Determination of lithium and its compounds in workplace air by inductively coupled plasma-mass spectrometry / 中国职业医学

OBJECTIVE: To evaluate the suitability of two pretreatment methods, the nitric acid digestion method and the elution method, and two measurement modes of inductively coupled plasma-mass spectrometry(ICP-MS), the No gas mode and the helium collision(He) mode, for the determination of lithium and its compounds in the workplace air. METHODS: We collected lithium and its compounds in the air of the workplace using the microporous filter membrane, and two pretreatment methods, the nitric acid digestion and elution methods were used for processing, and measured with the No gas mode and the He mode of ICP-MS. RESULTS: The good linearity range of lithium concentration in No gas mode and He mode of ICP-MS method was 0.00-500.00 μg/L, and the correlation coefficient was 0.999. The detection limit and the lower limit of quantification of lithium were 0.04 and 0.13 μg/L respectively in the No gas mode. In He gas mode: they were 0.12 and 0.39 μg/L respectively. Using the nitric acid digestion method for pre-treatment, the recovery rate of lithium addition was 96.9%-104.9%; the within-run and the between-run relative standard deviations were 3.3%-5.0% and 2.9%-5.3% respectively. Using the elution method for pre-treatment, the recovery rate of lithium addition was 97.6%-102.1%; the within-run and the between-run relative standard deviation were 3.3%-4.6% and 3.4%-4.8%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The ICP-MS method can be used as a new technology for detecting lithium and its compounds in the air of workplace. It is recommended that the elution method and the No gas mode be the first choice when measuring lithium and its compounds.

Adenovirus pneumonia with hemophagocytic lymphohistiocytosis in children: a clinical analysis of 7 children / 中国当代儿科杂志

OBJECTIVE@#To study the clinical features of children with adenovirus pneumonia and hemophagocytic lymphohistiocytosis (HLH).@*METHODS@#A retrospective analysis was performed on the mediacal data of 7 children with adenovirus pneumonia and HLH from March to September, 2019.@*RESULTS@#The age of these children ranged from 11 months to 5 years, and among these children, 5 were aged <2 years and 5 were boys. None of these children had underlying diseases. All children were hospitalized due to persistent high fever and cough, and the peak temperature of fever was 39°C to 41°C. With disease progression, 7 children developed hepatomegaly and 6 developed splenomegaly. Routine blood test results showed reductions in two or three lineages of blood cells, with increases in serum ferritin (SF), C-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH). Phagocytosis of blood cells was observed in 6 children. Radiological examination of lungs showed pneumonia changes. All 7 children were diagnosed with human adenovirus type 7 infection based on pathogenic metagenome detection. No abnormality was found by HLH gene detection and the children were diagnosed with secondary HLH. All children received intravenous immunoglobulin. Among these children, 4 received dexamethasone and etoposide chemotherapy, 3 received dexamethasone alone, and 4 received plasma exchange. Of the 7 children, 2 died and 5 were recovered. Compared with those who survived, the children who died had significantly greater reductions in the three lineages of blood cells and significantly greater increases in serum levels of CRP, PCT, SF, and LDH.@*CONCLUSIONS@#The children with adenovirus pneumonia and HLH have main clinical features of persistent high fever, progressive reductions in two or three lineages of peripheral blood cells, and involvement of other organ systems, including hepatosplenomegaly. Significant increases in serum levels of CRP, PCT, SF, and LDH may suggest a poor prognosis.

Simultaneous determination of cyclohexane and methylcyclohexane in workplace air by solvent desorption-gas chromatography / 中国职业医学

OBJECTIVE: To explore an improved method for determination of cyclohexane and methylcyclohexane in workplace air by solvent desorption-gas chromatography. METHODS: Cyclohexane and methylcyclohexane in workplace air were collected by activated carbon tubes,desorbed with carbon disulfide,separated by DB-1 capillary chromatography column,detected by flame ionization detector and quantified using the standard calibration curves. RESULTS: The linear range of the concentration of cyclohexane and methylcyclohexane were 1. 0-1 402. 2 and 0. 8-1 999. 4 mg / L respectively.Both the correlation coefficients were 0. 999 9. Both the detection limits were 0. 3 mg / L. The limits of quantification were1. 0 and 0. 8 mg / L respectively. Both the minimum detectable concentrations were 0. 2 mg / m3. The minimum quantitative mass concentrations of cyclohexane and methylcyclohexane were 0. 7 and 0. 6 mg / m3respectively( sample volume was 1. 5L). The average desorption efficiencies were 98. 5%-99. 3% and 97. 6%-99. 0% respectively. The relative standard deviations( RSD) of within-run precision were 0. 36%-0. 59% and 0. 34%-0. 50% respectively. The RSD of between-run precision were 0. 89%-2. 04% and 0. 87%-2. 22% respectively. The samples could be stored for up to 7 days at room temperature. CONCLUSION: This method has features of simple operation,high sensitivity and good precision,which is suitable for simultaneous determination of cyclohexane and methylcyclohexane in workplace air.

Effects of neonatal recurrent seizures on glucocorticoid receptor expression in the rat brain / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effets of flurothyl-induced neonatal recurrent seizures on glucocorticoid receptor (GR) expression in the rat brain.</p><p><b>METHODS</b>Forty-eight seven-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. Brains were sampled on postnatal days 13, 15 and 19. The expression of GR protein in the cerebral cortex was detected by Western blot and immunohistochemical method.</p><p><b>RESULTS</b>The expression of GR in the cerebral cortical plasma protein was significantly lower in the seizure group than in the control group on postnatal day 15. The expression of GR protein in the cerebral cortical nuclear protein decreased significantly in the seizure group compared with that in the control group on postnatal days 15 and 19 (p<0.05). Compared to the control group, the accumulated optical density (AOD) of GR immunoreactivity (IR) decreased significantly in the parietal cortex on postnatal day 13 (p<0.05), the AOD of GR IR decreased significantly in the parietal cortex and the temporal cortex on postnatal day 15 (p<0.05), and the AOD of GR IR decreased significantly in the parietal cortex, temporal cortex and the frontal cortex in the seizure group on postnatal day 19 (p<0.05).</p><p><b>CONCLUSIONS</b>Recurrent seizures in neonatal rats result in abnormal GR expression in the cerebral cortex which might play an important role in short-term brain injury induced by early recurrent seizures.</p>

Effect of magnesium-free on glucocorticoid receptor expression in primary cultured cortical neurons of fetal rats in vitro / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the changes of glucocorticoid receptor (GR) expression in embryonic rat cortical neurons exposed to transient Mg(2+)-free treatment.</p><p><b>METHODS</b>Six days after rat cortical neuronal cultures, two groups were created based on the medium to which were transiently exposed. The control group was exposed to a physiological solution (PS), and the Mg(2+)-free group was exposed to the same medium as the control group except for the removal of magnesium. The expression of GR mRNA and protein was determined by real-time PCR and immunocytochemistry staining 1, 7 and 12 days after transient Mg(2+)-free treatment.</p><p><b>RESULTS</b>Compared to the control group, the Mg(2+)-free group displayed the significantly less accumulated optical density (AOD) of GR immunoreactivity 12 days after transient Mg(2+)-free treatment (p<0.05). On the contrary, GR mRNA expression increased significantly 1 and 7 days after transient Mg(2+)-free treatment in the Mg(2+)-free group (p<0.05).</p><p><b>CONCLUSIONS</b>GR expression is modified following Mg-free-induced injury in cultured developing neurons in rats.</p>

Short-term effects of recurrent neonatal seizures on gamma-aminobutyric acid A receptor alpha1 and beta2 subunit expression in the rat brain / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the short-term effects of flurothyl-induced neonatal recurrent seizures on gamma-aminobutyric acid A receptor (GABAAR) alpha1 and beta2 subunit expression in the rat brain, and to study the relationship between the alterations of GABAAR subunits in the developing brain and seizure-induced brain injury.</p><p><b>METHODS</b>Sixty-four 7-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. The expression of GABAAR alpha1 and beta2 subunits protein in the cerebral cortex and the hippocampus were detected by Western blot and immunohistochemistry method 1 and 7 days after recurrent seizures.</p><p><b>RESULTS</b>Compared to the control, the accumulated optical density (AOD) of GABAAR alpha1 subunit immunoreactivity (IR) in the parietal cortex, the CA3-CA4 regions and the dentate gyrus in seizure rats increased significantly 1 day after recurrent seizures (P<0.05). The AOD of GABAAR alpha1 subunit IR in the parietal cortex, the CA1-CA4 regions and the dentate gyrus in seizure rats increased significantly 7 days after recurrent seizures compared with the control (P<0.05). The expression of GABAAR alpha1 subunit in the hippicampus and the cerebral cortex increased significantly in seizure rats compared with that in control rats 1 and 7 days after recurrent seizures. After 7 days of recurrent seizures, the AOD of GABAAR beta2 subunit IR in the CA1-CA2 regions increased significantly in the seizure group compared with that in the control group (P<0.05), but the AOD of GABAAR beta2 subunit IR in the thalamus decreased significantly in the seizure group compared with that in the control group (P<0.05). The expression of GABAAR beta2 subunit protein in the hippocampus increased significantly in the seizure group compared with that in the control group 7 days after recurrent seizures (P<0.05).</p><p><b>CONCLUSIONS</b>Recurrent neonatal seizures may result in the short-term alterations of GABAAR alpha1 and beta2 subunits expression in the cerebral cortex and the hippocampus in rats, suggesting the alterations of GABAAR subunit expression may be related to the developing brain injury following recurrent seizures.</p>