Flow cytometric immunobead assay for the detection of BCR-ABL fusion proteins in leukemia patients

BCR-ABL fusion proteins show increased signaling through their ABL tyrosine kinase domain, which can be blocked by specific inhibitors, thereby providing effective treatment. This makes detection of BCR-ABL aberrations of utmost importance for diagnosis, classification and treatment of leukemia patients. BCR-ABL aberrations are currently detected by karyotyping, fluorescence in situ hybridization (FISH) or PCR techniques, which are time consuming and require specialized facilities. We developed a simple flow cytometric immunobead assay for detection of BCR-ABL fusion proteins in cell lysates, using a bead-bound anti-BCR catching antibody and a fluorochrome-conjugated anti-ABL detection antibody. We noticed protein stability problems in lysates caused by proteases from mature myeloid cells. This problem could largely be solved by adding protease inhibitors in several steps of the immunobead assay. Testing of 145 patient samples showed fully concordant results between the BCR-ABL immunobead assay and reverse transcriptase PCR of fusion gene transcripts. Dilution experiments with BCR-ABL positive cell lines revealed sensitivities of at least 1%. We conclude that the BCR-ABL immunobead assay detects all types of BCR-ABL proteins in leukemic cells with high specificity and sensitivity. The assay does not need specialized laboratory facilities other than a flow cytometer, provides results within approximately 4 h, and can be run in parallel to routine immunophenotyping.

Control of a neuroprosthesis for grasping using off-line classification of electrocorticographic signals: case study

STUDY DESIGN

Proof of concept study to control a neuroprosthesis for grasping using identification of arm movements from ECoG signals.

OBJECTIVE

To test the feasibility of using electrocorticographic (ECoG) signals as a control method for a neuroprosthesis for grasping.

SETTING

Acute care hospital, Toronto Western Hospital and spinal cord injury (SCI) rehabilitation centre, Toronto Rehabilitation Institute, Lyndhurst Centre. Both hospitals are located in Toronto, Canada.

METHODS

Two subjects participated in this study. The first subject had subdural electrodes implanted on the motor cortex for the treatment of essential tremor (ET). ECoG signals were recorded while the subject performed specific arm movements. The second subject had a complete SCI at C6 level (ASIA B score) and was fitted with a neuroprosthesis, capable of identifying arm movements from ECoG signals off-line, for grasping. To operate the neuroprosthesis, subject 2 issued a command that would trigger the release of a randomly selected ECoG signal recorded from subject 1, associated with a particular arm movement. The neuroprosthesis identified which arm movement was performed at the time of recording and used that information to trigger the stimulation sequence. A correct ECoG classification resulted in the neuroprosthesis producing the correct hand function (that is grasp and release).

RESULTS

The neuroprosthesis classified ECoG signals correctly delivering the correct stimulation strategy with 94.5% accuracy.

CONCLUSIONS

The feasibility of using ECoG signals as a control strategy for a neuroprosthesis for grasping was shown.

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.

Is the relationship between syndromes of depression and dementia temporal? The MRC-ALPHA and Hefei-China studies

BACKGROUND

Recent studies have shown a temporal association between depressive symptoms and cognitive decline. However, the relationship between syndromes of depression and dementia is unknown.

METHOD

A total of 1736 people aged > or = 65 years in China and 5222 older people in the UK were interviewed using the Geriatric Mental State Examination (GMS) and reinterviewed at follow-up. Five levels of syndromes of depression and dementia were diagnosed using the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT).

RESULTS

Although there were fewer depressive syndromes in Chinese than British participants, both populations showed a similarly high level of syndromes of dementia (organic disorder) (20% for women, 14% for men). There was a significant cross-sectional correlation between syndrome levels of depression and dementia (correlation coefficients: 0.141-0.248 for Chinese, 0.168-0.248 for British). This was maintained for different age, gender and people with and without cardiovascular disease (CVD). The relationship between syndromes of baseline depression and follow-up dementia was less substantial: the correlation coefficient was 0.075 [95% confidence interval (CI) 0.021-0.128] for the Chinese sample at the 1-year follow-up, and 0.093 (95% CI 0.061-0.125) for the British at the 2-year follow-up and 0.093 (95% CI 0.049-0.130) at the 4-year follow-up. This relationship disappeared in participants without baseline organic syndromes. In a multiple adjusted logistic regression analysis, an increased risk of organic syndromes seemed to be associated with baseline, mainly in the highest level of, depressive syndromes.

CONCLUSIONS

The relationship between syndromes of depression and dementia might be temporal. The lack of an obvious dose-response relationship between baseline depressive syndromes and follow-up dementia syndromes suggests that the causal relationship between depression and dementia needs further investigation.

Cost-benefit evaluation of a decentralized water system for wastewater reuse and environmental protection

This paper proposed a net benefit value (NBV) model for cost-benefit evaluation of wastewater treatment and reuse projects, and attention was mainly paid to decentralized systems which are drawing wide interests all over the world especially in the water-deficient countries and regions. In the NBV model, all the factors related to project costs are monetary ones which can be calculated by using traditional methods, while many of the factors related to project benefits are non-monetary ones which need sophisticated methods for monetization. In this regard, the authors elaborated several methods for monetization of the benefits from wastewater discharge reduction, local environment improvement, and human health protection. The proposed model and methods were applied for the cost-benefit evaluation of a decentralized water reclamation and reuse project in a newly developed residential area in Xi'an, China. The system with dual-pipe collection and grey water treatment and reuse was found to be economically ineligible (NBV > 0) when all the treated water is reused for artificial pond replenishment, gardening and other non-potable purposes by taking into account the benefit of water saving. As environmental benefits are further considered, the economic advantage of the project is more significant.

WAFER-SCALE, SOLID FREEFORM FABRICATION OF FULLY-ASSEMBLED METAL MICRO-MECHANISMS FOR MINIMALLY-INVASIVE MEDICAL DEVICES

The EFAB process was first presented at the SFF Symposium in 1998, at a very early stage of its development. Currently, the technology is able to produce complex 3-D devices-including mechanisms built pre-assembled-in production volumes, using a three-step process of selective electrodeposition of one metal, blanket electrodeposition of another metal, and planarization. Layer thickness is as small as 4 μm, minimum feature size is down to 10 μm, and linear tolerances are ~2 μm. Metals are biocompatible materials with mechanical properties similar to stainless steel. The technology enables new instruments for minimally-invasive surgical and interventional procedures.

Streptococcus cristatus attenuates Fusobacterium nucleatum-induced interleukin-8 expression in oral epithelial cells

BACKGROUND AND OBJECTIVE

Oral epithelial cells may be invaded by a polymicrobial intracellular flora, including pathogens together with commensals. Various oral pathogens can induce the production of interleukin-8, a potent neutrophil chemotractant, in oral epithelial cells. Evidence from the gut suggests that commensal species may modulate inflammatory responses to pathogens. The aim of this study was to examine the interleukin-8 responses of oral epithelial cells to an oral pro-inflammatory species, Fusobacterium nucleatum, in combination with an oral commensal, Streptococcus cristatus.

MATERIAL AND METHODS

KB, TERT-2, TR146 and SCC15 cells were cocultured with F. nucleatum and S. cristatus, either alone or in combination, at 37 degrees C in 5% CO2 under various conditions. The mRNA expression of interleukin-8 was analyzed by reverse transcription-polymerase chain reaction and protein secretion was measured by enzyme-linked immunosorbent assay.

RESULTS

F. nucleatum alone evoked a potent interleukin-8 response, whereas S. cristatus alone did not induce significant interleukin-8 expression in oral epithelial cells. When present together, S. cristatus attenuated the F. nucleatum-induced interleukin-8 production in the four oral epithelial cell lines to varying degrees. The inhibitory effect of S. cristatus was independent of its viability and its co-aggregation with F. nucleatum, was not related to soluble bacterial products and appeared to require bacterial contact with epithelial cells. Similar effects were seen with several other species of oral streptococci.

CONCLUSION

Our data suggest that S. cristatus may exert immunomodulatory effects on the interleukin-8 response of oral epithelial cells to F. nucleatum challenge.

Chronic fatigue syndrome and the central nervous system

An increasing amount of neuroimaging evidence supports the hypothesis that chronic fatigue syndrome patients have structural or functional abnormalities within the brain. Moreover, some neurotrophic factors, neurotransmitters and cytokines have also been evaluated in order to elucidate the mechanism of abnormal neuropsychic findings in chronic fatigue syndrome. In this review, we suggest that the focal point of chronic fatigue syndrome research should be transferred to the central nervous system.

A Novel Adipocytokine, Visceral Adipose Tissue-derived Serine Protease Inhibitor (Vaspin), and Obesity

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an interesting novel adipocytokine with insulin-sensitizing effects. Some studies have suggested that vaspin could play an important role in the development of obesity and metabolic disorders. The induction of vaspin mRNA expression could represent a compensatory mechanism associated with obesity, severe insulin resistance and type 2 diabetes mellitus, however it is unclear whether a correlation exists between human vaspin serum levels and markers of insulin sensitivity and glucose or lipid metabolism. Vaspin serum concentrations have been shown to be lower in lean subjects and competitive sportsmen with long-term physical training, but they are increased with weight loss associated with a physical training programme. In conclusion, there is at present no clear proof of a causal link between vaspin and visceral fat accumulation, or insulin resistance. This article reviews the role of vaspin in obesity-associated diseases and its potential as a new biomarker for obesity and impaired insulin sensitivity.

Proteomic analysis of human bone marrow mesenchymal stem cells transduced with human telomerase reverse transcriptase gene during proliferation

OBJECTIVES

Previous studies have reported immortalization and tumorigenicity of human mesenchymal stem cells (hMSCs) transduced with exogenous human telomerase reverse transcriptase (hTERT). We also have established a line of hMSCs transduced with hTERT (hTERT-hMSCs) and we have cultured these cells for 290 population doublings (PDs) during which they demonstrated a large proliferation potential but with no tumorigenicity. The aim of this study was to investigate the protein expression profile of hTERT-hMSCs with two-dimensional gel electrophoresis and peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, to be able to analyse the effects of exogenous hTERT on protein expression in hMSCs.

MATERIALS AND METHODS

We generated proteome maps of primary hMSCs and hTERT-hMSCs at PD 95 and PD 275.

RESULTS

A total of 1543 +/- 145 protein spots in gels of primary MSCs at PD 12, 1611 +/- 186 protein spots in gels of hTERT-hMSCs at PD 95 and 1451 +/- 126 protein spots in gels of hTERT-hMSCs at 275 PD were detected. One hundred of these were successfully identified, including 20 which were differentially expressed.

CONCLUSIONS

The results suggest that sustaining levels of prohibitin and p53 expression along with differential expression of proteins in hTERT-hMSCs provide an insight into lack of transforming activity of hTERT-hMSCs during cell proliferation.

Controlled multipulse loading with a stuffed striker in classical split Hopkinson pressure bar testing

Controlled multipulse loading in classical split Hopkinson pressure bar (SHPB) testing is highly desirable for investigating loading history dependent phenomena but rarely explored. Here, we present a novel technique to achieve controlled multipulse loading in SHPB testing with a stuffed striker. This stuffed striker consists of a striker tube, and a striker bar and a gap enclosed inside the tube; upon impact on the input bar, it can produce two separated loading pulses. The gap controls the delay of the second pulse with respect to the first pulse, and the pulse separation (dwell time) can be continuously tuned from zero to hundreds of microseconds. The combination of the stuffed striker and the Lindholm technique [J. Mech. Phys. Solids 12, 317 (1964)] allows for controlled multipulse loading with triple or more pulses. We have validated the working principle of this technique with experiments, and demonstrated its feasibility and flexibility for acquiring relevant dynamic data with double- and triple-pulse loading on polycrystalline Cu. This precisely controlled multipulse loading technique is readily implementable and can be applied to investigating the dynamic response of a wide range of materials.

Regulation of IKKbeta by miR-199a affects NF-kappaB activity in ovarian cancer cells

Cancer progression is an abnormal form of tissue repair characterized by chronic inflammation. IkappaB kinase-beta (IKKbeta) required for nuclear factor-kappaB (NF-kappaB) activation plays a critical role in this process. Using EOC cells isolated from malignant ovarian cancer ascites and solid tumors, we identified IKKbeta as a major factor promoting a functional TLR-MyD88-NF-kappaB pathway that confers to EOC cell the capacity to constitutively secrete proinflammatory/protumor cytokines and therefore promoting tumor progression and chemoresistance. Furthermore, we describe for the first time the identification of the microRNA hsa-miR-199a as a regulator of IKKbeta expression. Our study describes the property of ovarian cancer cells to enhance the inflammatory microenvironment as a result of the expression of an active IKKbeta pathway. Identification of these markers in patients' tumor samples may facilitate the adequate selection of treatment and open new venues for the development of effective therapy for chemoresistant ovarian cancers.