The gut microbial metabolite trimethylamine N-oxide and cardiovascular diseases

Morbidity and mortality of cardiovascular diseases (CVDs) are exceedingly high worldwide. Researchers have found that the occurrence and development of CVDs are closely related to intestinal microecology. Imbalances in intestinal microecology caused by changes in the composition of the intestinal microbiota will eventually alter intestinal metabolites, thus transforming the host physiological state from healthy mode to pathological mode. Trimethylamine N-oxide (TMAO) is produced from the metabolism of dietary choline and L-carnitine by intestinal microbiota, and many studies have shown that this important product inhibits cholesterol metabolism, induces platelet aggregation and thrombosis, and promotes atherosclerosis. TMAO is directly or indirectly involved in the pathogenesis of CVDs and is an important risk factor affecting the occurrence and even prognosis of CVDs. This review presents the biological and chemical characteristics of TMAO, and the process of TMAO produced by gut microbiota. In particular, the review focuses on summarizing how the increase of gut microbial metabolite TMAO affects CVDs including atherosclerosis, heart failure, hypertension, arrhythmia, coronary artery disease, and other CVD-related diseases. Understanding the mechanism of how increases in TMAO promotes CVDs will potentially facilitate the identification and development of targeted therapy for CVDs.

Comparative Analysis of Machine Learning Algorithms on Surface Enhanced Raman Spectra of Clinical Staphylococcus Species

Raman spectroscopy (RS) is a widely used analytical technique based on the detection of molecular vibrations in a defined system, which generates Raman spectra that contain unique and highly resolved fingerprints of the system. However, the low intensity of normal Raman scattering effect greatly hinders its application. Recently, the newly emerged surface enhanced Raman spectroscopy (SERS) technique overcomes the problem by mixing metal nanoparticles such as gold and silver with samples, which greatly enhances signal intensity of Raman effects by orders of magnitudes when compared with regular RS. In clinical and research laboratories, SERS provides a great potential for fast, sensitive, label-free, and non-destructive microbial detection and identification with the assistance of appropriate machine learning (ML) algorithms. However, choosing an appropriate algorithm for a specific group of bacterial species remains challenging, because with the large volumes of data generated during SERS analysis not all algorithms could achieve a relatively high accuracy. In this study, we compared three unsupervised machine learning methods and 10 supervised machine learning methods, respectively, on 2,752 SERS spectra from 117 Staphylococcus strains belonging to nine clinically important Staphylococcus species in order to test the capacity of different machine learning methods for bacterial rapid differentiation and accurate prediction. According to the results, density-based spatial clustering of applications with noise (DBSCAN) showed the best clustering capacity (Rand index 0.9733) while convolutional neural network (CNN) topped all other supervised machine learning methods as the best model for predicting Staphylococcus species via SERS spectra (ACC 98.21%, AUC 99.93%). Taken together, this study shows that machine learning methods are capable of distinguishing closely related Staphylococcus species and therefore have great application potentials for bacterial pathogen diagnosis in clinical settings.

[Old Country in New Fate-Feng Youlan's viewpoints on traditional Chinese Medicine]

"Old Home land" is an obvious symbolism of traditional Chinese medicine. It has different features with modern medicine. In this new era, how to keep the TCM "new life" , how to preserve and develop it, has become an important subject. Feng Youlan is an important scholar in modern Chinese academic society. His idea on Chinese society is extensive and profound. According to Feng Youlan, we should understand the Chinese medicine from its attributes in philosophy, science and culture. And the medicine and pharmacy in the Chinese medicine need to be discussed from different point views. On the other hand, the dispute between Chinese and Western medicine itself maybe lead to a false direction. By his personal experience, Feng suggested that the traditional Chinese medicine should not lose its characters in the future time of modernization.

[Prognostic factors and model of primary liver cancer treated with transcatheter arterial chemoembolization combined with radiofrequency ablation]

Objective: To investigate the prognostic factors of primary liver cancer treated with transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA), and then to establish a prognostic model. Methods: Clinicopathological and follow-up data of 145 patients who underwent TACE combined with RFA from January 2010 to December 2012 were retrospectively analyzed. Univariate and multivariate survival analyses were performed using the Cox proportional hazards model, and the prognostic model was established. Results: The 1, 2, and 3-year survival rates were 92.6%, 81.4% and 66.2%, respectively. The 3-year recurrence and metastasis rate was 64.8%.Multivariate analysis showed that female cases and higher serum albumin levels were the protective factors for the 3-year overall and relapse-free survival of patients(P<0.05 for all). High levels of alpha-fetoprotein (AFP), alanine aminotransferase (ALT), total bilirubin (TBIL), portal vein thrombosis and higher Child Pugh stages were the independent risk factors for the 3-year overall survival(P<0.05 for all). High levels of AFP, TBIL, portal vein thrombosis and advanced stages of BCLC staging (B and C) were the independent risk factors for tumor recurrence and metastasis(P<0.05 for all). The predictive model established based on the multivariate analysis showed good sensitivity and specificity. The area under ROC curve were higher than 0.90. Conclusions: The prognosis of liver cancer patients treated with TACE combined with RFA is affected by various clinicopathological factors. The systematic evaluation of the relevant factors before treatment may help to select proper patients and improve prognosis.

Role of altered prednisolone-specific lymphocyte sensitivity in chronic renal failure as a pharmacodynamic marker of acute allograft rejection after kidney transplantation

The effects of four immunosuppressive agents on the in vitro blastogenesis of peripheral blood lymphocytes activated by concanavalin A have been studied using cells from 26 healthy subjects, 34 patients with chronic renal failure (CRF) and 30 kidney transplant recipients. Differences in lymphocyte sensitivity to prednisolone between the healthy subjects and the CRF patients were statistically significant (P less than 0.0002), with impaired sensitivity in CRF. Impaired lymphocyte sensitivity occurred in 3.8% and 52.9% of the healthy and CRF subjects, respectively. Lymphocyte sensitivity to prednisolone, both preoperatively and 3 months post-operatively, was strongly correlated with early allograft rejection during co-administration of prednisolone with cyclosporin or azathioprine. Lymphocyte sensitivity to cyclosporin, azathioprine, and mizoribine in CRF was not significantly less than that in healthy subjects. Since the pharmacokinetics of prednisolone are little altered in renal transplantation, it is concluded that lymphocyte sensitivity specific to prednisolone may be a pharmacodynamic marker characteristic of successful graft survival in patients with histo-incompatibility and/or drug resistance.

Recovery of decreased ability of peripheral-blood mononuclear cells from chronic renal failure to produce interleukin-1 alpha and beta after renal transplantation

The ability of cultured peripheral-blood mononuclear cells (PBMC) to release interleukin-1 alpha and beta (IL-1 alpha, IL-1 beta) in response to concanavalin A (con A) was investigated in patients with chronic renal failure (CRF) and in renal transplant recipients. Mean IL-1 alpha level released by PBMC of healthy subjects (n = 42), CRF patients (n = 42), or transplants 2 months after operation (n = 69) was 152 +/- 103, 110 +/- 80, or 154 +/- 87 pg/5 x 10(5) cells/ml culture, respectively. IL-1 alpha release from PBMC of recipients 2 months after renal transplantation was significantly higher than that of CRF patients (p less than 0.05). Mean IL-1 beta level released by PBMC of healthy subjects (n = 34), CRF (n = 30), or transplants (n = 55) was 223 +/- 159, 135 +/- 129, or 276 +/- 155 pg/5 x 10(5) cells, respectively. Similar to IL-1 alpha, the level in CRF was significantly lower than that in healthy subjects (p less than 0.05). A time course study indicated that the ability of PBMC from transplants to release IL-1 alpha and beta promptly decreased following the operation, possibly owing to prednisolone and ciclosporin immunosuppressive therapy. However, after maintaining a low level for 2-3 weeks, IL-1 release from PBMC gradually increased thereafter. The results were consistent with known characteristics of decreased immunity in CRF states, and further suggested that the decreased ability of PBMC to release IL-1 alpha and beta in response to con A in CRF patients is recovered 2 months after renal transplantation.

[Acid-base fractionation of lipophilic components in human urine and their high-performance liquid chromatography equipped with multichannel ultraviolet detector: an application to xanthine derivatives]

Column extraction technique was applied to acid-base fractionation of urinary lipophilic components. The acidified urine was retained on an extraction column packed with diatomaceous earth granules. Extraction solvent passed through the column was introduced directly into alkaline columns to fractionate strong and weak acidic components, the former being trapped on sodium hydrogen carbonate and the latter on sodium hydroxide column. Neutral components were eluted out without any chemical interaction with the support reagents. Acidic components retained in the column were recovered after acidified with acetic acid. Each fraction thus obtained was analyzed by silica gel high performance liquid chromatography equipped with a multi-channel ultraviolet detector using a solvent system consisted of 0.2% distilled water, 0.2% acetic acid, 15% ethanol and appropriate volume of n-hexane. Thus the comparative chromatographic studies of these three fractions became very easy. In our experiment, urinary components were extracted and chromatographed in the order of their partition coefficients. The method was applied to xanthine derivatives after the administration of caffeine tablets to a healthy volunteer.