Magnetically Actuated Cell Stretching Platform to Induce Phenotypic Changes in Metastatic Cells

Although metastasis is responsible for about 90% of cancer deaths, only few in vitro models can be used to evaluate dynamic behaviors of metastatic cancer cells. Many studies have shown that mechanical stimuli can trigger various cellular responses such as gene and protein expression, which could lead to changes in cellular phenotype. Similarly, metastasized breast cancer cells in the lung tissue are constantly stretched by cyclic mechanical stress due to breathing, which alters cellular morphology and proliferation state. Such transitions can make the secondary tumors resistant to the chemotherapy used to effectively treat the primary tumors. In this work, we developed an in vitro tumor microenvironment that simulates in vivo respiration to investigate the mechanism of the phenotypic changes of metastatic breast cancer cells due to mechanical stimulation. We designed and fabricated magnetic microactuators using maskless photolithography technique to stretch tumor cells. Next, we coated fibronectin fibrils over the gaps of microactuators to mimic natural ECM environment and seeded tumor cells on the fibronectin mesh to generate a tumor microenvironment. As a result, the amount of strain that our microdevice could apply on the fibronectin mesh corresponded to the amount of strain experienced during normal respiration. In conclusion, the magnetically actuated in vitro cell stretching platform can provide precise strain control over a large actuation range to mimic mechanical stimulation in the lung. In the future, we will evaluate potential changes in metastatic cell phenotype and provide additional insights on the mechanism of secondary tumor drug resistance

PowerCore: a program applying the advanced M strategy with a heuristic search for establishing core sets

AbstractMotivation: Core sets are necessary to ensure that access to useful alleles or characteristics retained in genebanks is guaranteed. We have successfully developed a computational tool named 'PowerCore' that aims to support the development of core sets by reducing the redundancy of useful alleles and thus enhancing their richness.Results: The program, using a new approach completely different from any other previous methodologies, selects entries of core sets by the advanced M (maximization) strategy implemented through a modified heuristic algorithm. The developed core set has been validated to retain all characteristics for qualitative traits and all classes for quantitative ones. PowerCore effectively selected the accessions with higher diversity representing the entire coverage of variables and gave a 100% reproducible list of entries whenever repeated.Availability: PowerCore software uses the .NET Framework Version 1.1 environment which is freely available for the MS Windows platform. The files can be downloaded from http://genebank.rda.go.kr/powercore/. The distribution of the package includes executable programs, sample data and a user manual.Contact: [email protected]

A Case of Pulmonary Arterial Hypertension Associated With Hyperthyroidism, Persistent After Euthyroidism Was Obtained

Cardiovascular manifestations in hyperthyroidism occur frequently with various phenotypes. An association between hyperthyroidism and pulmonary arterial hypertension has been reported. In previously reported cases, the hemodynamic and symptomatic recovery of pulmonary arterial hypertension is usually concomitant with achievement of euthyroidism. We report a patient who had pulmonary arterial hypertension associated with Graves' disease, which persisted after euthyroidism was obtained

Practice Pattern of Gastroenterologists for the Management of GERD Under the Minimal Influence of the Insurance Reimbursement Guideline: A Multicenter Prospective Observational Study

The objective of the study was to document practice pattern of gastroenterologists for the management of gastroesophageal reflux disease (GERD) under the minimal influence of the insurance reimbursement guideline. Data on management for 1,197 consecutive patients with typical GERD symptoms were prospectively collected during 16 weeks. In order to minimize the influence of reimbursement guideline on the use of proton pump inhibitors (PPIs), rabeprazole was used for the PPI treatment. A total of 861 patients (72%) underwent endoscopy before the start of treatment. PPIs were most commonly prescribed (87%). At the start of treatment, rabeprazole 20 mg daily was prescribed to 94% of the patients who received PPI treatment and 10 mg daily to the remaining 6%. At the third visits, rabeprazole 20 mg daily was prescribed to 70% of those who were followed and 10 mg daily for the remaining 30%. Continuous PPI treatment during the 16-week period was performed in 63% of the study patients. In conclusion, a full-dose PPI is preferred for the initial and maintenance treatment of GERD under the minimal influence of the insurance reimbursement guideline, which may reflect a high proportion of GERD patients requiring a long-term treatment of a full-dose PPI

Efficacy of Tandem High-Dose Chemotherapy and Autologous Stem Cell Rescue in Patients Over 1 Year of Age with Stage 4 Neuroblastoma: The Korean Society of Pediatric Hematology-Oncology Experience Over 6 Years (2000-2005)

The efficacy of tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) was investigated in patients with high-risk neuroblastoma. Patients over 1 yr of age who were newly diagnosed with stage 4 neuroblastoma from January 2000 to December 2005 were enrolled in The Korean Society of Pediatric Hematology-Oncology registry. All patients who were assigned to receive HDCT/ASCR at diagnosis were retrospectively analyzed to investigate the efficacy of single or tandem HDCT/ASCR. Seventy and 71 patients were assigned to receive single or tandem HDCT/ASCR at diagnosis. Fifty-seven and 59 patients in the single or tandem HDCT group underwent single or tandem HDCT/ASCR as scheduled. Twenty-four and 38 patients in the single or tandem HDCT group remained event free with a median follow-up of 56 (24-88) months. When the survival rate was analyzed according to intent-to-treat at diagnosis, the probability of the 5-yr event-free survival±95% confidence intervals was higher in the tandem HDCT group than in the single HDCT group (51.2±12.4% vs. 31.3±11.5%, P=0.030). The results of the present study demonstrate that the tandem HDCT/ASCR strategy is significantly better than the single HDCT/ASCR strategy for improved survival in the treatment of high-risk neuroblastoma patients

The Mildly Elevated Serum Bilirubin Level is Negatively Associated with the Incidence of End Stage Renal Disease in Patients with IgA Nephropathy

Oxidative stress plays various roles in the development and progression of IgA nephropathy, while bilirubin is known as a potent antioxidant. We therefore hypothesized that serum bilirubin would be associated with renal prognosis in IgA nephropathy. The study subjects comprised 1,458 adult patients with primary IgA nephropathy in Korea. We grouped patients according to the following quartile levels of bilirubin: <0.4 mg/dL (Q1), 0.4-0.5 mg/dL (Q2), 0.6-0.7 mg/dL (Q3), and >0.8 mg/dL (Q4). The outcome data were obtained from the Korean Registry of end-stage renal disease (ESRD). Eighty patients (5.5%) contracted ESRD during a mean follow-up period of 44.9 months. The ESRD incidences were 10.7% in Q1, 8.2% in Q2, 2.8% in Q3, and 2.8% in Q4 (p<0.001). The relative risk of ESRD compared to that in Q1 was 0.307 (95% confidence interval [CI], 0.126-0.751) in Q3 and 0.315 (95% CI, 0.130-0.765) in Q4. The differences of ESRD incidence were greater in subgroups of males and of patients aged 35 yr or more, with serum albumin 4.0 g/dL or more, with normotension, with eGFR 60 mL/min/1.73 m2 or more, and with proteinuria less then 3+ by dipstick test. In conclusion, higher bilirubin level was negatively associated with ESRD incidence in IgA nephropathy

Determinants of redox sensitivity in RsrA, a zinc-containing anti-sigma factor for regulating thiol oxidative stress response

Various environmental oxidative stresses are sensed by redox-sensitive regulators through cysteine thiol oxidation or modification. A few zinc-containing anti-sigma (ZAS) factors in actinomycetes have been reported to respond sensitively to thiol oxidation, among which RsrA from Streptomyces coelicolor is best characterized. It forms disulfide bonds upon oxidation and releases bound SigR to activate thiol oxidative stress response genes. Even though numerous ZAS proteins exist in bacteria, features that confer redox sensitivity to a subset of these have been uncharacterized. In this study, we identified seven additional redox-sensitive ZAS factors from actinomycetes. Comparison with redox-insensitive ZAS revealed characteristic sequence patterns. Domain swapping demonstrated the significance of the region K33FEHH37FEEC41SPC44LEK47 that encompass the conserved HX3CX2C (HCC) motif. Mutational effect of each residue on diamide responsive induction of SigR target genes in vivo demonstrated that several residues, especially those that flank two cysteines (E39, E40, L45, E46), contribute to redox sensitivity. These residues are well conserved among redox-sensitive ZAS factors, and hence are proposed as redox-determinants in sensitive ZAS. H37A, C41A, C44A and F38A mutations, in contrast, compromised SigR-binding activity significantly, apparently affecting structural integrity of RsrA. The residue pattern around HCC motif could therefore serve as an indicator to predict redox-sensitive ZAS factors from sequence information