Analysis of the Carry-Over of Ochratoxin A from Feed to Milk, Blood, Urine, and Different Tissues of Dairy Cows Based on the Establishment of a Reliable LC-MS/MS Method.

A rapid and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of ochratoxin A (OTA) and its metabolite ochratoxin α (OTα), for the first time, in dairy cow plasma, milk, urine, heart, liver, spleen, lung, and kidney. The established method was extensively validated by determining the linearity (R2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1-0.2 ng mL-1), recovery (75.3-114.1%), precision (RSD ≤ 13.6%), and stability (≥83.0%). Based on the methodological advances, the carry-over of OTA was subsequently studied after oral administration of 30 µg/kg body weight OTA to dairy cows. As revealed, OTA and OTα were detected in urine, with maximal concentrations of 1.8 ng mL-1 and 324.6 ng mL-1, respectively, but not in milk, plasma, or different tissues, verifying the protection effects of rumen flora against OTA exposure for dairy cows. Moreover, 100 fresh milk samples randomly collected from different supermarkets in Shanghai were also analyzed, and no positive samples were found, further proving the correctness of the in vivo biotransformation results. Thus, from the currently available data, regarding OTA contamination issues on dairy cows, no significant health risks were related to OTA exposure due to the consumption of these products.

Viral etiology, clinical and laboratory features of adult hemophagocytic lymphohistiocytosis.

Secondary hemophagocytic lymphohistiocytosis (SHLH) is a potentially fatal hyperinflammatory syndrome with a heterogeneous etiology and has nonspecific clinical and laboratory findings. The diagnosis and treatment of adult SHLH is challenging because the etiology of the disease is difficult to identify, and the majority of reported cases are pediatric patients. The aim of this study was to describe the etiology, clinical characteristics, and outcomes of adult SHLH. Fifty-four adult patients who fulfilled the criteria of SHLH were enrolled in the study. Viral etiology, blood biomarkers, and clinical manifestations of SHLH were analyzed in these patients. Twenty-four SHLH patients had viraemia, whereas 30 SHLH patients were secondary to other diseases. Epstein-Barr virus (EBV) was the most common virus that associated SHLH among all viruses studied. Severe SHLH patients with EBV-viraemia presented significantly high levels of ferritin, lactate dehydrogenase, aspartate transaminase (AST), and alanine transaminase (ALT). Positively relationships existed between EBV DNA titers and levels of AST and ALT (P < 0.05). The prognosis of SHLH patients with EBV viraemia was worse than that of non-EBV SHLH and non-viral SHLH. Our data reveal that EBV is the major pathogen in virus-associated SHLH, and EBV load influence disease development in SHLH patients with EBV infection that prognosis is worse than other viruses associated SHLH.

Development and Validation of an Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Simultaneous Determination of Four Type B Trichothecenes and Masked Deoxynivalenol in Various Feed Products.

A reliable and sensitive analytical method was developed for simultaneous determination of deoxynivalenol(DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), fusarenon X (FUS-X), and masked deoxynivalenol (deoxynivalenol-3-glucoside, D3G) in formula feed, concentrated feed, and premixed feed products. The method was based on an improved sample pretreatment with the commercially available HLB cartridges used for sample purification and enrichment followed by analysis using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Several key parameters including the extraction solvents, the positions of sample loading solvents, washing and elution solvents for HLB cartridges were carefully optimized to achieve optimal extraction and purification efficiencies. The established method was extensively validated by determining the linearity (R² ≥ 0.99), sensitivity (limit of quantification in the range of 0.08-4.85 µg/kg), recovery (79.3%-108.1%), precision (Intra-day RSDs ≤ 13.5% and Inter-day RSDs ≤ 14.9%), and then was successfully applied to determine the four type B trichothecenes and D3G in a total of 31 feed samples. Among them, 26 were contaminated with various mycotoxins at the levels of 2.1-864.5 µg/kg, and D3G has also been detected in 17 samples with the concentrations in the range of 2.1-34.8 µg/kg, proving the established method to be a valuable tool for type B trichothecenes and masked DON monitoring in complex feed matrices.

In Vivo Kinetics and Biotransformation of Aflatoxin B1 in Dairy Cows Based on the Establishment of a Reliable UHPLC-MS/MS Method.

The in vivo kinetics of aflatoxin B1 (AFB1) and its carry-over as aflatoxin M1 (AFM1) in milk as well as the toxin loads in the tissue of dairy cows were assessed through a repetitive feeding trial of an AFB1-contaminated diet of 4 µg kg-1 body weight (b.w.) for 13 days. This was followed by a clearance period that ended with a single dose trial of an AFB1-contaminated diet of 40 µg kg-1 b.w. An ultra-high performance liquid chromatography tandem mass spectrometry method was developed and successfully validated by the determination of linearity (R 2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1-0.2 ng ml-1), recovery (79.5-111.2%), and precision relative standard deviation (RSD) ≤14.7%) in plasma, milk, and various tissues. The repetitive ingestion of AFB1 indicated that the biotransformation of AFB1 to AFM1 occurred within 48 h, and the clearance period of AFM1 in milk was not more than 2 days. The carry-over rate of AFM1 in milk during the continuous ingestion experiment was in the range of 1.15-2.30% at a steady state. The in vivo kinetic results indicated that AFB1 reached a maximum concentration of 3.8 ± 0.9 ng ml-1 within 35.0 ± 10.2 min and was slowly eliminated from the plasma, with a half-life time (T1/2) of 931.1 ± 30.8 min. Meanwhile, AFM1 reached a plateau in plasma (0.5 ± 0.1 ng ml-1) at 4 h after the ingestion. AFB1 was found in the heart, spleen, lungs, and kidneys at concentrations of 1.6 ± 0.3, 4.1 ± 1.2, 3.3 ± 0.9 and 5.6 ± 1.4 µg kg-1, respectively. AFM1 was observed in the spleen and kidneys at concentrations of only 0.7 ± 0.2 and 0.8 ± 0.1 µg kg-1, respectively. In conclusion, the in vivo kinetics and biotransformation of AFB1 in dairy cows were determined using the developed UHPLC-MS/MS method, and the present findings could be helpful in assessing the health risks to consumers.

[Simultaneous determination of 30 mycotoxins in different feed products by ultra high performance liquid chromatography-tandem mass spectrometry].

A method for the simultaneous determination of 30 mycotoxins in different feed products was developed using a QuEChERS pretreatment procedure coupled with ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The samples were extracted with 5 mL water and 5 mL acetonitrile containing 1% (v/v) formic acid. An aliquot of the supernatant was dried by nitrogen gas, re-dissolved by 1mL water containing 5 mmol/L ammonium acetate-acetonitrile (80:20, v/v), and analyzed by UHPLC-MS/MS. Matrix-matched calibration curves and internal standards were used for accurate quantification. Satisfactory recoveries at low, medium and high spiked levels were ranged from 72.0% to 118.4% (n=5). Good linear relationships were obtained, the correlation coefficients (r2) were greater than 0.99. The limits of detection (LODs, S/N=3) and the limits of quantification (LOQs, S/N=10) ranged from 0.7 µg/L to 20 µg/L and from 2 µg/L to 50 µg/L, respectively. The proposed method is simple, rapid and valuable, which can be a powerful tool for quantitative analysis of the 30 mycotoxins in premixed feed, concentrated feed and formula feed products.

Clinical and laboratory features parameters of human granulocytic anaplasmosis (HGA) in patients admitted to hospital in Guangdong Province, China.

BACKGROUND: Human granulocytic anaplasmosis (HGA) is an acute tick-borne infectious disease with increasing morbidity and mortality, but is rarely considered in clinical practice. Because human-to-human transfusion or nosocomial transmission can occur, diagnosis is difficult when the history of tick bites is not clear. METHODS: We present clinical features and laboratory data of HGA patients who had no clear tick bite history. RESULTS: All patients in the study presented with a high fever, petechiae, purpura, nose bleeding and leukopenia, and patients had abnormally high levels of serum ferritin and C-reactive protein. Morulae in leukocytes were observed in three patients. Foamy histiocytes and slight erythrophagocytic activity were only found in severely ill patients. CONCLUSION: In patients with fever and thrombocytopenia in whom no other diagnosis is evident on clinical assessment, HGA should be considered in the differential diagnosis, and tested for serologically if possible. For patients in whom the diagnosis of HGA is possible, and to whom tetracyclines can safely be given, it is apparent that these drugs hasten recovery and improve the prognosis.