29 research outputs found
Laparoscopic Renal Denervation System for Treating Resistant Hypertension: Overcoming Limitations of Catheter-Based Approaches
Goal: In a pivotal clinical trial, the percutaneous catheter-based renal denervation system developed to treat resistant hypertension did not show effectiveness in reducing blood pressure because of its fundamental limitation to ablate deeper nerves present around the renal artery. Methods: We propose a new renal denervation strategy called laparoscopicdenervation system (LDS) based-on laparoscopy procedure to ablate the renal nerves completely but inhibit the thermal arterial damage.The system has flexible electrodes to bend around the arterial wall to ablate nervesThe simulation study using validated in-silico models evaluated the heat distributionon the outer arterial wall,and an acute animal study (swine model) was conducted to demonstrate the feasibility of LDS in vivo. Results: The simulation studyconfirmedthat LDS could localize the heat distributionbetween the electrode and the outer arterial wall. In the animal study, we could maximize nerve denervation by the localizing ablation energy within the renal nerves and achieve nerve denaturationand decrease in neural density by 20.78% (P < 0.001), while maintaining a constant tip temperature of 65 degrees C for the duration of 70 s treatment. The study confirmed intact lumen artery through histological analysis and acute reduction in systolic blood pressure by 9.55 mmHg (p < 0.001) Conclusion: The LDS presented here has potential to effectively and safely ablate the renal nerves, independent of anatomical variation and nerve distribution, to control hypertension in real clinical conditions. Significance: LDS approach is innovative, inventive, and presents a novel technique totreat hypertension.11Yscopu
Serotype-Independent Protection Against Invasive Pneumococcal Infections Conferred by Live Vaccine With lgt Deletion
Streptococcus pneumoniae is the most common respiratory bacterial pathogen among cases of community-acquired infection in young children, older adults, and individuals with underlying medical conditions. Although capsular polysaccharide-based pneumococcal vaccines have contributed to significant decrease in invasive pneumococcal infections, these vaccines have some limitations, including limited serotype coverage, lack of effective mucosal antibody responses, and high costs. In this study, we investigated the safety and immunogenicity of a live, whole-cell pneumococcal vaccine constructed by deleting the gene for prolipoprotein diacylglyceryl transferase (lgt) from the encapsulated pneumococcal strain TIGR4 (TIGR4Δlgt) for protection against heterologous pneumococcal strains. Pneumococcal strain TIGR4 was successfully attenuated by deletion of lgt, resulting in the loss of inflammatory activity and virulence. TIGR4Δlgt colonized the nasopharynx long enough to induce strong mucosal IgA and IgG2b-dominant systemic antibody responses that were cross-reactive to heterologous pneumococcal serotypes. Finally, intranasal immunization with TIGR4Δlgt provided serotype-independent protection against pneumococcal challenge in mice. Taken together, our results suggest that TIGR4Δlgt is an avirulent and attractive broad-spectrum pneumococcal vaccine candidate. More broadly, we assert that modulation of such “master” metabolic genes represents an emerging strategy for developing more effective vaccines against numerous infectious agents
Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel
Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 10(6) and 10(4) CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed. (C) 2011 Elsevier Ltd. All rights reserved.N
Progress toward a group B streptococcal vaccine
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of severe invasive disease in neonate, elderly, and immunocompromised patients worldwide. Despite recent advances in the diagnosis and intrapartum antibiotic prophylaxis (IAP) of GBS infections, it remains one of the most common causes of neonatal morbidity and mortality, causing serious infections. Furthermore, recent studies reported an increasing number of GBS infections in pregnant women and elderly. Although IAP is effective, it has several limitations, including increasing antimicrobial resistance and late GBS infection after negative antenatal screening. Maternal immunization is the most promising and effective countermeasure against GBS infection in neonates. However, no vaccine is available to date, but two types of vaccines, protein subunit and capsular polysaccharide conjugate vaccines, were investigated in clinical trials. Here, we provide an overview of the GBS vaccine development status and recent advances in the development of immunoassays to evaluate the GBS vaccine clinical efficacy
Polymer Thin Film Promotes Tumor Spheroid Formation via JAK2-STAT3 Signaling Primed by Fibronectin-Integrin α5 and Sustained by LMO2-LDB1 Complex
Cancer stem-like cells (CSCs) are considered promising targets for anti-cancer therapy owing to their role in tumor progression. Extensive research is, therefore, being carried out on CSCs to identify potential targets for anti-cancer therapy. However, this requires the availability of patient-derived CSCs ex vivo, which remains restricted due to the low availability and diversity of CSCs. To address this limitation, a functional polymer thin-film (PTF) platform was invented to induce the transformation of cancer cells into tumorigenic spheroids. In this study, we demonstrated the functionality of a new PTF, polymer X, using a streamlined production process. Polymer X induced the formation of tumor spheroids with properties of CSCs, as revealed through the upregulated expression of CSC-related genes. Signal transducer and activator of transcription 3 (STAT3) phosphorylation in the cancer cells cultured on polymer X was upregulated by the fibronectin-integrin α5-Janus kinase 2 (JAK2) axis and maintained by the cytosolic LMO2/LBD1 complex. In addition, STAT3 signaling was critical in spheroid formation on polymer X. Our PTF platform allows the efficient generation of tumor spheroids from cancer cells, thereby overcoming the existing limitations of cancer research
Targeted inhibition of FAK, PYK2 and BCL-XL synergistically enhances apoptosis in ovarian clear cell carcinoma cell lines.
Ovarian clear cell carcinoma (OCCC) displays a higher resistance to first line chemotherapy, requiring the development of new therapeutics. We previously identified a frequent chromosomal gain at 8q24 that harbors the focal-adhesion kinase (FAK) gene; the potential of this gene as a therapeutic target remains to be evaluated in OCCCs. We first examined the dependence of OCCCs on FAK and the PI3K/AKT signaling pathway. FAK was overexpressed in 20% of 67 OCCC samples, and this overexpression was correlated with its copy number gain. FAK copy number gains and mutations in PIK3CA accounted for about 40% of OCCC samples, suggesting that the FAK/PI3K/AKT axis is an attractive candidate for targeted therapeutics. We, therefore, treated ovarian cancer cell lines, including OCCC subtypes, with the FAK inhibitors PF-562,271 (PF271), and PF-573,228 (PF228). Ovarian cancer cells were more sensitive to PF271 than PF228. We then searched for single agents that exhibited a synergistic effect on cell death in combination with PF271. We found that co-treatment of PF271 with ABT-737, a BCL-2/BCL-XL antagonist, was profoundly effective at inducing apoptosis. RMGI and OVISE cells were more sensitive to ABT-737 than OVMANA and SKOV3 cells, which have PIK3CA mutations. Mechanistically, PF271 treatment resulted in the transient down-regulation of the anti-apoptotic protein MCL1 via the PI3K/AKT pathway. Therefore, PF271/ABT-737 treatment led to the inhibition of the anti-apoptotic proteins MCL1 and BCL-XL/BCL-2. We suggest that pharmacological inhibition of BCL-XL and FAK/PYK2 can be a potential therapeutic strategy for the treatment of OCCC
FAK overexpression was associated with an increased copy number in OCCCs.
<p>A, Paraffin-embedded tumor sections were immunohistochemically stained using an anti-FAK antibody. The FAK staining results were scored into four categories based on the signal intensity: 0, no detection; 1, weak; 2, moderate; 3, strong. B, Variation in the FAK copy number was assessed with quantitative PCR. Copy number log ratios higher than 0.32 and 1.00 were considered evidence of copy number gain and gene amplification, respectively. The X-axis represents the samples. C, FAK overexpression (IHC score 3) correlated with the gains in copy number (copy number log ratio >0.32). Weak expressions of FAK (IHC score 1) resulted in normal or reduced FAK copy numbers (copy number log ratio <0.32). D, Samples with a mutation in <i>PIK3CA</i> (<i>PIK3CA</i>_Mut) are marked as red diamonds on the plot. The vertical dotted line indicates a copy number log ratio of 0.32.</p
FAK and BCL2/BCL-XL inhibitors induced apoptosis.
<p>A, OCCC cell lines were treated with 1 µM ABT-737 (A), 1 µM BEZ235 (B), or 5 µM PF271 (P), individually or in combinations (AB indicates ABT-737/BEZ235; AP, ABT-737/PF271; BP, BEZ235/PF271; ABP, ABT-737/BEZ235/PF271) at the same drug concentrations for 6 hr. Cell lysates were prepared and subjected to Western blot analysis using the indicated antibodies. Cleavage of caspase-3 (CASP3), caspase-8 (CASP8), PARP, and FAK indicated that apoptosis had occurred. BCL-2 was not expressed in OVMANA and OVISE. B, TOV21G, RMGI and OVISE cells were treated individually or in combination with 1 µM ABT-737, 1 µM BEZ235 and/or 5 µM PF271 for 6 hr. The cells were fixed with 70% ethanol, were stained with propidium iodide (PI) and analyzed using a FACS Calibur flow cytometer.</p
Expression and Mutational Analysis of DinB-Like Protein DR0053 in <i>Deinococcus radiodurans</i>
<div><p>In order to understand the mechanism governing radiation resistance in <i>Deinococcus radiodurans</i>, current efforts are aimed at identifying potential candidates from a large repertoire of unique Deinococcal genes and protein families. DR0053 belongs to the DinB/YfiT protein family, which is an over-represented protein family in <i>D. radiodurans</i>. We observed that <i>dr0053</i> transcript levels were highly induced in response to gamma radiation (γ-radiation) and mitomycin C (MMC) exposure depending on PprI, RecA and the DrtR/S two-component signal transduction system. Protein profiles demonstrated that DR0053 is a highly induced protein in cultures exposed to 10 kGy γ-radiation. We were able to determine the transcriptional start site of <i>dr0053</i>, which was induced upon irradiation, and to assign the 133-bp promoter region of <i>dr0053</i> as essential for radiation responsiveness through primer extension and promoter deletion analyses. A <i>dr0053</i> mutant strain displayed sensitivity to γ-radiation and MMC exposure, but not hydrogen peroxide, suggesting that DR0053 helps cells recover from DNA damage. Bioinformatic analyses revealed that DR0053 is similar to the <i>Bacillus subtilis</i> protein YjoA, which is a substrate of bacterial protein-tyrosine kinases. Taken together, the DNA damage-inducible (<i>din</i>) gene <i>dr0053</i> may be regulated at the transcriptional and post-translational levels.</p></div