Scanning assay of beta-galactosidase activity

Beta-galactosidase, encoded by the lacZ gene in E. coli, can cleave lactose and structurally related compounds to galactose and glucose or structurally related products. Its activity can be measured using an artificial substrate, o-nitrophenyl-beta-D-galactopyranoside (ONPG). Miller firstly described the standard quantitative assay of beta-galactosidase activity in the cells of bacterial cultures by disrupting the cell membrane with the permeabilization solution instead of preparing cell extracts. Therefore, beta-galactosidase became one of the most widely used reporters of gene expression in molecular biology to reflect intracellular gene expression difference. But the Miller assay procedure could not monitor the beta-galactosidase reaction in real time and its results were greatly influenced by some operations in the Miller procedure, such as permeabilization time, reaction time and concentration of the cell suspension. A scanning method based on the Miller method to determine the intracellular beta-galactosidase activity in E. coli Tuner (DE3) expressing -galactosidase in real time was developed and the permeabilization time of cells was optimized for that. The comparison of 3 assays of beta-galactosidase activity (Miller, colorimetric and scanning) was made. The results proved that scanning method for the determination of enzyme activity with using ONPG as substrate is simple, fast and reproducible.

First Report of Fusicoccum aesculi Causing Leaf Spots of Paeonia suffruticosa in Henan Province, China

Tree peony (Paeonia suffruticosa) is regarded as the national flower of China and is cultivated throughout the country. In early August 2010, a moderately severe leaf spot was observed on tree peony cultivated in a garden of Zhengzhou, Henan Province, where approximately 15% of trees were diseased. In 2011, a less damaging leaf spot was also observed in another area of the city with approximately 10% of trees diseased. Early symptoms appeared as small, round, pale-brown lesions on the leaves. Lesions expanded into 5- to 20-mm-diameter spots that were elliptical or irregular, brown to dark brown. A fungus was consistently isolated from the leaf spots on potato dextrose agar (PDA) in grey-black colonies, but produced few pycnidia. Black pycnidia were ostiolate, globose, papillate, formed in uniloculate or multiloculate stromata that were immersed in the leaf, and became erumpent at maturity. Conidiophores or conidiogenous cells were hyaline and cylindrical. Conidia were hyaline, granular, fusoid to ellipsoid, aseptate, with a sub-truncate base, and 20 to 28 × 4.5 to 7.5 μm (mean dimensions of 50 conidia: 24.5 × 5.2 μm). The pathogen was identified as Fusicoccum aesculi, anamorphic stage of Botryosphaeria dothidea, on the basis of morphology (2). The identity of the fungus was confirmed to be F. aesculi by DNA sequence analysis of the internal transcribed spacer (ITS) region (GenBank Accession No. JQ323001), which was 100% identical to those of other F. aesculi isolates (GenBank Accession Nos. GU997686.1 and GU723469.1) (1). Pathogenicity tests were done by inoculating each of 10 leaves on one 7-year-old tree with a mycelial plug (0.5 cm diameter) harvested from the periphery of a 7-day-old colony. An equal number of leaves on the same tree, serving as controls, were mock-inoculated with plugs of PDA medium. Inoculated leaves were covered with plastic for 24 h to maintain high relative humidity and incubated at about 25°C. The plugs were removed after 48 h. After 7 days, 80% of the inoculated leaves showed symptoms identical to those observed in the field under natural conditions, whereas controls remained symptom-free. Reisolation of the fungus from lesions on inoculated leaves confirmed that the causal agent was F. aesculi. Pathogenicity tests were repeated on the other two trees by the same methods with the same results. To our knowledge, this is the first report of F. aesculi infecting P. suffruticosa in China. References: (1) S. Mohali et al. Mycol. Res. 110:405, 2006. (2) B. C. Sutton. The Coelomycetes. CABI Publishing, New York, 1980.

Nanoparticle biofabrication using English ivy (Hedera helix)

BACKGROUND

English ivy (Hedera helix) is well known for its adhesive properties and climbing ability. Essential to its ability to adhere to vertical surfaces is the secretion of a nanocomposite adhesive containing spherical nanoparticles, 60-85 nm in diameter, produced exclusively by root hairs present on adventitious roots. These organic nanoparticles have shown promise in biomedical and cosmetic applications, and represent a safer alternative to metal oxide nanoparticles currently available.

RESULTS

It was discovered that the maximum adventitious root production was achieved by a 4 h application of 1 mg/ml indole-3 butyric acid (IBA) to juvenile English ivy shoot segments cultured in custom vessels. After incubation of the shoots under continuous light at 83 μmol/m2 s at 20°C for 2 weeks, the adventitious roots were harvested from the culture system and it was possible to isolate 90 mg of dry weight nanoparticles per 12 g of roots. The nanoparticle morphology was characterized by atomic force microscopy, and found to be similar to previous studies.

CONCLUSIONS

An enhanced system for the production of English ivy adventitious roots and their nanoparticles by modifying GA7 Magenta boxes and identifying the optimal concentration of IBA for adventitious root growth was developed. This system is the first such platform for growing and harvesting organic nanoparticles from plants, and represents an important step in the development of plant-based nanomanufacturing. It is a significant improvement on the exploitation of plant systems for the formation of metallic nanoparticles, and represents a pathway for the generation of bulk ivy nanoparticles for translation into biomedical applications.

Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S. aureus of human origin (qacA/B and smr) and from bovine, equine, and caprine staphylococcal isolates (qacG, qacH, and qacJ). This study investigated the presence of AR genes in porcine MRSA isolates. Plasmid DNA from 100 MRSA ST9 strains isolated from pig carcasses was amplified for the presence of AR genes. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) to benzalkonium chloride (BC) and chlorhexidine gluconate (CHX) were determined in AR gene-positive isolates. qacG was present in 45 strains, eight of which also harbored smr. No strains carried qacA/B, qacH or qacJ. Presence of smr increased MICs to both BC and CHX and MBCs of CHX, but qacG presence only resulted in elevated MBC for CHX. This is the first report of AR genes from a porcine source. AR gene positivity has previously been associated with methicillin resistance and AR gene presence in these strains may increase their ability to persist in the environment. Improved implementation of hygiene measures during transportation and pre- and post-slaughter should be considered to prevent spread in the community.

p38 MAPK in myeloma cells regulates osteoclast and osteoblast activity and induces bone destruction

p38 mitogen-activated protein kinase (MAPK), which is constitutively activated in human myeloma, has been implicated in bone destruction by this cancer, but the processes it recruits are obscure. In this study, we show that p38 activity in myeloma inhibits osteoblast differentiation and bone formation, but also enhances osteoclast maturation and bone resorption. p38 regulated the expression and secretion of the Wnt pathway antagonist DKK-1 and the monocyte chemoattractant MCP-1. Attenuating p38, DKK-1, or MCP-1 were each sufficient to reduce bone lesions in vivo. Although it is well known that DKK-1 inhibits osteoblast differentiation, we found that together with MCP-1, it could also promote osteoclast differentiation and bone resorption. The latter effects were mediated by enhancing expression of RANK in osteoclast progenitor cells and by upregulating secretion of its ligand RANKL from stromal cells and mature osteoblasts. In summary, our study defined the mechanisms by which p38 signaling in myeloma cells regulates osteoblastogenesis, osteoclastogenesis, and bone destruction. Our findings, which may have implications for bone invasion by other cancers where p38 is elevated, strongly suggests that targeting p38 for inhibition may offer an effective therapeutic approach to treat osteolytic bone lesions in patients with myeloma.

[Expression of MMP-2 and MMP-9 in non-small-cell lung cancer and their prognostic value.]

BACKGROUND

To determine the expression of MMP-2 and MMP-9 in non-small cell lung cancer (NSCLC) tissues and their prognostic value.

METHODS

The expression of MMP-2 and MMP-9 were detected in 62 NSCLC tissues by immunohistochemical method , and 28 normal lung tissues and 32 para-cancerous dysplastic lung tissues as control.

RESULTS

The expression levels of MMP-2 (77. 4 % ,48/ 62) and MMP-9 (80. 6 % ,50/ 62) in the NSCLC tissues were significantly higher than those in the control groups ( P < 0. 005 , P < 0. 005) . The positive rates of MMP-2 and MMP-9 in adenocarcinoma and adenosquamous carcinoma were remarkably higher than those in squamous cell carcinoma ( P < 0. 005 , P < 0. 05) , were much higher in stage III+IV group than those in stage I+II group ( P < 0. 025 , P < 0. 05) , and were significantly higher in tumors with lymph node metastasis than those without lymphatic metastasis ( P < 0. 005 , P < 0. 05) . The patients surviving for 1 and 3 year had much higher MMP-2 and MMP-9 expression rates than those surviving for over 5 year ( P < 0. 05 , P < 0. 005) .

CONCLUSIONS

MMP-2 and MMP-9 expression in NSCLC tissues might be indicators of tumor behavior.

Face recognition using artificial neural network group-based adaptive tolerance (GAT) trees

Recent artificial neural network research has focused on simple models, but such models have not been very successful in describing complex systems (such as face recognition). This paper introduces the artificial neural network group-based adaptive tolerance (GAT) tree model for translation-invariant face recognition, suitable for use in an airport security system. GAT trees use a two-stage divide-and-conquer tree-type approach. The first stage determines general properties of the input, such as whether the facial image contains glasses or a beard. The second stage identifies the individual. Face perception classification, detection of front faces with glasses and/or beards, and face recognition results using GAT trees under laboratory conditions are presented. We conclude that the neural network group-based model offers significant improvement over conventional neural network trees for this task.

Reduction of albumin adsorption onto silicon surfaces by Tween 20

The ability of Tween 20 to reduce the adsorption of albumin on silicon surfaces of different hydrophobicity was investigated by ellipsometry. As expected, protein adsorption was found to depend on the degree of hydrophobicity of the surfaces and on the concentration of the surfactant. A reduction of 90% in albumin adsorption on hydrophobic methylated surfaces by 0.05% Tween 20 was achieved, whereas a reduction of only 15% on hydrophilic surfaces was observed. Experiments of time-dependent protein adsorption in both pure protein and protein-surfactant mixtures were conducted to ascertain the stability of physically adsorbed Tween 20 films on intermediate silicon surfaces. It was found that the adsorbed Tween 20 film was robust and there was no evidence of exchange of the Tween molecules with albumin for up to 240 min exposure. Adsorption minima were confirmed to correlate with minima in contact angle and critical micelle concentration (CMC). (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 618-625, 1997.

Dynamics of stochastic mutation to immunodominance

Although a virus contains several epitopes that can be recognized by cytotoxic T lymphocytes (CTL), the immune responses against different epitopes are not uniform. Only a few CTLs (sometimes just one) will be immunodominant. Mutation of epitopes has been recognized as an important mechanism of immunodominance. Previous research has studied the influences of sporadic, discrete mutation events. In this work, we introduce a bounded noise term to account for the intrinsic stochastic nature of mutation. Monte Carlo simulations of the stochastic model show abounding complex phenomena, and patterns observed from the numerical simulations shed lights on long term trends of immunodomnance.

Identification and analysis of the first 2009 pandemic H1N1 influenza virus from U.S. feral swine

The first case of pandemic H1N1 influenza (pH1N1) virus in feral swine in the United States was identified in Texas through the United States Department of Agriculture (USDA) Wildlife Services' surveillance program. Two samples were identified as pandemic influenza by reverse transcriptase quantitative PCR (RT-qPCR). Full-genome Sanger sequencing of all eight influenza segments was performed. In addition, Illumina deep sequencing of the original diagnostic samples and their respective virus isolation cultures were performed to assess the feasibility of using an unbiased whole-genome linear target amplification method and multiple sample sequencing in a single Illumina GAIIx lane. Identical sequences were obtained using both techniques. Phylogenetic analysis indicated that all gene segments belonged to the pH1N1 (2009) lineage. In conclusion, we have identified the first pH1N1 isolate in feral swine in the United States and have demonstrated the use of an easy unbiased linear amplification method for deep sequencing of multiple samples.

Protective efficacy evaluation induced by recombinant protein LHD-Sj23-GST of Schistosoma japonicum emulsified with three different adjuvants

As a complement to chemotherapy and other control approaches, the development of an effective vaccine is necessary to combat Schistosomiasis japonica that remains a serious public health problem in China. In the present study, mice were vaccinated with purified recombinant protein LHD-Sj23-GST (large hydrophilic domain of 23 kDa antigen of S. japonicum fused with Sj26GST) emulsified with Freund's adjuvant (FA), Montanide ISA 206 and Montanide ISA 70 M and challenged with cercariae, the protective efficacy induced by the recombinant protein was evaluated, and the LHD-Sj23-GST-specific IgG and its subtypes were determined. The result revealed that a significant worm burden reduction (58.8%, 26.3% and 54.3%; P<0.05) was obtained in mice vaccinated with LHD-Sj23-GST emulsified with three different adjuvants compared to those mice treated with respective adjuvant only. ELISA test suggested that the high-level production of LHD-Sj23-GST-specific IgG1, IgG2a and IgG3 antibodies may participate in protecting against schistosome infection.

Interleukin-17 signaling in inflammatory, Kupffer cells, and hepatic stellate cells exacerbates liver fibrosis in mice

BACKGROUND & AIMS

Interleukin (IL)-17 signaling has been implicated in lung and skin fibrosis. We examined the role of IL-17 signaling in the pathogenesis of liver fibrosis in mice.

METHODS

Using cholestatic and hepatotoxic models of liver injury, we compared the development of liver fibrosis in wild-type mice with that of IL-17RA(-/-) mice and of bone marrow chimeric mice devoid of IL-17 signaling in immune and Kupffer cells (IL-17RA(-/-) to wild-type and IL-17A(-/-) to wild-type mice) or liver resident cells (wild-type to IL-17RA(-/-) mice).

RESULTS

In response to liver injury, levels of Il-17A and its receptor increased. IL-17A increased appeared to promote fibrosis by activating inflammatory and liver resident cells. IL-17 signaling facilitated production of IL-6, IL-1, and tumor necrosis factor-α by inflammatory cells and increased the expression of transforming growth factor-1, a fibrogenic cytokine. IL-17 directly induced production of collagen type I in hepatic stellate cells by activating the signal transducer and activator of transcription 3 (Stat3) signaling pathway. Mice devoid of Stat3 signaling in hepatic stellate cells (GFAPStat3(-/-) mice) were less susceptible to fibrosis. Furthermore, deletion of IL-23 from immune cells attenuated liver fibrosis, whereas deletion of IL-22 exacerbated fibrosis. Administration of IL-22 and IL-17E (IL-25, a negative regulator of IL-23) protected mice from bile duct ligation-induced liver fibrosis.

CONCLUSIONS

IL-17 induces liver fibrosis through multiple mechanisms in mice. Reagents that block these pathways might be developed as therapeutics for patients with cirrhosis.

Oral health related quality of life among older adults in Central China

AIM

To obtain information about the impact of oral health status on the quality of life in older adults in Central China, and furthermore, to investigate the influence of various demographic and socio-economic factors on oral health related quality of life (OHRQoL).

METHODS

This study comprised a stratified random sample of 1,000 older adults in Central China. Questionnaires including demographic factors, education and income level, denture wearing status and Oral Health Impact Profile (OHIP)-14 were used in a face-to-face interview.

RESULTS

Of the study population 82% stated that they had some forms of problems related to their quality of life. The mean value of the simple count and single summary item scores for OHIP-14 were 0.47 (sd 0.50) and 6.83 (sd 6.84) respectively for the entire study population. "Uncomfortable to eat" and "taste worse" were the two most common problems reported using the simple count method for OHIP-14, while the "physical pain" being the highest scored domain of the measure. When the effect of all independent variables was analysed in multivariate analysis, education level and denture wearing status were significantly (p < 0.05) associated with the OHRQoL measure.

CONCLUSIONS

In this Chinese older adult sample, education level and denture wearing status were related to having oral problems as estimated using the OHIP-14.

Human papillomavirus modifies the prognostic significance of T stage and possibly N stage in tonsillar cancer

BACKGROUND

Despite the association with more advanced nodal stage, patients with human papillomavirus (HPV) positive oropharyngeal cancers have better outcomes. We examined whether the HPV can modify the effect of known prognostic factors in tonsillar cancer.

PATIENTS AND METHODS

A total of 489 patients from 10 centres were followed up for recurrence or death for a median of 3.2 years. Determinants of the rate of locoregional recurrence, death from tonsillar cancer and overall survival were modelled using Cox regression.

RESULTS

The prognostic value of T and N stages were modified by HPV as indicated by statistically significant interaction terms. After adjusting for age, gender and treatment, T stage appeared relevant only for HPV-positive cancers (where a higher T stage was associated with worse outcomes). There was some evidence that N stage was a more relevant prognostic factor for HPV-negative than -positive cancers. There was no evidence that the HPV modifies the effect of age, gender or grade on outcomes.

CONCLUSIONS

This study suggests that the prognostic significance of the conventional staging system in tonsillar cancer is modified by HPV.

Effect of stenting on patients with chronic internal carotid artery occlusion

AIM

Effects of carotid artery stenting (CAS) on patients with chronic internal carotid artery occlusion are unknown.

METHODS

This study included 21 patients who underwent successful CAS treatment and 41 patients who received optimal medical therapy. Modified Rankin Scale (mRS) and cardiocerebral vascular events were compared between CAS and medical therapy group.

RESULTS

The mRS in CAS group was lower than in control group during a 2-year follow up (P<0.05 or 0.01). The combined cerebrovascular events and mortality in study group was lower than in the control group (33.4% vs. 56.1%, P=0.045), but there was no statistically significant difference in the cerebrovascular event (28.6% vs. 46.3%, P=0.088) or mortality rate (4.8% vs. 9.8%, P=0.247) between the two groups. Cox regression analysis revealed that smoking (RR=3.189, 95% CI 1.020-9.968, P=0.046), diabetes (RR=2.717, 95% CI 1.113-6.631, P=0.028), and baseline National Institute of Health stroke scale (RR=2.984, 95% CI 1.049-8.485, P=0.040) were independent risk factors for major cerebrovascular events following CAS.

CONCLUSION

CAS was superior to drug therapy in achieving better functional outcomes in patients with chronic internal carotid artery occlusion. However, CAS was not associated with a statistically significant reduction in cerebrovascular events or mortality. Larger and randomized clinical trials are required to ascertain the long-term benefits of CAS in patients with chronic internal carotid artery occlusion.