974 resultados para transplantation of organs and tissues
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Teeth, with their high mineralisation, incremental growth, and lack of remodelling, serve as biological archives that document an individual's development. This project aims to utilise the potential of teeth in bioarchaeological studies to achieve three primary objectives: 1) to investigate the application of histological and histochemical methods in reconstructing developmental bio-chronologies and early life histories; 2) to refine the temporal precision of isotopic analysis of dentine collagen by developing a novel protocol that integrates micro-sampling techniques with high-resolution histomorphometrics; and 3) to synthesise data from enamel and dentine for a comprehensive understanding of early life development and dietary transitions. This study adopts an integrated multidisciplinary bioarchaeological approach, conducting histomorphometric analysis on enamel and dentine across deciduous and permanent dentitions. It applies high-temporal resolution trace element analysis to enamel using LA-ICPMS and δ13C and δ15N isotope analyses through sequential micro-sampling to dentine of permanent teeth. Samples were selected from diverse archaeological contexts across the Italian peninsula, covering the Upper Palaeolithic, Copper Age, and Early Medieval periods, providing insight into diachronic variations in infant development and life history. Findings highlight the efficacy of histological and histochemical techniques in accurately determining growth rates, physiological stress, dietary shifts (particularly timing of weaning), and age at death in infant remains. The consistency and comparison between enamel and dentine underscores the enhanced insight obtained from integrating information from both tissues. Importantly, the newly proposed protocol significantly improves the temporal accuracy of dentine collagen analysis, facilitating precise chronological placement of the results over broad developmental associations. This study reaffirms the significance of teeth as valuable bioarchaeological instruments. By introducing and testing multidisciplinary methods, it provides deeper insights into early life history and cultural practices across diverse chronological contexts, highlighting the importance of advanced methodologies in extracting detailed, accurate, and nuanced information from past populations.
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The behaviour of the albino and melanic variants of Biomphalaria glabrata of Belo Horizonte (MG. Brazil) was studied comparatively, in terms of their respective susceptibilities to infection by Schistosoma mansoni of the same origin, through observation of the elimination of cercariae for a three-month period and the calculation of mortality and infection rates, in control and in infected snails. The number of amoebocytes, granulocytes and hyalinocytes in the circulating hemolymph during different periods of infection was analyzed. The evolution of the infection in the tissues was observed by means of histological cross-sections. The melanic variant showed greater susceptibility to infection and a higher mortality rate. The albino variant showed a higher number of circulating amoebocytes, both granulocytes and hyalinocytes. A higher number of degenerated sporocysts were seen in the histological cross-sections of the albino variant. The results suggest that the melanic variant of B. glabrata was more susceptible to infection by S. mansoni than was the albino variant.
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PURPOSE: To analyze the effects of detachment and repositioning of the medial pterygoid muscle on the growth of the maxilla and mandible of young rats through cephalometry. METHODS: Thirty one-month-old Wistar rats were used, distributed into three groups: experimental, sham-operated and control. In the experimental group, unilateral detachment and repositioning of the medial pterygoid muscle was performed. The sham-operated group only underwent surgical access, and the control group did not undergo any procedure. The animals were sacrificed at the age of three months. Their soft tissues were removed and the mandible was disarticulated. Radiographs of the skull in axial projection and the hemimandibles in lateral projection were obtained, and cephalometry was performed. The values obtained were subjected to statistical analyses among the groups and between the sides in each group. RESULTS: There were significant differences in the length of the mandible relative to the angular process in the experimental group and in the height of the mandibular body in the sham-operated group. CONCLUSION: The experimental detachment and repositioning of the medial pterygoid muscle during the growth period in rats affected the growth of the angle region, resulting in asymmetry of the mandible.
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Background and Purpose: The right kidney has been less frequently used in live donor nephrectomy, because of the shorter length of the right renal vein (RRV) that is associated with technical difficulties and higher rates of venous thrombosis. In live open donor or deceased donor transplant nephrectomy, an additional cuff of the inferior vena cava is usually removed, but this is a more difficult and risky maneuver in laparoscopic nephrectomy. For this reason, laparoscopic right nephrectomy (LRN) for renal transplantation (RT) is not frequently performed in most medical institutions. We evaluate the difference between RRV and left renal vein (LRV) lengths in cadavers, as harvested for RT by three clamping methods. Our objective was to obtain information that could clarify when LRN for RT should be encouraged or avoided with regard to conventional surgery. Materials and Methods: Ninety adult fresh unfrozen cadavers were randomly divided into three groups of 30, according to the clamping device used: Satinsky, stapler, and Hem-o-lok clip. The abdominal viscera were removed through a median xyphopubic incision, and the veins were measured on the bench. Two lateral limits were used: The renal hilum and the tangential line of the renal poles. As for medial limits, the inferior vena cava or the laparoscopic clipping device on the RRV were used on the right side, while on the LRV, the medial border of the emergence of the adrenal vein was considered. After section of the renal vein, a slight traction of the extremity was applied for the measurement. All measurements were obtained three times using a metallic millimetric ruler, and the arithmetic mean was considered. The chi-square, one-way analysis of variance, and paired t tests were used for statistical analysis. Statistical significance was accepted at P <= 0.05. Results: The groups of cadavers were homogeneous in demographic characteristics. Regardless of the clamping method and considering the useful length of the LRV, the RRV was statistically smaller. The evaluation of the vein length did not depend on the lateral limit considered. Independent of the clamping method, on both sides, the lengths after the vein section were larger than before the section, a fact attributed to traction. Use of a stapler and a single Hem-o-lok presented the same waste of vein length on the right side. On average, the RRV was 13.7% shorter than the LRV. Conclusions: With the wide acceptance of laparoscopic live donor nephrectomy, the length difference between the veins of both kidneys is an important issue, and the right kidney is therefore used less than the left, compared with conventional surgery. This article represents the first step to quantify the anatomic length of renal veins in different situations. Certainly, more imagenologic or surgical studies should be carried out before decisions can be made for better selection of patients for LRN.
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Background: Cell therapy approaches for biologic cardiac repair hold great promises, although basic fundamental issues remain poorly understood. In the present study we examined the effects of timing and routes of administration of bone marrow cells (BMC) post-myocardial infarction (MI) and the efficacy of an injectable biopolymer scaffold to improve cardiac cell retention and function. Methodology/Principal Findings: (99m)Tc-labeled BMC (6x10(6) cells) were injected by 4 different routes in adult rats: intravenous (IV), left ventricular cavity (LV), left ventricular cavity with temporal aorta occlusion (LV(+)) to mimic coronary injection, and intramyocardial (IM). The injections were performed 1, 2, 3, or 7 days post-MI and cell retention was estimated by gamma-emission counting of the organs excised 24 hs after cell injection. IM injection improved cell retention and attenuated cardiac dysfunction, whereas IV, LV or LV* routes were somewhat inefficient (< 1%). Cardiac BMC retention was not influenced by timing except for the IM injection that showed greater cell retention at 7 (16%) vs. 1, 2 or 3 (average of 7%) days post-MI. Cardiac cell retention was further improved by an injectable fibrin scaffold at day 3 post-MI (17 vs. 7%), even though morphometric and function parameters evaluated 4 weeks later displayed similar improvements. Conclusions/Significance: These results show that cells injected post-MI display comparable tissue distribution profile regardless of the route of injection and that there is no time effect for cardiac cell accumulation for injections performed 1 to 3 days post-MI. As expected the IM injection is the most efficient for cardiac cell retention, it can be further improved by co-injection with a fibrin scaffold and it significantly attenuates cardiac dysfunction evaluated 4 weeks post myocardial infarction. These pharmacokinetic data obtained under similar experimental conditions are essential for further development of these novel approaches.
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The application of laser induced breakdown spectrometry (LIBS) aiming the direct analysis of plant materials is a great challenge that still needs efforts for its development and validation. In this way, a series of experimental approaches has been carried out in order to show that LIBS can be used as an alternative method to wet acid digestions based methods for analysis of agricultural and environmental samples. The large amount of information provided by LIBS spectra for these complex samples increases the difficulties for selecting the most appropriated wavelengths for each analyte. Some applications have suggested that improvements in both accuracy and precision can be achieved by the application of multivariate calibration in LIBS data when compared to the univariate regression developed with line emission intensities. In the present work, the performance of univariate and multivariate calibration, based on partial least squares regression (PLSR), was compared for analysis of pellets of plant materials made from an appropriate mixture of cryogenically ground samples with cellulose as the binding agent. The development of a specific PLSR model for each analyte and the selection of spectral regions containing only lines of the analyte of interest were the best conditions for the analysis. In this particular application, these models showed a similar performance. but PLSR seemed to be more robust due to a lower occurrence of outliers in comparison to the univariate method. Data suggests that efforts dealing with sample presentation and fitness of standards for LIBS analysis must be done in order to fulfill the boundary conditions for matrix independent development and validation. (C) 2009 Elsevier B.V. All rights reserved.
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Transplantation of pancreatic islets constitutes a promising alternative treatment for type 1 diabetes. However, it is limited by the shortage of organ donors. Previous results from our laboratory have demonstrated beneficial effects of recombinant human prolactin (rhPRL) treatment on beta cell cultures. We therefore investigated the role of rhPRL action in human beta cell survival, focusing on the molecular mechanisms involved in this process. Human pancreatic islets were isolated using an automated method. Islet cultures were pre-treated in the absence or presence of rhPRL and then subjected to serum starvation or cytokine treatment. Beta cells were labelled with Newport green and apoptosis was evaluated using flow cytometry analysis. Levels of BCL2 gene family members were studied by quantitative RT-PCR and western blot. Caspase-8, -9 and -3 activity, as well as nitric oxide production, were evaluated by fluorimetric assays. The proportion of apoptotic beta cells was significantly lowered in the presence of rhPRL under both cell death-induced conditions. We also demonstrated that cytoprotection may involve an increase of BCL2/BAX ratio, as well as inhibition of caspase-8, -9 and -3. Our study provides relevant evidence for a protective effect of lactogens on human beta cell apoptosis. The results also suggest that the improvement of cell survival may involve, at least in part, inhibition of cell death pathways controlled by the BCL2 gene family members. These findings are highly relevant for improvement of the islet isolation procedure and for clinical islet transplantation.
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This work discusses the determination of the breathing patterns in time sequence of images obtained from magnetic resonance (MR) and their use in the temporal registration of coronal and sagittal images. The registration is made without the use of any triggering information and any special gas to enhance the contrast. The temporal sequences of images are acquired in free breathing. The real movement of the lung has never been seen directly, as it is totally dependent on its surrounding muscles and collapses without them. The visualization of the lung in motion is an actual topic of research in medicine. The lung movement is not periodic and it is susceptible to variations in the degree of respiration. Compared to computerized tomography (CT), MR imaging involves longer acquisition times and it is preferable because it does not involve radiation. As coronal and sagittal sequences of images are orthogonal to each other, their intersection corresponds to a segment in the three-dimensional space. The registration is based on the analysis of this intersection segment. A time sequence of this intersection segment can be stacked, defining a two-dimension spatio-temporal (2DST) image. The algorithm proposed in this work can detect asynchronous movements of the internal lung structures and lung surrounding organs. It is assumed that the diaphragmatic movement is the principal movement and all the lung structures move almost synchronously. The synchronization is performed through a pattern named respiratory function. This pattern is obtained by processing a 2DST image. An interval Hough transform algorithm searches for synchronized movements with the respiratory function. A greedy active contour algorithm adjusts small discrepancies originated by asynchronous movements in the respiratory patterns. The output is a set of respiratory patterns. Finally, the composition of coronal and sagittal image pairs that are in the same breathing phase is realized by comparing of respiratory patterns originated from diaphragmatic and upper boundary surfaces. When available, the respiratory patterns associated to lung internal structures are also used. The results of the proposed method are compared with the pixel-by-pixel comparison method. The proposed method increases the number of registered pairs representing composed images and allows an easy check of the breathing phase. (C) 2010 Elsevier Ltd. All rights reserved.
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BACKGROUND: This study reported the effects of the daily intake of anthocyanins and ellagitannins (ET) extracted from blackberries on the markers for oxidative status in healthy rats. RESULTS: The phenolic compounds were administered from three different extracts: an aqueous extract of blackberry (BJ) and its two derived fractions: anthocyanin-enriched (AF) and ET-enriched (EF) fractions. After 35 days` administration, the AF and EF extracts significantly reduced thiobarbituric acid reactive substance levels and increased glutathione levels in the liver, kidney and brain. Plasma antioxidant capacity increased only in the group that received AF. Antioxidant enzyme activity and expression did not follow a pattern of response varying according to the tissues and extracts. A significant increase in the catalase activity was observed only in the plasma of the groups administered anthocyanin-containing extracts, which were the BJ and AF groups. Glutathione peroxidase activity was significantly increased in the liver and brain after EF treatment, and the highest increase in its expression was observed in the livers and brains of rats that received AF and EF, respectively. CONCLUSION: The results demonstrate that long-term intake of anthocyanin and ET through diet affects antioxidant enzyme activity and expression, and enhances oxidative markers in healthy rats. (C) 2010 Society of Chemical Industry
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Objective: In patients who have undergone hemodialysis, large amounts of reactive oxygen species (ROS) are produced and, at higher concentrations, ROS are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an anti-atherogenic influence by reducing oxidative stress. The richest known food source of selenium is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. We evaluated the effect of Brazil nut supplementation on blood levels of Se and glutathione peroxidase (GSH-Px) activity in patients on hemodialysis. Methods: A total of 81 patients on hemodialysis (52.0 +/- 15.2 y old, average time on dialysis 82.3 +/- 91.4 mo, body mass index 24.9 +/- 4.4 kg/m(2)) from the RenalCor and RenalVida Clinics in Rio de Janeiro, Brazil, were studied. All patients received one nut (around 5 g, averaging 58.1 mu g Se/g) a day for 3 mo. The Se concentrations in the nuts and in plasma and erythrocytes were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500). GSH-Px levels were measured using Randox commercial kits. Results: Plasma Se (18.8 +/- 17.4 mu g/L) and erythrocyte (72.4 +/- 37.9 mg/L) levels were below the normal, range before nut supplementation. After supplementation, the plasma level increased to 104.0 +/- 65.0 mu g/L and erythrocytes to 244.1 +/- 119.5 mg/L (P<0.0001). The activity of GSH-Px also increased after supplementation, from 46.6 +/- 14.9 to 55.9 +/- 23.6 U/g of hemoglobin (P<0.0001). Before supplementation, 11% of patients had GSH-Px activity below the normal range (27.5-73.6 U/g of hemoglobin). After supplementation, all patients showed GSH-Px activity within the normal range. Conclusion: The data revealed that the investigated patients presented Se deficiency and that the consumption of only one Brazil nut a day (5 g) during 3 mo was effective to increase the Se concentration and GSH-Px activity in these patients, thus improving their antioxidant status. (C) 2010 Elsevier Inc. All rights reserved.
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Aim: Statin disposition and response are greatly determined by the activities of drug metabolizing enzymes and efflux/uptake transporters. there is little information on the regulation of these proteins in human cells after statin therapy. In this study, the effects of atorvastatin and simvastatin on mRNA expression of efflux (ABCB1, ABCG2 and ABCC2) and uptake (SLCO1B1, SLCO2B1 and SLC22A1) drug transporters in Caco-2 and HepG2 cells were investigated. Methods: Quantitative real-time PCR was used to measure mRNA levels after exposure of HepG2 and Caco-2 cells to statins. Results: Differences in mRnA basal levels of the transporters were as follows: ABCC2>ABCG2>ABCB1>SLCO1B1>>>SLC22A1>SLC O2B1 for HepG2 cells, and SLCO2B1>>ABCC2>ABCB1>ABCG2>>>SLC22A1 for Caco-2 cells. While for HepG2 cells, ABCC2, ABCG2 and SLCO2B1 mRnA levels were significantly up-regulated at 1, 10 and 20 mu mol/L after 12 or 24 h treatment, in Caco-2 cells, only the efflux transporter ABCB1 was significantly down-regulated by two-fold following a 12 h treatment with atorvastatin. Interestingly, whereas treatment with simvastatin had no effect on mRNA levels of the transporters in HepG2 cells, in Caco-2 cells the statin significantly down-regulated ABCB1, ABCC2, SLC22A1, and SLCO2B1 mRnA levels after 12 or 24 h treatment. Conclusion: These findings reveal that statins exhibits differential effects on mRNA expression of drug transporters, and this effect depends on the cell type. Furthermore, alterations in the expression levels of drug transporters in the liver and/or intestine may contribute to the variability in oral disposition of statins.
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(Morpho-anatomical studies of seeds and seedlings of wild indigo, ""anileira"", Indigofera-Leguminosae). The common name ""wild indigo"" specifies Indigofera will L., I. suffruticosa Mill. (legitimate name) and I. truxillensis Kunth (legitimate name) that are very similar due to their external morphology. This work analyzed diagnostic characteristics of seeds and seedlings of these species since such features are widely used in taxonomic approaches within Leguminosae. We studied surface features and morpho-anatomy of seeds and cotyledons with scanning electronic microscopy and light microscopy, and described seedling phases. Although seedlings are similar, seed characteristics (size, shape, surface ornamentation, shape of the hilum and embryo size) and cotyledon characteristics (shape, trichome ornamentation, organization of spongy parenchyma along central veins and metabolite distribution in the tissues) have diagnostic features for the species. I. anil differs from I. suffruticosa in its larger seeds and acuminate-margined cotyledons. I. truxillensis is recognized by its cylindrical seeds and kidney-shaped cotyledons with large oil drops. We assume that the characteristics examined, plus fruit morphology and foliar anatomy suggest that I. anil, I. suffruticosa and I. truxillensis should not be synonymized.
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Magnetic resonance imaging (MRI) relies on the physical properties of unpaired protons in tissues to generate images. Unpaired protons behave like tiny bar magnets and will align themselves in a magnetic field. Radiofrequency pulses will excite these aligned protons to higher energy states. As they return to their original state, they will release this energy as radio waves. The frequency of the radio waves depends on the local magnetic field and by varying this over a subject, it is possible to build the images we are familiar with. In general, MRI has not been sufficiently sensitive or specific in the assessment of diffuse liver disease for clinical use. However, because of the specific characteristics of fat and iron, it may be useful in the assessment of hepatic steatosis and iron overload. Magnetic resonance imaging is useful in the assessment of focal liver disease, particularly in conjunction with contrast agents. Haemangiomas have a characteristic bright appearance on T-2 weighted images because of the slow flowing blood in dilated sinusoids. Focal nodular hyperplasia (FNH) has a homogenous appearance, and enhances early in the arterial phase after gadolinium injection, while the central scar typically enhances late. Hepatic adenomas have a more heterogenous appearance and also enhance in the arterial phase, but less briskly than FNH. Hepatocellular carcinoma is similar to an adenoma, but typically occurs in a cirrhotic liver and has earlier washout of contrast. The appearance of metastases depends on the underlying primary malignancy. Overall, MRI appears more sensitive and specific than computed tomography with contrast for the detection and evaluation of malignant lesions. (C) 2000 Blackwell Science Asia Pty Ltd.
Proteomic analysis of normal and malignant prostate tissue to identify novel proteins lost in cancer
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BACKGROUND. Alterations of important protein pathways, including loss of prostate secretory granules, and disruption of the prostatic secretory pathway have been identified as early events in malignancy. In this study, proteomics was used to map the differences in protein expression between normal and malignant prostate tissues and to identify and analyze differentially expressed proteins in human prostate tissue with particular regard to the proteins lost in malignancy. METHODS. Small quantities of normal and malignant prostate tissue were taken fresh from 34 radical prostatectomy cases. After histological examination, proteins were solubilized from selected tissues and separated using two-dimensional electrophoresis. Using image analysis, the proteome of normal and malignant tissues were mapped and differentially expressed proteins (present in normal and absent in malignant tissue) were identified and subsequently analyzed using peptide mass finger printing and N-terminal sequencing. Western blotting and immunohistochemistry were performed to examine expression profiles and tissue localization of candidate proteins. RESULTS. Comparison of protein maps of normal and malignant prostate were used to identify 20 proteins which were lost in malignant transformation, including prostate specific antigen (PSA), alpha-l antichymotrypsin (ACT), haptoglobin, and lactoylglutathione lyase. Three of the 20 had not previously been reported in human prostate tissue (Ubiquitin-like NEDD8, calponin, and a follistatin-related protein). Western blotting confirmed differences in the expression profiles of NEDD8 and calponin, and immunohistochemistry demonstrated differences in the cellular localization of these two proteins in normal and malignant prostate glands. CONCLUSIONS. The expression of NEDD8, calponin, and the follistatin-related protein in normal prostate tissues is a novel finding and the role of these important functional proteins in normal prostate and their loss or reduced expression in prostate malignancy warrants further investigations. (C) 2002 Wiley-Liss, Inc.
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The immunosurveillance of transformed cells by the immune system remains one of the most controversial and poorly understood areas of immunity. Gene-targeted mice have greatly aided our understanding of the key effector molecules in tumor immunity. Herein, we describe spontaneous tumor development in gene-targeted mice lacking interferon (IFN)-gamma and/or perform (pfp), or the immunoregulatory cytokines, interleukin (IL)-12, IL-18, and tumor necrosis factor (TNF). Both IFN-gamma and pfp were critical for suppression of lymphomagenesis, however the level of protection afforded by IFN-gamma was strain specific. Lymphomas arising in IFN-gamma deficient mice were very nonimmunogenic compared with those derived from pfp-deficient mice, suggesting a comparatively weaker immunoselection pressure by IFN-gamma. Single loss of IL-12, IL-18, or TNF was not sufficient for spontaneous tumor development. A significant incidence of late onset adenocarcinoma observed in both IFN-gamma- and pfp-deficient mice indicated that some epithelial tissues were also subject to immunosurveillance.