Shigella flexneri T3SS effector IpaH4.5 modulates the host inflammatory response via interaction with NF-κB p65 protein.

Shigella species possess a type III secretion system (T3SS), which is required for human infection and that delivers effector proteins into target host cells. Here, we show that the effector, IpaH4.5 dampens the pro-inflammatory cytokine response. In both the Sereny test and a murine lung infection model, the Shigella ΔipaH4.5 mutant strain caused more severe inflammatory responses and significantly induced higher pro-inflammatory cytokine levels (MIP-2 and TNF-α) in the lung homogenates of wild type-infected mice. Moreover, there was a threefold decrease in bacterial colonization of the mutant compared with the WT and ΔipaH4.5/ipaH4.5-rescued strains. Yeast two-hybrid screening showed that IpaH4.5 specifically interacts with the p65 subunit of NF-κB. Ten truncated versions of IpaH4.5 and p65 spanning different regions were constructed and expressed to further map the IpaH binding sites with p65. The results revealed thatthe p65 region spanning amino acids 1-190 of p65 interacted with the IpaH4.5/1-293 N-terminal region. In vitro, IpaH4.5 displayed ubiquitin ligase activity towards ubiquitin and p65. Furthermore, the transcriptional activity of NF-κB was shown to be inhibited by IpaH4.5 utilizing a dual-luciferase reporter gene detection system containing NF-κB promoter response elements. Thus, we conclude that the IpaH4.5 protein is an E3 ubiquitin ligase capable of directly regulating the host inflammatory response by inhibiting the NF-κB signalling pathway.

Silica nanoparticle design for colorectal cancer treatment: Recent progress and clinical potential.

Colorectal cancer (CRC) is the third most common cancer worldwide and the second most common cause of cancer death. Nanotherapies are able to selectively target the delivery of cancer therapeutics, thus improving overall antitumor efficiency and reducing conventional chemotherapy side effects. Mesoporous silica nanoparticles (MSNs) have attracted the attention of many researchers due to their remarkable advantages and biosafety. We offer insights into the recent advances of MSNs in CRC treatment and their potential clinical application value.

Proteomic analysis of clinical isolate of Stenotrophomonas maltophilia with blaNDM-1, blaL1 and blaL2 ß-lactamase genes under imipenem treatment.

The co-occurrence of L1 and AmpR-L2 with bla(NDM-1) gene with an upstream 250-bp promoter was detected in a clinical isolate of Stenotrophomonas maltophilia DCPS-01, which was resistant to all ß-lactams and sensitive only to colistin and fluoroquinolones. To investigate expression of resistance genes and the molecular mechanisms of bacteria resistance to carbapenems, proteomic profiles of the isolate was passaged with and without the drug by using 2D-PAGE. The results showed that 33 genes exhibiting a ≥3-fold change were identified as candidates that may help S. maltophilia survive drug selection. Strikingly, L1 was expressed more highly in cells grown with imipenem, and the abundant NDM-1 further increased, while very little L2 was detected even following induction. Specific activities for ß-lactamase revealed that L2 remained at constitutive low levels (10.6 U/mg), while L1 and NDM-1 showed clear activity (69.8 U/mg). Our data support that imipenem could specifically and reversibly induce L1 and NDM-1, which together played key roles in drug resistance in DCPS-01. Although NDM-1 mediated resistance to carbapenems has been found in very few cases, to our knowledge, this is the first proteomics research of S. maltophilia with NDM-1, giving very broad-spectrum antibiotic resistance profiles.

LuxS-dependent AI-2 regulates versatile functions in Enterococcus faecalis V583.

Bacteria utilize a quorum sensing (QS) system to coordinate gene expression by monitoring the concentration of molecules known as autoinducers (AI). In the present study, we confirmed the presence of a LuxS/AI-2 dependent QS system in vancomycin-resistant Enterococcus faecalis V583. Then, the cellular targets controlled by AI-2 were identified by comparative proteomics analysis in order to elucidate the possible role of AI-2 in E. faecalis. Results demonstrated 15 proteins that are differentially expressed upon the addition of AI-2, including proteins involved in metabolism, translation, energy production and/or conversion, and cell wall biogenesis. Glyceraldehyde-3-phosphate dehydrogenase and malate dehydrogenase associated with carbohydrate metabolism and energy production were up-regulated upon inducing by AI-2. In addition, externally added AI-2 could down-regulate acetyl-coenzyme A carboxylase and ornithine carbamoyltransferase, two key enzyme involved in metabolism. All these data suggest that AI-2 signaling may play a role in the regulation of a number of important metabolic properties of E. faecali. We further investigated the role of AI-2 in biofilm formation by E. faecalis, showing the addition of AI-2 to E. faecalis V583 cultures resulted in increased biofilm formation. Our results provide important clues to the role of a LuxS/AI-2 dependent QS system in vancomycin-resistant E. faecalis.

Sensitive and rapid detection of the new Delhi metallo-beta-lactamase gene by loop-mediated isothermal amplification.

New Delhi metallo-ß-lactamase 1 (NDM-1), which is associated with resistance to carbapenem, was first reported in 2008. A sensitive and rapid molecular assay to detect the plasmid bla(NDM-1) in clinical isolates is needed to control its spread. We describe a loop-mediated isothermal amplification (LAMP) assay for the rapid detection of bla(NDM-1) from pure culture and sputum, urine, and fecal samples. Eight sets of primers were designed to recognize six or eight distinct sequences on target bla(NDM-1), and one set was selected as the most appropriate set of primers for its rapid detection. The specificity and sensitivity of the primers in the LAMP reactions for bla(NDM-1) detection were determined. The sensitivity of the LAMP assay for bla(NDM-1) detection in sputum, urine, and fecal samples was also tested. Two methods, namely, monitoring of turbidity and addition of calcein to the reaction tube, were used to determine negative and positive results. The results showed that target DNA was amplified and visualized by the two detection methods within 70 min at an isothermal temperature of 65°C. The sensitivity of LAMP, with a detection limit of 10.70 pg/µl DNA, was 100-fold greater than that of PCR. Thirteen infection bacterial strains without bla(NDM-1) were selected for testing of specificity, and the results of the amplification were negative, which showed that the primers had good levels of specificity. The LAMP method reported here is demonstrated to be a potentially valuable means for the detection of bla(NDM-1) and rapid clinical diagnosis, being fast, simple, and low in cost.

Effect of biofeedback combined with high-quality nursing in treatment of functional constipation.

BACKGROUND: Functional constipation (FC) is a common functional gastrointestinal disease with various clinical manifestations. It is a physical and mental disease, which seriously affects patient physical and mental health and quality of life. Biofeedback therapy is the treatment of choice for FC, especially outlet obstructive constipation caused by pelvic floor dysfunction. High-quality nursing is a new nursing model in modern clinical work and a new concept of modern nursing service. AIM: To explore the effect of biofeedback combined with high-quality nursing in the treatment of FC. METHODS: A total of 100 patients with FC admitted to our hospital from March 2015 to July 2019 were selected for clinical observation. These patients were randomly divided into two groups of 50: Experimental group (biofeedback combined with high-quality nursing treatment group) and control group (biofeedback group). RESULTS: The constipation symptom score of the experimental group was significantly lower than that of the control group, and the difference was statistically significant (P < 0.05). The anal canal resting pressure and initial defecation threshold of the experimental group were significantly lower than those of the control group, and the maximum squeeze systolic pressure of the anal canal of the experimental group was significantly higher than that of the control group (P < 0.05). The Self-Rating Anxiety Scale and Zung's Self-Rating Depression Scale scores of the two groups were significantly lower than before treatment. The Self-Rating Anxiety Scale and Self-Rating Depression Scale scores of the experimental group were significantly lower than those of the control group (P < 0.05). The patient satisfaction score of the experimental group was significantly higher than that of the control group (P < 0.05). CONCLUSION: The application of biofeedback combined with high-quality nursing in the treatment of FC has significant advantages over pure biofeedback treatment, and it is worthy of promotion in clinical work.

Therapeutic effects of the TST36 stapler on rectocele combined with internal rectal prolapse.

BACKGROUND: The most common causes of outlet obstructive constipation (OOC) are rectocele and internal rectal prolapse. The surgical methods for OOC are diverse and difficult, and the postoperative complications and recurrence rate are high, which results in both physical and mental pain in patients. With the continuous deepening of the surgeon's concept of minimally invasive surgery and continuous in-depth research on the mechanism of OOC, the treatment concepts and surgical methods are continuously improved. AIM: To determine the efficacy of the TST36 stapler in the treatment of rectocele combined with internal rectal prolapse. METHODS: From January 2017 to July 2019, 49 female patients with rectocele and internal rectal prolapse who met the inclusion criteria were selected for treatment using the TST36 stapler. RESULTS: Forty-five patients were cured, 4 patients improved, and the cure rate was 92%. The postoperative obstructed defecation syndrome score, the defecation frequency score, time/straining intensity, and sensation of incomplete evacuation were significantly decreased compared with these parameters before treatment, and the differences were statistically significant (P < 0.05). The postoperative anal canal resting pressure and maximum squeeze pressure in patients decreased compared with before treatment, and the differences were statistically significant (P < 0.05). The initial and maximum defecation thresholds after surgery were significantly lower than those before treatment, and the differences were statistically significant (P < 0.05). The postoperative ratings of rectocele, resting phase, and defecation phase in these patients were significantly decreased compared with those before treatment, and the differences were statistically significant (P < 0.05). CONCLUSION: The TST36 stapler is safe and effective in treating rectocele combined with internal rectal prolapse and is worth promoting in clinical work.

Quarantine methods and prevention of secondary outbreak of pandemic (H1N1) 2009.

During the 2009 influenza (H1N1) pandemic, some countries used quarantine for containment or mitigation. Of 152 quarantined university students we studied, risk for illness was higher for students quarantined in a room with a person with a confirmed case; we found no difference between students quarantined in double or single rooms.

Superhydrophobic and oleophobic ultra-fine dry chemical agent with higher chemical activity and longer fire-protection.

The re-ignition of pool fires is a common hazard phenomenon in fire extinguishing. Dry chemicals with oleophobicity may solve this problem because powders can float on the oil surface and prevent evaporation of fuel pool. In this research, MAPP (modified ammonium polyphosphate) with superhydrophobicity, oleophobicity, and higher chemical activity is prepared which can quickly quench pool fires and provide longer protection. The activation indexes of MAPP for water, diesel, aviation kerosene and gasoline are 98.5%, 87.4%, 98.7% and 98.4%, respectively. Lower activation energy of MAPP means that it will show higher chemical activity in fire. The fire-extinguishing performance of MAPP is much higher than that of Commercial UDCA (ultra-fine dry chemical agent) during fire experiments. After extinguished by MAPP, the fuel pool is hard to be re-ignited. The significance of this study is to propose a new strategy for preventing the re-ignition of pool fires.

Clinical observations on the treatment of prolapsing hemorrhoids with tissue selecting therapy.

AIM: To compare the effects and postoperative complications between tissue selecting therapy stapler (TST) and Milligan-Morgan hemorrhoidectomy (M-M). METHODS: Four hundred and eighty patients with severe prolapsing hemorrhoids, who were admitted to the Shenyang Coloproctology Hospital between 2009 and 2012, were randomly divided into observation (n=240) and control (n=240) groups. Hemorrhoidectomies were performed with TST in the observation group and with the M-M technique in the control group. The therapeutic effects, operation security, and postoperative complications in the two groups were compared. The immediate and long-term complications were assessed according to corresponding criteria. Pain was assessed on a visual analogue scale. The efficacy was assessed by specialized criteria. The follow-up was conducted one year after the operation. RESULTS: The total effective rates of the observation and control groups were 99.5% (217/218) and 98.6% (218/221) respectively; the difference was not statistically significant (P=0.322). Their were significant differences between observation and control groups in intraoperative blood loss (5.07±1.14 vs 2.45±0.57, P=0.000), pain (12 h after the surgery: 5.08±1.62 vs 7.19±2.01, P=0.000; at first dressing change: 2.64±0.87 vs 4.34±1.15, P=0.000; first defecation: 3.91±1.47 vs 5.63±1.98, P=0.001), urine retention (n=22 vs n=47, P=0.001), anal pendant expansion after the surgery (2.35±0.56 vs 5.16±1.42, P=0.000), operation time (18.3±5.6 min vs 29.5±8.2 min, P=0.000), and the length of hospital stay (5.3±0.6 d vs 11.4±1.8 d, P=0.000). Moreover TST showed significant reductions compared to M-M in the rates of long-term complications such as fecal incontinence (n=3 vs n=16, P=0.003), difficult bowel movement (n=1 vs n=9, P=0.011), intractable pain (n=2 vs n=12, P=0.007), and anal discharge (n=3 vs n=23, P=0.000). CONCLUSION: TST for severe prolapsing hemorrhoids is a satisfactory technique for more rapid recovery, lower complication rates, and higher operation security.

Botulinum toxin type-A injection to treat patients with intractable anismus unresponsive to simple biofeedback training.

AIM: To evaluate the efficacy of botulinum toxin type A injection to the puborectalis and external sphincter muscle in the treatment of patients with anismus unresponsive to simple biofeedback training. METHODS: This retrospective study included 31 patients suffering from anismus who were unresponsive to simple biofeedback training. Diagnosis was made by anorectal manometry, balloon expulsion test, surface electromyography of the pelvic floor muscle, and defecography. Patients were given botulinum toxin type A (BTX-A) injection and pelvic floor biofeedback training. Follow-up was conducted before the paper was written. Improvement was evaluated using the chronic constipation scoring system. RESULTS: BTX-A injection combined with pelvic floor biofeedback training achieved success in 24 patients, with 23 maintaining persistent satisfaction during a mean period of 8.4 mo. CONCLUSION: BTX-A injection combined with pelvic floor biofeedback training seems to be successful for intractable anismus.

Rapid detection of Trichinella spiralis larvae in muscles by loop-mediated isothermal amplification.

Trichinella spiralis is a tissue-dwelling nematode parasite. A loop-mediated isothermal amplification (LAMP) assay was developed and validated for the sensitive and rapid detection of T. spiralis larvae in muscle samples. Sixteen sets of primers were designed to recognise distinct sequences of a conserved gene, a 1.6kb repetitive element of the Trichinella genome. One set of primers was selected as the most appropriate for rapid detection. The specificity and sensitivity of the primers in LAMP reactions for T. spiralis larvae and muscle samples of mice infected with T. spiralis were determined. Another 10 heterologous parasites were selected for specificity assays. The results showed that target DNA was amplified and visualised by monitoring turbidity and adding calcein detection methods within 70min at an isothermal temperature of 63°C. The sensitivity of LAMP with the detection limit of 362fg/µl was >10 times higher than that for PCR. The designed primers had a good specificity. No cross-reactivity was found with the DNA of any other parasites. The assay was able to detect T. spiralis in all mouse muscle samples infected with 10 T. spiralis larvae on day 20 p.i. We believe this is the first report regarding the application of the LAMP assay for detection of T. spiralis larvae in muscle samples from experimentally infected mice. This method demonstrates a potentially valuable means for the direct detection of T. spiralis larvae in meat inspection.