Alteration of the faecal microbiota composition in patients with constipation: evidence of American Gut Project.

There is limited information is known about the composition difference of the gut microbiota in patients with constipation and healthy controls. Here, the faecal 16S rRNA fastq sequence data of microbiota from the publicly available American Gut Project (AGP) were analysed. The tendency score matching (PSM) method was used to match in a 1:1 manner to control for confounding factors age, gender, body mass index (BMI), and country. A total of 524 participants including 262 patients with constipation and 262 healthy controls were included in this analysis. The richness and evenness of the gut microbiota in the constipation group were significantly lower than those in the control group. The dominant genera in the constipation group include Escherichia_Shigella, Pseudomonas, and Citrobacter. The dominant genera in the control group include Faecalibacterium, Prevotella, Roseburia, Clostridium_XlVa, and Blautia. The abundance of three butyrate production-related pathways were significantly higher in the constipation group than in the control groups. There was no significant difference in the diversity and gut microbiota composition in patients with constipation at different ages. In conclusion, patients with constipation showed gut microbiota and butyrate metabolism dysbiosis. This dysbiosis might provide a reference for the diagnosis and clinical therapy of diseases.

[Effects of aerosol inhalation of recombinant human keratinocyte growth factor 2 on the lung tissue of rabbits with severe smoke inhalation injury].

Objective: To investigate the effect of recombinant human keratinocyte growth factor 2 (rhKGF-2) on lung tissue of rabbits with severe smoke inhalation injury. Methods: A total of 120 New Zealand rabbits were divided into 5 groups by random number table after being inflicted with severe smoke inhalation injury, with 24 rats in each group. Rabbits in the simple injury group inhaled air, while rabbits in the injury+phosphate buffer solution (PBS) group inhaled 5 mL PBS once daily for 7 d. Rabbits in injury+1 mg/kg rhKGF-2 group, injury+2 mg/kg rhKGF-2 group, and injury+5 mg/kg rhKGF-2 group received aerosol inhalation of 1 mg/kg, 2 mg/kg, and 5 mg/kg rhKGF-2 (all dissolved in 5 mL PBS) once daily for 7 d, respectively. On treatment day 1, 3, 5, and 7, blood samples were taken from the ear central artery of 6 rabbits in each group. After the blood was taken, the rabbits were sacrificed, and the tracheal carina tissue and lung were collected. Blood pH value, arterial oxygen partial pressure (PaO(2)), arterial blood carbon dioxide pressure (PaCO(2)), and bicarbonate ion were detected by handheld blood analyzer. The expressions of pulmonary surfactant-associated protein A (SP-A) and vascular endothelial growth factor (VEGF) in lung tissue were detected by Western blotting. Pathomorphology of lung tissue and trachea was observed by hematoxylin-eosin staining. Data were processed with analysis of variance of two-way factorial design and Tukey test. Results: (1) Compared with those in simple injury group, the blood pH values of rabbits in the latter groups on treatment day 1-7 had no obvious change (P>0.05). The PaO(2) of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 5 and 7 were (75.0±2.4) and (71.0±4.5) mmHg (1 mmHg=0.133 kPa), respectively, which were significantly higher than (62.0±6.8) and (63.0±3.0) mmHg in simple injury group (q=4.265, 8.202, P<0.05 or P<0.01). The PaO(2) of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 7 was (82.0±4.9) mmHg, which was significantly higher than that in simple injury group (q=6.234, P<0.01). Compared with that in simple injury group, the PaCO(2) of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 3 was significantly decreased (q=4.876, P<0.01) and significantly increased on treatment day 5 (q=5.562, P<0.01); the PaCO(2) of rabbits in injury+5 mg/kg rhKGF-2 group was significantly increased on treatment day 5 and 7 (q=5.013, 4.601, P<0.05 or P<0.01). Compared with that in simple injury group, the serum bicarbonate ion of rabbits in injury+1 mg/kg rhKGF-2 group on treatment day 7 was significantly increased (q=5.142, P<0.01); the serum bicarbonate ion of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 5 and 7 were significantly increased (q=4.830, 6.934, P<0.01); the serum bicarbonate ion of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 5 were significantly increased (q=3.973, P<0.05). (2) The expressions of SP-A in lung tissue of rabbits in simple injury group and injury+PBS group in each treatment time point were close (P>0.05). The expressions of SP-A in lung tissue of rabbits in injury+2 mg/kg rhKGF-2 group and injury+5 mg/kg rhKGF-2 group on treatment day 3 were 0.091±0.007 and 0.101±0.009, respectively, significantly higher than 0.069±0.009 in simple injury group (q=10.800, 13.580, P<0.01). The expressions of SP-A in lung tissue of rabbits in injury+1 mg/kg rhKGF-2 group, injury+2 mg/kg rhKGF-2 group, and injury+5 mg/kg rhKGF-2 group on treatment day 5 and 7 were 0.127±0.008, 0.132±0.006, 0.194±0.006, 0.152±0.017, 0.166±0.004, 0.240±0.008, significantly higher than 0.092±0.003 and 0.108±0.005 in simple injury group (q=6.789, 12.340, 17.900, 9.875, 31.480, 40.740, P<0.01). (3) On treatment day 1 and 5, there was no significant difference in the expression of VEGF in lung tissue of rabbits among the 5 groups (P>0.05). Compared with those in simple injury group, the expressions of VEGF in lung tissue of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 3 and 7 were significantly increased (q=4.243, 8.000, P<0.05 or P<0.01), and the expression of VEGF in lung tissue of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 7 was significantly increased (q=20.720, P<0.01). (4) On treatment day 1, the injury of rabbits in each group was similar, with a large number of neutrophils infiltrated and abscess formed in the alveolar and interstitial tissue, thickened alveolar septum, some collapsed alveolar and atelectasis; large area of tracheal mucosa was degenerated and necrotic, with a large amount of inflammatory exudates blocking in the cavity. On treatment day 3, the inflammation of lung tissue and trachea in each group were improved, but the inflammation in simple injury group and injury+PBS group was also serious. On treatment day 5, the inflammation in lung tissue and trachea of rabbits in injury+2 mg/kg rhKGF-2 group and injury+5 mg/kg rhKGF-2 group were improved much obviously than those in the other groups. On treatment day 7, the inflammation in lung tissue of rabbits in injury+5 mg/kg rhKGF-2 group alleviated obviously than those in the other groups, most alveoli had no obvious exudative fluid, the alveolar cavity was intact and clear, the local alveolar dilated like a cyst, and the alveolar septum thinning; the improvement of inflammation of trachea was more obvious than the other groups, the tracheal mucosa tended to be more complete, and few neutrophils were infiltrated in the endotracheal cavity. Conclusions: Atomization inhalation of rhKGF-2 can improve the PaO(2) level of rabbits with severe smoke inhalation injury, reduce airway inflammation, increase the expression of SP-A and VEGF in lung tissue, thus promoting the repair of lung tissue.

Phenotypic classification of gastric signet ring cell carcinoma and its relationship with K-ras mutation.

We aimed to analyze gastric signet ring cell (SRC) carcinoma subtypes by investigating gastric and intestinal phenotypic marker expression, and explore the relationship between phenotype and K-ras mutation. Immunohistochemistry was performed on 163 SRC carcinoma patient specimens to detect gastric (MUC1, MUC5AC, and MUC6) and intestinal (MUC2 and CDX2) phenotypic markers, and tumors were classified into gastric (G), intestinal (I), and gastrointestinal (GI) phenotypes. DNA was extracted from the formalin-fixed, paraffin-embedded tumor samples, and K-ras mutations in codons 12, 13, and 61 were identified using polymerase chain reaction-based direct DNA sequencing. G, GI, and I phenotypes were observed in 63 (38.6%), 71 (43.5%), and 29 cases (17.8%), respectively. Expression of MUC2 was significantly associated with invasion depth and lymph node metastasis (P = 0.001 and 0.002, respectively), whereas that of CDX2 significantly corresponded to tumor size and submucosal invasion (P = 0.004 and 0.001, respectively). MUC5AC expression was inversely associated with gastric wall invasion (P = 0.001). Intestinal phenotypic marker expression was positively associated with gastric wall invasion and lymph node metastasis. K-ras mutations, all of which were in codon 12, were detected in 20 (12.27%) tumors, were significantly associated with the I phenotype, and exhibited an inverse relationship with MUC5AC and MUC6 expression. I-phenotype SRC carcinomas should be distinguished from those of the G phenotype because of their increased malignancy regarding invasion and metastasis, and higher K-ras aberration rate. The different K-ras mutation frequencies observed imply distinct genetic mechanisms in the carcinogenesis of I- and G-phenotype gastric SRC carcinomas.

A compact two-way high-power microwave combiner.

A compact 2-way high-power microwave (HPM) waveguide combiner as an important equipment to realize the coherent microwave combination was theoretically designed, built, and proof-of-principle experimentally tested. The theoretical and experimental S-parameters are basically consistent with each other: return loss <-25 dB, and the isolation degree between 2-channels of the HPM combiner >25 dB to avoid the inter-modulating between the HPM sources. The C-band HPM experiment was carried out, and the power capacity of the HPM combiner was demonstrated to reach multi-gigawatts.