Experimental vaccination of sheep and cattle against tick infestation using recombinant 5'-nucleotidase

Limited prior evidence suggests that 5′-nucleotidase, an ectoenzyme principally located in the Malpighian tubules of the tick Rhipicephalus (Boophilus) microplus, could be an effective antigen in an anti-tick vaccine. To assess this, recombinant 5′-nucleotidase was expressed in Escherichia coli and used in vaccination trials with both sheep and cattle. Vaccinated sheep were challenged with freshly moulted adult ticks. Those with high titres of anti-nucleotidase antibodies showed significant protection against tick infestation, although protection was less than that found with the previously characterized antigen, Bm86. Cattle were vaccinated, in separate groups, with 5′-nucleotidase, Bm86 and both antigens combined. Cattle, as the natural host, were challenged with larval ticks. Although Bm86 showed typical efficacy, no significant protection was seen in cattle vaccinated with 5′-nucleotidase. Cattle receiving a dual antigen formulation were no better protected than those receiving Bm86 alone. One possible reason for the difference between host species, namely antibody titre, was examined and shown to be an unlikely explanation. This demonstrates a limitation of using a model host like sheep in vaccine studies.

Rapid phase-shifting fiber interferometer with optical stylus

Optical fiber interferometry holds many advantages for the online measurement of high-precision surfaces. Here, a fiber interferometer with a wavelength-scanning probe is reported. Such an interferometer requires active stabilization against the effects of temperature drift and vibration. A method of multiplexing dual wavelengths into the same fiber, combined with rapid phase shifting and real-time phase calculation, is investigated. Experimental data show the successful stabilization of the interferometer regardless of environmental perturbation.

An approach to the management of chronic myeloid leukemia in British Columbia

Chronic myeloid leukemia (cml) is a myeloproliferative disorder whose therapy has changed dramatically since the late 1990s. With the introduction of the tyrosine kinase inhibitor (tki) imatinib mesylate, the treatment outcomes for patients with cml have improved markedly, and hematopoietic stem-cell transplantation is no longer routinely offered as first-line therapy for most patients in chronic phase.However, resistance to tki therapy is increasingly being recognized, and alternative therapy is needed for this group of patients. In addition, the development of models predicting response to tki therapy is desired, so that appropriate treatment strategies can be used for individual patients. The present report serves to outline the approach to the treatment of cml in British Columbia and to highlight areas of ongoing research.

Hypertonic saline ameliorates cerebral edema through downregulation of aquaporin-4 expression in the astrocytes

Osmotherapy with 10% hypertonic saline (HS) alleviates cerebral edema through osmotic force. Aquaporin-4 (AQP4) has been reported to be implicated in the pathogenesis of cerebral edema resulting from a variety of brain injury. This study aimed to determine if 10% hypertonic saline ameliorates cerebral edema through downregulation of AQP4 expression in the perivascular astrocytes in the ischemic cerebral edema. Adult male Sprague-Dawley (SD) rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO) and treated with a continuous i.v. infusion of 10% HS. Brain water content (BWC) analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats was attenuated after 10% HS treatment. This was coupled with the reduction of neuronal apoptosis in the peri-ischemic brain tissue. Concomitantly, downregulated expression of AQP4 in the perivascular astrocytes after 10% HS treatment was observed. Our results suggest that in addition to its osmotic force, 10% HS exerts anti-edema effects possibly through downregulation of AQP4 expression in the perivascular astrocytes. The reduction of brain edema after 10% HS administration can prevent ischemic brain damage.

Hexachlorobenzene dechlorination as affected by organic fertilizer and urea applications in two rice planted paddy soils in a pot experiment

Reductive dechlorination is a crucial pathway for HCB degradation, the applications of organic materials and nitrogen can alter microbial activity and redox potential of soils, thus probably influence HCB dechlorination. To evaluate hexachlorobenzene (HCB) dechlorination as affected by organic fertilizer (OF) and urea applications in planted paddy soils, a pot experiment was conducted in two types of soils, Hydragric Acrisols (Ac) and Gleyi-Stagnic Anthrosols (An). After 18 weeks of experiment, HCB residues decreased by 28.2-37.5% of the initial amounts in Ac, and 42.1-70.9% in An. The amounts of HCB metabolites showed that dechlorination rates in An were higher than in Ac, which was mainly attributed to the higher pH and dissolved organic carbon (DOC) content of An. Both in Ac and An, the additions of 1% and 2% OF had negative effect on HCB dechlorination, which was probably because excessive nitrogen in OF decreased degraders' activity and the degradation of organic carbon in OF accepted electrons. The application of 0.03% urea could enhance HCB dechlorination rates slightly, while 0.06% urea accelerated HCB dechlorination significantly both in Ac and An. It could be assumed that urea served as an electron donor and stimulated degraders to dechlorinate HCB. In addition, the methanogenic bacteria were involved in dechlorination process, and reductive dechlorination in planted paddy soil might be impeded for the aerenchyma and O(2) supply into the rhizosphere. Results indicated that soil types, rice root system, methanogenic bacteria, OF and urea applications all had great effects on dechlorination process.

High-resolution spectroscopy of Lambda16N by electroproduction

An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.

Microbiological analysis of composts produced on South Carolina poultry farms

AIMS

The purpose of this study was to determine whether the methods used in compost operations of small and medium-sized poultry farms resulted in the production of an amendment free of foodborne pathogens.

METHODS AND RESULTS

Nine compost heaps on five South Carolina poultry farms were surveyed at different stages of the composting process. Compost samples were analysed for coliforms and enriched for Escherichia coli O157:H7, Salmonella spp. and Listeria monocytogenes. The waste materials and composting practices differed among the surveyed farms. On two farms, new materials were added to heaps that had previously completed the active composting phase. Five compost heaps did not reach an internal temperature of 55 degrees C, and c. 62% of all internal samples in the first composting phase contained moisture contents <40%. Escherichia coli was detected in 63% of the surface samples (n = 38) and 9.8% of the internal samples (n = 82) from the first composting phase, as compared with 16.7% of the surface samples (n = 12) and 0% internal samples (n = 24) from the second composting phase. Salmonella was detected in 26 and 6.1% of all surface and internal samples collected from heaps in the first composting phase, respectively, but was absent in all compost samples undergoing a second composting phase. The predominant Salmonella serotypes were Thompson, Montevideo and Anatum. Neither E. coli O157:H7 nor L. monocytogenes was detected in any of the samples.

CONCLUSIONS

Our results indicate that the conditions at the compost surface are suitable for pathogen survival, and the complete composting process can result in the elimination of pathogens in poultry wastes.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research provides information regarding the effectiveness of the composting practices and microbiological quality of poultry compost produced by small- and medium-sized farms. Ensuring the safety of compost that may be applied to soils should be an integral part of preharvest food safety programme.

Chemical changes in heavy metals in the leachates from Technosols

A 2 month long column study was conducted to evaluate the mobility of heavy metals eluting from Technosols constituted from sewage sludges (aerobic or anaerobic) (as controls) or a mixture of different types of sewage sludges with green foundry sand (FS) or/and Linz-Donowitz slag (LD). The organic and inorganic wastes were mixed at a ratio of 56:44 (w/w). The mixtures and the controls were moistened to field capacity before adding them to the polypropylene columns (4.5 cm wide and 14 cm long). During the 8-week experimental period, the columns were watered, twice a week, with 100 mL of deionised water. The concentrations of heavy metals (Cu, Zn, Ni, Pb, Cd, and Cr) in the leachates were determined periodically. The concentrations of all the heavy metals were generally higher in the leachates from the Technosols containing anaerobic sewage sludge as a component. The concentration of Cu was strongly dependent on pH and was significantly higher (P<0.05) in the most alkaline leachates (pH>10) than in the other leachates. More Zn was mobilized in the most acidic leachates (pH<6) than in other leachates. The concentration of Ni in 80% of the leachates exceeded the EU drinking water limit for Ni (0.02 mgL(-1)). The concentrations of Pb were lower in the Technosols containing FS. The concentrations of Cd in the leachates from Technosols containing the conditioners were relatively high, while concentrations of Cr were higher in the controls. As far as the potential toxicity of heavy metals is concerned, the combination of aerobic sludge, inorganic conditioners able to buffer the pH to around neutrality, and reactive aluminosilicates, can be regarded as suitable choice for formulating Technosols from wastes.

Inflammasomes are differentially expressed in cardiovascular and other tissues

To determine the expression of components in Toll-like receptors (TLRs)/Nod-like receptors (NLRs)/inflammasome/caspase-1/interleukin (IL-1)-beta pathway, we examined the expression profiles of those genes by analyzing the data from expression sequence tag cDNA cloning and sequencing. We made several important findings: firstly, among 11 tissues examined, vascular tissues and heart express fewer types of TLRs and NLRs than immune and defense tissues including blood, lymph nodes, thymus and trachea; secondly, brain, lymph nodes and thymus do not express proinflammatory cytokines IL-1beta and IL-18 constitutively, suggesting that these two cytokines need to be upregulated in the tissues; and thirdly, based on the expression data of three characterized inflammasomes (NALP1, NALP3 and IPAF inflammasome), the examined tissues can be classified into three tiers: the first tier tissues including brain, placenta, blood and thymus express inflammasome(s) in constitutive status; the second tier tissues have inflammasome(s) in nearly-ready expression status (with the requirement of upregulation of one component); the third tier tissues, like heart and bone marrow, require upregulation of at least two components in order to assemble functional inflammasomes. Our original model of three-tier expression of inflammasomes would suggest a new concept of tissue inflammation privilege, and provides an insight to the differences among tissues in initiating acute inflammation in response to stimuli.

Combination of beta-TCP and BMP-2 gene-modified bMSCs to heal critical size mandibular defects in rats

OBJECTIVE

To investigate the effects of mandibular defects repaired by a tissue engineered bone complex with beta-tricalcium phosphate (beta-TCP) and bone morphogenic protein-2 (BMP-2) gene-modified bone marrow stromal cells (bMSCs).

MATERIALS AND METHODS

bMSCs derived from Fisher 344 rats were cultured and transduced with adenovirus AdBMP-2, AdEGFP gene in vitro. Osteogenic differentiation of bMSCs was determined by alkaline phosphatase staining, von Kossa assay and reverse transcription-polymerase chain reaction. Gene transduced or untransduced bMSCs were seeded on beta-TCP scaffolds to repair mandibular full thickness defects with a diameter of 5 mm. Eight weeks post-operation, X-ray examination, micro-computerized tomography and histological and histomorphological analysis were used to evaluate the bone healing effects.

RESULTS

Alkaline phosphatase staining and mineralized nodules formation were more pronounced in AdBMP-2 group 14 days after gene transduction when compared with that of AdEGFP or untransduced group. The mRNA expression of osteopontin and osteocalcin also significantly increased 9 days after AdBMP-2 gene transduction. Mandibular defects were successfully repaired with AdBMP-2-transduced bMSCs/beta-TCP constructs. The percentage of new bone formation in AdBMP-2 group was significantly higher than that of other control groups.

CONCLUSIONS

Bone morphogenic protein-2 regional gene therapy together with beta-TCP scaffold could be used to promote mandibular repairing and bone regeneration.

Antisense oligonucleotides targeting the large subunit (R1) of human ribonucleotide reductase synergistically increase the cytotoxicity of doxorubicin and paclitaxel to MCF-7 breast cancer cells

e14626

Ribonucleotide reductase (RR) is an essential enzyme that catalyzes the reduction of ribonucleotides to deoxyribonucleotides for use in DNA synthesis. Human RR consists of two subunits, a large subunit (R1) and small subunit (R2). RR provides an attractive target for anticancer therapy. In the present study, we synthesized phosphorothioated antisenses oligonucleotides (RR1AS1, RR1AS2, RR1AS3, RR1AS4 and RR1AS5) that target the R1 subunit of RR. We treated the human breast cancer cell line MCF-7 with antisenses, and doxorubicin or paclitaxel for 72 hours. Cell proliferation was measured by 3[H]- thymidine incorporation. The effects of the drug combinations were analyzed with Biosoft Calcusyn software. The levels of RR mRNA were measured by RT-PCR. We found two antisenses, RR1AS2 and RR1AS4, inhibited the proliferation of MCF-7 cells in a dose-dependent pattern (IC50s: 5.32+1.64μm and 2.57+2.72μm, respectively, 72 hours incubation). Also, RR1AS2 and RR1AS4 significantly suppressed the expression of RR1 mRNA. When MCF-7 cells were incubated in media with a mixture of antisense and doxorubicin or paclitaxel, both RR1AS2 and RR1AS4 synergistically increased the cytotoxicity of doxorubicin and paclitaxel. Calcusyn analysis showed that averaged combination index (CI) were 0.59+0.04, 0.66+0.22, 0.83+0.16 and 0.88+0.03, when MCF-7 cells were treated with the mixtures of RR1AS2 + doxorubicin, RR1AS2 + paclitaxel, RR1AS4 + doxorubicin and RR1AS4 + paclitaxel, respectively (CI<1 indicates synergism). These results suggest that the combination of RR antisenses and chemotherapeutic agents, such as doxorubicin or paclitaxel, may decrease both the dosages and side effects of both antisense oligonucleotides and chemotherapeutic agents (doxorubicin and paclitaxel) in cancer therapy.

No significant financial relationships to disclose.

Evaluation of ALK-1 expression in circulating endothelial cells (CECs) as an exploratory biomarker for PF-03446962 undergoing phase I trial in cancer patients

3573

Background: ALK-1 is a member of the TβRI family & a novel target for antiangiogenic therapy (Rx). PF- 03446962 (PF) is a fully human mAB (IgG2, κ) generated against ALK-1 with dose-dependent preclinical antiangiogenic activities (Hu-Lowe et al, Proc AACR, 2009). This study's objectives were to determine whether: 1) CECs in cancer patients express ALK-1; and 2) whether therapy with PF against ALK-1 will modulate ALK-1 expression or CEC function in an ongoing Ph I trial. Methods: The human mAb was conjugated with alexa fluor 647. ALK-1 expression was assayed by a standardized multicolor flow cytometry assay (Mancuso et al, CCR 2009). Results: ALK-1 expression was characterized on human vascular (HUVEC) & lymphatic (HDLC) endothelial cells; HUVEC & HDLC cells highly express ALK-1 (>99% of these cells are ALK- 1+). ALK-1 expression was assessed in healthy controls (n=17) & cancer patients after normalizing for CEC viability. Patients with advanced malignancies had increased numbers of ALK-1+ CECs: Patients with breast ca (n=12), melanoma (n=8), NSCLC (n=11), & CRC (n=4) had 16±12, 39±23, 50±30, & 62±25 ALK-1+ CECs/mL, respectively, vs 7±6 ALK-1+ CECs/mL in controls. In contrast, ALK-1 expression was minimally or not expressed in pts with hematologic malignancies; ALK-1 was absent in CD117+ or CD34+ bone marrow cells. In the Ph I trial, preliminary evidence suggests that PF may alter CEC function; ALK-1+ CECs were markedly reduced in the 1st two pts studied at EIO after 22 days on Rx. Conclusions: ALK-1 is expressed in CECs. Flow cytometry enables rapid assay of ALK-1 expression in cancer patient blood. ALK-1 is expressed in an increased number of CECs/mL in cancer pts with solid malignancies vs controls. ALK-1 expression in CECs in pts with NSCLC & CRC may correspond to high ALK-1 expression observed in corresponding nonmatched tumor microarrays in addition to other malignancies such as sarcoma, SCLC & neuroendrocine pancreatic ca (Fiedler, Proc ASCO, 2009). Additional preliminary Ph I results will be reported as part of assessing whether CECs may have any role as biomarkers to potentially detect patients with ALK-1+ solid malignancies or monitor anti-ALK-1 therapy.

[Table: see text]

Reversion of physiological drug resistance of weakly basic drugs: The discovery of a new mechanism of PEG-PCL nanoparticles

e13528

Background: A number of studies have reported the superior antitumor effect of nanoparticles loading chemotherapeutics than the free agents, yet the underlying mechanism has not attract enough attention. The extracellular pH of cancer cells is lower than that of the intracellular pH. Due to this pH gradient, weakly basic drug will protonated extracellularly and display decreased intracellular concentration. In this study, we aimed to reveal a new mechanism of PEG-PCL nanoparticles, namely the reversion of physiological drug resistance. Methods: Tetradrine (Tet), an alkaloid isolated from traditional Chinese medicine, was incorporated into the diblock copolymer methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL). In vitro cytotoxicity of free Tet and Tet-loaded nanoparticles at pH7.4 and pH6.8 was compared on four different cancer cell lines. Fluorescent particle cellular uptake study was also used. To evaluate the antitumor effect of the nanoparticles in a more complex model rather than monolayer cell culture, we used Histoculture Drug Resistance Assay (HDRA). The in vivo antitumor effect of the nanoparticles was also studied in ICR mice bearing H22 tumor with different in vivo pH values. Results: In vitro cytotoxicity study in four tumor cell lines showed that the cytotoxicity of free Tet decreased significantly (P<0.05) when the extracellular pH decreased from 7.4 to 6.8, while the cytotoxicity of Tet-loaded nanoparticles increased or didn’t change significantly. The possible mechanism may mainly be the endocytosis of nanoparticles, which was proven by fluorescent particle cellular uptake study. HDRA indicated better tissue penetration of nanoparticles over free Tet. As to in vivo study, the mice with in vivo tumor pH 6.8 and treated with Tet-loaded nanoparticles exhibited best tumor inhibit rate and mildest side effect, suggesting that the use of nanoparticles was more preferable than the manipulation of tumor pH by the use of basic water. Conclusions: Our study clearly demonstrated that the mPEG-PCL nanoparticles could overcome the drug resistance caused by low extracellular pH and enhance drug penetration in the tumor tissue, thus increasing the antitumor efficacy of weakly basic agents.

No significant financial relationships to disclose.

Nonlinear spectral imaging of human hypertrophic scar based on two-photon excited fluorescence and second-harmonic generation

BACKGROUND

A noninvasive method using microscopy and spectroscopy for analysing the morphology of collagen and elastin and their biochemical variations in skin tissue will enable better understanding of the pathophysiology of hypertrophic scars and facilitate improved clinical management and treatment of this disease.

OBJECTIVE

To obtain simultaneously microscopic images and spectra of collagen and elastin fibres in ex vivo skin tissues (normal skin and hypertrophic scar) using a nonlinear spectral imaging method, and to compare the morphological structure and spectral characteristics of collagen and elastin fibres in hypertrophic scar tissues with those of normal skin, to determine whether this approach has potential for in vivo assessment of the pathophysiology of human hypertrophic scars and for monitoring treatment responses as well as for tracking the process of development of hypertrophic scars in clinic.

METHODS

Ex vivo human skin specimens obtained from six patients aged from 10 to 50 years old who were undergoing skin plastic surgery were examined. Five patients had hypertrophic scar lesions and one patient had no scar lesion before we obtained his skin specimen. A total of 30 tissue section samples of 30 mum thickness were analysed by the use of a nonlinear spectral imaging system consisting of a femtosecond excitation light source, a high-throughput scanning inverted microscope, and a spectral imaging detection system. The high-contrast and high-resolution second harmonic generation (SHG) images of collagen and two-photon excited fluorescence (TPEF) images of elastin fibres in hypertrophic scar tissues and normal skin were acquired using the extracting channel tool of the system. The emission spectra were analysed using the image-guided spectral analysis method. The depth-dependent decay constant of the SHG signal and the image texture characteristics of hypertrophic scar tissue and normal skin were used to quantitatively assess the amount, distribution and orientation of their collagen and elastin components.

RESULTS

Our experiments and data analyses demonstrated apparent differences between hypertrophic scar tissue and normal skin in terms of their morphological structure and the spectral characteristics of collagen and elastin fibres. These differences can potentially be used to distinguish hypertrophic scar tissues from normal skin and to evaluate treatment responses.

CONCLUSIONS

All the measurements were performed in backscattering geometry and demonstrated that nonlinear spectral imaging has the ability to differentiate hypertrophic scar tissue from normal skin based on noninvasive SHG imaging, and TPEF imaging revealed the microstructure and spectral features of collagen and elastin fibres. With the advances in spectral imaging apparatus miniaturization, we have good reason to believe that this approach can become a valuable tool for the in vivo pathophysiology study of human skin hypertrophic scars and for assessing the treatment responses of this disfiguring disease in clinic. It can also be used to track the development of hypertrophic scars and to study wound healing processes in a noninvasive fashion without biopsy, fixation, sectioning and the use of exogenous dyes or stains.

Effects of PI3-k/Akt short hairpin RNA on proliferation, fibronectin production and synthesis of thrombospondin-1 and transforming growth factor-beta1 in glomerular mesangial cells induced by sublytic C5b-9 complexes

OBJECTIVES

To explore proliferation of glomerular mesangial cells (GMC) and secretion of extracellular matrix (fibronectin induced by sublytic C5b-9 complexes), and then ascertain the role of phosphatidylinositol 3-kinase (PI3-k)/Akt signal pathway in these processes, by using small hairpin RNAs.

MATERIAL AND METHODS

The expression of cyclin D(2), (3)H-thymidine into DNA and production of fibronectin including thrombospondin-1 and transforming growth factor-beta(1) in the GMCs stimulated by sublytic C5b-9 or transfected with expression vectors of PI3-k and Akt short hairpin RNA or LY294002 (PI3-k inhibitor) were measured by Real-time quantitative polymerase chain reaction (PCR), Western blot, enzyme-linked immunosorbent assay (ELISA) and (3)H-thymidine incorporation ((3)H-TdR), respectively.

RESULTS

The expression of cyclin D(2), (3)H-thymidine into DNA and fibronectin in the GMCs stimulated by sublytic C5b-9 could all be increased, and the elevations of these parameters mentioned above were also markedly reduced in the GMCs transfected with vectors of PI3-k and Akt short hairpin RNA or LY294002, respectively.

CONCLUSIONS

These data indicate that sublytic C5b-9 can promote proliferation of GMCs and secretion of fibronectin as well as synthesis of thrombospondin-1 and transforming growth factor-beta(1). The PI3-k/Akt signal pathway in these reactions, mediated by sublytic C5b-9 complexes, may play at least a partial role.