Assessment of atrial electromechanical coupling and influential factors in nonrheumatic paroxysmal atrial fibrillation.

BACKGROUND: Sequential analysis of atrial electromechanical coupling (P-A) by Doppler tissue imaging (DTI) might provide important insight into the mechanisms of paroxysmal atrial fibrillation (PAF). HYPOTHESIS: The purpose of this study was to evaluate P-A and the dispersion of P-A, and to analyze the influential factors of P-A. METHODS: One hundred and ten patients with PAF and 87 normal controls were enrolled. Using DTI, the time intervals from the beginning of P-wave to the onset of atrioventricular ring motion related to atrial contraction were measured. RESULTS: Atrial electromechanical coupling at the interventricular septum atrioventricular annulus (P-A1), left lateral mitral annulus (P-A2) and right lateral tricuspid annulus (P-A3) in PAF group were significantly longer than those in control (p < 0.001). The difference between P-A2 and P-A1 (T1), P-A2 and P-A3 (T3) in PAF group were greater than those in control before age correction (p < 0.05). The linear regression analysis showed that the duration of PAF episodes and age were the greatest influential factors of P-A1 (r = 0.564). Left atrial anterior-posterior dimension (LAD) and age were the greatest influential factors of P-A2 (r = 0.459). The LAD was the greatest influential factors of T1 and T3 (r = 0.408, 0.542). CONCLUSIONS: The atrial electromechanical coupling was significantly longer and the dispersion of P-A at left lateral mitral annulus was greater in PAF patients. The prolongation of P-A may be related to left atrial enlargement, long episodes of PAF and aging and the dispersion of P-A at left lateral mitral annulus to LAD.

Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes.

The storage and transportation of raw milk at low temperatures promote the growth of psychrotrophic bacteria and the production of thermo-stable enzymes, which pose great threats to the quality and shelf-life of dairy products. Though many studies have been carried out on the spoilage potential of psychrotrophic bacteria and the thermo-stabilities of the enzymes they produce, further detailed studies are needed to devise an effective strategy to avoid dairy spoilage. The purpose of this study was to explore the spoilage potential of psychrotrophic bacteria from Chinese raw milk samples at both room temperature (28 °C) and refrigerated temperature (7 °C). Species of Yersinia, Pseudomonas, Serratia, and Chryseobacterium showed high proteolytic activity. The highest proteolytic activity was shown by Yersinia intermedia followed by Pseudomonas fluorescens (d). Lipolytic activity was high in isolates of Acinetobacter, and the highest in Acinetobacter guillouiae. Certain isolates showed positive ß-galactosidase and phospholipase activity. Strains belonging to the same species sometimes showed markedly different phenotypic characteristics. Proteases and lipases produced by psychrotrophic bacteria retained activity after heat treatment at 70, 80, or 90 °C, and proteases appeared to be more heat-stable than lipases. For these reasons, thermo-stable spoilage enzymes produced by a high number of psychrotrophic bacterial isolates from raw milk are of major concern to the dairy industry. The results of this study provide valuable data about the spoilage potential of bacterial strains in raw milk and the thermal resistance of the enzymes they produce.

Apoptosis induction of colorectal cancer cells HTL-9 in vitro by the transformed products of soybean isoflavones by Ganoderma lucidum.

Soybean isoflavones have been one of the potential preventive candidates for antitumor research in recent years. In this paper, we first studied the transformation of soybean isoflavones with the homogenized slurry of Ganoderma lucidum. The resultant transformed products (TSI) contained (703.21±4.35) mg/g of genistein, with transformed rates of 96.63% and 87.82% of daidzein and genistein, respectively, and TSI also could enrich the bioactive metabolites of G. lucidum. The antitumor effects of TSI on human colorectal cancer cell line HTL-9, human breast cancer cell line MCF-7, and human immortalized gastric epithelial cell line GES-1 were also studied. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay showed that TSI could dramatically reduce the viability rates of HTL-9 cells and MCF-7 cells without detectable cytotoxicity on GES-1 normal cells when the TSI concentration was lower than 100 µg/ml. With 100 µg/ml of TSI, HTL-9 cells were arrested in the G1 phase, and late-apoptosis was primarily induced, accompanied with partial early-apoptosis. TSI could induce primarily early-apoptosis by arresting cells in the G1 phase of MCF-7 cells. For HTL-9 cells, Western-blot and reverse-transcriptase polymerase chain reaction (RT-PCR) analysis showed that TSI (100 µg/ml) can up-regulate the expression of Bax, Caspase-3, Caspase-8, and cytochrome c (Cyto-c), indicating that TSI could induce cell apoptosis mainly through the mitochondrial pathway. In addition, the expression of p53 was up-regulated, while the expression of Survivin and nuclear factor κB (NF-κB) was down-regulated. All these results showed that TSI could induce apoptosis of HTL-9 cells by the regulation of multiple apoptosis-related genes.

A study revealing the key aroma compounds of steamed bread made by Chinese traditional sourdough.

Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation-extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies.

Submerged fermentation production and characterization of intracellular triterpenoids from Ganoderma lucidum using HPLC-ESI-MS.

As the main bioactive metabolites of Ganoderma lucidum, triterpenoids have various pharmacological effects. In this paper, the nutritional requirements and culture conditions of a submerged culture of G. lucidum were optimized using the response surface methodology; maximum mycelia biomass and intracellular triterpenoid production reached 1.87 g/100 ml and 93.21 mg/100 ml, respectively, for a culture consisting of wort 4.10% (0.041 g/ml) and yeast extract 1.89% (0.0189 g/ml), pH 5.40. For the first time, we established that wort, which is cheap and abundant, can replace the more commonly used glucose as the sole source of carbohydrate. Using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS), 10 major ganoderic acids were tentatively identified based on the predominant fragmentation pathways with the elimination of H2O and CO2, as well as cleavage of the D-ring.

[The association between metabolic syndrome and atherosclerosis].

OBJECTIVE: To explore the association between metabolic syndrome and atherosclerosis. METHODS: Carotid intima-media thickness (IMT) was detected and the atherosclerotic plaque was classified, graded, and scored in 358 retired males, aged 55 approximately 74, including 95 (26.6%) with metabolic syndrome (metabolic syndrome group) and 263 (73.5%) without metabolic syndrome (non-metabolic syndrome group). The correlation of IMT with every characteristic of metabolic syndrome diagnostic criteria was studied. RESULTS: The metabolic syndrome group had higher carotid IMT (0.90 mm +/- 0.12 mm versus 0.84 mm +/- 0.11 mm, P < 0.05), plaque score (3.58 mm +/- 0.44 mm vs 2.45 mm +/- 0.25 mm, P < 0.05), plaque occurrence rate (64.2% vs 47.5%, P < 0.05) and cardiovascular event morbidity (20.0% versus 12.2%, P < 0.05) compared with the non-metabolic syndrome group. IMT was significantly but weakly positively correlated with systolic blood pressure, diastolic blood pressure, glucose, and waistline (r = 0.27, r = 0.17, r = 0.17 and r = 0.12 respectively, all P < 0.05). CONCLUSION: Metabolic syndrome accelerates the course of atherosclerosis. Detecting carotid artery as early as possible by vascular ultrasound is helpful to primary prevention of cardiovascular events in the patients with metabolic syndrome.