[Research progress of interaction models between intestinal microflora and host cells].

Intestinal microbes play an important role in human health. The development of various clinical diseases, such as obesity, diabetes and cardiovascular disease, is closely related to the imbalance of intestinal microflora. With the development of high-throughput sequencing technology, there has been a breakthrough in the understanding of intestinal microorganism. The interaction between intestinal epithelial cells and intestinal microbes has become one of the hotspots and difficulties of current research. Because of the constraints of ethical review and experimental cost, people are more interested in the development of interaction models between the intestinal microflora and the host cells. In this paper, interaction models between intestinal microflora and host cells, and its working principle and application prospect are reviewed, hoping to provide new techniques and new ideas for studying functions of intestinal microbes.

[Effects of different carbohydrates on the simulation of human intestinal bacterial flora with in vitro culture].

OBJECTIVE: To investigate the optimal growth condition of human fecal bacterial flora in vitro by comparing the effect of different carbohydrates as cultural media. METHODS: Three fecal samples (1, 2, 3) were collected and inoculated into a single-stage chemostat system, in which starch medium (VI) and starch polysaccharide medium(XP) were used. Samples were collected for bacterial genomic DNA extraction and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Bacterial composition and short chain fatty acid (SCFA) were then analyzed. RESULTS: The single stage chemostat system reached steady after operating 8 days, when evaluated by the PCR-DGGE. Bacterial 16s rRNA high-throughput sequencing showed that the intestinal bacteria of these three volunteers was mainly composed of four bacterial phyla, namely, Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria. When the influence of bacterial abundance was considered, the similarity of bacterial composition between the original fecal samples to the harvested flora after culture was 0.847, 0.825, 0.968 in VI medium and 0.927, 0.926, 0.836 in XP medium, respectively. The similarity was decreased to 0.553, 0.580, 0.623 with VI medium and 0.617, 0.520, 0.574 with XP medium, when the number of bacterial species was considered. The variation of host individual also influenced the simulation. VI medium favored fecal sample 3, while XP medium more benefited sample 1 and 2. Bacteroides and Lachnospiraceae_incertae_sedis grew in both VI and XP medium. However, some species were only detected in VI medium and some were specifically found in the XP medium. The SCFA concentration in fermenters was 15-35 mmol/L, mainly propionate and butyrate. CONCLUSIONS: The chemostat system works for stimulating human gut bacterial flora in vitro. The bacterial composition is affected by different carbohydrate in the culture medium yet with close simulation higher than 80%.

Sex influences on the penetrance of IL-1beta and IL-1RN genotypes for rheumatoid arthritis in the Chinese population.

Polymorphism (variable number of tandem repeats) in the second intron of the interleukin-1 receptor antagonist (IL-1Ra) gene and two single nucleotide polymorphisms at positions -511 and +3954 of the IL-1beta gene may be associated with an increased risk of rheumatoid arthritis (RA). This study used sex stratification to investigate a correlation of the three genetic polymorphisms with the risk of RA, on patients with RA and healthy controls. Polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were performed. The frequencies of the IL-1beta+3954 allele and genotype in female patients were significantly different compared with the controls; but in males, only the frequency of the IL-1beta+3954 allele was different. The frequency of the IL-1RN genotype in patients was not statistically different compared with the controls; however, the frequency of IL-1RN allele in female patients was different. The association of the three polymorphisms with the susceptibility to RA appears to be significantly affected by gender.

[The reasonable design of the combined spinal epidural needles (CSEN) in aneasthesia].

This paper discusses the reasonable factors of parameters in CSEN design and has also raised some useful reasonable parameters concerned.

Cross-replantation of lower extremities in multilimbed amputation: case report and literature review in China.

Presented is a case of a 20-year-old man on whom cross-replantation of the right leg onto the stump of the left was successfully conducted by means of unusual bone fixation. Follow-up showed that the result was satisfactory, with firm bone union and functional recovery of the replanted leg.

Keshan disease--an endemic mitochondrial cardiomyopathy in China.

Keshan disease (KD) is a cardiomyopathy endemic in certain areas of China, characterized by severe deterioration and multiple focal necrosis. In the present paper we describe abnormalities of the structure and function of myocardial mitochondria from patients with subacute Keshan disease. Activities of succinate dehydrogenase, succinic oxidase, cytochrome c oxidase, H(+)-ATPase and its sensitivity to oligomycin and the response of membrane potential to energization by ATP were significantly decreased. However, the spectrum of reduced-minus-oxidized cytochromes in patients' mitochondria showed no obvious difference in the content of cytochrome c oxidase (aa3). There was also a marked decrease in lipid fluidity of affected mitochondria, and an abnormal amount of moderately electron dense amorphous inclusions. Electron-microscopic x-ray microanalysis and exposure to protein digestion reagent demonstrated that these inclusions are not Ca3(PO4)2, but are, probably, proteinaceous in nature. Affected mitochondria had markedly decreased selenium content. The defects in myocardial mitochondria from patients with chronic Keshan disease were less extensive than those in patients with subacute Keshan disease. We propose that Keshan disease be classified as a form of "mitochondrial cardiomyopathy".