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In order to establish the preservation method of chive stems under cold storage by modified atmosphere packaging (MAP), the fresh pre-cooled chive stems (200±0.5) g were sealed and packaged into 25 cmx60 cm polyethylene (PE) film bags with the thickness of 10, 20, 25, 30, 45 μm respectively, and stored at (0±0.5) °C for 105 days. Then the effects of different film transmittance of O2 and CO2 on the volume fraction of O2 and CO2 in packaging bags and the qualities of chive stems during storage were investigated. The results showed that polyethylene film packaging with different O2 and CO2 transmittance could inhibit the deterioration of chive stems qualities. There were significant differences in the volume fraction of O2 and CO2 in bags among different treatment groups (P<0.05). The 45 μm PE bag treatment (O2 transmission of (4 080±352) cm³⋅m-2⋅d-1⋅0.1 MPa-1 and CO2 transmission of (16 566±1 415) cm³⋅m-2⋅d-1⋅0.1 MPa-1) for 15 d showed a significant decrease on the volume fraction of O2 in bags, and then the volume fraction of O2 remained at 3.94% to 6.66% (except for the 105th day). The volume fraction of O2 in the bag decreased significantly in the first 60 days of treatment, and then remained at 3.07%~3.53%. This treatment effectively inhibited the etiolization, flower buds opening and decay of chive stems. The cellulose contents were maintained at a low level when stored for 105 days, and the chive stems still had commercial value. Therefore, packaging chive stems with polyethylene film can maintain their commercial value during low-temperature storage and extend their shelf life. [ABSTRACT FROM AUTHOR]

Measurement of the serum levels of vitamin B12 (VB12) is key for evaluating VB12 deficiency-dependent anemia. Immunoassay, the major method for determining VB12, tends to give false-normal results because of the presence of anti-intrinsic factor (IF-Ab) or other factors such as heterophilic antibodies et al. This study aimed to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method that is helpful for distinguish false normal VB12 results measured by the immunoassay. Different forms of VB12 were derivatized into CN-B12, which was collected through solid-phase extraction and analyzed via LC-MS/MS. 236 serum samples were measured both by LC-MS/MS and immunoassay, results were compared, and the IF-Ab effect was evaluated. The LC-MS/MS assay afforded a linear slope from 20 to 4,000 pmol/L for CN-B12. OH-VB12, methyl-VB12, and CoA-VB12 showed recovery within 89.3–109.5%. The intra-assay CV of VB12 was 2.6–4.1%, whereas the total CV was 9.3–9.8%. Passing–Bablok regression between LC-MS/MS and immunoassay results showed that the slope was 1.085 and the intercept was −15.691. The Bland–Altman plot showed that the mean difference and difference% were −34.6 pmol/L and 0.3%, respectively. Inter-rater agreement analysis showed that the linear weighted kappa value was 0.885, implying good agreement between the two methods. However, two samples were falsely elevated and one sample was falsely normal in the immunoassay compared with LC-MS/MS. The LC-MS/MS method helped in the distinction of false-normal VB12 results shown by the immunoassay. The VB12 LC-MS/MS method can be used as an arbiter of clinically discordant immunoassay results. [ABSTRACT FROM AUTHOR]

Trimethylamine N -oxide (TMAO) and phenylacetylglutamine (PAGln) are associated with acute myocardial infarction (AMI) and type 2 diabetes mellitus (T2DM). This study developed and validated a simple method firstly for simultaneously quantifying serum TMAO and PAGln using liquid chromatography-tandem mass spectrometry (LC–MS/MS). Serum samples from patients with T2DM, AMI, and healthy subjects were analyzed using a new LC–MS/MS method to evaluate TMAO and PAGln levels. Statistical analyses were performed to evaluate TMAO and PAGln distributions among different groups. Retention and separation of the two metabolites were achieved within 5 min. For both analytes, the assay was linear in a 0.02–10 µg/mL range, with >0.99 average linear correlation coefficients, and quantification limit values of approximately 0.010 µg/mL. The average recoveries of TMAO and PAGln were 96.3 % and 96.4 %, respectively. The intra-run and total coefficient variations were 3.5–4.8 % and 3.9–5.7 % respectively for TMAO; and 4.0–5.1 % and 4.6–6.3 % respectively for PAGln. TMAO and PAGln showed a moderate correlation (P < 0.001) and their levels in patients with T2DM were significantly higher than those in healthy individuals (P < 0.001). TMAO levels were higher in patients with T2DM than in patients with AMI (P < 0.01). Patients with AMI had higher PAGln levels than healthy individuals (P < 0.05). After adjusting for sex and age, the top tertile of PAGln was positively correlated with T2DM and AMI while that of TMAO was positively correlated with T2DM. Overall, a robust isotope dilution LC–MS/MS method was established, which may be beneficial for assessing the association between two metabolites with AMI and T2DM. [ABSTRACT FROM AUTHOR]

Continuous disruption of circadian rhythms, as seen in human shift workers, has been associated with the development of a number of adverse mental and physiological conditions. However, scientific evidence linking circadian disruption to overall health, particularly in animal models, is not well documented. In this study, we have demonstrated that exposing C57BL/6J mice to 12-h phase shifts every 5 days for 3 mo had no effect on body weight or intestinal physiology. However, when animals were further challenged with dextran sodium sulfate to induce colitis, chronic shifting of the light-dark cycle led to a dramatic increase in the progression of the colitis as indicated by reduced body weight, abnormal intestinal histopathology, and an exacerbated inflammatory response. These data indicate that circadian disruption is an important predisposing factor that may provoke the onset or worsening of various disease states such as inflammatory disorders. This study provides further evidence for continued investigations using animal models of circadian disruption to examine the consequences of circadian disruption on health when organisms are faced with a 'challenging' environment. circadian rhythms; shift work; circadian disorganization