997 resultados para Small Acinar Proliferation
Resumo:
To analyze the effects of triamcinolone intravitreal injection on the wound healing processes after argon laser retinal photocoagulation, wild type C57BL/6J mice, 8-12 weeks old underwent a standard argon laser photocoagulation protocol. After pentobarbital anesthesia and pupil dilatation, argon laser lesions were induced (50microm, 400mW, 0.05s). Two photocoagulation impacts created two disc diameters from the optic nerve in both eyes. The photocoagulated mice were divided into four groups: Group I (n=12), photocoagulation controls, did not receive any intravitreous injection. Group II (n=12), received an intravitreous injection of 1microl of balanced salt solution (BSS). Group III (n=12), received an intravitreous injection of 1microl containing 15microg of triamcinolone acetonide (TAAC) in BSS. Two mice from each of these three groups were sacrificed at 1, 3, 7, 14 days and 2 and 4 months after photocoagulation. Group IV (n=10) received 1.5, 3, 7.5, 15, or 30microg of TAAC and were all sacrificed on day 14. The enucleated eyes were subjected to systematic analysis of the cellular remodeling processes taking place within the laser lesion and its vicinity. To this purpose, specific antibodies against GFAP, von Willebrand factor, F4/80 and KI67 were used for the detection of astrocytes, activated Müller cells, vascular endothelial cells, infiltrating inflammatory cells and actively proliferating cells. TUNEL reaction was also carried out along with nuclear DAPI staining. Temporal and spatial observations of the created photocoagulation lesions demonstrate that 24h following the argon laser beam, a localized and well-delineated affection of the RPE cells and choroid is observed in mice in Groups I and II. The inner retinal layers in these mice eyes are preserved while TUNEL positive (apoptotic) cells are observed at the retinal outer nuclear layer level. At this stage, intense staining with GFAP is associated with activated retinal astrocytes and Müller cells throughout the laser path. From day 3 after photocoagulation, dilated new choroidal capillaries are detected on the edges of the laser lesion. These processes are accompanied by infiltration of inflammatory cells and the presence of proliferating cells within the lesion site. Mice in Group III treated with 15microg/mul of triamcinolone showed a decreased number of infiltrating inflammatory cells and proliferating cells, which was not statistically significant compared to uninjected laser treated controls. The development of new choroidal capillaries on the edges of the laser lesion was also inhibited during the first 2 months after photocoagulation. However, on month 4 the growth of new vessels was observed in these mice treated with TAAC. Mice of Group IV did not show any development of new capillaries even with small doses. After argon laser photocoagulation of the mouse eye, intravitreal injection of triamcinolone markedly influenced the retina and choroid remodeling and healing processes. Triamcinolone is a powerful inhibitor of the formation of neovessels in this model. However, this inhibition is transient. These observations should provide a practical insight for the mode of TAAC use in patients with wet AMD.
Resumo:
A significant number of environmental microorganisms can cause serious, even fatal, acute and chronic infections in humans. The severity and outcome of each type of infection depends on the expression of specific bacterial phenotypes controlled by complex regulatory networks that sense and respond to the host environment. Although bacterial signals that contribute to a successful acute infection have been identified in a number of pathogens, the signals that mediate the onset and establishment of chronic infections have yet to be discovered. We identified a volatile, low molecular weight molecule, 2-amino acetophenone (2-AA), produced by the opportunistic human pathogen Pseudomonas aeruginosa that reduces bacterial virulence in vivo in flies and in an acute mouse infection model. 2-AA modulates the activity of the virulence regulator MvfR (multiple virulence factor regulator) via a negative feedback loop and it promotes the emergence of P. aeruginosa phenotypes that likely promote chronic lung infections, including accumulation of lasR mutants, long-term survival at stationary phase, and persistence in a Drosophila infection model. We report for the first time the existence of a quorum sensing (QS) regulated volatile molecule that induces bistability phenotype by stochastically silencing acute virulence functions in P. aeruginosa. We propose that 2-AA mediates changes in a subpopulation of cells that facilitate the exploitation of dynamic host environments and promote gene expression changes that favor chronic infections.
Determination of Flood Dischard Characteristics of Small Drainage Areas, HR-3, Progress Report, 1960
Resumo:
Project HR-3 of the Iowa Highway Research Board has been active since October 1, 1950. The project objective is the determination of flood discharge characteristics of small drainage areas. Funds for the project amount to $10,000 per year of which, by cooperative agreement, the Highway Commission and the U. S. Geological Survey each furnish $5,000. Previous reports have explained the set-up of the project and these explanations will not be repeated in this report.
Resumo:
in the paper we consider the nullification number of small knots with at most 9 crossings. We establish two inequalities (Corollary 2.1) relating the nullification number to other knot invariants and properties of the knot diagram. We show that these inequalities allow us to settle the nullification number for all of the 84 prime knots with at most 9 crossings.
Resumo:
Despite decades of research, therapeutic advances in non-small cell lung cancer (NSCLC) have progressed at a painstaking slow rate with few improvements in standard surgical resection for early stage disease and chemotherapy or radiotherapy for patients with advanced disease. In the past 18 months, however, we seemed to have reached an inflexion point: therapeutic advances that are centred on improvements in the understanding of patient selection, surgery that is undertaken through smaller incisions, identification of candidate mutations accompanied by the development of targeted anticancer treatments with a focus on personalised medicine, improvements to radiotherapy technology, emergence of radiofrequency ablation (RFA), and last but by no means least, the recognition of palliative care as a therapeutic modality in its own right. The contributors to this review are a distinguished international panel of experts who highlight recent advances in each of the major disciplines.
Resumo:
Malignant gliomas, including the most common and fatal form glioblastoma (GBM, WHO grade IV astrocytoma), remain a challenge to treat. In the United States and Europe, more than 30,000 patients per year are newly diagnosed with GBM. Despite ongoing trials, the best currently available multimodal treatment approaches include surgical resection followed by concomitant and adjuvant radiation (RT) and temozolomide (TMZ) therapy, resulting in a low median overall survival (OS) rate ranging from 12.2 - 15.9 months. The important role of genetic and epigenetic changes in DNA, RNA, and protein alteration as well as epigenetic changes secondary to the tumor microenvironment and outside selection pressure (therapeutic interventions), are increasingly being recognized. In GBM treatment, the focus is shifting toward a more patient-centered (personalized) therapy. In this regard, in particular, microRNAs are being increasingly studied. MicroRNAs are non¬protein coding small RNAs that serve as negative gene regulators by binding to a specific sequence in the promoter region of a target gene, thus regulating gene expression. A single microRNA potentially targets hundreds of genes; thus, microRNAs and their cognate target genes have important roles as tumor suppressors and oncogenes as well as regulators of various cancer- specific cellular features, such as proliferation, apoptosis, invasion, and metastasis. The identification of distinct microRNA-gene regulatory networks in GBM patients can be expected to provide novel therapeutic insights by identifying candidate patients for targeted therapies. To this end, in this work we identified and validated clinically relevant and meaningful novel gene- microRNA regulatory networks that correlated with MR tumor phenotypes, histopathology, and patient survival and response rates to therapy. - Le traitement des gliomes malins, y compris sous leur forme la plus commune et meurtrière, le glioblastome (GBM, ou astrocytome de grade IV selon l'OMS), demeure à ce jour un défi. Aux États-Unis et en Europe, un nouveau diagnostic de GBM est prononcé dans plus de 30Ό00 cas par an. En dépit de tests en cours, les meilleures approches thérapeutiques combinées actuellement disponibles comprennent la résection chirurgicale de la tumeur, suivie d'une radiothérapie adjuvante ainsi que d'un traitement au temozolomide (RT/TMZ), thérapies dont résulte une médiane de survie globale basse (overall survival, OS), comprise entre 12.2 et 15.9 mois. On reconnaît de plus en plus le rôle majeur de l'ADN, de l'ARN et de l'altération des protéines ainsi que des modifications épigénétiques, secondaires par rapport au microenvironnement de la tumeur et à la pression de sélection extérieure (les interventions thérapeutiques). Dans le traitement du GBM, le centre d'intérêt se déplace vers une thérapie centrée sur le cas individuel du patient. Dans ce but, en particulier les microARN sont de plus en plus analysés. Les microARN sont de petits ARN non-codants (les protéines) qui servent de régulateurs négatifs de gènes en s'attachant à une séquence spécifique dans la région promotrice d'un gène-cible, régulant ainsi l'expression du gène. Un seul microARN cible potentiellement des centaines de gènes; on a ainsi découvert que les microARN et leurs gènes-cibles apparentés ont une fonction importante en tant que suppresseurs de tumeurs et d'oncogènes, ainsi que comme régulateurs de diverses caractéristiques cellulaires spécifiques du cancer, comme la prolifération, l'apoptose, l'invasion et la métastase. On peut s'attendre à ce que l'identification de réseaux microARN régulateurs de gènes, distincts selon les patients de GBM, fournisse une approche thérapeutique inédite par la détermination des patients susceptibles de réagir favorablement à des thérapies ciblées.
Resumo:
Visual areas 17 and 18 were studied with morphometric methods for numbers of neurons, glia, senile plaques (SP), and neurofibrillary tangles (NFT) in 13 cases of Alzheimer's disease (AD) as compared to 11 controls. In AD cases, the mean neuronal density was significantly decreased by about 30% in both areas 17 and 18, while the glial density was increased significantly only in area 17. The volume of area 17 was unchanged in AD cases but its total number of neurons was decreased by 33% and its total number of glia increased by 45% compared to controls. In AD the number of SP was similar in areas 17 and 18, while that of NFT was significantly higher in area 18. The number of neurons with NFT was only 2% in area 17 and about 10% in area 18. The discrepancy between the loss of neurons and the amount of NFT suggests that neuronal loss can occur without passing through NFT degeneration. The deposition of SP was correlated with glial proliferation, but not with neuronal loss or neurofibrillary degeneration.
Resumo:
OBJECTIVES: Studies of small area variations of health care utilization are more and more frequent. Such variations are often considered to be an indication of variations in the quality of medical care. The variations in the rate of operations for hip fractures are among the lowest studied to date, due to the fact that a consensus exists concerning this surgery. Our objective is to examine these variations within the context of relatively small and heterogeneous districts. METHOD: Based on anonymous computerized data on public hospital stays, this study describes the variations in population rates (crude and standardized) of operations for hip fracture among the health districts of the Canton of Vaud for the period from 1986 to 1991. District populations vary from 22,000 to 164,000. Using the extremal quotient (EQ), the importance of these variations was determined. RESULTS: The study population consists of 2363 cases, of which 78% are women. Mean age is 80.4 for women and 70.6 for men. Standardized rates of operation for hip fracture per 100,000 in the Canton Vaud for the years 1986 to 1991 are, respectively: 56; 67; 86; 91; 89 and 94. The EQ for the years 1986 to 1991 are respectively: 8.2; 4.0; 3.5; 2.7; 1.9 and 1.9. The high EQ, especially for the earlier years, are contrary to the initial premise of absence of variation. The progressive implementation in the Canton Vaud of VESKA medical statistics could play a role, as could the small size of many of the districts, with resultant instability of rates. CONCLUSIONS: Considering the wide variations shown here for an operation hardly regarded as subject to variations, it is important to exercise caution in interpreting published data of small area variations.
Resumo:
BACKGROUND: Induction radiochemotherapy, followed by resection, for T4 non-small cell lung cancer, has shown promising long-term survival but may be associated with increased postoperative morbidity and death, depending on patient selection. Here, we determined the effect of induction radiochemotherapy on pulmonary function and whether postinduction pulmonary function changes predict hospital morbidity and death and long-term survival. METHODS: A consecutive prospective cohort of 72 patients with T4 N0-2 M0 non-small cell lung cancer managed by radiochemotherapy, followed by resection, is reported. All patients underwent thoracoabdominal computed tomography or fusion positron emission tomography-computed tomography, brain imaging, mediastinoscopy, echocardiography, ventilation-perfusion scintigraphy, and pulmonary function testing before and after induction therapy. Resection was performed if the postoperative forced expiratory volume in 1 second and diffusion capacity of the lung for carbon monoxide exceeded 30% predicted and if the postoperative maximum oxygen consumption exceeded 10 mL/kg/min. RESULTS: The postoperative 90-day mortality rate was 8% (lobectomy, 2%; pneumonectomy, 21%; p=0.01). All deaths after pneumonectomy occurred after right-sided procedures. The 3-year and 5-year survival was 50% (95% confidence interval, 36% to 62%) and 45% (95% confidence interval, 31% to 57%) and was significantly associated with completeness of resection (p=0.004) and resection type (pneumonectomy vs lobectomy, p=0.01). There was no correlation between postinduction pulmonary function changes and postoperative morbidity or death or long-term survival in patients managed by lobectomy or pneumonectomy. CONCLUSIONS: In properly selected patients with T4 N0-2 M0 non-small cell lung cancer, resection after induction radiochemotherapy can be performed with a reasonable postoperative mortality rate and long-term survival, provided the resection is complete and a right-sided pneumonectomy is avoided. Postinduction pulmonary function changes did not correlate with postoperative morbidity or death or with long-term outcome.
Resumo:
Abstract
Resumo:
OBJECTIVES: To assess the performance of 45F vs. 36F smartcanula in CPB with gravity drainage alone. METHODS: Twenty patients were randomly assigned to two groups receiving for venous drainage a smartcanula which is collapsed over a mandrel for trans-atrial insertion into the inferior vena cava and expanded in situ to either 45F or 36F. RESULTS: Valve replacement/repair was realized in 7/10 and/or CABG in 6/10 for 36F (69+/-13 years) vs. 5/10 and 5/10, respectively, for 45F (63+/-11 years: NS). Body weight and surface area (BSA) were 83+/-9 kg (1.9+/-0.2 m2, max 2.2 m2) for 36F vs. 79+/-6 kg: NS (1.9+/-0.1 m2 (NS), max 2.1 m2) for 45F. Insertion and access orifice diameter (area) was 6 mm and 10 mm (78.5 mm2) for the 36F vs. 6 mm and 13 mm (132 mm2) for the 45F (+69%). Calculated target pump flow (2.4 l/min/m2) was 4.7+/-0.4 l/min for 36F vs. 4.5+/-0.3 l/min for 45F. Achieved pump flow accounted for 5.0+/-0.3 l/min for 36F (8% above target) vs. 4.8+/-0.3 l/min for 45F (8% above target): NS. The water balance during the pump run (clear volume added minus hemofilter and urine output) was 2.2+/-0.3 l for 36F vs. 2.0 l for 45F: NS. CONCLUSION: Due to its 'open' wall (the vena cava provides the seal), its reduced wall thickness (range: 0.0-0.4 mm), and its self-expanding design, the 36F smartcanula requiring a 30F access orifice has sufficient drainage capacity by gravity alone for full CPB in adults with a BSA up to 2.2 mm2.