970 resultados para Fluid filtration model
Resumo:
There is a positive correlation between the intensity of use of a given antibiotic and the prevalence of resistant strains. The more you treat, more patients infected with resistant strains appears and, as a consequence, the higher the mortality due to the infection and the longer the hospitalization time. In contrast, the less you treat, the higher the mortality rates and the longer the hospitalization time of patients infected with sensitive strains that could be successfully treated. The hypothesis proposed in this paper is an attempt to solve such a conflict: there must be an optimum treatment intensity that minimizes both the additional mortality and hospitalization time due to the infection by both sensitive and resistant bacteria strains. In order to test this hypothesis we applied a simple mathematical model that allowed us to estimate the optimum proportion of patients to be treated in order to minimize the total number of deaths and hospitalization time due to the infection in a hospital setting. (C) 2007 Elsevier Inc. All rights reserved.
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We hypothesized that bone marrow-derived mononuclear cells (BMDMC) would attenuate the remodeling process in a chronic allergic inflammation model. C57BL/6 mice were assigned to two groups. In OVA, mice were sensitized and repeatedly challenged with ovalbumin. Control mice (C) received saline under the same protocol. C and OVA were further randomized to receive BMDMC (2 x 10(6)) or saline intravenously 24 h before the first challenge. BMDMC therapy reduced eosinophil infiltration, smooth muscle-specific actin expression, subepithelial fibrosis, and myocyte hypertrophy and hyperplasia, thus causing a decrease in airway hyperresponsiveness and lung mechanical parameters. BMDMC from green fluorescent protein (GFP)-transgenic mice transplanted into GFP-negative mice yielded lower engraftment in OVA. BMDMC increased insulin-like growth factor expression, but reduced interleukin-5, transforming growth factor-beta, platelet-derived growth factor, and vascular endothelial growth factor mRNA expression. In conclusion, in the present chronic allergic inflammation model, BMDMC therapy was an effective pre-treatment protocol that potentiated airway epithelial cell repair and prevented inflammatory and remodeling processes. (C) 2010 Elsevier B.V. All rights reserved.
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This study evaluated the use of Raman spectroscopy to identify the spectral differences between normal (N), benign hyperplasia (BPH) and adenocarcinoma (CaP) in fragments of prostate biopsies in vitro with the aim of developing a spectral diagnostic model for tissue classification. A dispersive Raman spectrometer was used with 830 nm wavelength and 80 mW excitation. Following Raman data collection and tissue histopathology (48 fragments diagnosed as N, 43 as BPH and 14 as CaP), two diagnostic models were developed in order to extract diagnostic information: the first using PCA and Mahalanobis analysis techniques and the second one a simplified biochemical model based on spectral features of cholesterol, collagen, smooth muscle cell and adipocyte. Spectral differences between N, BPH and CaP tissues, were observed mainly in the Raman bands associated with proteins, lipids, nucleic and amino acids. The PCA diagnostic model showed a sensitivity and specificity of 100%, which indicates the ability of PCA and Mahalanobis distance techniques to classify tissue changes in vitro. Also, it was found that the relative amount of collagen decreased while the amount of cholesterol and adipocyte increased with severity of the disease. Smooth muscle cell increased in BPH tissue. These characteristics were used for diagnostic purposes.
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This study presents the results of Raman spectroscopy applied to the classification of arterial tissue based on a simplified model using basal morphological and biochemical information extracted from the Raman spectra of arteries. The Raman spectrograph uses an 830-nm diode laser, imaging spectrograph, and a CCD camera. A total of 111 Raman spectra from arterial fragments were used to develop the model, and those spectra were compared to the spectra of collagen, fat cells, smooth muscle cells, calcification, and cholesterol in a linear fit model. Non-atherosclerotic (NA), fatty and fibrous-fatty atherosclerotic plaques (A) and calcified (C) arteries exhibited different spectral signatures related to different morphological structures presented in each tissue type. Discriminant analysis based on Mahalanobis distance was employed to classify the tissue type with respect to the relative intensity of each compound. This model was subsequently tested prospectively in a set of 55 spectra. The simplified diagnostic model showed that cholesterol, collagen, and adipocytes were the tissue constituents that gave the best classification capability and that those changes were correlated to histopathology. The simplified model, using spectra obtained from a few tissue morphological and biochemical constituents, showed feasibility by using a small amount of variables, easily extracted from gross samples.
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The goal of the study was to compare the effects of different assisted ventilation modes with pressure controlled ventilation (PCV) on lung histology, arterial blood gases, inflammatory and fibrogenic mediators in experimental acute lung injury (ALI). Paraquat-induced ALI rats were studied. At 24 h, animals were anaesthetised and further randomized as follows (n = 6/group): (1) pressure controlled ventilation mode (PCV) with tidal volume (V (T)) = 6 ml/kg and inspiratory to expiratory ratio (I:E) = 1:2; (2) three assisted ventilation modes: (a) assist-pressure controlled ventilation (APCV1:2) with I:E = 1:2, (b) APCV1:1 with I:E = 1:1; and (c) biphasic positive airway pressure and pressure support ventilation (BiVent + PSV), and (3) spontaneous breathing without PEEP in air. PCV, APCV1:1, and APCV1:2 were set with P (insp) = 10 cmH(2)O and PEEP = 5 cmH(2)O. BiVent + PSV was set with two levels of CPAP [inspiratory pressure (P (High) = 10 cmH(2)O) and positive end-expiratory pressure (P (Low) = 5 cmH(2)O)] and inspiratory/expiratory times: T (High) = 0.3 s and T (Low) = 0.3 s. PSV was set as follows: 2 cmH(2)O above P (High) and 7 cmH(2)O above P (Low). All rats were mechanically ventilated in air and PEEP = 5 cmH(2)O for 1 h. Assisted ventilation modes led to better functional improvement and less lung injury compared to PCV. APCV1:1 and BiVent + PSV presented similar oxygenation levels, which were higher than in APCV1:2. Bivent + PSV led to less alveolar epithelium injury and lower expression of tumour necrosis factor-alpha, interleukin-6, and type III procollagen. In this experimental ALI model, assisted ventilation modes presented greater beneficial effects on respiratory function and a reduction in lung injury compared to PCV. Among assisted ventilation modes, Bi-Vent + PSV demonstrated better functional results with less lung damage and expression of inflammatory mediators.
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Leishmania (Viannia) shawl was recently characterized and few studies concerning modifications in cellular and humoral immune responses in experimental leishmaniasis have been conducted. In this work, immunopathological changes induced by L. shawl in chronically infected BALB/c mice were investigated. Infected BALB/c mice developed increased lesion size associated with strong inflammatory infiltrate diffusely distributed in the dermis, with highly infected macrophages. The humoral immune response was predominantly directed toward the IgG1 isotype. The functional activity of CD4(+) and CD8(+) T cells showed significantly increased TNF-alpha mRNA levels associated with reduced IFN-gamma expression by CD4(+) T cells and the double negative (dn) CD4CD8 cell subset. High IL-4 levels expressed by CD8(+) T cells and dnCD4CD8 and TGF-beta by CD4(+) and CD8(+) T cells were detected, while IL-10 was highly expressed by all three cell subpopulations. Taken together, these results show an evident imbalance between TNF-alpha and IFN-gamma that is unfavorable to amastigote replication control. Furthermore, L. shawi seems to regulate different cell populations to express deactivating cytokines to avoid its own destruction. This study indicates BALB/c mice as a potentially good experimental model for further studies on American cutaneous leishmaniosis caused by L. shawi. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
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Objectives: Injectable corticosteroids have been used in phonosurgery to prevent scarring of the vocal fold because of their effects of wound healing, and to ensure better voice quality. We histologically evaluated the effects of dexamethasone sodium phosphate infiltration on acute vocal fold wound healing in rabbits 3 and 7 days after surgically induced injury by quantification of the inflammatory reaction and collagen deposition. Methods: A standardized surgical incision was made in the vocal folds of 12 rabbits, and 0.1 mL dexamethasone sodium phosphate (4 mg/mL) was injected into the left vocal fold. The right vocal fold was not injected and served as the control. The larynges were collected 3 and 7 days after surgery. For histologic analysis, the vocal folds were stained with hematoxylin-eosin for quantification of the inflammatory response and with picrosirius red for qunatification of collagen depostion. Results: There was no quantitative difference in the inflammatory response between vocal folds injected with the corticosteroid and control vocal folds. However, the rate of collage deposition was significantly lower in the corticosteroid-treated group at 3 and 7 days after injury (p = 0.002). Conclusions: The present results suggest that dexamethasone reduces collagen depostion during acute vocal fold wound healing.
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The impact of obesity on the inflammatory process has been described in asthma, however little is known about the influence of diet-induced obesity on lung remodeling. For this purpose, 56 recently weaned A/J mice were randomly divided into 2 groups. In the C group, mice were fed a standard chow diet, while OB animals received isocaloric high-fat diet to reach 1.5 of the mean body weight of C. After 12 weeks, each group was further randomized to be sensitized and challenged with ovalbumin (OVA) or saline. Twenty-four hours after the last challenge, collagen fiber content in airways and lung parenchyma, the volume proportion of smooth muscle-specific actin in alveolar ducts and terminal bronchiole, and the number of eosinophils in bronchoalveolar lavage fluid were higher in OB-OVA than C-OVA. In conclusion, diet-induced obesity enhanced lung remodeling resulting in higher airway responsiveness in the present experimental chronic allergic asthma. (C) 2011 Elsevier B.V. All rights reserved.
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This study shows the creation of a graphical representation after the application of a questionnaire to evaluate the indicative factors of a sustainable telemedicine and telehealth center in Sao Paulo, Brazil. We categorized the factors into seven domain areas: institutional, functional, economic-financial, renewal, academic-scientific, partnerships, and social welfare, which were plotted into a graphical representation. The developed graph was shown to be useful when used in the same institution over a long period and complemented with secondary information from publications, archives, and administrative documents to support the numerical indicators. Its use may contribute toward monitoring the factors that define telemedicine and telehealth center sustainability. When systematically applied, it may also be useful for identifying the specific characteristics of the telemedicine and telehealth center, to support its organizational development.
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Background: The swine is an essential model for carrying out preclinical research and for teaching complex surgical procedures. There is a lack of experimental models describing anatomical and surgical aspects of total pancreatectomy in the pig. Materials and Methods: The experiments were performed on 10 white male swine weighing 27-33 kg. The animals were premedicated with midazolam (0.4 mg/kg, i.m.) and ketamine (4 mg/kg, i.m.). Anesthesia was induced with propofol (1-2 mg/kg, i.v.) and was maintained with propofol and fentanyl (0.3 mg and 0.1 mu g/kg/min, respectively, i.v.). The surgical period ranged from 44 to 77 min. The pancreas anatomy, and the main arterial, venous and pancreatic duct anatomy were assessed. Results: The pancreas anatomy was composed of 3 lobes, the `splenic`, `duodenal` and `connecting` lobe which is attached to the anterior portion of the portal vein. The splenic artery and the junction of the splenic vein and portal vein were divided. The left gastric artery was dissected and separated from its origin at the splenic artery. The head of the pancreas is disposed in a C shape. The pancreas was dissected and liberated from the right portion of the portal vein and the infrahepatic vena cava. The pancreas was separated from the duodenum preserving the pancreaticoduodenal artery, then we performed the total pancreatectomy preserving the duodenum, common bile duct and spleen. Conclusion: Total pancreatectomy with duodenum, bile duct and spleen preservation in the pig is feasible and an important instrument for research purposes and teaching surgical technique. Copyright (C) 2010 S. Karger AG, Basel
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Obstetric complications play a role in the pathophysiology of schizophrenia. However, the biological consequences during neurodevelopment until adulthood are unknown. Microarrays have been used for expression profiling in four brain regions of a rat model of neonatal hypoxia as a common factor of obstetric complications. Animals were repeatedly exposed to chronic hypoxia from postnatal (PD) day 4 through day 8 and killed at the age of 150 days. Additional groups of rats were treated with clozapine from PD 120-150. Self-spotted chips containing 340 cDNAs related to the glutamate system (""glutamate chips"") were used. The data show differential (up and down) regulations of numerous genes in frontal (FR), temporal (TE) and parietal cortex (PAR), and in caudate putamen (CPU), but evidently many more genes are upregulated in frontal and temporal cortex, whereas in parietal cortex the majority of genes are downregulated. Because of their primary presynaptic occurrence, five differentially expressed genes (CPX1, NPY, NRXN1, SNAP-25, and STX1A) have been selected for comparisons with clozapine-treated animals by qRT-PCR. Complexin 1 is upregulated in FR and TE cortex but unchanged in PAR by hypoxic treatment. Clozapine downregulates it in FR but upregulates it in PAR cortex. Similarly, syntaxin 1A was upregulated in FR, but downregulated in TE and unchanged in PAR cortex, whereas clozapine downregulated it in FR but upregulated it in PAR cortex. Hence, hypoxia alters gene expression regionally specific, which is in agreement with reports on differentially expressed presynaptic genes in schizophrenia. Chronic clozapine treatment may contribute to normalize synaptic connectivity.
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Background: Biochemical analysis of fluid is the primary laboratory approach hi pleural effusion diagnosis. Standardization of the steps between collection and laboratorial analyses are fundamental to maintain the quality of the results. We evaluated the influence of temperature and storage time on sample stability. Methods: Pleural fluid from 30 patients was submitted to analyses of proteins, albumin, lactic dehydrogenase (LDH), cholesterol, triglycerides, and glucose. Aliquots were stored at 21 degrees, 4 degrees, and-20 degrees C, and concentrations were determined after 1, 2, 3, 4, 7, and 14 days. LDH isoenzymes were quantified in 7 random samples. Results: Due to the instability of isoenzymes 4 and 5, a decrease in LDH was observed in the first 24 h in samples maintained at -20 degrees C and after 2 days when maintained at 4 degrees C. Aside from glucose, all parameters were stable for up to at least day 4 when stored at room temperature or 4 degrees C. Conclusions: Temperature and storage time are potential preanalytical errors in pleural fluid analyses, mainly if we consider the instability of glucose and LDH. The ideal procedure is to execute all the tests immediately after collection. However, most of the tests can be done in refrigerated sample;, excepting LDH analysis. (C) 2010 Elsevier B.V. All rights reserved.
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SETTING: A tertiary care research centre in Sao Paolo, Brazil. OBJECTIVE: To quantify interleukin (IL) 8, tumour necrosis factor alpha (TNF-alpha), vascular endothelial growth factor (VEGF) and transforming growth factor beta(1), (TGF-beta(1))in pleural fluid from tuberculous patients, correlating its values with the histopathological patterns in pleural biopsies. DESIGN: Cytokines were quantified in patients with transudatcs secondary to congestive heart failure (n = 8) and exudates secondary to tuberculosis (TB; n = 39). In parietal pleural biopsies from TB patients, the histological patterns of the inflammatory response were quantified by morphometric analysis (stereological point-counting method). RESULTS: IL-8, TNF-alpha, VEGF and TGF-beta(1) levels were higher in TB than in transudates. A positive correlation existed between components of the fibrinoid exudative phase with pleural fluid IL-8 (R = 0.52, P = 0.004) and VEGF (R = 0.42, P = 0.0021) levels. A negative correlation existed between pleural fluid IL-8 (R = -0.37, P = 0.048) and VEGF (R = -0.44, P = 0.0015) levels with tissue components of fibroproliferation. CONCLUSION: The high pleural levels of TNF-a, IL-8, VEGF and TGF-beta(1) suggest the involvement of these cytokines in the TB immunological response. The positive correlation between pleural fluid IL-8 and VEGF with the components of the acute exudative phase and the negative correlation between these cytokines with the fibroproliferative components suggest a temporary inflammatory response in the pleural space.