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Biomedical subjects

Xiao-Peng Hu

Publications and source records attributed to Xiao-Peng Hu.

5 recordsLinked to original sources

One-stage total or subtotal aortic replacement.

BACKGROUND: The goal of total aortic resection surgery is to correct the extensive or multiple sites of aortic pathology, which involves the entire length of the vessel. This study describes our experience in this operation at Fuwai Cardiovascular Hospital. METHODS: From February 2004 to October 2005, thirteen patients with Marfan syndrome underwent one-stage total or subtotal aortic replacement for aortic dissection or aortic aneurysms. Four patients received subtotal aortic replacement (ascending aorta to the abdominal aorta). Nine patients underwent total aortic replacement (ascending aorta to the aortic bifurcation). Operations were performed under circulatory arrest with profound hypothermia. Patients were opened with a mid-sternotomy and a thoracoabdominal incision. Extracorporeal circulation was instituted with two arterial cannulae and a single venous cannula in the right atrium. During cooling, the ascending aorta or aortic root was replaced. At the nasopharyngeal temperature of 20 degrees C, the aortic arch was replaced with selective antegrade cerebral perfusion. After brain reperfusion, staged aortic occlusions allowed for replacement of descending thoracic and abdominal aorta. Intercostal, visceral, and renal arteries were anastomosed to the graft. RESULTS: There was no operative or early postoperative death. One case of postoperative complication was noted for cerebral infarction secondary to embolism. Spinal neurologic deficits did not occur. At the last follow-up, ranging from 4 to 24 months postoperatively, all 13 patients were alive and had good functional status. CONCLUSIONS: One-stage total or subtotal aortic replacement for treatment of extensive aortic disease is feasible with acceptable surgical risks and satisfactory results. It can eliminate the risk of remnant aortic aneurysm rupture in staged total aortic replacement.

Adult↗

Analysis of visual search patterns with EMD metric in normalized anatomical space.

Eye movements provide important insight into the cognitive processes underlying the visual search tasks. For image understanding, although the visual search patterns of different observers while studying the same scene bear some common characteristics, the idiosyncrasy associated with individual observers provides both research opportunities and challenges. The aim of this paper is to study the spatial characteristics of visual search, together with the intrinsic visual features of the fixation points for comparing different visual search strategies. An analysis framework based on earth mover's distance (EMD) in normalized anatomical space is proposed, and the results are demonstrated with high resolution computed tomography (HRCT) images of the lungs. The study shows that through the effective use of both spatial and feature space representation, it is possible to untangle what appear to be uncorrelated fixation distribution patterns to reveal common visual search behaviors.

Artificial Intelligence↗

Hot spot detection based on feature space representation of visual search.

This paper presents a new framework for capturing intrinsic visual search behavior of different observers in image understanding by analysing saccadic eye movements in feature space. The method is based on the information theory for identifying salient image features based on which visual search is performed. We demonstrate how to obtain feature space fixation density functions that are normalized to the image content along the scan paths. This allows a reliable identification of salient image features that can be mapped back to spatial space for highlighting regions of interest and attention selection. A two-color conjunction search experiment has been implemented to illustrate the theoretical framework of the proposed method including feature selection, hot spot detection, and back-projection. The practical value of the method is demonstrated with computed tomography image of centrilobular emphysema, and we discuss how the proposed framework can be used as a basis for decision support in medical image understanding.

Adult↗

The use of visual search for knowledge gathering in image decision support.

This paper presents a new method of knowledge gathering for decision support in image understanding based on information extracted from the dynamics of saccadic eye movements. The framework involves the construction of a generic image feature extraction library, from which the feature extractors that are most relevant to the visual assessment by domain experts are determined automatically through factor analysis. The dynamics of the visual search are analyzed by using the Markov model for providing training information to novices on how and where to look for image features. The validity of the framework has been evaluated in a clinical scenario whereby the pulmonary vascular distribution on Computed Tomography images was assessed by experienced radiologists as a potential indicator of heart failure. The performance of the system has been demonstrated by training four novices to follow the visual assessment behavior of two experienced observers. In all cases, the accuracy of the students improved from near random decision making (33%) to accuracies ranging from 50% to 68%.

Algorithms↗

[The effects of antisenes oligodeoxynucleotide on the cyclic nucleotide monophosphates in smooth muscle cells of human corpus cavernosum].

OBJECTIVES: To investigate the effects of antisense oligodeoxynucleotide(ASON) on the cyclic nucleotide monophosphates (cNMP) in smooth muscle cells of human corpus cavernosum, and provide experimental groundwork for the gene therapy of erectile dysfunction. METHODS: PDE5 gene ASON(containing exon 1) was transfected into the corpus cavernosum smooth muscle cells with the presence of liposome DOTAP. Another sense oligodeoxynucleotide(SON) and 1% of bovine serum were also transducted into the cells as controls. Two of cNMP, cAMP and cGMP, were probed and measured by ELISA at 1, 2, 4, 6, 10, 24 and 48 h after transfection. RESULTS: After transfection, the level of cGMP(1-6 h) in human corpus cavernosum smooth muscle cells was significantly higher than that in controls(P < 0.01). CONCLUSIONS: The PDE5 gene ASON had been showed to manifest stimulative effect on the cGMP in smooth muscle cells of human corpus cavernosum in vitro, and it provides experimental groundwork for the gene therapy of erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases↗