BACKGROUND: Neuropeptide Y (NPY) neurons are extensively located in various brain regions such as cerebral cortex, caudate-putamen nucleus, syslimbic system, thalamus and brain stem. They are also involved in various brain activities such as motor learning, motor memory and motor integration. Considering the fact that cerebellum can reorganize through motor learning, we tried to identify the morphology and distribution of NPY neurons in rat's cerebellar cortex to obtain the morphologic knowledge that is related to its cerebellar-cortex-based motor learning.OBJECTIVE: To investigate the morphology and distribution of NPY -immunoreactive neurons in rat's cerebellar cortex, and discuss the relationship between NPY neurons and cerebellum motor learning and motor memory.DESIGN: A single-sample-study based on animal samples.SETTING: Anatomy Department, Pathophysiology Department and Morphology Center in Xinxiang Medical College.MATERIALS: From July to December 2001, the experiment was performed at the Morphology Center in Xinxiang Medical College. Ten Sprague-Dawley (SD) rats, clean grade, regardless of their gender and weighing 100-200 g,were selected.METHODS: After intraperitoneal injection anesthesia and ascending aorta infusion fixation, the cerebellum was taken out by craniosurgery. The cerebellum was immersed in the same fixative fluid for duration of 48 hours, and then was embedded in paraffin. The next step was to make continuous sagittal sections. NPY neurons were identified by SP immunohistochemical staining, using rats cerebral section as the positive control. In the negative control, the first antibody replaced by Bovine Calf Serum(BCS), and the second antibody replaced by 0.01 mol/L PBS. Sequentially the light-microscopic observation and micrography were recorded.MAIN OUTCOME MEASUREMENTS: The Morphology and distribution of NPY neurons in rat's cerebellar cortex were taken as main outcome measurements.RESULTS: NPY-immunoreactive neurons were distributed in the Purkinje layer of the cerebellum. They had pear-like or spherical shapes, clear and unstained nucleus, unstained axons and dendrites, and their axons stretching out into the granular layer while the reticular dendrites elongated into the molecular layer. NPY-immunoreactive fibers, instead of neurons, were found in the molecular layer and granular layer.CONCLUSION: NPY-immunoreactive neurons in the Purkinje layer of the cerebellum may be involved in motor learning, motor memory, visceral activity and higher motor integration.

BACKGROUND:Studies have found that a variety of biological materials can be used for preparing corneal stroma scaffolds that have good biocompatibility, but research on preparation and biocompatibility of the acel ular porcine corneal stroma scaffold is little. OBJECTIVE:To explore the preparation and biocompatibility of the acel ular porcine corneal stroma scaffold. METHODS:Acel ular porcine corneal stroma scaffold and its extract were prepared. Wel-grown human corneal stromal cel s were selected and cultured in the extract of acel ular porcine corneal stroma scaffold (experimental group) or in the complete medium (control group), respectively. After 1, 2 and 3 days of culture, the proliferation ability of human corneal stromal cel s was detected by MTT assay. In the meanwhile, human corneal cel s were directly seeded onto the acel ular porcine corneal stroma scaffold, and then the cel growth on the scaffold was detected using immunochemical method. RESULTS AND CONCLUSION:The number of human corneal stromal cel s was in a rise with time in the two groups, and absorbance values had no significant difference between two groups at different time points of culture. Human corneal stromal cel s grew wel on the scaffold, and were positive for cel integrinβ1, vimentin, aldehyde dehydrogenase 3A1, as wel as CD34, CDK2 and K-Ras. These results show that the acel ular porcine corneal stroma scaffold has no cytotoxicity, and has good biocompatibility.

Objective To investigate whether hepatocyte growth factor ( HGF ) and insulin-like growth factor (IGF1) induce cardiac stem cells (CSCs) to proliferate and directly differentiate into cardiomyocytes in vitro.Methods The myocardial tissues were dissected for primary culture of CSCs with the method of explants .The expressions of c-kit and CD34 were examined with immunofluorescence .Primary cells were purified with c-kit by flow cytometry.CFDA SE fluorescent probe was used to detect the proliferation of c-kit+CSCs.C-kit +CSCs were divided into two groups , and cardiac stem cells group and co-cultured with cardiomyocytes group , both group were cultured with HGF and IGF 1.An inverted microscope was used to observe changes in cell number and morphology in different periods .Living cells workstation was used to observe CFDA SE fluorescence intensity , to acquire images and do statistical analysis .Immunofluorescence technique was used to detect the expression of Nkx 2.5 and cardiac troponin T .Results In cardiac stem cells group ,CSCs had no obvious changes in cell number .In co-cultured with cardiomyocytes group , CSCs proliferated and had changes in morphology .Nkx2.5 and cTnT were positively expressed . Several CSCs differentiated into beating cardiomyocytes . Conclusion In co-cultured with cardiomyocytes condition , HGF and IGF1 may promote CSCs to proliferate and differentiate into beating cardiomyocytes .

BACKGROUND: Angiotensin Ⅱ (Ang Ⅱ) can induce cardiac hypertrophy and platelet-derived growth factor(PDGF) also stimulates cardiac hypertrophy. Is AngⅡ responsible for the pathogenesis of cardiac hypertrophy by inducing PDGF receptor expression?OBJECTIVE: To investigate the effect of mitogen activated protein kinase (MAPK) on the role of cardiac hypertrophy induced by Ang Ⅱ in cardiac myocytes so as to provide theoretical basis for clinical prevention and cure of cardiac hypertrophy.DESIGN: Controlled experimental study taking cardiac myocytes of cultured neonatal rats as subjects.SETTING: Department of pathophysiology in a university.MATERIALS: The experiment was completed in the Department of Pathophysiology, Medical College of Peking University. A total of 80 Wistar rats of either gender, aged 1 - 3 days, were provided by the Animal Center of Medical College, Peking University. Their hearts were removed for myocyte culture in the Cell Culture Laboratory.INTERVENTIONS: The cultured neonatal rat cardiac myocytes treated with 10-7mol/L Ang Ⅱ were Ang Ⅱ group, and those preincubated with 10-5mol/L PD98059(an antagonist of MAPK) for 30 minutes and then treated with Ang Ⅱ were PD98059 group. Cardiac myocytes of normal neonatal rats were as control group. The expression of PDGF-β was detected by western blot at 24 hours.MAIN OUTCOME MEASURES: Content of PDGF-β receptor in neonatal rat cardiac myocytes.RESULTS: The expression of PDGF-β receptor induced by Ang Ⅱ at neonatal rat cardiac myocytes markedly increased at 24 hours (432.41 ± 54.08) compared with that of control group(197.65 ± 44. 10) ( q = 6.77, P< 0.01 ). PDGF-β receptor expression of PD98059 group(317.2 ± 21.12) decreased compared with that of Ang Ⅱ group(q = 3.91, P < 0.05) .However, the expression did not return to the level of control group, and there was significant difference between PD98059 group and control group( q= 3.85, P <0.05).CONCLUSION: The results indicate that angiotensin Ⅱ promotes cardiac hypertrophy through inducing expression of PDGF receptor, in which mitogen activated protein kinase participates in. Maybe it is another important mechanism for Ang Ⅱ -induced cardiac hypertrophy. The results can provide experimental data for the primary and secondary prevention in heart rehabilitation.

AIM: To investigate the crosstalk between angiotensin Ⅱ (AngⅡ)-mediated and platelet-derived growth factor (PDGF)-mediated signal transduction in vascular smooth muscle proliferation.METHODS: A model of renal hypertension was made by two kidney/one-clip operation. Level of PDGF receptor β subunit of aorta was measured by Western Blot analysis. The effect of Ang Ⅱ on PDGF receptor β subunit expression was investigated in culture rat aortic vascular smooth muscle cells (VSMC).RESULTS: Systolic blood pressure obviously increased at 8th week after operation, whereas the level of PDGF receptor β subunit of aorta significantly increased by 126.6% (P＜0.05) in 2K1C rats compared with control group. The expression of PDGF receptor β subunit in cultured VSMC stimulated by AngⅡ was higher than that of control by 192.74%(P＜0.01). The effect of AngⅡ was inhibited remarkably by pretreated with losartan, a kind of specific AngⅡ receptor 1 (AT1) subtype antagonist and U73122, a kind of phospholipase C inhibitor. The effect was partly blocked by PD98059, which inhibit the activity of mitogen-activated, ERK-activating kinase (MEK).CONCLUSION: AngⅡ-induced PDGF receptor β subunit expression is regulated by the AT1 and its downstream signal molecule-PLC and ERK, might participate in the intracellular signal transduction pathway.

AIM: To investigate the crosstalk between angiotensin Ⅱ (AngⅡ)-mediated and platelet-derived growth factor (PDGF)-mediated signal transduction in vascular smooth muscle proliferation.METHODS: A model of renal hypertension was made by two kidney/one-clip operation. Level of PDGF receptor ? subunit of aorta was measured by Western Blot analysis. The effect of Ang Ⅱ on PDGF receptor ? subunit expression was investigated in culture rat aortic vascular smooth muscle cells (VSMC).RESULTS: Systolic blood pressure obviously increased at 8th week after operation, whereas the level of PDGF receptor ? subunit of aorta significantly increased by 126.6% ( P

AIM: To investigate the role of G?q/11-mediated signal transduction pathway in cardiac hypertrophy induced by angiotensin II (AngII). METHODS: Renal hypertension was performed by placing a sliver clip around the left renal artery(2K1C). Hemodynamic parameters, the ratio of left ventricular weight to body weight, the AngII contents and the activities of phospholipase C (PLC) in myocardium were measured at 1st, 2nd, 4th and 8th week after operation, respectively. The levels of G?q/11 were assayed by Western blot analysis. -leucine incorporation and levels of G?q/11 were measured in cultured neonatal rats ventricular myocyte after AngII stimulation. RESULTS: In 2K1C group, blood pressure and the ratio of left ventricle of heart to body weight were significantly increased compared with sham group between 2nd to 8th week. AngII content increased from 1st to 8th week after operation. Compared with the sham group, levels of G?q/11 in 2K1C group increased by 25.0% and 35.8% at 4th and 8th week( P

Objective:To investigate the levels of dose to eye lens of interventional radiology workers in China from 2017 to 2019.Methods:The monitoring data on eye lens doses to the interventional radiology workers in 28 provinces across the country were collected from National Individual Dose Registry. Monitoring was carried out using TLDs on their left eyes and evaluated in terms of the personal dose equivalent Hp(3). By using Mann-Whitney U test and Kruskal-Wallis H test, statistical analyses were made of the average annual lens doses to interventional radiology workers in the hospitals of different types at different levels for different years. Results:From 2017 to 2019, the data on eye lens doses to 2 981 interventional radiology workers were collected, with doses ranging from below the minimum detectable level (MDL) to 64.48 mSv, the average annual eye dose of 1.38 mSv, and the annual doses incurred by 0.97% monitored workers exceeding the recently recommended dose limits, 20 mSv per year. The average annual lens dose monitored in general hospitals and in cancer hospitals were 1.33 and 1.77 mSv, respectively, without statistically significant difference ( P>0.05). The average annual lens dose in tertiary hospitals was 1.39 mSv, significantly higher than that in secondary hospitals where the value was 1.16 mSv ( Z=2.894, P<0.05). Conclusions:The estimated annual eye lens doses to the interventional radiology workers during 2017-2019 were in accordance with the current national standard GB 18871-2002, but with a few exceptions exceeding the current international standards. This means that there exists, to a certain degree, a potential risk for the eye lens in this work category to exceed the international limits. It is suggested to continue in effort to enhance the monitoring of eye lens dose for these workers and to increase risk awareness, and take effective protective measures so as to lower the level of eye lens doses.

Objective To estimate the radiation dose and cancer risk of thyroid for children who underwent head CT or chest CT scans.Methods The parameters used in the CT scans were accessed from the DICOM files through PACS used DCMTK software, then the thyroid radiation dose was estimated with the CT-Expo(C) software and the cancer risk induced by CT scan was projected based on BEIR Ⅱ model combined with the Chinese cancer incidence and lifetime table in 2008.Results CT parameters used for different ages were roughly the same, the thyroid equivalent dose for head CT ranged from 1.2-2.0 mGy, the highest thyroid cancer risk occurs for newborn girls, about 9.6/100 thousand population;while for chest CT the thyroid equivalent dose ranged from 8.1 to 38.0 mGy, the highest thyroid cancer risk was also for newborn girls, about 244.7/100 thousand population.The radiation dose and cancer risk for thyroid decreased with the increased age.Conclusions The radiation dose for thyroid from chest CT was relatively higher than head CT, especially for newborn babies;therefore more protection should be given to the thyroid and other radio-sensitive organs during CT scanning.

Objective To ascertain the frequency distribution of CT examinations in children.Method A wide range of information was collected through the radiology information system (RIS),including ID,sex,birth date,examination time,the examined part of body and other relevant ones related to children who underwent CT examinations between Jan 1,2012 and Dec 31,2012.The SAS software was used for data processing and statistical analysis.Results A total of 1 542 children underwent 1 670 examinations,of which 67％ were male.Head CT examination was the most frequent,accounting for 71.9％ of all CT examinations,and followed by the abdomen/pelvis examinations.The number of examinations of children undergoing the repetitive examination accounted for 6.4％; 51.7％ of the examinations was for trauma.The positive rate of CT examination was 51％,dependent upon the age and examined body parts to some extent.The younger patients had lower positive rate,and the positive rate of head CT examination was lower than those in other parts.Conclusions To reduce the possible cancer risk to be induced by the ionizing radiation from CT,justification of CT examination should be considered for children.