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排序方式: 共有464条查询结果,搜索用时 15 毫秒
1.
D Rodríguez-Pérez Oscar Sotolongo-Grau Ramón Espinosa Riquelme Oscar Sotolongo-Costa J Antonio Santos Miranda J C Antoranz 《Mathematical medicine and biology》2007,24(3):287-300
A cytokine-based periodic immunotherapy treatment is included in a model of tumour growth with a delay. The effects of dose schedule are studied in the case of a weak immune system and a growing tumour. We find the existence of 'metastable' states (that may last for tens of years) induced by the treatment and also potentially adverse effects of the dosage frequency on the stabilization of the tumour. These two effects depend on the delay between the tumour growth and the immune system response, the cytokine dose burden, and other parameters considered in the model. 相似文献
2.
Herrera EA Riquelme RA Sanhueza EM Gajardo C Parer JT Llanos AJ 《High altitude medicine & biology》2000,1(3):175-184
The fetal llama has a marked increase in the peripheral vascular resistance and no augmentation of brain blood flow during hypoxemia. In spite of the substantial plasma arginine-vasopressin (AVP) increase during hypoxemia, up to 8 times greater than in fetal sheep, there are no changes of carotid and femoral blood flows during hypoxemia with a V1 receptor blockade, as is seen in the fetal sheep. The aim of this study was to assess the role of AVP function in mediating the combined ventricular output and organ blood flow in the hypoxemic llama fetus. Six fetal llamas at 0.65 of gestation were instrumented under general anesthesia, and cardiorespiratory responses and blood flows determined under normoxemic and hypoxemic conditions. The AVP effect was determined using a V1 antagonist during normoxemic and hypoxemic conditions. Organ blood flows were measured with the radioactive microsphere technique. No significant differences in organ blood flow or in their vascular resistances were seen between the control and treated fetuses during hypoxemia. We conclude that V1 blockade did not have any important role in the cardiovascular response to acute hypoxemia in the llama fetus, in contrast with lowland fetuses. AVP may be playing a role in other regions, possibly in kidney or lung, during hypoxemia. 相似文献
3.
Magne Aldrin Ragnhild Raastad Ingunn Fride Tvete Dag Berild Arnoldo Frigessi Truls Leegaard Dominique L. Monnet Mette Walberg Fredrik Müller 《Statistics in medicine》2013,32(8):1407-1418
Association between previous antibiotic use and emergence of antibiotic resistance has been reported for several microorganisms. The relationship has been extensively studied, and although the causes of antibiotic resistance are multi‐factorial, clear evidence of antibiotic use as a major risk factor exists. Most studies are carried out in countries with high consumption of antibiotics and corresponding high levels of antibiotic resistance, and currently, little is known whether and at what level the associations are detectable in a low antibiotic consumption environment. We conduct an ecological, retrospective study aimed at determining the impact of antibiotic consumption on antibiotic‐resistant Pseudomonas aeruginosa in three hospitals in Norway, a country with low levels of antibiotic use. We construct a sophisticated statistical model to capture such low signals. To reduce noise, we conduct our study at hospital ward level. We propose a random effect Poisson or binomial regression model, with a reparametrisation that allows us to reduce the number of parameters. Inference is likelihood based. Through scenario simulation, we study the potential effects of reduced or increased antibiotic use. Results clearly indicate that the effects of consumption on resistance are present under conditions with relatively low use of antibiotic agents. This strengthens the recommendation on prudent use of antibiotics, even when consumption is relatively low. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
4.
Arnoldo Téllez Teresa Sánchez-Jáuregui Dehisy M. Juárez-García Manuel García-Solís 《The International journal of clinical and experimental hypnosis》2016,64(4):456-469
The authors evaluated the efficacies of audio-recorded hypnosis with background music and music without hypnosis in the reduction of emotional and physical disturbances in patients scheduled for breast biopsy in comparison with a control group. A total of 75 patients were randomly assigned to 3 different groups and evaluated at baseline and before and after breast biopsy using visual analog scales of stress, pain, depression, anxiety, fatigue, optimism, and general well-being. The results showed that, before breast biopsy, the music group presented less stress and anxiety, whereas the hypnosis with music group presented reduced stress, anxiety, and depression and increased optimism and general well-being. After the biopsy, the music group presented less anxiety and pain, whereas the hypnosis group showed less anxiety and increased optimism. 相似文献
5.
Federico Cagnazzo Pierre-Henri Lefevre Daniel Mantilla Aymeric Rouchaud Riccardo Morganti Paolo Perrini Davide Di Carlo Cyril Dargazanli Gregory Gascou Carlos Riquelme Alain Bonafe Vincent Costalat 《Journal of neuroradiology. Journal de neuroradiologie》2019,46(1):9-14
Background and purpose
Placement of flow-diverters across the ostia of major ICA branches carries a risk of arterial occlusion. We determined the rate of occlusion of the supraclinoid ICA branches and the related symptoms, following coverage with flow-diverters.Materials and methods
A systematic search was performed in PubMed, MEDLINE, and EMBASE. We selected studies reporting treatments with flow-diverters in which the device was placed across the ostium of the OphtA, PcomA, or AchorA. Random-effects meta-analysis was used to pool the following outcomes: rate of arterial occlusion, diminished flow, incidence of related symptoms, factors associated with arterial occlusion.Result
Twenty-one studies evaluating 1152 supraclinoid ICA branches were included in the meta-analysis. The incidence of OphtA occlusion and associated symptoms was 5.9% (95 CI%?=?3.1–8.6%) (incidence rate?=?6% per patient-year), and 0.8% (95% CI?=?0.1–1.4%) (incidence rate?=?0.8% per patient-year), respectively. Although asymptomatic in all cases, PcomA showed a higher occlusion rate (20.7%, 95% CI?=?8.9–32.4%) (incidence rate?=?19.5% per patient-year). AchorA was occluded in 1% (95% CI?=?0.3–2.4%) of cases, with approximately 1% (95% CI?=?0.4–2.3%) of transient neurological symptoms (incidence rate?=?0.96% per patient-year). There was a trend toward higher odds of arterial patency among arteries arising from the aneurysm (OR?=?2.94, P?=?0.06). Demographic factors and multiple stents were not associated with higher risk of arterial impairment. Adequate collateral circulation was reported in 94.5% of patients with arterial occlusion.Conclusions
During aneurysm treatment, the ostium of the supraclinoid ICA branches can be covered with flow-diverter devices with low rates of neurological symptoms related to arterial occlusion. 相似文献6.
Hemostatic gene polymorphisms and the prevalence of thrombotic complications in polycythemia vera and essential thrombocythemia. 总被引:3,自引:0,他引:3
Vahid Afshar-Kharghan José A López Leigh A Gray Arnoldo Padilla Gautam Borthakur Stacy C Roberts Rajiv K Pruthi Ayalew Tefferi 《Blood coagulation & fibrinolysis》2004,15(1):21-24
Patients with polycythemia vera and essential thrombocythemia are at risk for thrombotic and bleeding complications. Currently, no diagnostic test can predict thrombohemorrhagic complications. In a prospective study of 86 patients with polycythemia vera (43 patients) or essential thrombocythemia (43 patients), we examined the possible role of polymorphisms of platelet adhesion receptors [glycoprotein (GP) Ibalpha, GPIa, GPIIIa) and clotting factor II (prothrombin's G20210A mutation) and clotting factor V (Leiden mutation) in determining the risk of thrombotic or bleeding complications. Except for an association between vasomotor symptoms and prothrombin mutation (P < 0.001), no significant correlation between polymorphism of clotting factors and thrombohemorrhagic complications was identified. When the entire patient cohort was considered, the polymorphisms of platelet adhesion receptors were not associated with the risk for thrombotic or bleeding complications. However, among patients with polycythemia vera, the presence of the PlA2 allele of GPIIIa was associated with an increased risk of arterial thrombosis. In view of previous studies linking the presence of the PlA2 allele of GPIIIa to a higher risk for coronary artery thrombosis, our data have physiologic relevance. However, they need to be confirmed in a larger study. 相似文献
7.
Juan P Arab Roberto Candia Rodrigo Zapata Cristián Mu?oz Juan P Arancibia Jaime Poniachik Alejandro Soza Francisco Fuster Javier Brahm Edgar Sanhueza Jorge Contreras M Carolina Cuellar Marco Arrese Arnoldo Riquelme 《World journal of gastroenterology : WJG》2014,20(34):12182-12201
AIM: To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice.METHODS: NAFLD has now reached epidemic proportions worldwide. The optimal treatment for NAFLD has not been established due to a lack of evidence-based recommendations. An expert panel of members of the Chilean Gastroenterological Society and the Chilean Hepatology Association conducted a structured analysis of the current literature on NAFLD therapy. The quality of the evidence and the level of recommendations supporting each statement were assessed according to the recommendations of the United States Preventive Services Task Force. A modified three-round Delphi technique was used to reach a consensus among the experts.RESULTS: A group of thirteen experts was established. The survey included 17 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 93.8% in the first round and 100% in the second and third rounds. The final recommendations support the indication of lifestyle changes, including diet and exercise, for all patients with NAFLD. Proven pharmacological therapies include only vitamin E and pioglitazone, which can be used in nondiabetic patients with biopsy-proven nonalcoholic steatohepatitis (the progressive form of NAFLD), although the long-term safety and efficacy of these therapies have not yet been established.CONCLUSION: Current NAFLD management is rapidly evolving, and new pathophysiology-based therapies are expected to be introduced in the near future. All NAFLD patients should be evaluated using a three-focused approach that considers the risks of liver disease, diabetes and cardiovascular events. 相似文献
8.
Luis Antonio D az Francisco Idalsoaga Macarena Cannistra Roberto Candia Daniel Cabrera Francisco Barrera Alejandro Soza Rondell Graham Arnoldo Riquelme Marco Arrese Michael D Leise Juan Pablo Arab 《World journal of gastroenterology : WJG》2020,26(48):7693-7706
BACKGROUNDCoronavirus disease 2019 (COVID-19) disease can frequently affect the liver. Data on hepatic histopathological findings in COVID-19 is scarce.AIMTo characterize hepatic pathological findings in patients with COVID-19.METHODSWe conducted a systematic review with meta-analysis registered on PROSPERO (CRD42020192813), following PRISMA guidelines. Eligible trials were those including patients of any age and COVID-19 diagnosis based on a molecular test. Histopathological reports from deceased COVID-19 patients undergoing autopsy or liver biopsy were reviewed. Articles including less than ten patients were excluded. Proportions were pooled using random-effects models. Q statistic and I2 were used to assess heterogeneity and levels of evidence, respectively.RESULTSWe identified 18 studies from 7 countries; all were case reports and case series from autopsies. All the patients were over 15 years old, and 67.2% were male. We performed a meta-analysis of 5 studies, including 116 patients. Pooled prevalence estimates of liver histopathological findings were hepatic steatosis 55.1% [95% confidence interval (CI): 46.2-63.8], congestion of hepatic sinuses 34.7% (95%CI: 7.9-68.4), vascular thrombosis 29.4% (95%CI: 0.4-87.2), fibrosis 20.5% (95%CI: 0.6-57.9), Kupffer cell hyperplasia 13.5% (95%CI: 0.6-54.3), portal inflammation 13.2% (95%CI: 0.1-48.8), and lobular inflammation 11.6% (95%CI: 0.3-35.7). We also identified the presence of venous outflow obstruction, phlebosclerosis of the portal vein, herniated portal vein, periportal abnormal vessels, hemophagocytosis, and necrosis.CONCLUSIONWe found a high prevalence of hepatic steatosis and vascular thrombosis as major histological liver features. Other frequent findings included portal and lobular inflammation and Kupffer cell hyperplasia or proliferation. Further studies are needed to establish the mechanisms and implications of these findings. 相似文献
9.
Antonio Rollan Juan Pablo Arab M Constanza Camargo Roberto Candia Paul Harris Catterina Ferreccio Charles S Rabkin Juan Cristóbal Gana Pablo Cortés Rolando Herrero Luisa Durán Apolinaria García Claudio Toledo Alberto Espino Nicole Lustig Alberto Sarfatis Catalina Figueroa Javier Torres Arnoldo Riquelme 《World journal of gastroenterology : WJG》2014,20(31):10969-10983
AIM: To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.METHODS: Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.RESULTS: A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing.CONCLUSION: These achievable steps toward better region-specific management can be expected to improve clinical health outcomes. 相似文献
10.