process by which small particles are bonded, by means of various techniques, in coherent and stable masses (granules), in which the original particles are still identifiable. In wet granulation processes, the powder particles are aggregated through the use of a liquid phase called binder. The main purposes of size-enlargement process of a powder or mixture of powders are to improve technological properties and/or to realize suitable forms of commercial products. A modern and rational approach in the production of granular structures with tailored features (in terms of size and size distribution, flowability, mechanical and release properties, etc.) requires a deep understanding of phenomena involved during granules formation. By this knowledge, suitable predictive tools can be developed with the aim to choose right process conditions to be used in developing new formulations by avoiding or reducing costs for new tests. In this chapter, after introductive notes on granulation process, the phenomenological aspects involved in the formation of the granules with respect to the main process parameters are presented by experimental demonstration. Possible mathematical approaches in the granulation process description are also presented and the one involving the population mass balances equations is detailed

    Herbicidal potential of phenolic and cyanogenic glycoside compounds isolated from Mediterranean plants

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    This study was conducted to test five phenolic and cyanogenic glycoside compounds for growth regulating activity on the germination and seedling growth of Portulaca oleracea L., Amaranthus retroflexus L., and Lactuca sativa L. at different concentrations. Overall, the tested compounds revealed growth-regulating activity in species-specific and concentration dependent manner. The most powerful effects were much pronounced on seedling growth rather than on germination. In fact, the compounds 1 (amygdalin) and 2 (salicylic acid) were the most phytotoxic on root growth of  P. oleracea, and they caused, respectively, an inhibition of 55% and 85% at 10-6 M and 10-4 M. On the other hand, the lettuce seedling growth was more sensitive than weeds growth to the compounds 4 (3,4,5-trihydroxybenzoic acid) and 5 (7-hydroxycoumarin), which exhibited a moderate inhibition at the highest concentration. This selectivity and specificity of these active allelopathic compounds could be very useful for the development of new application of natural substances to control the aggressive weeds. Thus, our findings suggest that the integration of these compounds may maintain irrigation system and reduce the massive use of agrochemicals in agro-ecosystems

    Impaired Mitochondrial Morphology and Functionality in Lonp1wt/- Mice

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    LONP1 is a nuclear-encoded mitochondrial protease crucial for organelle homeostasis; mutations ofLONP1have been associated with Cerebral, Ocular, Dental, Auricular, and Skeletal anomalies (CODAS) syndrome. To clarify the role of LONP1 in vivo, we generated a mouse model in whichLonp1was ablated. The homozygousLonp(-/-)mouse was not vital, while the heterozygousLonp1(wt/-)showed similar growth rate, weight, length, life-span and histologic features as wild type. Conversely, ultrastructural analysis of heterozygous enterocytes evidenced profound morphological alterations of mitochondria, which appeared increased in number, swollen and larger, with a lower complexity. Embryonic fibroblasts (MEFs) fromLonp1(wt/-)mice showed a reduced expression ofLonp1andTfam, whose expression is regulated by LONP1. Mitochondrial DNA was also reduced, and mitochondria were swollen and larger, albeit at a lesser extent than enterocytes, with a perinuclear distribution. From the functional point of view, mitochondria from heterozygous MEF showed a lower oxygen consumption rate in basal conditions, either in the presence of glucose or galactose, and a reduced expression of mitochondrial complexes than wild type. In conclusion, the presence of one functional copy of theLonp1gene leads to impairment of mitochondrial ultrastructure and functions in vivo

    An unusual spontaneous recanalization by multiple palmar arteriovenous connections of a chronically occluded radiocephalic hemodialysis fistula

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    Preservation of a vascular access is crucial in the management of hemodialysis patients. In this regard, percutaneous transluminal angioplasty (PTA) is an effective tool if performed after an adequate understanding of preliminary fistulograms. The present case showed a chronic dysfunction of a radial-cephalic arteriovenous fistula (AVF) due to arterial occlusion and partially relieved by the spontaneous development of multiple small arteriovenous connections in the palmar region of the hand. This dense network had been so far able to ensure a sufficient retrograde blood flow for an effective hemodialytic performance. The angioplasty of the post-anastomotic stenotic segment of the radial artery was effective in restoring this neoformed AVF patency
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