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1.
Polymers (Basel) ; 16(7)2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38611128

RESUMEN

In this work, a multivariate approach was utilized for gaining some insights into the processing-structure-properties relationships in polyethylene-based blends. In particular, two high-density polyethylenes (HDPEs) with different molecular weights were melt-compounded using a twin-screw extruder, and the effects of the screw speed, processing temperature and composition on the microstructure of the blends were evaluated based on a Design of Experiment-multilinear regression (DoE-MLR) approach. The results of the thermal characterization, interpreted trough the MLR (multilinear regression) response surfaces, demonstrated that the composition of the blends and the screw rotation speed are the two most important parameters in determining the crystallinity of the materials. Furthermore, the rheological data were examined using a Principal Component Analysis (PCA) multivariate approach, highlighting also in this case the most prominent effect of the weight ratio of the two base polymers and the screw rotation speed.

2.
Plant Physiol Biochem ; 207: 108366, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38244387

RESUMEN

Carotenoids are susceptible to degrading processes initiated by oxidative cleavage reactions mediated by Carotenoid Cleavage Dioxygenases that break their backbone, leading to products called apocarotenoids. These carotenoid-derived metabolites include the phytohormones abscisic acid and strigolactones, and different signaling molecules and growth regulators, which are utilized by plants to coordinate many aspects of their life. Several apocarotenoids have been recruited for the communication between plants and arbuscular mycorrhizal (AM) fungi and as regulators of the establishment of AM symbiosis. However, our knowledge on their biosynthetic pathways and the regulation of their pattern during AM symbiosis is still limited. In this study, we generated a qualitative and quantitative profile of apocarotenoids in roots and shoots of rice plants exposed to high/low phosphate concentrations, and upon AM symbiosis in a time course experiment covering different stages of growth and AM development. To get deeper insights in the biology of apocarotenoids during this plant-fungal symbiosis, we complemented the metabolic profiles by determining the expression pattern of CCD genes, taking advantage of chemometric tools. This analysis revealed the specific profiles of CCD genes and apocarotenoids across different stages of AM symbiosis and phosphate supply conditions, identifying novel reliable markers at both local and systemic levels and indicating a promoting role of ß-ionone in AM symbiosis establishment.


Asunto(s)
Dioxigenasas , Micorrizas , Norisoprenoides , Oryza , Oryza/genética , Oryza/metabolismo , Dioxigenasas/genética , Carotenoides/metabolismo , Micorrizas/fisiología , Plantas/metabolismo , Fosfatos/metabolismo
3.
Sci Rep ; 13(1): 15034, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37699911

RESUMEN

Passive Gamma Emission Tomography (PGET) has been developed by the International Atomic Energy Agency to directly image the spatial distribution of individual fuel pins in a spent nuclear fuel assembly and determine potential diversion. The analysis and interpretation of PGET measurements rely on the availability of comprehensive datasets. Experimental data are expensive and limited, so Monte Carlo simulations are used to augment them. However, Monte Carlo simulations have a high computational cost to simulate the 360 angular views of the tomography. Similar challenges pervade numerical science. With the aim to create a large dataset of PGET simulated scenarios, we addressed the computational cost of Monte Carlo simulations by developing a physics-aware reduced order modeling approach. This approach combines a small subset of the 360 angular views (limited views approach) with a computationally inexpensive proxy solution (real-time forward model) that brings the essence of the physics to obtain a real-time high-fidelity solution at all angular views but at a fraction of the computational cost. The method's ability to reconstruct 360 views with accuracy from a limited set of angular views is demonstrated by testing its performance for different types of reactor fuel assemblies.

4.
Analyst ; 148(11): 2415-2424, 2023 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-37092509

RESUMEN

Gadolinium-based contrast agents (GBCAs) are massively employed in radiology to increase the diagnostic power of MRI. However, investigations aiming at detecting possible metabolic perturbations or adverse health effects due to gadolinium deposition are still lacking. In this work, aqueous organs extract and plasma samples were analyzed by GC-MS and 1H-NMR, respectively, to investigate the effects of multiple administrations of one linear (Omniscan) and one macrocyclic (ProHance) GBCA, on the main metabolic pathways in healthy mice. Multivariate analysis revealed that plasma metabolome was not differently perturbed by the two GBCAs, while, the multiorgan analysis displayed a clear separation of the Omniscan-treated from the control and the ProHance-treated groups. Interestingly, the most affected organs were the brain, cerebellum and liver. Thus, this work paves the way to both the safest use of the commercially available GBCAs and the development of new GBCAs characterized by lower general toxicity.


Asunto(s)
Gadolinio , Compuestos Organometálicos , Ratones , Animales , Gadolinio/toxicidad , Gadolinio/metabolismo , Gadolinio DTPA/metabolismo , Compuestos Organometálicos/toxicidad , Medios de Contraste/toxicidad , Medios de Contraste/metabolismo , Encéfalo/metabolismo , Imagen por Resonancia Magnética
5.
Front Plant Sci ; 14: 1303771, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38250450

RESUMEN

Introduction: Given that rice serves as a crucial staple food for a significant portion of the global population and with the increasing number of individuals being diagnosed with diabetes, a primary objective in genetic improvement is to identify and cultivate low Glycemic Index (GI) varieties. This must be done while ensuring the preservation of grain quality. Methods: 25 Italian rice genotypes were characterized calculating their GI "in vivo" and, together with other 29 Italian and non-Italian genotypes they were studied to evaluate the grain inner structure through Field Emission Scanning Electron Microscopy (FESEM) technique. Using an ad-hoc developed algorithm, morphological features were extracted from the FESEM images, to be then inspected by means of multivariate data analysis methods. Results and Discussion: Large variability was observed in GI values (49 to 92 with respect to glucose), as well as in endosperm morphological features. According to the percentage of porosity is possible to distinguish approximately among rice varieties having a crystalline grain (< 1.7%), those intended for the preparation of risotto (> 5%), and a third group having intermediate characteristics. Waxy rice varieties were not united by a certain porosity level, but they shared a low starch granules eccentricity. With reference to morphological features, rice varieties with low GI (<55) seem to be characterized by large starch granules and low porosity values. Our data testify the wide variability of Italian rice cultivation giving interesting information for future breeding programs, finding that the structure of the endosperm can be regarded as a specific characteristic of each variety.

6.
Foods ; 11(11)2022 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-35681393

RESUMEN

Fish species substitution is one of the most common forms of fraud all over the world, as fish identification can be very challenging for both consumers and experienced inspectors in the case of fish sold as fillets. The difficulties in distinguishing among different species may generate a "grey area" in which mislabelling can occur. Thus, the development of fast and reliable tools able to detect such frauds in the field is of crucial importance. In this study, we focused on the distinction between two flatfish species largely available on the market, namely the Guinean sole (Synaptura cadenati) and European plaice (Pleuronectes platessa), which are very similar looking. Fifty fillets of each species were analysed using three near-infrared (NIR) instruments: the handheld SCiO (Consumer Physics), the portable MicroNIR (VIAVI), and the benchtop MPA (Bruker). PLS-DA classification models were built using the spectral datasets, and all three instruments provided very good results, showing high accuracy: 94.1% for the SCiO and MicroNIR portable instruments, and 90.1% for the MPA benchtop spectrometer. The good classification results of the approach combining NIR spectroscopy, and simple chemometric classification methods suggest great applicability directly in the context of real-world marketplaces, as well as in official control plans.

7.
Foods ; 12(1)2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36613250

RESUMEN

Hazelnuts (Corylus avellana L.) are among the most consumed dry fruits all over the world. Their commercial quality is defined, above all, by origin and dimension, as well as by lipid content. Evaluation of this parameter is currently performed with chemical methods, which are expensive, time consuming, and complex. In the present work, the near-infrared (NIR) spectroscopy, using both a benchtop research spectrometer and a retail handheld instrument, was evaluated in comparison with the traditional chemical approach. The lipid content of hazelnuts from different growing regions of origin (Italy, Chile, Turkey, Georgia, and Azerbaijan) was determined with two NIR instruments: a benchtop FT-NIR spectrometer (Multi Purpose Analyser-MPA, by Bruker), equipped with an integrating sphere and an optic fibre probe, and the pocket-sized, battery-powered SCiO molecular sensor (by Consumer Physics). The Randall/Soxtec method was used as the reference measurement of total lipid content. The collected NIR spectra were inspected through multivariate data analysis. First, a Principal Component Analysis (PCA) model was built to explore the information contained in the spectral datasets. Then, a Partial Least Square (PLS) regression model was developed to predict the percentage of lipid content. PCA showed samples distributions that could be linked to their total crude fat content determined with the Randall/Soxtec method, confirming that a trend related to the lipid content could be detected in the spectral data, based on their chemical profiles. PLS models performed better with the MPA instrument than SCiO, with the highest R2 of prediction (R2PRED = 0.897) achieved by MPA probe, while this parameter for SCiO was much lower (R2PRED = 0.550). Further analyses are necessary to evaluate if more acquisitions may lead to better performances when using the SCiO portable spectrometer.

8.
Molecules ; 26(5)2021 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-33800512

RESUMEN

The consumers' interest towards beer consumption has been on the rise during the past decade: new approaches and ingredients get tested, expanding the traditional recipe for brewing beer. As a consequence, the field of "beeromics" has also been constantly growing, as well as the demand for quick and exhaustive analytical methods. In this study, we propose a combination of nuclear magnetic resonance (NMR) spectroscopy and chemometrics to characterize beer. 1H-NMR spectra were collected and then analyzed using chemometric tools. An interval-based approach was applied to extract chemical features from the spectra to build a dataset of resolved relative concentrations. One aim of this work was to compare the results obtained using the full spectrum and the resolved approach: with a reasonable amount of time needed to obtain the resolved dataset, we show that the resolved information is comparable with the full spectrum information, but interpretability is greatly improved.


Asunto(s)
Cerveza/análisis , Cerveza/microbiología , Metabolómica/métodos , Espectroscopía de Resonancia Magnética/métodos
9.
Foods ; 10(3)2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33802548

RESUMEN

The sale of frozen-thawed fish and fish products, labeled as fresh, is currently one of the most common and insidious commercial food frauds. For this reason, the demand of reliable tools to identify the storage conditions is increasing. The present study was performed on two species, commonly sold in large-scale distribution: Cuttlefish (Sepia officinalis) and musky octopus (Eledone spp.). Fifty fresh cephalopod specimens were analyzed at refrigeration temperature (2 ± 2 °C), then frozen at -20 °C for 10 days and finally thawed and analyzed again. The performance of three near-infrared (NIR) instruments in identifying storage conditions were compared: The benchtop NIR Multi Purpose Analyzer (MPA) by Bruker, the portable MicroNIR by VIAVI and the handheld NIR SCiO by Consumer Physics. All collected spectra were processed and analyzed with chemometric methods. The SCiO data were also analyzed using the analytical tools available in the online application provided by the manufacturer to evaluate its performance. NIR spectroscopy, coupled with chemometrics, allowed discriminating between fresh and thawed samples with high accuracy: Cuttlefish between 82.3-94.1%, musky octopus between 91.2-97.1%, global model between 86.8-95.6%. Results show how food frauds could be detected directly in the marketplace, through small, ultra-fast and simplified handheld devices, whereas official control laboratories could use benchtop analytical instruments, coupled with chemometric approaches, to develop accurate and validated methods, suitable for regulatory purposes.

10.
NMR Biomed ; 33(3): e4234, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31825557

RESUMEN

Magnetic resonance imaging (MRI) is the current gold standard for the diagnosis of brain tumors. However, despite the development of MRI techniques, the differential diagnosis of central nervous system (CNS) primary pathologies, such as lymphoma and glioblastoma or tumor-like brain lesions and glioma, is often challenging. MRI can be supported by in vivo magnetic resonance spectroscopy (MRS) to enhance its diagnostic power and multiproject-multicenter evaluations of classification of brain tumors have shown that an accuracy around 90% can be achieved for most of the pairwise discrimination problems. However, the survival rate for patients affected by gliomas is still low. The High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance (HR-MAS NMR) metabolomics studies may be helpful for the discrimination of gliomas grades and the development of new strategies for clinical intervention. Here, we propose to use T2 -filtered, diffusion-filtered and conventional water-presaturated spectra to try to extract as much information as possible, fusing the data gathered by these different NMR experiments and applying a chemometric approach based on Multivariate Curve Resolution (MCR). Biomarkers important for glioma's discrimination were found. In particular, we focused our attention on cystathionine (Cyst) that shows promise as a biomarker for the better prognosis of glioma tumors.


Asunto(s)
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Glioma/metabolismo , Glioma/patología , Metabolómica , Adulto , Anciano , Análisis Discriminante , Humanos , Análisis de los Mínimos Cuadrados , Metaboloma , Persona de Mediana Edad , Clasificación del Tumor , Análisis de Componente Principal , Espectroscopía de Protones por Resonancia Magnética
11.
Anal Chim Acta ; 1061: 70-83, 2019 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-30926041

RESUMEN

Multivariate exploratory data analysis allows revealing patterns and extracting information from complex multivariate data sets. However, highly complex data may not show evident groupings or trends in the principal component space, e.g. because the variation of the variables are not grouped but rather continuous. In these cases, classical exploratory methods may not provide satisfactory results when the aim is to find distinct groupings in the data. To enhance information extraction in such situations, we propose a novel approach inspired by the concept of combining weak classifiers, but in the unsupervised context. The approach is based on the fusion of several adjacency matrices obtained by different distance measures on data from different analytical platforms. This paper is intended to present and discuss the potential of the approach through a benchmark data set of beer samples. The beer data were acquired using three spectroscopic techniques: Visible, near-Infrared and Nuclear Magnetic Resonance. The results of fusing the three data sets via the proposed approach are compared with those from the single data blocks (Visible, NIR and NMR) and from a standard mid-level data fusion methodology. It is shown that, with the suggested approach, groupings related to beer style and other features are efficiently recovered, and generally more evident.


Asunto(s)
Cerveza/análisis , Benchmarking , Espectroscopía de Resonancia Magnética , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja Corta
12.
Perit Dial Int ; 37(5): 509-515, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28698251

RESUMEN

BACKGROUND: The development of modern, biocompatible peritoneal dialysis (PD) fluids has not entirely eliminated the local pro-inflammatory effects of PD fluid administration. The present study was performed in order to establish the importance of known signaling pathways connected to mechano-, osmo- and chemo-sensors of the transient receptor potential (TRP) family for the acute inflammatory response to PD. METHODS: Rats were exposed to a single 4-hour dwell of lactate-buffered, 2.5% glucose, filter-sterilized PD fluid through an implanted PD catheter. In some groups, the PD dwell was preceded by intravenous administration of blockers of TRPV1 (BCTC), TRPA1 (HC030031), or neurokinin 1 (NK1) (Spantide II) receptors. Cytokine messenger ribonucleic acid (mRNA) expressions were quantified in tissue biopsies (real-time polymerase chain reaction [qPCR]), and cytokine concentrations were quantified in dialysate samples by enzyme-linked immunosorbent assay (ELISA). Tissue expressions of TRPV1, TRPA1, and NK1 were evaluated immuno-histochemically. RESULTS: The PD dwell induced peritoneal synthesis of Il1b, Tnf, and Il6 and a secretion of interleukin-6 (IL-6) into the dialysate. The catheter implantation already induced the transcription of Il1b and Tnf but did not significantly affect Il6 transcription. The Il6 response to the PD dwell could be virtually eliminated by blocking TRPA1 but was not affected by TRPV1 blockade. Blocking the substance P receptor, NK1, produced an insignificant trend towards Il6 inhibition. TRPA1 and NK1 showed a stronger immuno-reactivity than TRPV1 on cells of the peritoneal tissue. CONCLUSION: The results show that IL-6 synthesis and secretion were connected to acute PD fluid exposure, and this response was triggered by TRPA1 receptors, possibly located to non-neuronal cells.


Asunto(s)
Interleucina-6/metabolismo , Diálisis Peritoneal/efectos adversos , Peritonitis/etiología , Canal Catiónico TRPA1/metabolismo , Animales , Soluciones para Diálisis/efectos adversos , Ensayo de Inmunoadsorción Enzimática , Inmunohistoquímica , Interleucina-1beta/metabolismo , Masculino , Mecanorreceptores/metabolismo , Diálisis Peritoneal/métodos , Peritoneo/metabolismo , Peritonitis/metabolismo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Neuroquinina-1/metabolismo , Transducción de Señal , Canales Catiónicos TRPV/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
13.
Oncotarget ; 6(24): 20043-57, 2015 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-26343374

RESUMEN

Follicular T helper (Tfh) cells are recognized by the expression of CXCR5 and the transcriptional regulator Bcl-6. Tfh cells control B cell maturation and antibody production, and if deregulated, may lead to autoimmunity. Here, we study the role of the proto-oncogene survivin in the formation of Tfh cells. We show that blood Tfh cells of patients with the autoimmune condition rheumatoid arthritis, have intracellular expression of survivin. Survivin was co-localized with Bcl-6 in the nuclei of CXCR5+CD4 lymphocytes and was immunoprecipitated with the Bcl-6 responsive element of the target genes. Inhibition of survivin in arthritic mice led to the reduction of CXCR5+ Tfh cells and to low production of autoantibodies. Exposure to survivin activated STAT3 and induced enrichment of PD-1+Bcl-6+ subset within Tfh cells. Collectively, our study demonstrates that survivin belongs to the Tfh cell phenotype and ensures their optimal function by regulating transcriptional activity of Bcl-6.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Proteínas de Unión al ADN/inmunología , Proteínas Inhibidoras de la Apoptosis/inmunología , Animales , Autoinmunidad/inmunología , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Genes p53 , Humanos , Proteínas Inhibidoras de la Apoptosis/química , Proteínas Inhibidoras de la Apoptosis/metabolismo , Masculino , Ratones , Ratones Endogámicos DBA , Modelos Moleculares , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Estructura Secundaria de Proteína , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-bcl-6 , Proteínas Represoras/genética , Proteínas Represoras/inmunología , Survivin
14.
Mol Med ; 21: 536-43, 2015 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-26062018

RESUMEN

T-helper cells producing interleukin (IL)-17A and IL-17F cytokines (Th17 cells) are considered the source of autoimmunity in rheumatoid arthritis (RA). In this study, we characterized specific pathogenic features of Th17 cells in RA. By using nano-string technology, we analyzed transcription of 419 genes in the peripheral blood CCR6(+)CXCR3(-) CD4(+) cells of 14 RA patients and 6 healthy controls and identified 109 genes discriminating Th17 cells of RA patients from the controls. Th17 cells of RA patients had an aggressive pathogenic profile and in addition to signature cytokines IL-17, IL-23 and IL-21, and transcriptional regulators RAR-related orphan receptor gamma of T cells (RORγt) and Janus kinase 2 (JAK2), they produced high levels of IL-23R, C-C chemokine ligand type 20 (CCL20), granulocyte-monocyte colony-stimulating factor (GM-CSF ) and transcription factor Tbet required for synovial homing. We showed that Th17 cells are enriched with Helios-producing Foxp3- and IL2RA-deficient cells, indicating altered regulatory profile. The follicular T-helper (Tfh) cells presented a functional profile of adaptor molecules, transcriptional regulator Bcl-6 and B-cell activating cytokines IL-21, IL-31 and leukemia inhibitory factor (LIF ). We observed that anti-tumor necrosis factor (TNF) treatment had a limited effect on the transcription signature of Th17 cells. Patients in remission retained the machinery of receptors (IL-23R and IL-1R1), proinflammatory cytokines (IL-17F, IL-23, IL-21 and TNF ) and adaptor molecules (C-X-C chemokine receptor 5 [CXCR5] and cytotoxic T-lymphocyte-associated protein 4 [CTLA-4]), essential for efficient transdifferentiation and accumulation of Th17 cells. This study convincingly shows that the peripheral blood CCR6(+)CXCR3(-) CD4(+) cells of RA patients harbor pathogenic subsets of Th17 and Tfh cells, which may transdifferentiate from Tregs and contribute to perpetuation of the disease.


Asunto(s)
Artritis Reumatoide/genética , Transdiferenciación Celular/genética , Células Th17/inmunología , Factor de Necrosis Tumoral alfa/administración & dosificación , Adulto , Anciano , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Femenino , Humanos , Interleucina-17/inmunología , Masculino , Persona de Mediana Edad , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Células Th17/patología , Transcriptoma/genética , Transcriptoma/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo
15.
Eur J Immunol ; 45(4): 1228-37, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25546233

RESUMEN

Selection of the primary antibody repertoire takes place in pro-/pre-B cells, and subsequently in immature and transitional B cells. At the first checkpoint, µ heavy (µH) chains assemble with surrogate light (SL) chain into a precursor B-cell receptor. In mice lacking SL chain, µH chain selection is impaired, and serum autoantibody levels are elevated. However, whether the development of autoantibody-producing cells is due to an inability of the resultant B-cell receptors to induce central and/or peripheral B-cell tolerance or other factors is unknown. Here, we show that receptor editing is defective, and that a higher proportion of BM immature B cells are prone to undergoing apoptosis. Furthermore, transitional B cells are also more prone to undergoing apoptosis, with a stronger selection pressure to enter the follicular B-cell pool. Those that enter the marginal zone (MZ) B-cell pool escape selection and survive, possibly due to the B-lymphopenia and elevated levels of B-cell activating factor. Moreover, the MZ B cells are responsible for the elevated IgM anti-dsDNA antibody levels detected in these mice. Thus, the SL chain is required for central and peripheral B-cell tolerance and inhibits anti-DNA antibody production by MZ B cells.


Asunto(s)
Anticuerpos Antinucleares/biosíntesis , Linfocitos B/inmunología , Tolerancia Inmunológica/inmunología , Inmunoglobulina de Cadenas Ligeras Subrogadas/genética , Animales , Anticuerpos Antinucleares/inmunología , Formación de Anticuerpos/genética , Apoptosis/inmunología , Autoanticuerpos/biosíntesis , Autoanticuerpos/sangre , Factor Activador de Células B/metabolismo , Receptor del Factor Activador de Células B/metabolismo , Proteínas de Homeodominio/genética , Inmunoglobulina de Cadenas Ligeras Subrogadas/inmunología , Inmunoglobulina M/inmunología , Cadenas mu de Inmunoglobulina/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Antígenos de Linfocitos B/biosíntesis
16.
Perit Dial Int ; 32(2): 168-76, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21965619

RESUMEN

BACKGROUND: The triggers of the acute local inflammatory response to peritoneal dialysis (PD) fluid exposure remain unknown. In the present study, we investigated the effects of neurogenic inflammation and mast cell degranulation on water and solute transport in experimental PD. METHODS: Single 2-hour dwells in rats with PD catheters were studied. Histamine and the neuropeptides substance P and calcitonin gene-related peptide (CGRP) were measured in PD fluid samples by ELISA. Radiolabeled albumin ((125)I and (131)I respectively) was used as an intraperitoneal (IP) and intravascular tracer. Glucose and urea concentrations were measured in plasma and PD fluid. The effects of varying the volume and osmolarity of a lactate-buffered PD fluid were compared and related to the effects of pharmacologic intervention. RESULTS: Application of 20 mL 3.9% glucose PD fluid induced an IP histamine release during the first 30 minutes, blockable by the mast cell stabilizer doxantrazole and the substance P neurokinin-1 receptor (NK1R)-blocker spantide. Histamine release was also inhibited at a reduced PD volume (14 mL), but was not affected by normalizing the PD fluid osmolarity. Blockade of NK1R also reduced plasma albumin leakage to the peritoneal cavity. Inhibition of CGRP receptors by CGRP8-37 improved osmotic (transcapillary) and net ultrafiltration and reduced the dialysate urea concentration. Neuropeptide release was not clearly related to activation of the TrpV1 receptor, the classic trigger of neurogenic inflammation. CONCLUSIONS: Neuropeptide release exaggerated albumin loss and reduced ultrafiltration in this rat PD model. Intervention aimed at the neuropeptide action substantially improved PD efficiency.


Asunto(s)
Neuropéptidos/metabolismo , Diálisis Peritoneal/efectos adversos , Albúmina Sérica/metabolismo , Ultrafiltración , Animales , Degranulación de la Célula/inmunología , Modelos Animales de Enfermedad , Histamina/biosíntesis , Inflamación , Mastocitos/inmunología , Neuropéptidos/biosíntesis , Ratas
17.
Perit Dial Int ; 30(6): 602-10, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20421429

RESUMEN

BACKGROUND: Single-dwell studies in rats and humans have shown that supplementing citrate for lactate in peritoneal dialysis (PD) fluids improves ultrafiltration (UF). ♢ METHODS: The long-term effects of citrate-substituted PD fluids on PD catheter patency, UF, and peritoneal morphology were evaluated in a rat model over 5 weeks of daily PD fluid exposure. A standard 2.5% glucose 40 mmol/L lactate PD fluid and a corresponding 10/30 mmol/L citrate/lactate PD fluid were compared. In a control group, rats with catheters received no PD fluid. ♢ RESULTS: The average patency time (% of 36 days) of silicone rubber PD catheters was significantly longer in the citrate PD group (98.8% ± 1.2%) and the control group (100% ± 0%) compared to the lactate PD group (54.7% ± 9.5%). In a separate experiment, heparin-coated polyurethane catheters were used to study peritoneal morphology and fluid transport. The citrate group had a higher net UF than the lactate group at the beginning and at the end of the 5 weeks. During the experiment, both fluid-treated groups suffered from UF loss; the control group showed the highest net UF at the end of the 5 weeks. Peritoneal vascular density and submesothelial thickness, indicators of angiogenesis and fibrosis, were not significantly different among the groups. Fibrosis was significantly negatively correlated to osmotic UF. ♢ CONCLUSION: A positive acute effect of citrate on UF was confirmed and conserved over time. Citrate PD strongly improved PD catheter patency time compared with lactate. Both citrate PD and lactate PD induced negative long-term effects on UF compared with control animals.


Asunto(s)
Catéteres de Permanencia , Citratos/administración & dosificación , Soluciones para Diálisis/administración & dosificación , Diálisis Peritoneal/métodos , Peritoneo/anatomía & histología , Animales , Anticoagulantes/química , Transporte Biológico , Tampones (Química) , Citratos/farmacocinética , Materiales Biocompatibles Revestidos/química , Epitelio/anatomía & histología , Diseño de Equipo , Fibrosis , Glucosa/administración & dosificación , Heparina/química , Ácido Láctico/administración & dosificación , Ácido Láctico/farmacocinética , Masculino , Mesenterio/anatomía & histología , Microvasos/anatomía & histología , Modelos Animales , Neovascularización Fisiológica/fisiología , Epiplón/anatomía & histología , Peritoneo/irrigación sanguínea , Peritoneo/metabolismo , Poliuretanos/química , Ratas , Ratas Sprague-Dawley , Elastómeros de Silicona/química , Factores de Tiempo , Ultrafiltración/métodos
18.
Perit Dial Int ; 29(1): 36-43, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19164251

RESUMEN

BACKGROUND: Exposure to peritoneal dialysis (PD) fluid induces an inflammatory response in the peritoneal cavity. Blockers of complement and coagulation have improved ultrafiltration in animal models of PD. Citrate is a clinically established anticoagulant that also blocks complement activation. OBJECTIVE: The aim of the present study was to evaluate the effects on ultrafiltration of a gradual substitution of citrate for lactate in an experimental model of PD. METHODS: Fractions (0, 5, 10, and 15 mmol/L) of the 40 mmol/L lactate buffer of filter-sterilized 2.5% glucose PD fluid were replaced by citrate. The modified fluids were compared in a rat model of single PD fluid exposure through an indwelling catheter. The initial kinetics of citrate and ionized calcium were evaluated in separate, single, short time dwell experiments. RESULTS: Replacing 10 and 15 mmol/L of the lactate buffer by sodium citrate significantly increased osmotic ultrafiltration (by 24.7%+/-7.7% at 10 mmol/L), net ultrafiltration, and glucose retention at 4 hours of dwell time in the rat model. Osmotic ultrafiltration was significantly correlated to citrate concentration and glucose concentration. Citrate was rapidly eliminated from the peritoneal cavity, concentrations falling to less than half in 1 hour and concentrations of calcium ions concomitantly normalized. CONCLUSIONS: Substituting citrate for lactate induced a dose-dependent increase in ultrafiltration. Mechanisms probably involve the relation between diffusion and ultrafiltration, leading to increased glucose retention. The increase in ultrafiltration was quantitatively important at a citrate concentration (10 mmol/L) that is compatible with clinical applications of citrate.


Asunto(s)
Citratos/administración & dosificación , Soluciones para Diálisis/farmacología , Lactatos/aislamiento & purificación , Diálisis Peritoneal/métodos , Ultrafiltración/métodos , Animales , Líquido Ascítico/química , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Inyecciones Intraperitoneales , Lactatos/análisis , Masculino , Peritoneo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley
19.
Biol Reprod ; 79(4): 667-73, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18562708

RESUMEN

Interdependence between sperm concentration, motility, morphology, and the percentage of aneuploid sperm was explored to test whether oligoasthenoteratospermia (OAT) may have a multiple origin in idiopathic infertile males. A total of 174 men (age, 35.8 +/- 4.3 yr) with idiopathic infertility were studied. Seven patients had nonobstructive azoospermia, 55 had severe OAT, 30 had OAT, 27 had isolated alterations of motility, 45 had alterations of morphology and of motility, and 10 had isolated alterations of morphology. The sperm morphology was assessed with strict criteria. The percentage of aneuploid sperm was assessed with fluorescent in situ hybridization for chromosomes X, Y, 13, 15, 16, 17, 18, 21, and 22. Relationships between sperm features, and the relationship between sperm features and aneuploidies were analyzed with multivariate regression analysis. Statistical analysis did not find any significant relationship between the percentage of typical forms and sperm concentration or between morphology and motility. On the other hand, a positive and significant relationship was found between sperm concentration and motility. The percentage of aneuploid sperm was inversely and significantly related to the percentage of typical forms but not to motility and concentration. Sperm morphology is an independent characteristic with respect to concentration and motility, whereas it showed a significant inverse relationship with respect to the percentage of aneuploid sperm. This means that idiopathic OAT may occur by means of at least two independent pathways, the first affecting concentration and/or motility and the second affecting morphology.


Asunto(s)
Astenozoospermia/complicaciones , Genes del Desarrollo/fisiología , Infertilidad Masculina/genética , Oligospermia/complicaciones , Adulto , Aneuploidia , Azoospermia/genética , Análisis Citogenético , Humanos , Infertilidad Masculina/etiología , Masculino , Recuento de Espermatozoides , Motilidad Espermática/genética
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