Enhanced production of aureofuscin by over-expression of AURJ3M, positive regulator of aureofuscin biosynthesis in Streptomyces aureofuscus

AIMS

 The production of aureofuscin is very low in the wild-type strain. We attempt to increase the production of aureofuscin by over-expression of a controlling gene in the wild-type strain.

METHODS AND RESULTS

The aurj3M gene was PCR-amplified from Streptomyces aureofuscus SYAU0709, ligated into vector pMD19 and sequenced. The predicted translation of the 579-bp cloned fragment was 97% similar to pimM from Streptomyces natalensis, which has an N-terminal PAS domain and a LuxR-type C-terminal helix-turn-helix. Recombinant bacterial strains were constructed by transforming SYAU0709 with an expression plasmid (pBJJ3M) that contained aurj3M, thereby increasing the number of aurj3M gene copies.

CONCLUSIONS

Bioassays for the antibiotic compound aureofuscin indicated that the recombinant bacteria had greater antifungal activity than the wild-type strain. Specifically, the recombinant strain produced approx. 600% more aureofuscin, as quantified by high-performance liquid chromatography analysis.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this approach has not been attempted in S. aureofuscus before and few genes in the aureofuscin pathway have been cloned and characterized.

The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general

OBJECTIVE

To evaluate new classification criteria for peripheral spondyloarthritis (SpA) in patients with SpA with peripheral manifestations only.

METHODS

In this Assessment of SpondyloArthritis international Society (ASAS) study, two prespecified sets of criteria were compared against the European Spondylarthropathy Study Group (ESSG) and Amor criteria in newly referred consecutive patients with undiagnosed peripheral arthritis, and/or enthesitis, and/or dactylitis that usually began before 45 years of age. The clinical diagnosis (SpA vs no SpA) made by the ASAS rheumatologist served as reference standard.

RESULTS

In all, 24 ASAS centres included 266 patients, with a final diagnosis of SpA being made in 66.2%. After adjustments a final set of criteria showed the best balance between sensitivity (77.8%) and specificity (82.9%): arthritis and/or enthesitis and/or dactylitis plus (A) one or more of the following parameters: psoriasis, inflammatory bowel disease, preceding infection, human leucocyte antigen B27, uveitis, sacroiliitis on imaging, or (B) two or more other parameters: arthritis, enthesitis, dactylitis, inflammatory back pain in the past, family history of SpA. The new criteria performed better than modified versions of the ESSG (sensitivity 62.5%, specificity 81.1%) and the Amor criteria (sensitivity 39.8%, specificity 97.8%), particularly regarding sensitivity. In the entire ASAS population of 975 patients the combined use of ASAS criteria for axial SpA and ASAS criteria for peripheral SpA also had a better balance (sensitivity 79.5%, specificity 83.3%) than the modified ESSG (sensitivity 79.1%, specificity 68.8%) and Amor criteria (sensitivity 67.5%, specificity 86.7%), respectively.

CONCLUSIONS

The new ASAS classification criteria for peripheral SpA performed well in patients presenting with peripheral arthritis, enthesitis and/or dactylitis.

p21WAF1/CIP1 gene transcriptional activation exerts cell growth inhibition and enhances chemosensitivity to cisplatin in lung carcinoma cell

Background

Non-small-cell lung carcinomas (NSCLCs) exhibit poor prognosis and are usually resistant to conventional chemotherapy. Absence of p21WAF1/CIP1, a cyclin-dependent kinase (cdk) inhibitor, has been linked to drug resistance in many in vitro cellular models. RNA activation (RNAa) is a transcriptional activation phenomena guided by double-strand RNA (dsRNA) targeting promoter region of target gene.

Methods

In this study, we explored the effect of up-regulation of p21 gene expression on drug-resistance in A549 non-small-cell lung carcinoma cells by transfecting the dsRNA targeting the promoter region of p21 into A549 cells.

Results

Enhanced p21 expression was observed in A549 cells after transfection of dsRNA, which was correlated with a significant growth inhibition and enhancement of chemosensitivity to cisplatin in A549 cells in vitro. Moreover, in vivo experiment showed that saRNA targeting the promoter region of p21 could significantly inhibit A549 xenograft tumor growth.

Conclusions

These results indicate that p21 plays a role in lung cancer drug-resistance process. In addition, this study also provides evidence for the usage of saRNA as a therapeutic option for up-regulating lower-expression genes in lung cancer.

Postischemia myocardial injury in coronary artery bypass patients (PP6)

PURPOSE

To investigate the reperfusion injury of the myocardium in patients undergoing elective coronary artery bypass surgery (CABG) with cardiopulmonary bypass (CPB), we monitored the blood levels of troponin I (TNI), white blood cells, oxygen radicals, malondialdehyde, and myeloperoxidase seeking to define the relationship between the CABG-induced systemic inflammation and myocardial injury.

MATERIALS AND METHODS

We selected 10 patients undergoing primary CABG with CPB at moderate hypothermia and cardioplegic arrest concomitant with intermittent warm blood cardioplegia. We compared all data with their own baseline values to study the reperfusion injury. After release of the aortic clamp, blood was drawn from the coronary sinus, via a catheter placed through the right atrium. We measured plasma levels of inflammatory mediators, such as malondialdehyde, myeloperoxidase, oxygen radicals, and the myocardium injury parameter of TNI.

RESULTS

Patients showed no difference concerning aortic clamp time. TNI increased significantly at 1, 15, and 30 minutes after the onset of reperfusion. Blood levels of white blood cells, oxygen radicals, malondialdehyde, and myeloperoxidase also increased significantly with reperfusion time.

CONCLUSIONS

Reperfusion of ischemic myocardium induced increased TNI, which may be related to the systemic inflammatory responses induced by ischemia and reperfusion of the myocardium among patients undergoing elective coronary bypass surgery.

Differential profiles of gene expression in grouper Epinephelus coioides, infected with Singapore grouper iridovirus, revealed by suppression subtractive hybridization and DNA microarray

Suppression subtractive hybridization (SSH) was used to generate a subtracted cDNA library enriched with gene transcripts differentially expressed in the spleen of orange-spotted grouper Epinephelus coioides after 5 days of infection with Singapore grouper iridovirus (SGIV). In the forward and reverse-subtracted libraries, 260 and 153 non-redundant expressed sequence tags (EST), respectively, were identified. These annotated genes responding to SGIV infection were grouped into eight gene categories related to immunity, cell structure, transcription-translation, cell signalling, metabolism, mitochondrial proteins, ribosomal proteins and unknown or hypothetical proteins. A DNA microarray containing all the differentially expressed genes was constructed, and the gene expression patterns in different tissues were investigated in virus-infected E. coioides. Of these genes, four associated with the infection processes were identified and further investigated by quantitative real-time PCR. These results provide new insights into the molecular basis of host-pathogen interactions in E. coioides, and will help the development of control strategies against SGIV infection.

A survey of the anti-apoptotic Bcl-2 subfamily expression in cancer types provides a platform to predict the efficacy of Bcl-2 antagonists in cancer therapy

We investigated the mRNA expression levels of all six antiapoptotic Bcl-2 subfamily members in 68 human cancer cell lines using qPCR techniques and measured the ability of known Bcl-2 inhibitors to induce cell death in 36 of the studied tumor cell lines. Our study reveals that Mcl-1 represents the anti-apoptotic Bcl-2 subfamily member with the highest mRNA levels in the lung, prostate, breast, ovarian, renal, and glioma cancer cell lines. In leukemia/lymphoma and melanoma cancer cell lines, Bcl-2 and Bfl-1 had the highest levels of mRNA, respectively. The observed correlation between the cell killing properties of known Bcl-2 inhibitors and the relative mRNA expression levels of anti-apoptotic Bcl-2 proteins provide critical insights into apoptosis-based anticancer strategies that target Bcl-2 proteins. Our data may explain current challenges of selective Bcl-2 inhibitors in the clinic, given that severe expression of Bcl-2 seems to be limited to leukemia cell lines. Furthermore, our data suggest that in most cancer types a strategy targeted to Mcl-1 inhibition, or combination of Bfl-1 and Mcl-1 inhibition for melanoma, may prove to be more successful than therapies targeting only Bcl-2.

Pharmacokinetics of methotrexate in solid tumors

The transport of methotrexate (MTX) into Walker 256 carcinoma (W256) and hepatoma 5123 (H5123) transplanted in rats was investigated after a pulse injection and continuous infusion of the drug. A mathematical model was developed which adequately described the distribution and transport of MTX in both solid tumors. In H5123 the uptake was limited by the amount of drug carried by plasma (flow-limited transport), but in W256 MTX uptake was limited by the rate at which the drug crossed the tissue barriers (tissue-limited transport). Relative uptake by the solid tumors was almost eightfold more efficient with low than with high doses. MTX concentration in tumor interstitial fluid equilibrated with that of plasma in about 50 hr using a micropore chamber with a diffusion coefficient of 0.5 microm/min as sampling device. MTX concentration was higher in resistant than in responsive tumors.

Early Onset of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) after Allogeneic Haematopoietic Stem Cell Transplantation: Case Report and Review of the Literature

Severe hyponatraemia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a rare but fatal complication following stem cell transplantation (SCT). This case report details a patient with early-onset SIADH after allogeneic haematopoietic SCT (allo-HSCT) and reviews the literature on risk factors for the development of this condition. The patient, who had chronic myelogenous leukaemia, developed acute graft-versus-host disease (GVHD) on day 5 after allo-HSCT, which was relieved promptly by steroids. On day 18, he presented with hyponatraemia, which was refractory. Despite intensive restriction of fluid and administration of hypertonic saline, his condition worsened and he died of multiple systemic organ dysfunction. A review of the literature reveals that early-onset SIADH following SCT is insidious, but progresses rapidly. The severity of the disorder is underestimated because of the non-specific clinical features and the lack of effective treatment. Myeloablative conditioning and acute GVHD are two major important predisposing factors in SIADH.

Production and characterization of a recombinant single-chain antibody against Hantaan virus envelop glycoprotein

Hantaan virus (HTNV) is the type of Hantavirus causing hemorrhagic fever with renal syndrome, for which no specific therapeutics are available so far. Cell type-specific internalizing antibodies can be used to deliver therapeutics intracellularly to target cell and thus, have potential application in anti-HTNV infection. To achieve intracellular delivery of therapeutics, it is necessary to obtain antibodies that demonstrate sufficient cell type-specific binding, internalizing, and desired cellular trafficking. Here, we describe the prokaryotic expression, affinity purification, and functional testing of a single-chain Fv antibody fragment (scFv) against HTNV envelop glycoprotein (GP), an HTNV-specific antigen normally located on the membranes of HTNV-infected cells. This HTNV GP-targeting antibody, scFv3G1, was produced in the cytoplasm of Escherichia coli cells as a soluble protein and was purified by immobilized metal affinity chromatography. The purified scFv possessed a high specific antigen-binding activity to HTNV GP and HTNV-infected Vero E6 cells and could be internalized into HTNV-infected cells probably through the clathrin-dependent endocytosis pathways similar to that observed with transferrin. Our results showed that the E. coli-produced scFv had potential applications in targeted and intracellular delivery of therapeutics against HTNV infections.

The detecting and clinical value of anti-cyclic citrullinated peptide antibodies in patients with systemic lupus erythematosus

The aim of this article is to compare the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in systemic lupus erythematosus (SLE) patients with and without arthritis and in patients with rheumatoid arthritis (RA). Anti-CCP antibodies were measured using ELISA in 159 SLE patients with arthritis (12 patients with erosive arthritis), 108 SLE patients without arthritis, 76 RA patients, and 87 healthy subjects (controls). The following had anti-CCP antibodies above the cut-off level (5 U/ml): 27.3% of SLE patients, 42.1% SLE patients with arthritis, 5.6% SLE patients without arthritis, 85.5% RA patients and 1.1% controls. The mean titre of anti-CCP antibodies in the SLE group was much lower than that in the RA group (33 +/- 72 vs. 160 +/- 125 U/ml), but higher in SLE patients with erosive arthritis than those with non-erosive arthritis (221 +/- 88 vs. 32 +/- 42 U/ml). Hand poly-arthritis occurred more frequently in anti-CCP-positive SLE patients with erosive arthritis than those with non-erosive arthritis. Anti-CCP antibodies were prevalent in some SLE patients, more prevalent in SLE patients with arthritis than those without arthritis. Anti-CCP-positive SLE patients were more likely associated with hand poly-arthritis, and high titre of anti-CCP antibodies might be used as a predictor for the complication of erosive arthritis.

Effects of moderately high pressure plus heat on the germination and inactivation of Bacillus cereus spores lacking proteins involved in germination

AIMS

To determine the germination and inactivation of Bacillus cereus spores lacking various germination proteins using moderately high pressure (MHP) and heat.

METHODS

The inactivation and germination of wild-type B. cereus spores in buffer by MHP (150 MPa) at various temperatures, as well as the MHP inactivation and germination of B. cereus spores lacking individual germinant receptors and monovalent cation antiporters, was determined.

RESULTS

Loss of individual germinant receptors had no large effects on spore inactivation or germination, although germination of receptor-deficient spores was generally slightly decreased. Loss of the GerN in particular the GerN and GerT antiporters also decreased spore germination by MHP, especially at 40 and 50 degrees C.

CONCLUSIONS

Both inactivation and germination of B. cereus spores by MHP increased with rise of temperature; however, mutant strains lacking individual germinant receptor had similar levels of germination as compared to wild-type spores. To evaluate the role of germinant receptors in MHP, a strain lacking a large number of germinant receptors is needed.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this work may lead to a better understanding of how MHP causes germination of spores of B. cereus.

EPR Study of Mouse Tissues in Search for Adaptive Responses to Low Level Whole-body X-irradiation

Effect of a low dose of whole-body X-irradiation (D1 = 0.075 Gy) of mice on some biochemical changes induced in the spleen and thymus by a subsequent challenge dose (D2 = 1.5 Gy) was studied by electron paramagnetic resonance (EPR). Kunming and SHK mice were used. Concentration of ribonucleotide reductase (RR) in the spleen and thymus of unirradiated Kunming mice was 0.70 and 0.46 microM respectively, and of unirradiated SKH mice--0.37 and 0.21 microM respectively (systematic error 45%). For mice exposed only to the low dose (D1 group), a stimulating effect on RR activity in spleen and thymus was found, while in mice subjected only to the D2 dose (D2 group) activity of the enzyme in the organs decreased considerably 18 h after irradiation. The group of mice irradiated with D1 and D2 doses, given at a 6-h interval (D1 plus D2 group), showed a RR activity in the organs lower than D1 and higher than D2 groups. This finding indicates that there exists an adaptation-like response to a low-dose whole-body irradiation in murine spleen and thymus. This low 'inductive' dose makes the organs' RR less susceptible to inhibition induced by a subsequent challenge dose. Preliminary results showed that the same kind of response is probably a characteristic of the RR content of splenocytes as well as of the rate of thymidine incorporation into splenocytes. 5-Thyml radicals of DNA (TH radicals) induced in whole tissues by gamma-irradiation in vitro at 77 K were also studied. Radiochemical yield of these radicals (4.0 and 5.3 nmol j-1), for spleen and thymus respectively of unirradiated Kunming mice, and 2.3 and 2.6 nmol J-1, for spleen and thymus respectively of unirradiated SHK mice (systematic error 30%), decreased significantly in both organs upon D2 irradiation. This decrease, however, was the consequence of DNA content diminishing upon D2 irradiation rather than change of DNA radiosensitivity: the beta value of TH radicals, i.e. yield of radicals per unit mass of DNA in each organ was equal for the mice from all D1, D1 plus D2, D2 and control groups. The beta values of TH radicals in mouse spleen and thymus were of the same order of magnitude compared with the yield of the single-strand breaks of DNA measured previously in rat organs just after whole-body irradiation, i.e. about 1 x 10(2) (Gy x 10(12) Da)-1.