Correction to: Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides.

Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs.

Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides.

Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs. In this study, hybrid peptides from different species were investigated, and three hybrid antimicrobial peptides, LI, LN, and LC, were designed by combining the typical fragment of human cathelicidin-derived LL37 with either indolicidin, pig nematode cecropin P1 (CP-1) or rat neutrophil peptide-1 (NP-1). In an aqueous solution, all hybrid peptides had an unordered conformation. In simulated membrane conditions, the hybrid peptide LI displayed more ß-turn and ß-hairpin structures, whereas LN and LC folded into α-helix structures. The three interspecific hybrid peptides LI, LN, and LC exhibited different levels of antimicrobial activity against Gram-positive and Gram-negative bacteria. LI demonstrated the highest antimicrobial activity and cell selectivity. The results of the swimming motility indicated that LI repressed bacterial motility in a concentration-dependent method. Endotoxin binding assay demonstrated that hybrid peptide LI conserved the binding ability to LPS (polyanionic lipopolysaccharides) of its parental peptides. Fluorescence assays, flow cytometry, and SEM further revealed that hybrid peptide LI acted through different bacteriostatic mechanisms than LL37 and indolicidin and that LI killed bacterial cells via membrane damage. In summary, this study demonstrated that hybrid peptide LI produced by interspecific hybrid synthesis possessed strong cell selectivity and is a promising therapeutic candidate for drug-resistant bacteria infection.

Clinical analysis of patients with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis.

This prospective study analyzed the clinical characteristics of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis and explored the relationship between MPO-ANCA and clinical manifestations of the associated vasculitis in 132 p-ANCA and MPO-ANCA-positive patients (average age, 62.3 ± 14.8 years) who were initially diagnosed with ANCA-associated vasculitis. The p-ANCA and MPO-ANCA levels in peripheral blood were detected in all patients. Among these, 128 (97%) had microscopic polyangiitis (MPA), 3 (2.3%) had granulomatous polyangiitis, and 1 (0.7%) had eosinophilic granulomatous vasculitis. The average time of diagnosis was 10.2 ± 18 months; only 14 (10.6%) patients were diagnosed within 1 month. The main organs involved and the corresponding number of patients were: renal, 95 (72%); lung, 89 (67.4%); joints, 35 (26.5%); heart, 26 (19.7%); peripheral nerve, 23 (17.4%); skin rash, 14 (10.6%); and CNS, 13 (9.8%). Older patients were more likely to show lung involvement in the early disease stage, whereas the joints were involved mostly in the younger patients. The p-ANCA levels (mean titers, 1:60) were not correlated with disease activity and extent of organ involvement, and the MPO-ANCA levels were positively correlated with disease activity, but had no correlation with the extent of organ involvement. MPO-ANCA vasculitis is a common occurrence in China; it mainly involves the elderly and presents as clinical manifestations of MPA. However, the multiple organ damage is not specific leading to delay in diagnosis. MPO-ANCA may play a pathogenic role in the associated vasculitis, and the diverse clinical manifestations might be related with the different characteristics of MPO-ANCA.

Cell specificity and molecular mechanism of antibacterial and antitumor activities of carboxyl-terminal RWL-tagged antimicrobial peptides.

Antimicrobial peptides (AMPs) constitute a diverse class of naturally occurring or synthetic antimicrobial molecules that have potential for use in the treatment of drug-resistant infections. Several undesirable properties of AMPs, however, may ultimately hinder their development as antimicrobial agents. Thus, new synthetic strategies, including primarily the de novo design of AMPs, urgently need to be developed. In this study, a series of peptides, H-(RWL) n (n = 1, 2, 3, 4, or 5), were designed. H represents GLRPKYS from the C-terminal sequence of AvBD-4. Our results showed that these RWL-tagged peptides can kill not only bacteria but also human hepatocellular carcinoma HepG2 cells. However, the peptide tagged with two repeats of RWL (GW13) showed less affinity to human embryonic lung fibroblast MRC-5 cells or human red blood cells (hRBCs) than HepG2 cells. These results demonstrated that GW13, with high amphiphilicity, exerted great selectivity toward bacteria and cancer cells, sparing host mammalian cells. The mechanism of action against bacteria was elucidated through combined studies of scanning electron microscopy (SEM) and fluorescence assays, showing that the peptide possessed membrane-lytic activities against microbial cells. The fluorescence assays illustrated that GW13 induced apoptosis in HepG2 cells. The cell morphology of HepG2 cells, observed by SEM, further illustrated that GW13 causes cell death by damaging the cell membrane. Our results indicate that GW13 has considerable potential for future development as an antimicrobial and antitumor agent.

Cytomegalovirus immediate-early promoter efficiently drives heterogeneous gene expression in Spodoptera frugiperda (Sf9) insect cells.

Recently, wide attention has been given to the potential of recombinant baculovirus as a gene transfer vehicle for mammalian gene therapy. In this study, we packaged the recombinant baculoviruses with cytomegalovirus immediate-early (CMV-IE) promoter in Spodoptera frugiperda (Sf9) insect cells, and found that the CMV-IE promoter could efficiently drive the exogenic gene expression in the cells 12 h post-infection (h.p.i.). The expression level at 72 h.p.i. was only around half of that driven by polyhedrin promoter (Ppolh). However, the biological activity of the reporter proteins at 72 h.p.i. were similar with that driven by Ppolh. In addition, the Sf9 cells transfected with CMV-IE-containing plasmids also expressed foreign genes, suggesting that the CMV-IE-directed heterogeneous gene expression in the Sf9 cells was baculovirus-independent. These results demonstrate that the CMV-IE promoter might be used as a regular promoter in Sf9 cells.

Rational design of cationic antimicrobial peptides by the tandem of leucine-rich repeat.

Antimicrobial peptides represent ancient host defense effector molecules present in organisms across the evolutionary spectrum. Lots of antimicrobial peptides were synthesized based on well-known structural motif widely existed in a variety of lives. Leucine-rich repeats (LRRs) are sequence motifs present in over 60,000 proteins identified from viruses, bacteria, and eukaryotes. To elucidate if LRR motif possesses antimicrobial potency, two peptides containing one or two LRRs were designed. The biological activity and membrane-peptide interactions of the peptides were analyzed. The results showed that the tandem of two LRRs exhibited similar antibacterial activity and significantly weaker hemolytic activity against hRBCs than the well-known membrane active peptide melittin. The peptide with one LRR was defective at antimicrobial and hemolytic activity. The peptide containing two LRRs formed α-helical structure, respectively, in the presence of membrane-mimicking environment. LRR-2 retained strong resistance to cations, heat, and some proteolytic enzymes. The blue shifts of the peptides in two lipid systems correlated positively with their biological activities. Other membrane-peptide experiments further provide the evidence that the peptide with two LRRs kills bacteria via membrane-involving mechanism. The present study increases our new understanding of well-known LRR motif in antimicrobial potency and presents a potential strategy to develop novel antibacterial agents.

Effect of surgery treatment on hypersplenism caused by cirrhotic portal hypertension.

AIM: Aim of the study was to summarize the types and quantities of peripheral hematocytopenia in the patients of hypersplenism caused by cirrhotic portal hypertension and investigate the effect of surgery, including splenectomy on the patient's peripheral blood cells and liver function. METHODS: The quantities of peripheral blood cells in the 322 patients of hypersplenism, caused by cirrhotic portal hypertension, were retrospectively studied. Then, the preoperative and postoperative values of peripheral blood cells and liver function were compared in 266 patients who were followed up. The liver function was scored and graded according to Child-Pugh scoring system. RESULTS: The study enrolled 322 patients who showed hematocytopenia, including multi-hemocyte decrease in 206 patients (64%) and simple hemocyte decrease in 116 patients (36%). After surgical treatment in the 226 patients who were followed up, the quantities of peripheral blood cells significantly increased (P<0.01), Child-Pugh grade A increased by 32 patients (14.2%), while Child-Pugh grade C increased only by 2 patients (0.9%), the liver function scores decreased (P<0.05). CONCLUSION: Hypersplenism caused by cirrhotic portal hypertension mainly manifests as a multi-hemocyte decrease and rarely shows single types of hematocytopenia. Surgical intervention including splenectomy can increase the reduction of hemocytes and promote the recovery of liver function.

Effects of different sources and levels of dietary gossypol on gossypol residues in plasma and milk of lactating cows.

Free gossypol residues in tissues or milk from feeding whole cottonseed and cottonseed meal were measured for their effect on health of dairy cows and humans. Forty lactating cows were randomly assigned to 5 treatments in a 60-d experiment to investigate the effects of sources and dietary level of gossypol on plasma and milk gossypol concentrations in lactating cows. Five experimental diets had identical net energy for lactation and crude protein content on a dry matter (DM) basis. Soybean meal was the main protein ingredient used in the control diet. Cottonseed meal (CSM) or whole cottonseed (WCS) substituted for part of the soybean meal in the other 4 diets. Gossypol levels in the 5 diets were 0 (control), 91.15 mg/kg of DM in CSM1, 117.31mg/kg of DM in CSM2, 385.43 mg/kg of DM in WCS1, and 611.13 mg/kg in WCS2. Yields of 3.5% fat-corrected milk were significantly higher for cows in the WCS2 group; cows in the CSM1 and WCS1 groups showed no differences but both were numerically higher than the control and CSM2 groups. Milk protein concentration was lower for cows consuming WCS1 compared with the control group. Lactose concentration was lower for cows in the CSM2 group compared with the WCS2 group, but no differences were observed among other diets. Aspartate aminotransferase in serum was significantly higher for the WCS2 group compared with the control and WCS1 groups, but no difference was observed with the CSM1 and CSM2 groups. Concentrations of gossypol in plasma and milk of cows in the WCS1 and WCS2 groups were both higher than those of the other groups. No adverse effects were observed on cows fed diets containing 12.0% CSM, and no gossypol was found in plasma and milk. When WCS comprised 15% of the diet DM, yields of 3.5% fat-corrected milk were increased in cows and gossypol was detected in plasma and milk but not at harmful levels.

Effect of ulinastatin on myocardial ischemia reperfusion injury through ERK signaling pathway.

OBJECTIVE: To study the effect of ulinastatin (UTI) on myocardial ischemia-reperfusion injury (MIRI) through the extracellular signal-regulated kinase (ERK) signaling pathway. MATERIALS AND METHODS: A total of 24 Sprague-Dawley rats were randomly divided into sham group (n=8), I/R group (n=8), and UTI group (n=8), and the rat model of MIRI was established. The changes in the content of serum biochemical indexes, including superoxide dismutase (SOD) and malondialdehyde (MDA), were detected using the kits, and the changes in the expressions of serum inflammatory factors, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were detected using the quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) kits. Moreover, the ERK phosphorylation level in myocardial tissues was detected using the immunofluorescence method, and the ERK phosphorylation level and cleaved caspase-3 expression were detected via qRT-PCR and Western blotting. RESULTS: Compared with those in sham group, the serum SOD content significantly declined, while the MDA content was significantly increased in I/R group, and they were significantly improved in UTI group (p<0.01). The results of detection using qRT-PCR and ELISA kits revealed that the inflammatory factors (IL-6 and TNF-α) in UTI group were significantly improved (p<0.01). The immunofluorescence results showed that the ERK phosphorylation level in myocardial tissues was significantly increased in UTI group. The results of qRT-PCR and Western blotting manifested that both ERK phosphorylation level and cleaved caspase-3 expression were significantly improved in UTI group (p<0.01). CONCLUSIONS: UTI can play a protective role in MIRI through up-regulating the ERK signaling pathway.

MiRNA-155 promotes the invasion of colorectal cancer SW-480 cells through regulating the Wnt/ß-catenin.

OBJECTIVE: To investigate the role of microRNA-155 (miR-155) in the potential invasion of colon cancer cell and the underlying mechanism. PATIENTS AND METHODS: The expression level of miR-155 in colon cancer and adjacent normal tissues was detected by Real-time quantitative polymerase chain reaction (RT-PCR). miR-155 mimics (miR-155), or siRNA against ß-catenin (ß-catenin siRNA), was transfected into human colon cancer cell line SW-480 using Lipofectamine 2000, respectively. RT-PCR was used to measure the expression levels of miR-155 and ß-catenin mRNA, and ß-catenin protein expression level was detected by Western blot. The in-vitro cell invasion abilities were determined by transwell invasion assays after up-regulating miR-155 or knocking down of ß-catenin. RESULTS: MiR-155 directly regulates ß-catenin at the transcriptional level, and promotes the invasion potential of colon cancer cell, at least partly through the upregulation of ß-catenin. CONCLUSIONS: The findings of this study suggest that miR-155 and ß-catenin may have a unique potential as a novel biomarker candidate for diagnosis and treatment of tumor metastasis.

[Frequency and position characteristics of the vestibular dysfunction in vestibular neuritis patients].

Objective:To investigate frequency and position characteristics of the vestibular dysfunction in vestublar neuritis patients. Method:Colaric test (CT), head impulse test (HIT), cervical vestibular evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP) were applied in 43 vestublar neuritis patients to assess their vestublar dysfunction. Superior vestublar nerve (S-VN), inferior vestibular nerve (I-VN), total vestibular nerve (T-VN) and each vestibular end organ incidence rate were calculated and statistically analyzed. Result:CT incidence rate (93.0%) was statistically higher than that of HIT (72.1%) (P<0.01). Total frequency incidence rate (72.1%) was statistically higher than that of low frequency (20.9%) (P<0.01). No high frequency only case was observed. The incidence rate of S-VN only, I-VN only and T-VN was 44.2%, 4.7% and 51.2% respectively. Among them, the incidence rate of I-VN was significantly lower than the others (P<0.01). The incidence rate of vestibular end organs was 17.4% (S-SCC), 44.2% (H-SCC), 20.9% (P-SCC), 39.5% (utricule) and 26.7% (saccule) respectively. The incidence rate of H-SCC was remarkably higher than the other semicircular canals (P<0.01). The difference between utricule and saccule was not statistically significant. Conclusion:The semicricular canal dysfunction in vestibular neuritis patients mainly involves total frequency of vestibular function, low frequency is more common than high frequency. Total vestibular nerve and single S-VN are mostly involved in vestibular neuritis.

[The clinical value of vestibular autorotation test in the diagnosis of otogenic vertigo].

Objective:To explore the clinical value of vestibular autorotation test (VAT) in the treatment for otogenic vertigo patients. Method:One hundred and twenty-nine definite otogenic vertigo patients were included. All patients underwent the VAT and caloric test (CT). The results were analyzed statistically. Result:In VAT examination, 89 (69.0%) cases were abnormal. In CT examination, 56 (43.4%) cases were abnormal. In the contrast test of VAT and CT, VAT results were abnormal in 47 (36.4%) patients and CT results were abnormal in 14 (10.9%) patients. The number of patients whose both VAT and CT results were abnormal was 42 (32.6%). The total number of patients with various abnormal results was 103 (79.8%). According to statistical analysis, the abnormal result rate of VAT was higher than that of CT. The abnormal result rate of both VAT and CT was higher than that of each single test. There was statistic significance in the difference (χ²=1.670, P<0.05). Conclusion:For otogenic vertigo patients, their abnormal result rate of VAT is higher than that of CT. VAT and CT can be mutually complementary. The combination of VAT and CT can help to understand the function of semicircular canal in the general and provide reference for the treatment of otogenic vertigo diseases.

Paclitaxel and gemcitabine combinational drug-loaded mucoadhesive delivery system in the treatment of colon cancers.

The combination of two different types of chemo-therapeutic drugs via nanocarriers is emerged as a promising strategy for treating multiple cancers. Such a co-delivery system will synchronize the drug exposure and synergize the therapeutic effects. Herein, we prepared a paclitaxel (PTX) and gemcitabine (GEM)-loaded N-succinyl chitosan nanoparticles (NSC NP) to target colon cancer. NSC NP showed a pH sensitive swelling at colonic pH and exhibited a sequential release pattern for both the drugs. Binary drug combination exhibited a synergistic cytotoxicity against HT-29 colon cancer cells with a remarkable G2/M phase arrest. Specifically, in vivo antitumor efficacy study showed that NSC NP prolonged the survival time of tumor-bearing mice up to 45 days wherein 50% of mice were still alive. Therefore, these results suggest that co-delivery of drugs with a suitable delivery system could potentially improve the therapeutic efficacy in colon cancers. The study can be further continued by using different types of chemotherapeutic drugs that targets different molecular targets using pH-sensitive nanocarriers.

Key factors of therapeutic effects for surgery in patients with cirrhotic portal hypertension.

OBJECTIVE: In the clinical management of cirrhotic portal hypertension, surgery is often necessary; however, the operative mortality rate is high. PATIENTS AND METHODS: Data from 161 patients, who underwent surgery for cirrhotic portal hypertension, were analyzed, and 24 potential predictors of surgical outcome were assessed. A Kruskal-Wallis rank sum test was used for single-factor comparisons, and multivariate logistic regression for multifactor comparisons to identify key factors for poor surgical outcomes and calculate their scores. RESULTS: Six predictors of poor surgical outcomes were identified: postoperative bleeding within 30 h of > 2 L, with a score of 3; severe liver atrophy (an anteroposterior diameter of the left lobe of ≤ 55 mm and an oblique diameter of the right lobe ≤ 110 mm), with a score of 3; a base excess of <-3 mmol/L, with a score of 3; a platelet count of <3 T/L, with a score of 2; an amount of intraoperative bleeding of > 2 L, with a score of 2; and a red blood cell count of < 3 G/L, with a score of 1. For patients with good outcome (n = 147), all patients had a score of ≤ 3, except one patient who had a score of 4. With respect to patients who died (n = 14), all had a score of ≥ 5, except one patient who had a score of 4. A significant difference was observed between the two groups (p < 0.05). The mortality was 100% in patients with a score of ≥ 7. CONCLUSIONS: Six key factors for poor surgical outcomes were identified in this study. Operative mortality appears to be significantly increased in patients with a score of 5-6. Surgery should be contraindicated in patients with a score of ≥ 7. To reduce mortality, close attention should be paid to preoperative and intraoperative treatment and prevention to achieve a score of < 4.