315 research outputs found

    1H NMR study of the interaction of trans-resveratrol with soybean phosphatidylcholine liposomes

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    Resveratrol (RSV) is a well-known natural derivative with a wide range of biological and pharmacological activities. Despite of these demonstrated properties, it exhibits low both aqueous solubility and chemical stability and therefore low bioavailability. Consequently, the major concern of the technological research is to exploit delivery systems able to overcome bioavailability problems. In the recent past liposomes have been successfully studied for these purposes. In this paper, 1H-NMR spectroscopy, Nuclear Overhauser Spectroscopy (NOESY) as well as Paramagnetic Relaxation Enhancements (PRE) experiments have been carried out to quantitatively investigate the incorporation of resveratrol, at both the liposome preparation stage and by preformed liposomes, also with the aim to characterize resveratrol- soybean phosphatidylcholine (P90G) lipid bilayer interactions. Overall results of 1H NMR spectroscopy analysis suggest that RSV is located nearby the phosphocholine headgroups and also provide quantitative data on the incorporation of RSV (5% w/w), which corresponds to a 150-fold increase with respect to the solubility of RSV in water. Beside, considering that the same level of RSV incorporation was obtained via spontaneous uptake by preformed P90G liposomes, it can be concluded that RSV easily diffuses through the lipid bilayer

    Structural changes in intestinal enteroendocrine cells after ileal interposition in normal rats

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    INTRODUCTION: No therapeutic approach has significantly impacted the progression of diabetes. As early improvement of glicaemic control is observed after bariatric surgeries, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Glicaemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. The interposition of ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glicaemic control.
AIMS: To investigate long-term histological modifications of intestinal mucosa of rats submitted to interposition of ileum segment to a proximal region (jejunum).
METHODS: Forty 8-week old male Wistar-EPM1 rats (Rattus norvegicus albinus) were randomly distributed into 3 groups: the Interposition Group (IG) was subjected to ileal interposition, the Sham Group (SG) was subjected to sham operations, and the Control Group (CG) was not subjected to surgery. All animals were followed until the 60th postoperative day (8 postoperative week) when they were euthanized. Segments of jejunum and ileum from all groups were collected and analyzed by optical microscopy and immunohistochemistry.
RESULTS: No structural nor histological changes in intestinal L cells in the interposed intestinal segment and other intestinal segments were noted after ileal interposition surgery. 
CONCLUSION: As L cells endocrine characteristics were likely maintained, the use of metabolic surgical techniques for the treatment of metabolic diseases, especially diabetes, seems to be justified

    Deliveries by caesarean sections on request of women: legal-medical evidence

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    Introduction: In Italy the use of caesarean delivery has a rising trend moving away from European standards appeared on Euro-Peristat on maternal and child health, presenting the highest percentage of use of this procedure with significant regional differences. This study have analyzed the most recent data of a Sicilian reality about normal delivery and caesarean sections carried out in a hospital situated in Messina (Italy). Materials and methods: A total number of 1,573 medical records from 1st January 2011 to 31st December 2013 were analyzed and data gathered were statistically examined to describe general and specific parameters of the sample making use of Epi Info 7.1.4 software (CDC Atlanta – USA). Chi-square test was used to show any statistic differences among studied population. Results: Overall data showed that were carried out 38.27% of spontaneous deliveries, 7.06% of induced labor, and 54.67% of caesarean deliveries. There were no significant statistical differences between recourse to caesarean section and vaginal delivery in relation to nationality, age, level of education and/or work. The enrolled group, based on the parameters examined, was divided into appropriate caesarean section, in 79.49% of cases, inappropriate in 7.20% (mother’s request) and unjustified in 13.31% (with no indication, incomplete medical record). An examination of the anesthetic medical records showed that the caesarean section was considered to be urgent in 31.74% of the cases; however in 17.92% of these cases there is no information in the medical records justifying the use of emergency procedures. Conclusion: The reported data from the study that we conducted, lead to medical-legal and juridical considerations, especially as regards the use of caesarean delivery on the woman request. The complexity of the phenomenon requires the development of a variety of intervention strategies, not only for issues related to the reduction of health care costs, but also with regard to the clinical risk management and medical legal aspects related to the several profiles of professional responsibility

    TranscutolÂź p containing slns for improving 8-methoxypsoralen skin delivery

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    Topical psoralens plus ultraviolet A radiation (PUVA) therapy consists in the topical application of 8-methoxypsoralen (8-MOP) followed by the skin irradiation with ultraviolet A radiation. The employment of classical 8-MOP vehicles in topical PUVA therapy is associated with poor skin deposition and weak skin permeability of psoralens, thus requiring frequent drug administration. The aim of the present work was to formulate solid lipid nanoparticles (SLNs) able to increase the skin permeation of 8-MOP. For this purpose, the penetration enhancer TranscutolŸ P (TRC) was added to the SLN formulation. SLNs were characterized with respect to size, polydispersity index, zeta potential, entrapment efficiency, morphology, stability, and biocompatibility. Finally, 8-MOP skin diffusion and distribution within the skin layers was investigated using Franz cells and newborn pig skin. Freshly prepared nanoparticles showed spherical shape, mean diameters ranging between 120 and 133 nm, a fairly narrow size distribution, highly negative ζ potential values, and high entrapment efficiency. Empty and loaded formulations were almost stable over 30 days. In vitro penetration and permeation studies demonstrated a greater 8-MOP accumulation in each skin layer after SLN TRC 2% and TRC 4% application than that after SLN TRC 0% application. Finally, the results of experiments on 3T3 fibroblasts showed that the incorporation of TRC into SLNs could enhance the cellular uptake of nanoparticles, but it did not increase their cytotoxicity

    Trimethyl chitosan hydrogel nanoparticles for progesterone delivery in neurodegenerative disorders

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    Progesterone is a sex hormone which shows neuroprotective effects in different neurodegenerative disorders, including Parkinson’s disease, stroke, and Alzheimer’s disease. However, the pharmacokinetic limitations associated with the peripheral administration of this molecule highlight the need for more efficient delivery approaches to increase brain progesterone levels. Since the nose-to-brain administration of mucoadhesive hydrogel nanoparticles is a non-invasive and convenient strategy for the delivery of therapeutics to the central nervous system, in this work, progesterone-loaded hydrogel nanoparticle formulations have been prepared, characterized, and tested in vivo. Nanoparticles, loaded with different progesterone concentrations, have been obtained by polyelectrolyte complex formation between trimethyl chitosan and sodium alginate, followed by ionotropic gelation with sodium tripolyphosphate as a cross-linking agent. All formulations showed a mean diameter ranging from 200 nm to 236 nm, a polydispersity index smaller than 0.23, and a high progesterone encapsulation efficiency (83–95%). The zeta potential values were all positive and greater than 28 mV, thus ensuring nanoparticles stability against aggregation phenomena as well as interaction with negative sialic residues of the nasal mucosa. Finally, in vivo studies on Sprague–Dawley male rats demonstrated a 5-fold increase in brain progesterone concentrations compared to basal progesterone level after 30 min of hydrogel nanoparticle inhalation

    Identification of MGMT Downregulation Induced by miRNA in Glioblastoma and Possible Effect on Temozolomide Sensitivity

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    Glioblastoma multiforme (GBM) remains one of the tumors with the worst prognosis. In recent years, a better overall survival (OS) has been described in cases subjected to Gross Total Resection (GTR) that were presenting hypermethylation of Methylguanine-DNA methyltransferase (MGMT) promoter. Recently, also the expression of specific miRNAs involved in MGMT silencing has been related to survival. In this study, we evaluate MGMT expression by immunohistochemistry (IHC), MGMT promoter methylation and miRNA expression in 112 GBMs and correlate the data to patients' clinical outcomes. Statistical analyses demonstrate a significant association between positive MGMT IHC and the expression of miR-181c, miR-195, miR-648 and miR-767.3p between unmethylated cases and the low expression of miR-181d and miR-648 and between methylated cases and the low expression of miR-196b. Addressing the concerns of clinical associations, a better OS has been described in presence of negative MGMT IHC, in methylated patients and in the cases with miR-21, miR-196b overexpression or miR-767.3 downregulation. In addition, a better progression-free survival (PFS) is associated with MGMT methylation and GTR but not with MGMT IHC and miRNA expression. In conclusion, our data reinforce the clinical relevance of miRNA expression as an additional marker to predict efficacy of chemoradiation in GBM

    Isolated ileal interposition in enteroendocrine L cells differentiation

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    INTRODUCTION: 
Due to the progressive nature of type 2 diabetes, its complexity and drug treatment perpetuity, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Diabetic patients glycemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. Early and extended improvement of diabetes in patients submitted to bariatric surgeries awakened the necessity of investigating the isolated ileal interposition as a surgical alternative for the treatment of diabetes. The interposition of this ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glycemic control. However, in order to consolidate the ileal interposition as a surgical treatment of diabetes it is necessary that the interposed ileum keep the same differentiation rate into L cells for a long period to justify the intervention.

AIMS: 
To investigate the isolated ileal interposition influence on the differentiation of intestinal precursor cells into enteroendocrine L cells over time.

METHODS: 
Twelve 12-week-old male Wistar rats (Rattus norvegicus albinus) of the WAB strain (heterogeneous) will be used. All animals will receive a high-calorie, high-fat diet for 16 weeks or more until they develop glucose dysmetabolism confirmed by glycemic test. They will be divided into two groups of 10 animals each: the isolated ileal interposition group (GI) and the control group (GC), comprising animals that will not be submitted to any surgical intervention. Blood samples will be collected under anesthesia at the weeks 12, 26, 36 and 44 for the determination of serum levels of glucose, insulin, GLP-1, glucagon, C-peptide and glycosilated hemoglobin. The insulin tolerance test will be performed and insulin resistance will be calculated. For the comparative analysis of the ileal precursor cells differentiation into enteroendocrine cells among the two groups, the following intestinal fragments will be collected after euthanasia: interposed ileum and remaining ileum from GI, jejunum and ileum from GC. These fragments will be analyzed by imunofluorescence and also by Real Time PCR using PCR Arrays for target genes including the main ones related to stem cell, stem cell signaling, diabetes, Wnt and Notch signaling pathways and other genes and pathways involved in the differentiation of intestinal precursor cells into enteroendocrine cells, especially GLP-1-producing L cells that play important role in euglycemia

    Organic consequences of ileal transposition in rats with diet-induced obesity

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    INTRODUCTION: The clinical management of metabolic syndrome - especially diabetes mellitus type 2 - is notoriously complex due to the progressive nature of this disease. At present, there is a need for a surgical procedure that is effective for the treatment of diabetes mellitus type 2, even in non-obese individuals. The isolated ileal transposition theory could lead to an effective alternative therapy. This intervention has not yet been performed in humans, and there are no reports of its use in an experimental model of diet-induced metabolic syndrome.
 OBJECTIVES: The objective of this study is to evaluate the physiological effects of ileal transposition in rats with diet-induced metabolic syndrome. The effects of this procedure on glucose and lipid metabolism will be assessed. 
METHODS: Forty 12-week-old male rats (albino Rattus norvegicus, Wistar, 2BAW, heterogeneous) will be divided into four groups of 10 animals each: the ileal transposition group (TG) comprising animals on a hypercaloric-hyperlipidic diet; the sham group (SG) containing animals that receive the same diet and undergo the sham surgery; control group 1 (CG1), which will receive a hypercaloric-hyperlipidic diet and will not undergo surgery; and control group 2 (CG2), which will consume standard feed and will not undergo surgery. The surgeries will be performed in 20-week-old animals. Blood samples for laboratory testing will be collected from 12-week-old animals on the day of surgery and after eight postoperative weeks, following determination of the weights of the animals and the administration of anesthesia. The levels of serum glucose, insulin, triglycerides, total cholesterol and fractions, glucagon-like peptide-1, C-peptide and glycated hemoglobin will be assessed in all of the animals. The insulin tolerance test will be performed using PRISMA software, and insulin resistance will be calculated by the HOMA-IR indirect test. On specific days, two 20-week-old rats will be separated and randomly distributed in TG and SG. These animals will be followed until the eighth postoperative week. Subsequently, they will be euthanized, and the retroperitoneal and periepididymal fat deposits will be collected and weighed using a precision scale. In addition, the pancreas, liver and intestinal segments will be sent for pathological and immunohistochemical studies.
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