1,323 research outputs found
Irradiation-induced localization of IL-12-expressing mesenchymal stem cells to enhance the curative effect in murine metastatic hepatoma
Irradiation in conjunction with gene therapy is considered for efficient cancer treatment. Mesenchymal stem cells (MSCs), due to their irradiation-promotable tumor tropism, are ideal delivery vehicles for gene therapy. In this study, we investigated whether treatment with radiation and interleukin (IL)-12-expressing MSCs (MSCs/IL-12) exerts improved antitumor effects on murine metastatic hepatoma. HCa-I and Hepa 1-6 cells were utilized to generate heterotopic murine hepatoma models. Tumor-bearing mice were treated with irradiation or MSCs/IL-12 alone, or a combination. Monocyte chemoattractant protein-1 (MCP-1/CCL2) expression was assessed in irradiated hepatoma tissues to confirm a chemotactic effect. Combination treatment strategies were established and their therapeutic efficacies were evaluated by monitoring tumor growth, metastasis and survival rate. IL-12 expression was assessed and the apoptotic activity and immunological alterations in the tumor microenvironment were examined. MCP-1/CCL2 expression and localization of MSCs/IL-12 increased in the irradiated murine hepatoma cells. The antitumor effects, including suppression of pulmonary metastasis and survival rate improvements, were increased by the combination treatment with irradiation and MSCs/IL-12. IL-12 expression was increased in tumor cells, causing proliferation of cluster of differentiation 8(+) T-lymphocytes and natural killer cells. The apoptotic activity increased, indicating that the cytotoxicity of immune cells was involved in the antitumor effect of the combined treatment. Treatment with irradiation and MSCs/IL-12 showed effectiveness in treating murine metastatic hepatoma. IL-12-induced proliferation of immune cells played an important role in apoptosis of tumor cells. Our results suggest that treatment with irradiation and MSCs/IL-12 may be a useful strategy for enhancing antitumor activity in metastatic hepatoma. What's new? Mesenchymal stem cells (MSCs) are promising gene-delivery vehicles, with the potential to improve antitumor effects when used in combination with existing therapies. In the present study, the combined use of interleukin (IL)-12-expressing MSCs (MSCs/IL-12) and radiation therapy increased antitumor activity in murine metastatic hepatoma, a model that is representative of human metastatic hepatocellular carcinoma (HCC), which affects nearly half of HCC patients. Treatment with MSCs/IL-12 resulted in increased IL-12 expression in tumor cells and immune cell proliferation. Immune cell cytotoxicity, evidenced by increased apoptotic activity, appeared to play a role in MSCs/IL-12 augmentation of antitumor effects.1178Ysciescopu
Oral immunization of haemaggulutinin H5 expressed in plant endoplasmic reticulum with adjuvant saponin protects mice against highly pathogenic avian influenza A virus infection
Pandemics in poultry caused by the highly pathogenic avian influenza (HPAI) A virus occur too frequently globally, and there is growing concern about the HPAI A virus due to the possibility of a pandemic among humans. Thus, it is important to develop a vaccine against HPAI suitable for both humans and animals. Various approaches are underway to develop such vaccines. In particular, an edible vaccine would be a convenient way to vaccinate poultry because of the behaviour of the animals. However, an edible vaccine is still not available. In this study, we developed a strategy of effective vaccination of mice by the oral administration of transgenic Arabidopsis plants (HA-TG) expressing haemagglutinin (HA) in the endoplasmic reticulum (ER). Expression of HA in the ER resulted in its high-level accumulation, N-glycosylation, protection from proteolytic degradation and long-term stability. Oral administration of HA-TG with saponin elicited high levels of HA-specific systemic IgG and mucosal IgA responses in mice, which resulted in protection against a lethal influenza virus infection with attenuated inflammatory symptoms. Based on these results, we propose that oral administration of freeze-dried leaf powders from transgenic plants expressing HA in the ER together with saponin is an attractive strategy for vaccination against influenza A virus.X111411Ysciescopu
Are autistic traits measured equivalently in individuals with and without an Autism Spectrum Disorder?:An invariance analysis of the Autism Spectrum Quotient Short Form
It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two group
Basic Biomedical Sciences and the Future of Medical Education: Implications for Internal Medicine
The academic model of medical education in the United States is facing substantial challenges. Apprenticeship experiences with clinical faculty are increasingly important in most medical schools and residency programs. This trend threatens to separate clinical education from the scientific foundations of medical practice. Paradoxically, this devaluation of biomedical science is occurring as the ability to use new discoveries to rationalize clinical decision making is rapidly expanding. Understanding the scientific foundations of medical practice and the ability to apply them in the care of patients separates the physician from other health care professionals. The de-emphasis of biomedical science in medical education poses particular dangers for the future of internal medicine as the satisfaction derived from the application of science to the solving of a clinical problem has been a central attraction of the specialty. Internists should be engaged in the ongoing discussions of medical education reform and provide a strong voice in support of rigorous scientific training for the profession
Appointment waiting times and education level influence the quality of bowel preparation in adult patients undergoing colonoscopy
<p>Abstract</p> <p>Background</p> <p>Risk factors for poor bowel preparation are recognized to be independent of the type of bowel preparation method used. Patient and administrative factors influencing bowel preparation are known to vary in different healthcare systems.</p> <p>Methods</p> <p>A prospective, cross-sectional study of patients undergoing colonoscopy in an Asian tertiary centre was conducted to identify risk factors associated with poor bowel preparation, and to evaluate the impact of poor bowel preparation on technical performance and patient comfort.</p> <p>Results</p> <p>Data on 501 patients (mean age 60.1 ± 14.0 years old, 51.2% males, 60.9% with secondary education or higher) was available for analysis. Poor bowel preparation was present in 151 patients (30.1%). Lower education level (OR = 2.35, 95% CI = 1.54 - 3.60), colonoscopy appointment waiting time beyond 16 weeks (OR = 1.86, 95% CI = 1.04 - 3.37) and non-adherence to bowel preparation instructions (OR = 4.76, 95% CI = 3.00 - 7.55) were identified as independent risk factors for poor bowel preparation. Poor bowel preparation was associated with a lower cecal intubation rate (78.1% versus 98.3%, p < 0.001), prolonged total colonoscopy time (25.4 ± 12.6 minutes versus 16.7 ± 10.2 minutes, p < 0.001), and increased patient discomfort during colonoscopy (patient with moderate to severe abdominal discomfort 31.8% versus 3.2%, p < 0.001).</p> <p>Conclusions</p> <p>Education levels and appointment waiting times, in addition to non-adherence to bowel preparation instructions, increase the risk of poor bowel preparation in adult patients undergoing colonoscopy. The latter has a significant impact on colonoscopy performance and patient comfort.</p
Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair
The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway
Stain-Free Quantification of Chromosomes in Live Cells Using Regularized Tomographic Phase Microscopy
Refractive index imaging is a label-free technique that enables long-term monitoring of the internal structures and molecular composition in living cells with minimal perturbation. Existing tomographic methods for the refractive index imaging lack 3-D resolution and result in artifacts that prevent accurate refractive index quantification. To overcome these limitations without compromising the capability to observe a sample in its most native condition, we have developed a regularized tomographic phase microscope (RTPM) enabling accurate refractive index imaging of organelles inside intact cells. With the enhanced accuracy, we quantify the mass of chromosomes in intact living cells, and differentiate two human colon cancer lines, HT-29 and T84 cells, solely based on the non-aqueous (dry) mass of chromosomes. In addition, we demonstrate chromosomal imaging using a dual-wavelength RTPM, which shows its potential to determine the molecular composition of cellular organelles in live cells.National Institute of Biomedical Imaging and Bioengineering (U.S.) (9P41EB015871-26A1
A case of native valve endocarditis caused by Burkholderia cepacia without predisposing factors
Reengineering the clinical research enterprise to involve more community clinicians
<p>Abstract</p> <p>Background</p> <p>The National Institutes of Health has called for expansion of practice-based research to improve the clinical research enterprise.</p> <p>Methods</p> <p>This paper presents a model for the reorganization of clinical research to foster long-term participation by community clinicians.</p> <p>Based on the literature and interviews with clinicians and other stakeholders, we posited a model, conducted further interviews to test the viability of the model, and further adapted it.</p> <p>Results</p> <p>We propose a three-dimensional system of checks and balances to support community clinicians using research support organizations, community outreach, a web-based registry of clinicians and studies, web-based training services, quality audits, and a feedback mechanism for clinicians engaged in research.</p> <p>Conclusions</p> <p>The proposed model is designed to offer a systemic mechanism to address current barriers that prevent clinicians from participation in research. Transparent mechanisms to guarantee the safety of patients and the integrity of the research enterprise paired with efficiencies and economies of scale are maintained by centralizing some of the functions. Assigning other responsibilities to more local levels assures flexibility with respect to the size of the clinician networks and the changing needs of researchers.</p
Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis
<p><b>Background:</b> Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.</p>
<p><b>Methods and Findings:</b> Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.</p>
<p><b>Conclusions:</b> Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.</p>
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