Objective To compare the value of standard deviation(SD)method and root mean square(RMS)method for measuring signal-to-noise ratio(SNR)of MRI of American College of Radiology(ACR)phantom based on phased array coils.Methods ACR phantom was scanned with head coil(Head),abdominal coil(Anterior),dual piece flexible coil(Flex L)and abdominal coil+flexible coil(Anterior+Flex L)each for 6 times,respectively,with sequences of axial T 1W-spin echo(SE)and T2W-SE.And the scanning schemes were divided into 8 groups based on 4 types of coils and 2 sequences.SNR of 8 groups were measured with standard deviation method and root mean square method,respectively,and the differences between the above 2 methods were observed.Results For T1W-SE sequence,SNRsD of MRI based on Head,Anterior,Flex L and Anterior+Flex L was 1.25±0.07,0.56±0.02,1.15±0.10 and 1.04±0.11,respectively,while SNRRMs was 1.10±0.07,0.58±0.03,1.01±0.13 and 1.31±0.15,respectively.For T2W-SE sequence,SNRsD was 1.40±0.08,0.48±0.02,1.04±0.07 and 1.08±0.06,respectively,while SNRRMs was 1.29±0.09,0.53±0.03,0.84±0.08 and 1.35±0.12,respectively.Compared pairwise,significant difference of SNRsD was found in 9 pairs(all P＜0.05),while of SNRRMs was detected in 10 pairs(all P＜0.05).Conclusion Compared with standard deviation method,root mean square method was more suitable for measuring SNR of MRI of ACR phantom based on phased array coils.

Objective To compare the value of standard deviation(SD)method and root mean square(RMS)method for measuring signal-to-noise ratio(SNR)of MRI of American College of Radiology(ACR)phantom based on phased array coils.Methods ACR phantom was scanned with head coil(Head),abdominal coil(Anterior),dual piece flexible coil(Flex L)and abdominal coil+flexible coil(Anterior+Flex L)each for 6 times,respectively,with sequences of axial T 1W-spin echo(SE)and T2W-SE.And the scanning schemes were divided into 8 groups based on 4 types of coils and 2 sequences.SNR of 8 groups were measured with standard deviation method and root mean square method,respectively,and the differences between the above 2 methods were observed.Results For T1W-SE sequence,SNRsD of MRI based on Head,Anterior,Flex L and Anterior+Flex L was 1.25±0.07,0.56±0.02,1.15±0.10 and 1.04±0.11,respectively,while SNRRMs was 1.10±0.07,0.58±0.03,1.01±0.13 and 1.31±0.15,respectively.For T2W-SE sequence,SNRsD was 1.40±0.08,0.48±0.02,1.04±0.07 and 1.08±0.06,respectively,while SNRRMs was 1.29±0.09,0.53±0.03,0.84±0.08 and 1.35±0.12,respectively.Compared pairwise,significant difference of SNRsD was found in 9 pairs(all P＜0.05),while of SNRRMs was detected in 10 pairs(all P＜0.05).Conclusion Compared with standard deviation method,root mean square method was more suitable for measuring SNR of MRI of ACR phantom based on phased array coils.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology has the characteristics of high specificity and high throughput, making it rapidly applied and developed in the field of clinical testing. Its application in the monitoring of therapeutic drugs can effectively improve the quantitative accuracy and sensitivity, and formulate a personalized and optimal dosing plan for patients. However, this technology still faces some challenges, and automation, quality control, and quantitative traceability will be the future development direction.

Objective To observe the neuropsychiatric behavioral performance of kainic acid(KA)-induced epilepsy rats;investigate gender differences in acute seizure and behavioral performance tasks relating to sense,motor,learning,and memory in the remission phase;and explore the potential neurobiological mechanisms of action.Methods Healthy SD rats aged 4 weeks were randomly divided into control and model groups,with 22 rats in each group(11 males and 11 females).An epileptic rat model was induced by intraperitoneal injection of KA.Seizure latency and frequency within 2 hours of KA injection were observed,seizure grade was assessed using the Racine grade standard,and a cortical electroencephalogram(EEG)was recorded.Behavioral performance was observed in a series of tasks including open field testing,balance beam walking,elevated plus maze,Y-maze,and novel object recognition.The level of GABA in the hippocampus was detected by ELISA,injury to hippocampal neurons was observed by Nissl staining,and the protein expression of synapsin-1 and synaptotagmin 1 in the hippocampus were detected by Western Blot.Results Both male and female rats presented typical epileptic behaviors after KA injection.However,compared with the effects in males,the latency of the first seizure(P=0.014)and Ⅳ～Ⅴ grading in female model rats were more pronounced(P＜0.01),and the frequency of epileptic seizures within 2 hours was significantly reduced(P=0.019).In the open field testing,KA-induced epileptic rats presented more motor but fewer hedonic behaviors,as indicated by the decrease in total movement distance in the central area,compared with the control group.Moreover,grooming frequency was significantly reduced in the female model rats compared with not only that in the control but also that in male model rats(P＜0.01).The model rats spent more time completing and had a higher score in the balance beam walking task,indicating their poorer stability and balance.In the elevated plus maze,the exploration times of male model rats in the closed arm was increased.The preference index of rats for the novel arm or object decreased in the Y-maze and novel object recognition,suggesting impairments to their learning and memory abilities.Moreover,neuronal injuries were found in the hippocampus of the model rats that were accompanied with a decline in GABA concentration and protein expression of synapsin-1 and synaptotagmin 1,with no gender differences.Conclusions Intraperitoneal injection of KA successfully induced an epilepsy rat model.However,there was a gender difference in the characters of acute seizures and performance of sensory,motor,and learning memory during epileptic remission.There was no gender differences in the hippocampal GABA concentration or expression of synaptic plasticity-related proteins,and thus no evidence was found for the mechanisms underlying the gender differences.

A young female patient with acne and elevated testosterone level underwent plasma steroid hormones testing and found a significant increase in aldosterone. We excluded testing interference and verified the absence of hypertension, hypokalemia, and adrenal occupancy, as well as primary and secondary hyperaldosteronism. During follow-up, a temporal correlation was found between aldosterone levels and the use of drospirenone and ethinylestradiol tablets. It was observed that the combination of drospirenone and ethinylestradiol could lead to the increase of aldosterone level and the concentration ratio of aldosterone to direct renin through different mechanisms. Drospirenone exerts an antagonistic effect on mineralocorticoid receptor to prevent the development of hypertension or hypokalemia. In clinical practice, it is necessary to pay attention to the effect of this drug on screening markers for primary aldosteronism. In the laboratory examination, when female patients with no symptoms of hypertension and hypokalemia but with elevated aldosterone levels are encountered, it can be verified whether they have a history of use of compound estrogen-progestin such as drospirenone and ethinylestradiol tablets, and appropriate tips are provided in the report.

Background: Twenty-four-hour urinary free cortisol (UFC) measurement is the initial diagnostic test for Cushing’s syndrome (CS). We compared UFC determination by both direct and extraction immunoassays using Abbott Architect, Siemens Atellica Solution, and Beckman DxI800 with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, we evaluated the value of 24-hr UFC measured by six methods for diagnosing CS. Methods: Residual 24-hr urine samples of 94 CS and 246 non-CS patients were collected.A laboratory-developed LC-MS/MS method was used as reference. UFC was measured by direct assays (D) using Abbott, Siemens, and Beckman platforms and by extraction assays (E) using Siemens and Beckman platforms. Method was compared using Passing–Bablok regression and Bland–Altman plot analyses. Cut-off values for the six assays and corresponding sensitivities and specificities were calculated by ROC analysis. Results: Abbott-D, Beckman-E, Siemens-E, and Siemens-D showed strong correlations with LC-MS/MS (Spearman coefficient r = 0.965, 0.922, 0.922, and 0.897, respectively), while Beckman-D showed weaker correlation (r = 0.755). All immunoassays showed proportionally positive bias. The areas under the curve were 0.975 for Abbott-D, 0.972 for LCMS/MS, 0.966 for Siemens-E, 0.948 for Siemens-D, 0.955 for Beckman-E, and 0.877 for Beckman-D. The cut-off values varied significantly (154.8–1,321.5 nmol/24 hrs). Assay sensitivity and specificity ranged from 76.1% to 93.2% and from 93.0% to 97.1%, respectively. Conclusions Commercially available immunoassays for measuring UFC show different levels of analytical consistency compared to LC-MS/MS. Abbott-D, Siemens-E, and Beckman-E have high diagnostic accuracy for CS.

Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.

Objective:To evaluate the performance of magnetic beads extraction method (MGE) for the measurement of catecholamine metabolites by liquid chromatography tandem mass spectrometry.Methods:This is a methodological evaluation study. The linearity, limit of quantitation, recovery, precision, and matrix effect of catecholamine metabolites 3-methoxyepinephrine (MN), 3-methoxynorepinephrine (NMN) and 3-methoxytyramine (3-MT) extracted by MGE method were evaluated according to CLSI C62-A. Consensus of method development and validation of liquid chromatography-tandem mass spectrometry in clinical laboratories and other guidelines, 132 clinical residual plasma samples were collected and extracted by automated MGE and traditional solid phase extraction (SPE) method to compare the harmonization of the two extraction methods.Results:The linearity of MN, NMN and 3-MT extracted by automated MGE was>0.99, and the LOQ for MN, NMN and 3-MT were 0.033 5 nmol/L, 0.054 7 nmol/L and 0.011 0 nmol/L, respectively. The repeatability of MN, NMN and 3-MT were 1.3%-5.1%, 2.2%-5.6% and 1.7%-7.1%, respectively. The total imprecision in the laboratory were 1.5%-8.2%, 2.2%-7.7%, 2.1%-11.2%. Although the absolute recovery is low, the average relative recoveries of MN, NMN and 3-MT were 91.5%-108.5%, 92.0%-108.6%, and 89.3%-104.1%, respectively, and the percentage deviation from the expected concentration was within 15%. After isotope internal standard correction, the relative matrix effect is close to 100%, which can compensate for the potential matrix effect. The results of MGE and SPE of MN, NMN and 3-MT showeda good correlation (correlation coefficient r>0.99). The average relative deviations of MN, NMN and 3-MT were 0.2%, -1.4% and 1.0%, respectively. Conclusion:The automatic MGE method hasa good performance in extracting catecholamine metabolites, and is expected to be used in high-throughput analysis of samples in clinical in the future.

Peritoneal metastases (PM) are defined as the primary or secondary occurrence/progression of malignant tumor in peritoneum. PM were previously thought to be a terminal disease without effective treatment, with short survival and poor prognosis. With the change in the understanding of PM, the oncology communities regard it as a curable regional cancer metastasis, and create a comprehensive treatment technology system with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy as the core, and establish professional PM treatment centers based on this. The professional PM treatment centers have significantly prolonged the survival of patients, and some patients can even achieve clinical cure. However, in China, there are very few professional PM treatment centers, but the number of PM patients is huge, and most of the patients can't receive professional treatment, resulting in poor survival and prognosis. Based on the cancer statistics in 2015 published by China National Cancer Center Registry and clinical outcome literature on peritoneal metastasis, this paper uses clinical epidemiology methodology to calculate the number of newly diagnosed patients with peritoneal metastasis, to estimate the number of specialized peritoneal cancer centers required, to provide data support for the promotion of professional treatment technology system for PM in our country, and to boost the development of peritoneal oncology.

Background: Thyroid diseases are highly prevalent worldwide, but their diagnosis remains a challenge. We established reference intervals (RIs) for thyroid-associated hormones and evaluated the prevalence of thyroid diseases in China. Methods: After excluding outliers based on the results of ultrasound screening, thyroid antibody tests, and the Tukey method, the medical records of 20,303 euthyroid adults, who visited the Department of Health Care at Peking Union Medical College Hospital from January 2014 to December 2018, were analyzed. Thyroid-associated hormones were measured by the Siemens Advia Centaur XP analyzer. The RIs for thyroid-associated hormones were calculated according to the CLSI C28-A3 guidelines, and were compared with the RIs provided by Siemens. The prevalence of thyroid diseases over the five years was evaluated and compared using the chi-square test. Results: The RIs for thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total thyroxine (TT4), and total triiodothyronine (TT3) were 0.71–4.92 mIU/L, 12.2–20.1 pmol/L, 3.9–6.0 pmol/L, 65.6–135.1 nmol/L, and 1.2–2.2 nmol/L, respectively. The RIs of all hormones except TT4 differed significantly between males and females. The RIs of TSH increased with increasing age. The prevalence of overt hypothyroidism, overt hyperthyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism was 0.5% and 0.8%, 0.2% and 0.6%, 3.8% and 6.1%, and 3.3% and 4.7% in males and females, respectively, which differed from those provided by Siemens. Conclusions Sex-specific RIs were established for thyroid-associated hormones, and the prevalence of thyroid diseases was determined in the Chinese population.