The correlation between gut microbiome and atrial fibrillation: pathophysiology and therapeutic perspectives

Regulation of gut microbiota and its impact on human health is the theme of intensive research. The incidence and prevalence of atrial fibrillation (AF) are continuously escalating as the global population ages and chronic disease survival rates increase; however, the mechanisms are not entirely clarified. It is gaining awareness that alterations in the assembly, structure, and dynamics of gut microbiota are intimately engaged in the AF progression. Owing to advancements in next-generation sequencing technologies and computational strategies, researchers can explore novel linkages with the genomes, transcriptomes, proteomes, and metabolomes through parallel meta-omics approaches, rendering a panoramic view of the culture-independent microbial investigation. In this review, we summarized the evidence for a bidirectional correlation between AF and the gut microbiome. Furthermore, we proposed the concept of "gut-immune-heart" axis and addressed the direct and indirect causal roots between the gut microbiome and AF. The intricate relationship was unveiled to generate innovative microbiota-based preventive and therapeutic interventions, which shed light on a definite direction for future experiments.

A MEMS SOI-based piezoresistive fluid flow sensor

In this paper, a SOI (silicon-on-insulator)-based piezoresistive fluid flow sensor is presented; the presented flow sensor mainly consists of a nylon sensing head, stainless steel cantilever beam, SOI sensor chip, printed circuit board, half-cylinder gasket, and stainless steel shell. The working principle of the sensor and some detailed contrastive analysis about the sensor structure were introduced since the nylon sensing head and stainless steel cantilever beam have distinct influence on the sensor performance; the structure of nylon sensing head and stainless steel cantilever beam is also discussed. The SOI sensor chip was fabricated using micro-electromechanical systems technologies, such as reactive ion etching and low pressure chemical vapor deposition. The designed fluid sensor was packaged and tested; a calibration installation system was purposely designed for the sensor experiment. The testing results indicated that the output voltage of the sensor is proportional to the square of the fluid flow velocity, which is coincident with the theoretical derivation. The tested sensitivity of the sensor is 3.91 × 10^-4 V ms²/kg.

[Clinical experience on the employment of the staged step-up approach in the treatment of local complications secondary to severe acute pancreatitis]

Objective: To explore the experience and prognostic factors associated with the employment of the step-up approach in the treatment of local complications secondary to severe acute pancreatitis (SAP). Methods: The clinical data of 279 patients admitted to the Department of Pancreatic and Biliary Surgery, First Affiliated Hospital of Harbin Medical University from January 2011 to December 2015, whose local complications secondary to SAP were treated in a staged step-up framework, were retrospectively analyzed.For patients with documented or suspected infected pancreatic necrosis or gastrointestinal tract obstruction, some non-surgical interventions were initialed with the aim of postponing the timing of surgery to the forth week from the onset of SAP.The first-step intervention was a percutaneous catheter drainage (PCD) under the guidance of ultrasound. A minimal access retroperitoneal pancreatic necrosectomy, representing the second-step intervention, was conducted when PCD had failed. Finally, an open necrosectomy (the third-step intervention) was immediately resorted to when all of previous minimal invasive interventions had failed.Normally distributed quantitative variables were analyzed by t-test, non-normally distributed quantitative variables were analyzed by Wilcoxon chi-square test and categorical variables were analyzed by χ² test or Fisher's exact test.A multivariable Logistic regression analytic model was established to figure out the prognostic factors that were independently associated with the requirement of debridement in addition to drainage procedure during the staged step-up framework of patients with local complications secondary to SAP. Results: The initial interventions in this series were performed at 12 d (9-22 d) from the on-set of SAP and 104 cases (37.3%) were cured with ultrasound guided PCD alone.There were 152 cases (54.5%) cured by debridement in addition to PCD with the time interval of 30 d (25 to 44 d) since the on-set of the disease.The overall incidence of postoperative complications was 22.6% (63 cases) and in-hospital mortality was 8.2% (23 cases) in the present series.Multiple organ failures(MOF)(P<0.01, OR=3.15), heterogeneous collections (P<0.01, OR=2.40) and tertiary transfer (P=0.03, OR=1.80) were verified as the prognostic factors that were independently associated with the requirement of debridement in addition to PCD during the staged step-up framework of patients with local complications secondary to SAP. Conclusions: The staged step-up framework is a promising innovation that complies well with the era of minimal invasive surgery and is optimally suitable for the surgical interventions against SAP.MOF, heterogeneous collections and tertiary transfer are the prognostic factors that are independently associated with the requirement of debridement in addition to PCD during the staged step-up framework of patients with local complications secondary to SAP.

Lycopene protects pancreatic acinar cells against severe acute pancreatitis by abating the oxidative stress through JNK pathway

This study investigated the anti-oxidative and anti-inflammatory effects of lycopene on severe acute pancreatitis (SAP) in both in vivo and in vitro models. Utilizing a rat model, we found that lycopene administration protected against SAP, as indicated by the decreased levels of serum amylase and C-reactive protein. Pathological changes were alleviated by pretreatment with lycopene. The serum levels of tumor necrosis factor-α, interleukin-6, macrophage inflammatory protein-1α, and monocyte chemotactic protein-1 were decreased by lycopene. The decreased reactive oxygen species (ROS) content in the pancreatic tissues of the lycopene-treated group were indirectly evaluated by measuring the levels of myeloperoxidase, lipid peroxidase, and superoxide dismutase. Lycopene protected acinar cells against necrosis and apoptosis by relieving the mitochondrial and endoplasmic stress caused by ROS which was shown in electron microscopy and immunohistochemistry staining of active nuclear factor-κB p65. The protective effect was also observed in a simulated SAP model in a rat acinar cell line. ROS and apoptotic staining were compared between groups. Lycopene exerts protective effects against SAP in rats that may be related to its anti-inflammatory property through inhibiting the expression of damage-associated molecular patterns, and anti-oxidative property which can thus maintain cellular homeostasis and prevent the phosphorylation of JNK pathway.

Effect of the route of foot-and-mouth disease virus infection of piglets on the course of disease

Three different routes of Foot-and-mouth disease virus (FMDV) infection of piglets, namely intranasal (i.n.) through drops, intradermal (i.d.) into the foot, and intramuscular (i.m.) were compared regarding the onset and severity of the disease. The results showed that the i.d. injection of the virus resulted in the fastest onset of the disease. The i.m. injection led to a delayed onset, but the final effect was identical with i.d. injection. Moreover, the i.m. injection was simpler to perform and easier to evaluate. Therefore, the i.m. injection of piglets is recommended as the optimal infection route for evaluation of the FMDV vaccine potency.

[Treatment of refractory acute rejection after renal transplantation with lymphogloline]

156 patients received renal transplantation in the Nanfang Hospital from October 1992 to December 1993. 27 patients developed refractory acute rejection (RAR). Of them, rejection was reversed completely with lymphogloline (ATG) in 22 patients and reversed with OKT3 in 4. One patient died of cerebral hemorrhage after removal of the donor's kidney. The results suggest that ATG is safe, effective, highly specific, sensitive, and of less side-effect. The pathogenesis, diagnosis of RAR and cautions for ATG are discussed.

[Hypertensive chemotherapy of advanced gastric cancer]

Hypertensive chemotherapy of advanced gastric cancer is reported in this paper. The blood pressure of the patient was first elevated by intravenous angiotensin II, then mitomycin C was given for two consecutive days at doses of 20 mg and 10 mg. Out of 20 cases, it was effective in 11 (55%), especially for those with Borrmann III and IV types and poorly differentiated adenocarcinoma which recurred after subtotal gastrectomy. The side effect of this treatment was not marked and the response satisfactory Therefore, it may easily be accepted as the treatment for advanced gastric cancer.