In recent years,the medical imaging technology has developed rapidly.New imaging methods are unceasingly emerging,and the existed imaging modes have been continuously improved.The trends of medical imaging technology have developed from two-dimension imaging to three-dimension imaging,from localized imaging to whole-body imaging,from static imaging to dynamic imaging and from structure to function.This thesis introduces the new imaging methods,such as Molecular Imaging,Near Infrared Imaging and so on.

Objective To design an image pre-processing system of low-density gene chips based on MATLAB, which can process the colored images by cy3 and cy5 fluorescence staining of low-density chips obtained by the array scanning system. It can filter out noise, enhance the contrast gradient of image, improve the quality of image, and implement the functions of image segmentation, edge detection and region identification. Methods The median filter method of the wavelet was used to implement the function of image denoising and improve the image quality. Edge detection was accomplished by wavelet, combining with edge operators. Image segmentation was developed by genetic algorithms. Results It could reduce the effect of spot, noise and other factors, improve the quality of image, and detect the periphery of image better and the region of sampling point more precisely. It can also effectively separate the valuable weak signal points and background or noise with the system. Conclusion The system can accomplish the functions of image pre-processing of low-density gene chips, and the adopted methods are feasible. It can provide relative accurate data information for future analysis.

The present study investigated the effect of BN50739, a new PAF antagonist, on the early reperfusion-induced arrhythmia in anesthetized SD rats, and by this to elucidate the role of PAF in the mechanism of early reperfusion-induced arrhythmia. The results indicated that the BN50739 group had lower incidences of premature ventricular contraction (PVQ, ventricular tachycardia (VT) and ventricular fibrillation (VF) during reperfusion than the control group (58.3% vs 66.7%, 50% vs 77.8%, and 16.7% vs 88.9%). But only VF incidence had a significant difference. Also the BN50739 group had shorter duration of VT+VF and of total arrhythmias than control group (58.8+171.9 vs 296.4+291.4, and 76.4+173.9 vs 361.8 + 286.5, P

Objective To study MR imaging manifestations of the mesorectum and mesorectal fascia. Methods 100 cases were divided into five groups according to the age. All MR images were retrospectively observed and analyzed by two radiologists.The observing contents included: ①exhibition of the mesorectal fascia, ②the signal intensity of the mesorectum and the pelvic fat and ③the thickness ratio of the mesorectum and the subcutaneous fat in different ages. All data were dealed with SPSS 10.0 software. Results The showing rate of the anterior, posterior, left and right mesorectal fascia respectively were 77, 100, 91 and 93 by MR imaging. The signal intensity of the mesorectum(550.8843) was significantly higher than that(469.8693) of pelvic fat in all five groups(P﹤0.05) and the signal difference between the mesorectum and the pelvic fat could be detected by naked eye. The thickness of the mesorectum and the subcutaneous fat had no association with ages.Conclusion MRI can display the mesorectum and mesorectal fascia clearly. The signal intensity of the mesorectum is significantly higher than that of pelvic fat in five groups. The thickness of the mesorectum and the subcutaneous fat have no association with ages.

Diastolic transmitral blood flow was measured by Doppler echocardiography in 66 patients with hypertension and 33 normal persons. The results showed that isovolumic ventricular relaxation time and peak. A velocity increased and E/A ratio decreased significantly in hypertensive patients without left ventricular (LV) hypertrophy. Patients with LV hypertrophy had not only significant change of these parameters, but also significant decrease of peak E velocity and deceleration of E velocity. Left atria was larger in hypertensive patients, especially in those with LV hypertrophy. It is suggested that LV diastolic dysfunction in patients with hypertension may occur before the development of LV hypertrophy, and LV hypertrophy may worsen the diastolic dysfunction.

We studied the effects of the selective thromboxane synthetase inhibitor, dazoxiben (UK-37 248), on the reperfusion arrhythmias induced by ischemia-reperfusion in rats. The results indicated that the administration of dazoxiben (2.5 mg/kg i.v.) 15 min prior to coronary occlusion significantly decreased the incidence of ventricular fibrillation induced by 5 inin ischemia and reperfusion from 11/13 in control to 4/13 in drug-treated (P

Objective To explore the possible roles of PI3K pathway and MAPK pathway in mediating the survival and differentiation-promoting effect of glial cell line-derived neurotrophic factor(GDNF) on midbrain dopaminergic neurons.(Methods Midbrain) slices of early postnatal rats were cultured,the slices were divided into four groups according to the different substances added into the culture medium: i.e.blank control group,GDNF group,Wortmanin plus GDNF group,and PD98059 plus GDNF group.On the 6th day,some slices were fixed,embedded and sectioned.The sections were processed for tyrosine hydroxylase(TH) immunohistochemistry,and then examined under microscope to determine the morphologic index for statistic analysis(n=6).Meanwhile,some slices were taken for Western blot to examine the expression of TH protein in midbrain slices(n=4). Results GDNF group slices showed the morphologic maturity,the density and the diameter of TH positive neurons,as well as the level of TH expression,were all significantly higher than that of the control groups.The survival effect of GDNF on DA neurons was almost abolished when the PI3K pathway was blocked with Wortmannin;while the MAP kinase and ERK kinase(MEK) inhibitor PD 98059 was added to block the MAPK pathway,the diameter of TH positive neurons was decreased significantly.Conclusion The PI3K pathway might mediate the survival effect of GDNF,while the MAPK pathway seems to be involved in the differentiation process.

Objective To observe the proliferation and differentiation of the neural progenitors in the midbrain substantia nigra(SN) of adult rat when dopaminergic neurons(DA neurons) were destroyed. Methods The Parkinson disease model(PD model) was induced in adult SD rats by steriotaxic injection of 6-OHDA into the right striatum,and then assessed by behavioral analysis to screen the qualified models.After varied survival period,the brain of model rats were perfused and fixed by 4% paraformaldehyde,moved the segment of SN,embedded with paraffin and coronally sectioned continuously.The microsections were processed by immunohistochemistry labeling separately the neural progenitors with anti-nestin monoclonal antibody,the dividing cells with anti-PCNA(proliferation cell nuclear antigen),the neuronal precursors with anti-Tuj1(?-tubulin isotype Ⅲ),and DA neurons with anti-TH(tyrosine hydroxylase).The labeled cells were counted under microscope and analyzed statistically.(Results It) was found in the right SN of PD model rats that: 1.Nestin positive(Nestin~+) cells appeared 10d after 6-OHDA injection,became abundant on 14d,declined in number on 17d,and disappeared on 21d.2.Weakly positive PCNA(PCNA~+) cells appeared on 7d.PCNA~+ cells were abundant on 14d,decreased in number from 21d,with only a few positive cells noticed on 28d.3.Tuj1 positive cells appeared in small number on 10d,became abundant on 14d,decreased in number from 17d and dropped nearly to zero on 21d.4.The number of TH positive neurons was significantly less than the normal control(by 24%) on 7d,and became even less as time elapsed.Conclusion When 6-OHDA is injected into the striatum of adult rats to cause degeneration and death of the DA neurons there,there would be a certain period of time in which a number of neural progenitors will be induced to proliferate actively and differentiate toward neuronal cells(except DA neurons).

Objective The image segmentation of low-density gene chips based on genetic algorithm, which can implement the function of region identification, is achieved. Methods After image denoising by wavelet analysis, image segmentation is accomplished by genetic algorithm. Results The method can detect the region of sampling point more precisely. It can also effectively separate the valuable weak signal points and background or noise. Conclusion The method can accomplish the function of image segmentation of low-density gene chips, which can provide relative accurate data information for future image analysis

ObjectiveTo analyze the correlation between the changes of myocardial enzyme level in serum before and after radiotherapy and dose - volume histogram ( DVH ) parameters of the heart.Methods A total of 102 patients with 68 cases of lung cancer and 34 cases of esophageal cancer were recruited.All patients received three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT),with the radiation beams passing through the heart.Aspertate aminotransferase (AST),creatine kinase (CK),creatine kinase isozyme ( CK-MB ),lactate dehydrogenase ( LDH ),α-hydroxybutyrate dehydrogenase (α-HBDH) were determined in the serum before and after radiotherapy.All the enzyme levels before and after radiotherapy were compared through paired t-test.Independent sample t-test was conducted between sub-groups.And the dose-volume histogram (DVH) parameters of the heart were calculated ( the volume percentage of heart receiving dose equal to or exceeding x Gy ( Vx ).The correlation between myocardial enzyme level and DVH parameters was analyzed through Pearson method.Results Serum AST,CK-MB,LDH,α-HBDH levels increased significantly after radiotherapy ( 19.42∶ 27.89,14.72∶19.57,178.80 ∶ 217.57,140.32 ∶ 176.25,t =-3.39 - -6.92,all P=0.000).In Group IMRT,significant correlations between the increase of myocardial enzyme concentration and DVH parameters of the heart are found,AST with V20,V25,V30 of heart ( r=0.302 - 0.431,P =0.039 - 0.003 ),CK with V30of heart (r=0.345,P=0.013),and CK-MB,LDH,α-HBDH with V25,V30(r=0.465 -0.376,P=0.001-0.005).In Group CRT,there are significant correlations between changes of CK-MB,LDH level and V30 of heart (r =0.330,0.274,P=0.014,0.033),α-HBDH and V25,V30,and V35 of heart (r=0.270-0.331,P=0.046-0.014).When the irradiation dose was more than 50 Gy,significant correlations were found between the concentration changes of AST,LDH,α-HBDH and V25,V30 of heart (r=0.256-0.359,P =0.019-0.006),CK-MB and V30(r=0.233,P=0.037).When the irradiation dose was 50 Gy or less,only the concentration change of serum CK has significant correlation with V5 and V45 of heart (r=0.581,0.536,P=0.023,0.043).ConclusionsThere exists certain correlations between changes of myocardial enzymes level before and after radiation and DVH parameters of the heart,which indicates that the DVH parameters of heart are helpful to evaluate the radiation-induced myocardial damage.