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Objectives To explore the dose-response relationship between low-dose ionizing radiation and thyroid hormone levels of radiation medical workers and provide theoretical basis for occupational health protection to this population. Methods Using a prospective cohort study design, we collected health examination reports on employees that worked on jobs with occupational exposure to radiation at hospital with individually dose monitoring data for 1 237 workers. The effective cumulative radiation dose was divided into three groups: 0～2.586 mSv, 2.586～3.757 mSv, 3.758～31.272 mSv by the interquartile range. The low-dose group was used as a reference to compare the changes in thyroid hormones of medical workers in different cumulative radiation dose groups. The generalized linear models and restricted cubic spline model were used to examine the association and dose-response relationship between the cumulative effective dose and changing thyroid hormones. Results There were statistically significant differences in changing thyroxine (T4) and Free triiodothyronine (FT3) levels among three different dose groups of 1237 subjects (P < 0.05). The results of generalized linear models analysis revealed that 2.586～3.757 mSv was a significant risk factors of changing T4, with β of 3.514 (95% confidence interval [95% CI]: 0.900～6.128) after adjusting for gender, age, working duration, occupation, medical level and smoking, while the association with changing FT3 was not observed (P > 0.05). The restrictive cubic spline (RCS) model analysis indicated a non-linear dose-response correlation between cumulative radiation dose with changing T4 (P = 0.023). Conclusion Long-term exposure to low-dose ionizing radiation could induce the thyroid damage among medical occupational population. And there is a dose-response relationship between cumulative radiation dose and changing thyroxine.
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Activating metabolite glutamate receptor 8 (mGluR8) has anti-hyperpathia effect in central nervous system, however, studies of effects in gastrointestinal tract are rare. Visceral hypersensitivity is one of the pathogenesis factors of irritable bowel syndrome (IBS). Aims: To investigate the effect and potential mechanism of activating mGluR8 on visceral hypersensitivity in neonatal maternally separated (NMS) rats. Methods: Twenty-four male newborn SD rats were randomly divided into normal control (NC) group, NMS group and mGluR8 agonist (S)-3, 4-DCPG group (3, 10 mg/kg). Newborn rats were subjected to 3 hours daily maternal separation on postnatal day 2-14 to establish the NMS model; in (S)-3, 4-DCPG group, (S)-3, 4-DCPG (3 or 10 mg/kg) were administered 1 hour prior to the visceral sensitivity test in NMS rats. Abdominal withdrawal reflex (AWR) score and abdominal electromyography (EMG) activity were used to measure visceral sensitivity. mGluR8 mRNA and protein expressions in colon mucosa were measured by RT-PCR and Western blotting, respectively; TNF-α, IL-1β and IL-6 mRNA expressions in colon mucosa were measured by RT-PCR. The protein expression of myeloperoxidase (MPO) was measured by immunohistochemistry. Results: AWR score and EMG activity in NMS group were significantly higher than those in NC group under different colorectal distension (CRD) pressure. AWR score and EMG activity were significantly decreased in (S)-3, 4-DCPG group. mGluR8 mRNA and protein expressions in NMS group were significantly higher than those in NC group (P<0.05). Compared with NMS group, TNF-α mRNA expression was significantly decreased in 3 mg/kg (S)-3, 4-DCPG group (P<0.05), and MPO protein expression was significantly decreased in 10 mg/kg (S)-3, 4-DCPG group (P<0.05). Conclusions: Activating mGluR8 attenuates visceral hypersensitivity in NMS rats, the mechanism may be related to decrease of pro-inflammatory cytokine TNF-α.
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Objective To investigate the therapeutic effect of silencing fibrinogen-like protein 2 (FGL2) gene on acute necrotic pancreatitis (ANP) mice.Methods Eighteen C57/BL mice were randomly divided into SO (sham operation) group,ANP group and Ad-FGL2-siRNA group carrying FGL2 siRNA adenovirus,with 6 in each group.Sodium taurocholate was retrogradely injected into the biliopancreatic ducts of the mice to induce ANP mice model.The mice in Ad-FGL2-siRNA group were injected intravenously in the tail vein with Ad-FGL2-siRNA befor the model establishment.The mice were sacrificed 6 h later,and then the pancreatic tissue and blood were collected.TNF-α and IL-1β expression were measured with ELISA,pancreatic tissue was examined with routine pathological examination,FGL2 mRNA and protein expression were measured with reverse transcription-PCR,western blotting and immunohistochemical staining,and cell apoptosis was assessed by TUNEL method.Results The pathological score of the pancreatic tissue in SO group,ANP group and Ad-FGL2-miRNA group was(1.33 ±0.21),(9.17 ±0.98) and (6.26 ±0.52),respectively.The serum TNF-α level in SO group,ANP group and Ad-FGL2-miRNA group was(63.8 ± 4.2),(240.4 ± 18.6)and(123.0 ± 10.3)ng/L,respectively.The serum IL-1β level was (43.6 ±4.4),(186.6 ± 18.7)and (92 ±10.9)ng/L.The mRNA expressions of FGL2 was 1.20 ±0.22,4.40 ± 1.21 and 2.15 ± 0.56.The protein expressions of FGL2 was 0.33 ± 0.08,1.23 ± 0.24 and 0.68 ± 0.09.The rate of FGL2 positive cells was (2.56 ± 0.31) ％,(15.10 ± 3.23) ％ and (8.68 ± 1.81) ％.The number of apoptotic cells was (4.51 ±1.21),(35.81 ± 4.11) and (11.79 ± 3.02) / × 200HPF,which in the ANP group was higher than that in SO group,and in the Ad-FGL2-siRNA group was significantly lower than that in ANP group and higher than that in SO group.All the differences were statistically significant (all P values ＜ 0.05),except that on the FGL2 mRNA expression between Ad-FGL2-siRNA group and SO group.Conclusions Silencing FGL2 gene may alleviate pancreatic injury in ANP by reducing the release of inflammatory factors and inhibiting cell apoptosis.
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Objective To explore the carry rate and antimicrobial resistance of Staphylococcus aureus (S.aureus) among primary school students.Methods Nasal swab samples were collected from healthy primary school students in Guangzhou.Antibiotic susceptibility testing was applied to test S.aureus strains.Results The overall carriage rate of S.aureus,methicillin-resistant S.aureus (MRSA) and multi-drug-resistant S.aureus (MDRSA) among 1 012 primary school students were 40.1％,1.2％ and 4.0％,respectively.Most S.aureus isolates were resistant to penicillin,erythromycin and clindamycin.The dominant multidrug resistance patterns of MDRSA isolates were resistant to erythromycin-clindamycin-tetracycline and erythromycin-clindamycin-cefoxitin.Multifactor dimensionality reduction analysis showed that the rate of resistance to cefoxitin,tetracycline and chloromycetin among MDRSA was 104.39 times as much as that of nonMDRSA.Conclusions The carriage rate of S.aureus in healthy primary school students from Guangzhou was high and these isolates showed multidrug resistance.These data provide basis for guiding the rational use of antibiotics.
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Background:Endoscopic ultrasonography( EUS)is the first choice for examining submucosal protuberant lesions in the gastrointestinal tract,however,it is very difficult to differentiate gastric stromal tumor from gastric leiomyoma. Photoshop software now is tried to differentiate some easily misdiagnosed diseases. Aims:To investigate the value of Photoshop software in differentiating EUS image of gastric stromal tumor from gastric leiomyoma. Methods:EUS image of 118 cases of gastric stromal tumor and 42 cases of gastric leiomyoma confirmed by pathological and immunohistochemical examination were collected,mean gray value( intensity of echo)and gray value standard deviation( uniformity of echo)of EUS image of lesion were determined by Photoshop software,and the differentiation value was analyzed. Results:The mean gray value of EUS image of gastric stromal tumor was significantly higher than that of gastric leiomyoma(71. 94 vs. 48. 99,P<0. 01). The gray value standard deviation of EUS image of gastric stromal tumor was significantly higher than that of gastric leiomyoma(16. 63 vs. 9. 80,P<0. 01). Conclusions:Under EUS,gastric stromal tumor exhibits higher intensity of echo and less uniformity of echo than gastric leiomyoma. EUS combined with Photoshop software is helpful for differentiating gastric stromal tumor from gastric leiomyoma by analyzing mean gray value and gray value standard deviation of the lesion.
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Objective To explore the advantages of the technique of bile duct mini-incision (BDM) for stone removal in choledocholithiasis,and to further clarify the indications for T tube insertion during surgery.Methods 85 BDM operations were performed.The use of MRCP (Magnetic resonance cholangiopancreatography),Advantage Workstation AW4.2 0.7sdc software,choledochoscopic imaging system and illustrations were used to study the applicability of the BDM technique in stone removal.Results The width of common bile duct (CBD) was usually over 8 mm in the patients with choledocholithiasis,and the width was related to the number and size of the stones.In the patients who had a CBD width of over 11mm (n 16),the MRCP stone imaging area (MRCP-SIA) was significantly larger when compared with that [(148±67)mm2 vs.(47±31)mm2,P＜0.05] in the patients (n=14) with CBD width of less than 11 mm.T tube insertion for secondary choledochoscopic examination should be performed when the stones were non drifting,multiple,and closely related to the lower part of CBD indicating difficulty in complete stone removal.Conclusions Unnecessary T tube insertion could be avoided by the BDM technique for stone removal which was especially suitable for patients with early diagnosis of choledocholithiasis.T tube insertion should only be performed in patients with difficulty in complete stone removal and in other complicated situations.
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Objective To evaluate the effect of spectral CT monochromatic imaging on the detection of hepatic tumors. Methods Forty-two patients with hepatic tumors (14 patients with hepatocellular carcinoma, 12 patients with metastatic tumor, 16 patients with hemangioma) underwent CT spectral imaging. During arterial phase, portal phase and venous phase, 140 kVp polychromatic images and 70 keV monochromatic images were obtained. Paired-sample t tests were used to compare the image quality score,liver noise and tumor-to-liver contrast-to-noise ratio (CNR) between the two image data sets. The detection rates of various tumors during each phase were compared. Results The image quality scores of various tumors during three phases were (4. 30 ± 0. 25) and (3.63 ± 0. 22) averagely for the 70 keV and 140 kVp images. The liver noises were (8. 82 ± 0. 82) and ( 10. 66 ± 1.10) , and the CNRs were 5.39 and 3. 89,respectively. The image quality score, the liver noise and the CNR of 70 keV images were significantly greater than those of 140 kVp images (P ＜0. 05 ). The detection rates of various tumors during each phase were higher with 70 keV images (78％-100％) than with 140 kVp images (65％-96％), except the hepatic metastatic tumors and the hepatic hemangiomas during the arterial phase. The detection rate was more increased for the small lesions less than 1 cm (57％-100％ vs. 14％-91％ ). Conclusion By substantially improving the image quality and increasing the tumor-to-liver conspicuity, the 70 keV monochromatic imaging of spectral CT improves the detection of hepatic tumors and is more sensitive for the detection of small lesions.
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Objective To investigate magnetic resonance imaging(MRI) characteristics of autoimmune pancreatitis(AIP) in middle-aged and elderly patients. Methods MRI were performed in 17 middle-aged and elderly patients with AlP proved histopathologically or clinically. All clinical and MRI data were reviewed. Results Of 17 cases, MRI showed diffuse enlargement of the pancreas in 13 cases, and focal lesions in 4 cases. Swelled pancreas was hypointense on T1-weighted images, mildly hyperintense on T2-weighted images, decreased enhancement on artery phase of dynamic imaging, and moderate enhancement on delayed phase images. Capsule-like enhanced rim was found around swelled pancreas in 13 patients. Stricture of distal common bile duct was present in 15 patients, and diffuse irregular narrowing of the main pancreatic duct was showed in 5 cases. The mean apparent diffusion coefficient(ADC) value of AIP was 1.64×10~(-3) mm~2/s in 13 cases. Conclusions AIP occurs more often in middle-aged and elderly people. AIP shows some characterized MRI findings including swelled pancreas looking like banana or sausage, delayed enhanced capsule-like rim around the lesion and diffuse irregular narrowing of pancreatic duct. MRI will play an important role not only in the diagnosis of AIP, but also in evaluating curative effect of AIP.
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ncreatic enlargement, MRI is comparable to CT.
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This article discusses how to improve teaching quality of health statistics from four main aspects: paying attention to training statistical thinking,paying attention to understanding basic concepts and methods,paying attention to modernistic teaching instrumentality,and paying attention to intercommunion between teachers and students.Practice indicates it facilitates impoving teaching quality.