Objective To evaluate the radiation dose in both low radiation dose and to conventional radiation dose mode in multislice spiral CT scan for children with embedded teeth,and explore the lowest conditions of exposure in multislice spiral CT scan for children embedded teeth.Methods Eighty cases of children with embedded teeth examined by 16 slices spiral CT were divided into 5 ,25,125 and 250 mAs scanning groups.The scanned pictures of four groups were evaluated by two chief physicians and three associate chief physicians in the radiological department with double blind method.The CTDI_w and DLP in different radiation dose mode were recorded and analyzed with statistics.Results All the four groups scanned pictures in different radiation dose mode could accurately show the structure and the adjacency relation of embedded teeth.Even though the resolution of scanned pictures in S mAs group were inferior to the other three groups on bone trabecula,gingiva and their surrounding soft tissue,it still could meet the requirements of examination.The average DLP in 5 mAs group was only 2% of value in 250 mAs group.Conclusions MSCT in 5 mAs group can not only meet the requirements of examination,but also reduce the radiation dose to patients to the greatest extent.

Objective Comparing the enhancement of contrast-enhanced ultrasound(CEUS) with the intensity of the blood signals of breast masses, and producing the parameter of peak intensity (PI), to determine whether they can reflect the differentiation of the benign breast masses from the malignant ones.Methods Fifty patients with the breast masses (25 benign,25 malignant) were implemented the contrastenhanced ultrasound inspection.The blood signals of the masses could be got before performing the CEUS,then the CEUS was performed.The enhancement of the masses was divided into 4 grades according to the enhancement of breast which was around the mass (no enhancement, low enhancement, equal enhancement,and high enhancement as well).The PIs of all masses and high enhanced massed were calculated by software in machine,then them were compared according to "the groups which had been classified by their maximal diameters.Results Forty-one of 50 cases showed an obvious enhancement using CEUS compared with the routine CDFI.Malignant masses were more obviously than that of benign ones ( P＜0.05).In the 50 cases,the no enhanceed ones( n = 2) and equal enhanced ones( n = 5) were benign,and 1 case of the low enhanced masses( n = 9) was malignant.The high enhanced masses ( n = 34) were malignant or benigh.About the high enhanced masses, there were statistics meanings using the parameter of PI for the masses whose maximal diameters＜2 cm( P＜0.05),and no statistics meanings when their maximal diameters≥2 cm(P＞0.05).Conclusions The CEUS of breast can improve the appreance of the tumor' s blood vessel obviously, especially for malignant masses.The PI of the breast benign masses are different from the malignant ones.Combination of them can help to discriminate benign masses from malignant ones.The parameter of PI is useless for differentially diagnosing the breast masses if their maximal diameters≥2 cm and the blood flow grade Ⅲ before CEUS.

Objective To study possible clinical relationships of myeloperoxidase (MPO) and carotid atherosclerosis in diabetic patients on maintenance hemodialysis(MHD).Methods Levels of plasma MPO and serum elastase (ELT) of diabetic patients on MHD were determined by enzyme-linked immunosorbent assay.Carotid intima media thickness(CIMT),quantity and area of carotid plaque were measured by B-mode ultrasonography.Results Plasma MPO was significantly higher after hemodialysis(HD) than before HD(414.6 (198.9,671.5) μg/L vs 176.4 (69.9,243.3) μg/L,Z =-4.51,P ＜ 0.01).There was no significant difference of serum ELT before and after HD(198.0(146.9,270.5) μg/L vs 230.9(40.2,308.0) μg/L,Z =-1.87,P ＞ 0.05).There was positive correlation between the age and CIMT,quantity or area of carotid plaqueor(correlation coefficient:0.764,0.416 and 0.446 respectively,P ＜ 0.01 or P ＜ 0.05),There was positive correlation between MPO level before HD and age,Levels of serum ELT before HD,or CIMT(correlation coefficient:0.592,0.476 and 0.810 respectively,P ＜ 0.01).There was positive correlation between MPO level after HD and levels of serum ELT after HD (correlation coefficient:0.364,P ＜ 0.05).There was no correlation between the levels of plasma MPO after HD and CIMT,quantity or area of carotid plaqueor (P ＞ 0.05).Conclusion (1) Age and MPO level before HD contribute to carotid atherosclerosis in patients on MHD.(2)There was no relation between higher MPO level after HD and carotid atherosclerosis.

OBJECTIVE: To observe the pathological changes of rat silicosis model at different time points. METHODS: The specific pathogen free SD rats were randomly divided into control group and 7, 15, 21, 30, 45, 60, 75 and 90 day model groups based on their body weight, with 5 rats in each group. Non-exposed endotracheal intubation was performed. Silicosis rat model was established by intratracheal instillation of 250 g/L silica suspension in each rat, and 0.9% sodium chloride solution was perfused into the trachea of rats in the control group. The rats in the control group were sacrificed on the 90 th day after exposure, and the model rats in the other 8 groups were sacrificed on the 7 th, 15 th, 21 st, 30 th, 45 th, 60 th, 75 th and 90 th days after the end of exposure. The gross appearance of the lung tissue of rats was observed. The rat lung tissues were stained with hematoxylin-eosin and Masson staining to observe the pathological changes, and Ashcroft score was evaluated. RESULTS: The gross observation showed that the lungs of rats in the model groups had varying degree of gray changes, hardened texture, and spots and nodules on the surface of the lobes. These changes were aggravated with the increase of time after dust exposure. The results of histopathological examination of the lungs showed that the rats developed acute alveolar inflammation, and a large number of macrophages and neutrophils were seen in the lung tissues in the 7 th and 15 th day model groups. Cellular nodules appeared in the lung tissue, and fibrosis appeared in the center of the nodule in the rats of 21 st, 30 th, and the 45 th day model groups; the silicosis nodules appeared in the lung tissues of rats in the 60 th, 75 th, and 90 th day model groups, and the small nodules gradually merged into larger ones. Simultaneously, with the increase of time after dust exposure, the lung tissue of rats gradually showed severe pulmonary fibrosis. The lung organ coefficient and Aschcroft score of rats increased with the increase of time after dust exposure(P<0.01). CONCLUSION: The rat lung changes after dust exposure. Acute alveolar inflammation occurs on the 7 th to 15 th day after dust exposure; cellular nodules develop on the 21 st to 45 th day after dust exposure; silicosis nodules develop on the 60 th to 90 th day after dust exposure. The severity of lung fibrosis after dust exposure showed a time-effect relationship in rats.

OBJECTIVE: To explore the non-neoplastic hepatic lesions in SD rats at different ages. METHODS: The specificpathogen free SD rats were collected from the blank control groups used in subacute toxicity tests,subchronic toxicity tests and chronic toxicity combined with carcinogenic tests for safety evaluation. At the end of each experiment,i. e. week 10,19,56 and 108(assigned into four groups: 10,19,56 and 108 weeks,each contained 100 rats with each sex),rats were executed. The liver organ coefficient was calculated,the pathological examination was performed,and the non-tumorous lesions in the liver were analyzed. RESULTS: The liver organ coefficients at the age of 19,56,108 weeks were lower than that of 10 weeks(P < 0. 05); those at the age of 56 and 108 weeks were lower than that of 19 weeks(P < 0. 05),and that of 108 weeks was greater than of 56 weeks(P < 0. 05). Among the 10-week-old,19-week-old,56-week-old and 108-week-old groups,the types of non-neoplastic hepatic lesions detected in the female rats were 6,6,13 and 15 respectively,meanwhile those in the male rats were 6,6,13 and 15 respectively. Both male and female rats,the incidences of hepatocyte fatty degeneration,edema and hepatic infiltration of inflammatory cells were significantly increased with the increase of age in each group(P < 0. 05). The incidences of intrahepatic bile duct proliferation and intrahepatic bile duct fibrosis in rats at the age of 56 and 108 weeks were higher than those at the age of 10 and 19 weeks(P < 0. 008).Moreover,the frequency of hepatic sinus expansion lesions in rats at the age of 108 weeks was higher than those of 19 weeks(P < 0. 008). CONCLUSION: Spontaneous non-neoplastic lesions in the liver of SD rats were common,primarily demonstrated as hepatocyte fatty degeneration,edema and infiltration of inflammatory cells. The incidences of lesions increased with the increase of age.

OBJECTIVE: To explore the spontaneous non-tumor lesion of kidney and its correlation with different age and sex in SD rats. METHODS: Eight hundred specific pathogen free SD rats were collected from the blank control groups used in subacute toxicity tests,subchronic toxicity tests and 1 or 2 years of chronic toxicity combined with carcinogenic tests. Rats were randomly divided into 4 groups with 10,19,56 or 108 weeks of experimental periods. Each group consisted of 100 female and 100 male rats. The renal tissues were collected at the end of each experiment,and the renal organ coefficients were calculated. The pathological non-tumor changes of the kidneys were analyzed. RESULTS: The renal organ coefficients in female rats at the age of 56 and 108 weeks were both lower than that of 10 and 19 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 56 weeks was lower than that of 10 and 19 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 108 weeks was higher than that of 56 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 108 weeks was higher than that of female rats of 108 weeks( P < 0. 008). The incidence of renal tubular calcium salt deposition,interstitial inflammatory cell infiltration and renal tubular dilatation in the female rats at the age of 108 weeks were higher than those in the male rats at the age of 108 weeks( P < 0. 05). The chronic progressive nephropathy incidence of female rats at the age of 108 weeks was lower than that of male rats aged 108 weeks( P < 0. 01).The renal tubular calcium salt deposition incidence of female rats aged 56 weeks was higher than that of male rats aged 56weeks( P < 0. 01). CONCLUSION: The spontaneous non-tumor lesions in the kidney of SD rats were common. The incidence of some lesions was different in the same age group with different sex.