Infection of the human central nervous system by Balamuthia mandrillaris is very rare and is mostly observed in people engaged in agriculture-related occupations，with a high fatality rate. This article reports a case of Balamuthia mandrillaris amoebic encephalitis in southern Hunan, China，which was finally confirmed by metagenomic next-generation sequencing of cerebrospinal fluid. The patient gave up treatment and was discharged from the hospital without achieving remission after antiviral，anti-fungal，and anti-parasitic therapies，cranial pressure reduction，and symptomatic supportive treatment，and the patient died at 5 months after confirmed diagnosis. This article reviews related literature to improve the understanding of this disease among clinicians，and it is necessary to consider the possibility of this disease in case of encephalitis of unknown etiology. Early diagnosis and timely comprehensive anti-infective therapy should be performed to improve the success rate of treatment.
Balamuthia mandrillaris

Objective To investigate the radioactivity levels of gross α and gross β in foods around Zhangzhou nuclear power plant, China before operation. Methods Forty-nine samples from 33 kinds of foods in 5 categories of daily food around Zhangzhou nuclear power plant were collected, pretreated, dried, and ashed. The radioactivity levels of gross α and gross β were measured by the low-background α and β measuring instrument. The atomic absorption technique was employed to measure the level of potassium (K), and the radioactivity level of gross β (subtracting ⁴⁰K) was calculated with K concentrations in different foods consulted from the nutritional dietary system. Results The radioactivity levels of gross α in vegetables and fruits, grain, poultry and livestock, aquatic products, and tea around Zhangzhou nuclear power plant were < minimum detectable level (MDL)-7.97, < MDL-6.82, < MDL, < MDL-20.76, and 11.90-23.08 Bq/kg, respectively; the radioactivity levels of gross β were 34.56-122.81, 13.05-188.96, 56.00-108.34, 17.86-169.01, and 123.74-171.63 Bq/kg, respectively; the radioactivity levels of gross β (subtracting ⁴⁰K) were not detected (ND)-14.27, ND-27.86, ND-48.72, ND-45.85, and 6.69-13.79 Bq/kg, respectively. Conclusion The radioactivity of gross α and gross β in foods around Zhangzhou nuclear power plant before operation is basically at the same level as that in other areas of China.

Objective:To ascertain the activity concentration of gross α and β in foods around Fuqing nuclear power plant (NPP) site.Methods:Totally 167 food samples of 25 kinds within 6 categories were collected from the surveillance areas and control areas around Fuqing NPP site. The total radioactivity was analyzed using the food samples. Paired rank sum test was used to determine the influence of the operation of Fuqing NPP on the total radioactivity in foods in surrounding areas. The multiple local rank sum test was used to assess the difference in total radioactivity in different types of foods.Results:The average gross α in poultry meat, vegetables, crops, aquatic products, milk and tea was 0.65, 1.96, 1.41, 3.80, 1.33, 7.67 Bq/kg in surveillance areas and 0.56, 3.24, 2.04, 3.70, 2.24, 9.05 Bq/kg in reference areas, respectively, around Fuqing NPP site. The average gross β (subtracting 40K) in poultry meat, vegetables, crops, aquatic products, milk and tea was 7.0, 10.5, 6.1, 23.5, 24.7, 8.6 Bq/kg in surveillance areas and 7.4, 8.3, 14.5, 22.1, 21.3, 11.0 Bq/kg in reference areas, respectively, around Fuqing NPP site. The Wilcoxon paired rank test showed that there was no significant difference in the gross α and β in foods between surveillance and reference areas around Fuqing NPP site ( P>0.05). The Kruskal-Wallis H test showed that the radioactivity of gross α and β in different foods was statistically significant ( χ2=23.325, 13.918, P<0.05). Conclusions:The increase was not found in total radioactivity in the surrounding foods since the operation of Fuqing NPP in 2015.

Objective:To investigate the differences in applicability of both the portable high-purity germanium (HPGe) γ spectrometer and the portable lanthanum bromide (LaBr) γ spectrometer for measuring thyroid 131I activity and internal exposure monitoring for radiation workers. Method:Both DETECTIVE-DX100-KT portable HPGe γ spectrometer and InSpector 1000 portable LaBr γ spectrometer were used to measure the 131I content in thyroid of radiation workers for comparison of the measuring result, minimum detectable activity (MDA) and corresponding annual committed effective doses between two types of spectrometers. Results:The detection rate of 131I in thyroid of radiation workers was 67.7% for HPGe γ spectrometer and 26.2% for LaBr γ spectrometer, respectively. The MDA was 12.26-14.74 Bq (measuring time: 3-5 min) for HPGe γ spectrometer and 56.56-80.37 Bq for LaBr γ spectrometer (measuring time: 2-4 min). The annual committed effective dose corresponding to MDA was 0.07-0.08 mSv (3-5 min) for HPGe and 0.31-0.45 mSv (2-4 min) for LaBr, respectively, in the case of using chronic continuous intake mode and 7 d monitoring period. Conclusions:The minimum detectable activity (MDA) of the two types of portable spectrometers could meet the requirements specified in GBZ 129-2016 Specifications for individual monitoring of occupational internal exposure for thyroid monitoring equipment. The two types of spectrometers could be used for routine monitoring of internal contamination. The difference between the monitoring result of LaBr γ and HPGe γ spectrometers might be due to such factors as large uncertainty in short measuring time and low activity concentrations, incomplete identical of distance between probe and neck, probe angle setting, different response of equipment to the environment, background deduction method.

Objective:To analyze the clinical features of autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A).Methods:A retrospective analysis was performed. Data of 14 patients with GFAP-A, admitted to Department of Neurology, Chenzhou First People's Hospital from December 1, 2020 to May 1, 2022, were collected.Results:The mean age of these 14 patients was (46±31) years, and the male patients were more than female ones (10∶4). All patients had acute onset, and the main clinical symptoms included dizziness and headache ( n=10), fever ( n=8), urination and defecation function disturbance ( n=5), mental and behavioral abnormality ( n=4), limb weakness ( n=4), and tremor ( n=3). No tumors were found; 8 patients were with hyponatremia. Twelve patients responded well to hormone and/or immunosuppressive therapy; 2 patients refused corticosteroid and/or immunosuppressive therapy for personal reasons, and their condition did not improve at discharge. Conclusion:In these GFAP-A patients, relatively heterogeneous clinical manifestations are noted; many are complicated with hyponatremia, and some have clinical manifestations similar to nervous system infectious diseases; the prognosis is good after immunotherapy.

Objective:To explore the assessment methodology for internal dose to workers exposed to 131I radionuclide. Methods:Workers were chosen in a 131I radiopharmaceutial manufacturer and a nuclear medicine department in a hospital using 131I to treat hyperthyroidism and thyroid cancer. A portable high purity germanium (HPGe) gamma spectrometer was used to measure the content of 131I in the thyroid for 4 consecutive times in a period of 7 d. The internal dose was estimated combining with the work rotation mode for workers dealing with 131I. Results:When the monitoring month was used as a typical month to estimate the internal dose, the annual committed effective dose was 0.09-1.93 mSv for the production staff engaged in the repackaging of 131I radiopharmaceuticals in the surveyed enterprise, and 0.06-0.58 mSv for the nuclear medicine staff in the surveyed hospital. After adjusting the monitoring result of the current monitoring period based on the rotation mode, the annual committed effective dose was estimated to be 0.06-1.22 mSv for radiopharmaceutical production workers and 0.03-0.15 mSv for nuclear medicine workers, respectively. Conclusions:In the assessment of internal dose to radiation workers exposed to 131I, using a single time measurement result to estimate the annual dose would lead to a larger error. In the case of continuous monitoring, the result of subsequent monitoring periods should be corrected according to the result of previous monitoring periods. In order to accurately estimate the internal dose of workers exposed to 131I, it is necessary to take full account of the 131I exposure pattern, time and frequency and the internal contamination route. For workers who may be exposed to 131I with potential internal dose greater than 1 mSv/year, a 14 day-routine monitoring period was appropriate.

Objective To investigation the radioactivity level of ⁹⁰Sr in tea leaves within and outside 30 km range of Ningde nuclear power plant. Methods The tea leaves within and outside the 30 km range of Ningde Nuclear Power Plant were collected from 2013 to 2018. According to“Radiochemical analysis of strontium-90 in water and ash of biological samples” (HJ 815—2016), the separation and analysis of ⁹⁰Sr-⁹⁰Y were carried outusing the method of di (2-ethylhexyl) phosphate (HDEHP) chromatography. Results During the period of 2013-2018, the radioactivity concentrations of ⁹⁰Sr in the tea leaves within the range of 30 km around the Ningde nuclear power plant were 0.486～13.29 Bq/kg and that of ⁹⁰Sr in the tea leaves outside the range of 30 km around the nuclear power station were 1.021～17.19 Bq/kg. Conclusion During the six years of operation in Ningde Nuclear Power Plant, there was no increase in the radioactivity level of ⁹⁰Sr in the tea leaves around the nuclear power plant.

Three prime repair exonuclease 1 (TREX1), also known as DNase IE, is a major 3'-5' restriction exonuclease in most of tissues and cell types of the mammals. The exonuclease activity of TREX1 plays an essential role in maintaining the immune tolerance of the innate immune system, which avoids the excessive activation of the innate immune system and massive production of auto-antibodies induced by the abnormal accumulation of cytosolic DNA. cGAS-STING signaling was identified as an important innate immune response to pathogens and maintained cellular environmental homeostasis. TREX1 prevents occasional leakage of nuclear DNA into the cytosol, which activates cGAS and triggers the downstream type I interferons cascade. Mutations of human TREX1 cause a series of autoimmune diseases, such as Aicardi-Goutieres syndrome (AGS), Familial chilblain lupus (FCL), Systemic lupus erythematosus (SLE) and Leukodystrophy-related retinopathy (RVCL). Besides, TREX1 inhibits the innate immune response to human immunodeficiency virus type 1 (HIV-1) and plays an important role in mediating the viral immune evasion. Moreover, TREX1 acts as an upstream regulator of the DNA sensing pathway, which maintains tumor immune tolerance and prevents cell senescence. Here, we focus on the immune regulation of TREX1 and demonstrate the role of TREX1 in autoimmune diseases, HIV-1 infection, cancer and cell senescence to provide the basic theoretical guidance for human disease therapy.

Objective:To explore the main risk factors and to assess the risk of thyroid 131I exposure among nuclear medical workers. Methods:From March to October in 2019, cluster sampling was adopted to collect the number of 131I automatic packer and patients treated for thyroid cancer, hyperthyroidism and liven cancer used 131I, the practicing categories, job rotation and 131I operation condition of nuclear medical staff were also investegated in the 21 nuclear medicine hospitals in Fujian Province that carried out 131I nuclide diagnosis and treatment in 2018. 131I aerosol and personnel thyroid 131I were measured in 20 hospitals using 131I for thyroid cancer or hyperthyroidism. The main risk factors leading to thyroid 131I exposure of nuclear medical staff were found and aninternal exposure risk assessment model was established. Results:The detection rate of 131I aerosol and personnel thyroid 131I were 80.0% (16/20) and 25.5% (62/243) in 20 hospitals. The situation of packaging and administration about 131I in the nearly 10 effective half-life, the concentration of 131I aerosol in the nuclear medicine workplace, the number of patients treated with 131I for thyroid cancer or hyperthyroidism were the main risk factors leading to thyroid 131I internal exposure ( OR=5.857, 6.808, 1.983, 1.150, P<0.05) . Conclusion:131I exposure is common among nuclear medical workers, attention should be paid to the protection of internal radiation, strengthen the control of main risk factors, so as to reduce the risk of internal radiation.

Objective:To explore the main risk factors and to assess the risk of thyroid 131I exposure among nuclear medical workers. Methods:From March to October in 2019, cluster sampling was adopted to collect the number of 131I automatic packer and patients treated for thyroid cancer, hyperthyroidism and liven cancer used 131I, the practicing categories, job rotation and 131I operation condition of nuclear medical staff were also investegated in the 21 nuclear medicine hospitals in Fujian Province that carried out 131I nuclide diagnosis and treatment in 2018. 131I aerosol and personnel thyroid 131I were measured in 20 hospitals using 131I for thyroid cancer or hyperthyroidism. The main risk factors leading to thyroid 131I exposure of nuclear medical staff were found and aninternal exposure risk assessment model was established. Results:The detection rate of 131I aerosol and personnel thyroid 131I were 80.0% (16/20) and 25.5% (62/243) in 20 hospitals. The situation of packaging and administration about 131I in the nearly 10 effective half-life, the concentration of 131I aerosol in the nuclear medicine workplace, the number of patients treated with 131I for thyroid cancer or hyperthyroidism were the main risk factors leading to thyroid 131I internal exposure ( OR=5.857, 6.808, 1.983, 1.150, P<0.05) . Conclusion:131I exposure is common among nuclear medical workers, attention should be paid to the protection of internal radiation, strengthen the control of main risk factors, so as to reduce the risk of internal radiation.