Cross-species analysis of transcriptome emphasizes a critical role of TNF-α in mediating MAP2K7/AKT2 signaling in zearalenone-induced apoptosis

Zearalenone (ZEN) is a widespread and transgenerational toxicant that can cause serious reproductive health risks, which poses a potential threat to global agricultural production and human health; its estrogenic activity can lead to reproductive toxicity through the induction of granulosa cell apoptosis. Herein, comparative transcriptome analysis, single-cell transcriptome analysis, and weighted gene co-expression network analysis (WGCNA) combined with gene knockout in vivo and RNA interference in vitro were used to comprehensively describe the damage caused by ZEN exposure on ovarian granulosa cells. Comparative transcriptome analysis and WGCNA suggested that the tumor necrosis factor (TNF)-α-mediated mitogen-activated protein kinase 7 (MAP2K7)/ AKT serine/threonine kinase 2 (AKT2) axis was disordered after ZEN exposure in porcine granulosa cells (pGCs) and mouse granulosa cells (mGCs). In vivo gene knockout and in vitro RNA interference verified that TNF-α-mediated MAP2K7/AKT2 was the guiding signal in ZEN-induced apoptosis in pGCs and mGCs. Moreover, single-cell transcriptome analysis showed that ZEN exposure could induce changes in the TNF signaling pathway in offspring. Overall, we concluded that the TNF-α-mediated MAP2K7/AKT2 axis was the main signaling pathway of ZEN-induced apoptosis in pGCs and mGCs. This work provides new insights into the mechanism of ZEN toxicity and provides new potential therapeutic targets for the loss of livestock and human reproductive health caused by ZEN.

A Prospective Study of Bevacizumab and Neoadjuvant Concurrent Chemoradiation in Locally Advanced Esophageal Squamous Cell Carcinoma: Paradoxical Increase in Circulating Vascular Endothelial Growth Factor-A and Effect on Outcome

PURPOSE/OBJECTIVE(S)

In the prior prospective biomarker study, high serum vascular endothelial growth factor-A (VEGF-A) was associated with a poor prognosis. We conducted a prospective phase II trial of adding Bevacizumab, an anti-VEGF-A monoclonal antibody, to neoadjuvant concurrent chemoradiation (neoCCRT) for patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). This prospective biomarker study aims to evaluate the expressions of angiogenesis-associated circulating biomarkers before and after neoCCRT and compare clinical outcomes for patients receiving platinum/5-fluorouracil (PF) with or without Bevacizumab.

MATERIALS/METHODS

Patients with biopsy-proven resectable non-T4 LA-ESCC were enrolled for the prospective phase II trial investigating PF-neoCCRT plus Bevacizumab (BPF group). A parallel patient cohort enrolled in a prospective biomarker study receiving PF-neoCCRT was included in the present analysis as the control group (PF group). Radiotherapy was delivered with 40 Gy in 20 fractions. All patients had restaging workups after enoCCRT and underwent radical esophagectomy if the disease remained resectable. Serums were collected before and after neoCCRT. The serum concentrations of angiogenesis-associated biomarkers were determined by the multiplex enzyme-linked immunosorbent assay. Survival analyses were performed by the Kaplan-Meier method. The t-test and log-rank test were used to compare differences in biomarker expression and survival between groups.

RESULTS

From 2016 to 2019, 43 patients (BPF/PF group: 21/22) were enrolled in the study. Twenty patients in each group had serum samples available for biomarker analysis. 15 out of 21 patients in the BPF group and 20 out of 22 patients in the PF group underwent radical esophagectomy. Six patients in the BPF group and nine patients in the PF group achieved pathological complete responses. The median overall survival for the BPF and PF group was 20.8 months and not-reached, respectively (hazard ratio = 1.33, long rank p = 0.58). In the BPF group, the serum VEGF-A level was significantly increased from an average value of 446 pg/mL to 723 pg/mL after neoCCRT (p = 0.037), while its level was decreased from 815 ng/mL to 380 pg/mL in the PF group (p = 0.104). In addition, the expression value of circulating Angiopoietin-1 was not changed in the BPF group (before neoCCRT, mean value = 828 pg/mL; after neoCCRT, mean value 762 pg/mL, p = 0.67). In contrast, serum Angiopoietin-1 level was reduced from an average value of 659 pg/mL before neoCCRT to 271 pg/mL after neoCCRT (p = 0.002) in the PF group.

CONCLUSION

The addition of Bevacizumab to PF-neoCCRT did not improve pathological or survival outcomes in patients with resectable LA-ESCC. Adding a single dose of Bevacizumab paradoxically increases circulating VEGF-A while maintaining the Angiopoietin-1 serum level after neoCCRT. Further investigation by using additional VEGF-A inhibition may be required to achieve sustained angiogenesis blocked for tumor control.

[Comparison the characteristics of serum adrenocortical hormone profile in patients with adrenal cortical carcinoma and adrenal coritcal adenoma]

Objective: To compare the characteristics of serum adrenocortical hormone profiles detected by liquid chromatography tandem mass spectrometry in patients with adrenal cortical carcinoma and adrenal adenoma. Methods: A total of 23 patients with adrenal cortical carcinoma and 119 patients with adrenal cortical adenoma/hyperplasia who visited the Department of Endocrinology and/or the Department of Urology of Peking University First Hospital from January 2018 to June 2022 were analyzed retrospectively. The imaging characteristics and serum adrenal cortical hormone profiles detected by liquid chromatography tandem mass spectrometry were analyzed retrospectively. The independent related factors of adrenal cortical carcinoma were screened by univariate analysis and multivariate logistic regression analysis. Results: The age of patients with adrenal cortical carcinoma was 46 (35, 57) years, and 15 (65.2%) were female; The age of adrenal cortical adenoma patients was 49 (40, 58) years old, and 80 (67.2%) were female. There was no significant difference in age and gender between the two groups (all P values>0.05). The maximum tumor diameter M (Q₁, Q₃) of patients with adrenocortical carcinoma was 7.05 (5.45, 9.78) cm, which was larger than that of patients with adrenocortical adenoma [2.1 (1.6, 3.0) cm] (P<0.001). Compared with patients with adrenal adenoma, the androstenedione (AD) of patients with adrenal cortical carcinoma [4.056 9 (1.619 5, 7.907 9) nmol/L vs 1.517 5 (0.935 1, 2.582 1) nmol/L (P<0.001)] was significantly increased; 11-ketotestosterone/11-ketoandrostenedione [0.034 3 (0.020 6, 0.079 2) vs 0.041 0 (0.028 6, 0.061 5) (P=0.089)] and 11-ketoandrostenedione/11-hydroxyandrostenedione [0.013 0 (0.006 4, 0.086 7) vs 0.063 0 (0.018 2, 0.162 5) (P=0.042)] were significantly decreased. Multivariate analysis found that AD, the largest diameter of the tumor, 11-ketotestosterone/11-ketoandrostenedione and 11-ketoandrostenedione/11-hydroxyandrostenedi-one were related factors for adrenal cortical carcinoma, with OR values (95%CI) of 1.841 (1.093-3.100), 5.130 (2.332-11.285), 0.381 (0.167-0.867) and 0.000 (0.000-0.014), respectively, all P values <0.05. Conclusions: The larger diameter of adrenal cortical tumor and the higher the level of androstenedione are independent risk factors for adrenal cortical carcinoma. The reduction conversion of 11-hydroxyandrostenedione to 11-ketoandrostenedione and 11-ketoandrostenedione to 11-ketotestosterone were independently associated with adrenal cortical carcinoma.

[Use of oral anticoagulants and related factors among new-onset acute ischemic stroke patients with nonvalvular atrial fibrillation: A report from the China Atrial Fibrillation Registry Study]

Objective: This study aimed to investigate the oral anticoagulant (OAC) usage among new-onset acute ischemic stroke (AIS) patients with nonvalvular atrial fibrillation (NVAF) in China, and to explore the possible influencing factors of influent anticoagulant therapy in these patients. Methods: The NVAF patients who experienced new-onset and non-fatal AIS from August 2011 to December 2018 in the China Atrial Fibrillation Registry (China-AF), were enrolled. The follow-up ended in December 2019. Information including patients' demographic characteristics, medical history, medication usage, which were collected before and after the index stroke, were analyzed. Patients were classified into OAC group or non-OAC group according to OAC usage within 3 months post stroke. Multivariate logistic regression analysis were conducted to calculate the odds ratios (ORs) of factors which might be associated with OAC usage within 3 months post stroke. Results: A total of 957 new-onset AIS patients were enrolled, 39.4% (377/957) patients were treated with OAC within 3 months after AIS. Covering by high-reimbursement-rate insurance (OR: 1.91, 95%CI: 1.28-2.86, P=0.002), higher number of concomitant drugs (1-2 types OR: 2.10, 95%CI: 1.36-3.23, P=0.001; ≥3 types OR: 2.31, 95%CI: 1.37-3.91, P=0.002) and 3-month-peri-stroke AF recurrence (OR: 3.34, 95%CI: 2.34-4.76, P<0.001) were associated with OAC usage within 3 months post stroke, while higher HASBLED score (OR: 0.49, 95%CI: 0.40-0.60, P<0.001) and pre-stroke antiplatelet usage (OR: 0.29, 95%CI: 0.20-0.43, P<0.001) were related to no OAC usage within 3 months post stroke. Conclusions: In China, the proportion of NVAF patients who initiated OAC therapy within 3 months after new-onset AIS is as low as about 39.4%. Factors related to the OAC usage within 3 months post stroke are 3-month-peri-stroke AF recurrence, number of concomitant drugs and patients with high-reimbursement-rate insurance coverage, but higher HASBLED score and pre-stroke antiplatelet usage are related to no OAC usage within 3 months post stroke.

[Varieties and standards of Corydalis medicinal plants]

Through literature research and standard retrieval, Corydalis-derived medicinal materials, the origins, and related standards were summarized. Finally, 27 medicinal materials were screened out, involving 71 species(varieties). Among them, only 11 are recorded in Chinese Pharmacopoeia(2020), National Standard for Chinese Patent Drugs·Tibetan Medicine, Tibetan Medicine Standards, and other local standards, including Corydalis Bungeanae Herba and Corydalis Herba. The names and original plants of the medicinal materials are different in different standards, and the phenomena of &quot;same medicinal material with different names&quot; and &quot;same name for different medicinal materials&quot; are prominent. Most standards only include the traits, microscopic identification, and physico-chemical property identification, with unsound quality criteria. Thus, efforts should be made to strengthen the sorting of Corydalis medicinal plants, herbal textual research, and investigation of the resources and utilization. Moreover, via modern techniques, the chemical components and medicinal material basis of different original plants should be explored and sound quality standards should be established to improve the safety and quality of Corydalis-derived medicinal materials. Summarizing Corydalis medicinal plants, Corydalis-derived medicinal materials, and related standards, this study is expected to provide a reference for the standard formulation, quality evaluation, expansion of drug sources, and rational development and utilization of Corydalis resources.

[Radial artery thrombosis in optical coherence tomography guided transradial coronary angiography and percutaneous coronary intervention in acute coronary syndrome patients and its risk factors analysis]

Objective: To observe the radial artery thrombosis (RAT) during transradial coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) by optical coherence tomography (OCT), and to investigate the risk factors of RAT during the CAG and/or PCI. Methods: In this retrospective study, we consecutively reviewed the radial artery OCT examination results of the patients who underwent OCT guided transradial CAG and/or PCI for acute coronary syndrome in heart center of Beijing Luhe hospital, Capital Medical University from October 2017 to July 2018. The incidence of RAT was observed. The patients were divided into the RAT group and non-RAT group, clinical data were collected and compared. Moreover, the types and distributions of thrombus in radial artery as well as the acute radial artery injuries under OCT were observed. Univariate analysis followed by multivariate analysis were performed to identify potential risk factors. The radial artery patency and ischemic symptoms of the involved limb were followed up at the 24-hour and the 1-month after procedure. Results: A total of 107 patients were included, the age was (58.1±12.5), and 78.5% were male (n=84). The incidence of RAT was 26.2% (n=28, 95%CI 17.9%-34.5%), and the main type of thrombus was white thrombus (n=15, 53.6%). The commonest position of RAT was the proximal portion of radial artery (n=17, 60.7%). The median thrombus volume was 0.05(0.03, 0.38) mm3, and the median thrombus score was 6.5 (3.3, 13.8). In univariate analysis, the frequency of acute radial artery injury and use of bivalirudin were significantly higher and the procedure time was significantly longer in RAT group than those in non-RAT group (all P<0.05). Multivariate regression analysis showed that the radial artery acute injury (OR=5.82, 95%CI: 2.09-16.20, P=0.001) and the procedure time (OR=1.04, 95%CI: 1.01-1.06, P=0.006) were independent risk factors of RAT. Rate of radial artery occlusion at 24 hours follow-up was similar between RAT and non-RAT group (7.14%(2/28), vs. 10.13%(8/79), P=1.000). None of the patients complicated severe ischemic symptom of the operative limb. Conclusions: RAT is a high frequency access complication during transradial coronary intervention. This phenomenon can be accurately observed by OCT. Acute radial artery injury and prolonged procedure time are risk factors of RAT during transradial coronary intervention.

[Clinical characteristics of primary aldosteronism with concurrent adrenal Cushing's syndrome]

Objective: To analyze and summarize the clinical characteristics of primary aldosteronism (PA) with concurrent adrenal Cushing's syndrome (ACS). Methods: The clinical, imaging and pathological data of 87 patients with PA admitted to Peking University First Hospital from January 1st, 2013 to December 31th, 2016 were reviewed. There were 45 males (51.7%) and 42 females (48.3%) with an average age of (52.7±10.5) years (range: 15-70 years). According to whether they were diagnosed with ACS, the patients were divided into PA with concurrent ACS group (n=11) and pure PA group (n=55). The clinical characteristics of PA with concurrent ACS were summarized. Results: Ten of the eleven patients in PA with concurrent ACS group were diagnosed with subclinical ACS. Compared with these in pure PA group, the patients in PA with concurrent ACS group were older [(55.6±9.1) years vs (48.4±10.2) years, P=0.033], with larger diameters of adrenal tumors [(2.3±1.6) cm vs (1.4±0.6) cm, P=0.015], higher serum cortisol levels in the circadian rhythm [158 (92, 217) nmol/L vs 71 (43, 128) nmol/L at 0∶00, P=0.004], lower plasma adrenocorticotropic hormone (ACTH) levels in the circadian rhythm [0.80 (<0.22, 1.45) pmol/L vs 4.40 (2.58, 5.93) pmol/L at 8∶00, P<0.001; 0.25 (<0.22, 0.91) pmol/L vs 2.03 (0.74, 3.69) pmol/L at 16∶00, P<0.001;<0.22 (<0.22, 0.44) pmol/L vs 1.27 (<0.22, 2.66) pmol/L at 0∶00, P<0.001], and higher serum cortisol levels after 1 mg overnight dexamethasone suppression test [95 (73, 142) nmol/L vs 30 (22, 41) nmol/L, P<0.001]. Unilateral adrenalectomy was performed in 31 patients, of whom 3 patients in PA with concurrent ACS group (3/8) and 3 patients in pure PA group (3/23) presented with adrenal insufficiency and received glucocorticoid replacement therapy after adrenalectomy. Conclusions: PA with concurrent ACS is not rare in PA patients, which are mainly complicated with subclinical ACS and easily misdiagnosed. It is recommended that elderly PA patients with large adrenal tumors should be screened for ACS by means of cortisol and ACTH circadian rhythm and 1 mg overnight dexamethasone suppression test. Postoperative adrenal insufficiency is prone to occur in those patients, who should be followed up closely after adrenalectomy, and receive glucocorticoid replacement therapy in time.

[Ergonomic risk factors of carpal tunnel syndrome in workers of an automobile factory]

Objective: To investigate the occurrence of pain symptoms and risk factors of carpal tunnel syndrome (CTS) in automobile manufacturing workers and provide theoretical basis for the prevention of CTS. Methods: From Nov.5th to Nov.19th, 2017, 446 workers in an automobile factory whose work age was above one year participate in questionnaires by cluster sampling. Chi square test and multifactor logistics regression analysis were used to analyze the factors related to the occurrence of CTS pain symptoms in workers. Results: The incidence of CTS pain among workers in this automobile factory was 20.8%. Working in the same position for a long time (OR=2.137, 95% CI:1.183-3.862) and unable to work reasonably because of uncomfortable posture (OR =2.067, 95% CI: 1.075-3.974) were identified as the risk factors of CTS pain symptoms by multifactor logistics regression analysis. Working age (OR=0.537, 95%CI:0.311-0.926) and work break (OR= 0.489, 95% CI: 0.282-0.849) were identified as the benefit factors of CTS pain symptoms. Conclusion: The incidence of CTS pain in automobile manufacturing workers is related to the posture in the process of labor . Effective ergonomic interventions should be carried out to prevent the occurrence of CTS pain in automobile manufacturing workers.

99Non-ruptured plaque and platelet-rich thrombi in ST-segment elevation myocardial infarction: new insight into early spontaneous reperfusion

Objectives

To detect the potential mechanism of early spontaneous reperfusion (ESR) in STEMI.

Background

Early spontaneous reperfusion occurs in around 20% of STEMI and is associated with favorable outcomes. Optical coherence tomography (OCT) is more accurate in detecting subtle morphological details of the culprit lesion.

Methods

In this prospective study, a total of 107 consecutive patients with STEMI were enrolled from July 2016 to May 2017. Of that total, 21 (19.6%) met the criteria of angiographic ESR (TIMI-3 flow in the initial angiogram). Among those without ESR (TIMI-0 flow in the initial angiogram), 21 patients were assigned into the control group according to propensity score matching with the ESR group. The OCT findings and one-year clinical outcomes were compared between the two groups.

Results

Although baseline characteristics were comparable, plaque features significantly differed between the ESR and control group (P<0.001), including plaque rupture (23.8% vs. 66.7%), plaque erosion (47.6% vs. 33.3%), calcified nodule (9.5% vs. 0%) and vasospasm (19.1% vs. 0%). Red thrombus (19.1% vs. 85.7%) was far less found whereas white thrombus (61.9% vs. 14.3%) was more common in the ESR group. In addition, despite of less stent placement (0.6±0.5 vs. 1.3±0.9, P<0.001), patients in the ESR group had a non-statistically lower rate of cardiac adverse events (4.8% vs. 14.3%, P=0.269) during one-year follow up.

The OCT finding Variables ESR group (n=21) Control group (n=21) P value The OCT imaging <0.001   Plaque erosion 10 (47.6) 7 (33.3)   Plaque rupture 5 (23.8) 14 (66.7)   Calcified nodule 2 (9.5) 0 (0)   Vasospasm 4 (19.1) 0 (0) The Type of Thrombus <0.001   Red thrombus 4 (19.1) 18 (85.7)   White thrombus 13 (61.9) 3 (14.3)   No thrombus (vasospasm) 4 (19.1) 0 (0)   MLA (mm2) 2.7±2.2 2.3±2.4 0.534 Values are n (%), mean ± SD. ESR = early spontaneous reperfusion; MLA = Minimum lumen area; OCT = optical coherence tomography.

ESR and control group

Conclusions

Relief of coronary occlusion induced by non-ruptured plaque and platelet-rich thrombi may be one of the main mechanism underlying early spontaneous reperfusion in STEMI.

Acknowledgement/Funding

No.81470491 from the National Natural Science Foundation of China and No.7192078 from Beijing Municipal Natural Science Foundation to Dr. Li.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

Molecular identification of hemoplasma and piroplasma species from Rattus edwardsi based on sequences analysis of ribosomal DNA, China

The present study provides the first report on the molecular epidemiological data regarding infection by hemoplasma and piroplasma species in wild Rattus edwardsi, from China. In the current study, blood samples were investigated from 32 wild Rattus edwardsi from Hunan (23) and Guangxi (9) provinces, China. The prevalence of hemoplasma and piroplasma was 65.63% (21/32) and 6.25% (2/32), respectively. Phylogenetic analyses indicated that hemoplasmas (HQ183731, HQ183732) derived from wild Rattus edwardsi in China, can be grouped into a solitary clade closely related to H. muris (HMU82963) and M. haemomuris (AB758435). In addition, it was shown that piroplasmas from this study have very close genetic distance to other unidentified piroplasma species isolated from China (AB242140) and Japan (AB188086). The results suggested that hemoplasmas isolated in this study should be represented as a new genotype. Piroplasmas on the other hand needs more sequenced samples in its life-cycle and evidence to check its taxonomic status. These data may have important implications for researching on the epidemiology and population biology as well as for studying the taxonomy status of hemoplasmas and piroplasmids of wild rodents.

[Bit1 mediates the malignant behaviors in pancreatic cancer and its potential clinical significance]

Objective: To investigate the potential role of Bit1 in the pathogenesis of pancreatic ductal cancer cells(PDAC) and its potential clinical application value. Methods: Real-time PCR and Western blot were employed to detect the expression of Bit1 in six pancreatic cancer cells, then the tool cells were selected to further study the function of Bit1.PolyHEMA was used to monitor the suspended cell culture condition in vitro.The invasion and migration abilities of pancreatic cancer cells were detected through Transwell assay. Western blot and confocal assay were used to explore the potential mechanism of Bit1 in the process of metastasis.The expression of Bit1 was detected through tissue microarray, the potential relationship between Bit1 and other clinical factors were analyzed. Results: The results of real-time PCR and Western blot indicated that the expression of Bit1 was highest in the PANC1 cells and lowest in the Mia paca2 cells (gene: 3.13±0.40 vs. 1.00±0.35, protein: 1.77±1.00 vs. 0.23±0.45). The shBit1 PANC1 and Bit1-OE(over expression) Mia paca2 cells were successfully constructed.Bit1 over expression could promote the anoikis rate of Mia paca2 cells, and Bit knockdown could inhibit the anoikis incidence.Bit1 over expression suppressed the motility and invasion of Mia paca2 cells, but Bit1 knockdown could accelerate the migration and invasion ability of PANC1 cells.Bit1 could potentially affect pancreatic cancer cells' malignant behaviors through epithelial-mesenchymal transition process.Bit1 expression was significantly associated with pancreatic cancer's neural invasion (P<0.05). Conclusions: Bit1 could affect the anoikis incidence of pancreatic cancer, Bit1 negatively affect the migration and invasion abilities of PDAC, the EMT process was potentially involved in the whole modulation process.Bit1 expression is associated with neural invasion in pancreatic cancer patients.

[Current situation and thoughts on precision medicine about the treatment of tumor in China]

With United States starting"precision medical plan", it is widespread all over the world and opens a new direction to the development of medicine. Our country also starts the plan, trying to take the opportunity. At present, tumor threats human health with high incidence and mortality. In China, the incidence and mortality of tumor has been on the rise.So the tumor has become one of the most important fields of precision medicine.Precision medicine, hoping to reveal the Chinese characteristics of precision medicine, and getting the personal and social maximize health benefits are discussed in the paper.

Dual analyte flow injection fluorescence immunoassays using thiophilic gel reactors and synchronous scanning detection

Heterogeneous fluorescence immunoassays have been automated using flow injection manifolds incorporating thiophilic gel solid phase reactors to separate antibody-bound and unbound analyte molecules. Antibody elution is achieved by changes in ionic strength, thus allowing the use of pH sensitive fluorescent labels. This facilitates the development of dual analyte systems, in which two competitive immunoassays with separate labels are monitored in parallel. Detection of the fluorophores by high speed synchronous fluorescence scanning while the flow is briefly stopped utilises either one synchronous interval which detects both fluorophores, or two separate scans at different wavelength intervals, one for each fluorophore. Simultaneous analyses of serum albumin and transferrin exemplify these novel approaches. Spectroscopic interferences are very small, analyte recoveries are close to 100%, with a relative standard deviation of 5-6% and a sampling rate of 20 h-1.