Dimeric configuration of SeqA protein bound to a pair of hemi-methylated GATC sequences

The binding of SeqA protein to hemi-methylated GATC sequences (hemi-sites) regulates chromosome initiation and the segregation of replicated chromosome in Escherichia coli. We have used atomic force microscopy to examine the architecture of SeqA and the mode of binding of one molecule of SeqA to a pair of hemi-sites in aqueous solution. SeqA has a bipartite structure composed of a large and a small lobe. Upon binding of a SeqA molecule to a pair of hemi-sites, the larger lobe becomes visibly separated into two DNA binding domains, each of which binds to one hemi-site. The two DNA binding domains are held together by association between the two multimerization domains that make up the smaller lobe. The binding of each DNA binding domain to a hemi-site leads to bending of the bound DNA inwards toward the bound protein. In this way, SeqA adopts a dimeric configuration when bound to a pair of hemi-sites. Mutational analysis of the multimerization domain indicates that, in addition to multimerization of SeqA polypeptides, this domain contributes to the ability of SeqA to bind to a pair of hemi-sites and to its cooperative behavior

Vagus Nerve Stimulation in Intractable Childhood Epilepsy: a Korean Multicenter Experience

We evaluated the long-term outcome of vagus nerve stimulation (VNS) in 28 children with refractory epilepsy. Of these 28 children, 15 (53.6%) showed a >50% reduction in seizure frequency and 9 (32.1%) had a >75% reduction. When we compared seizure reduction rates according to seizure types (generalized vs. partial) and etiologies (symptomatic vs. cryptogenic), we found no significant differences. In addition, there was no correlation between the length of the stimulation period and treatment effect. The seizure reduction rate, however, tended to be inversely related to the seizure duration before VNS implantation and age at the time of VNS therapy. VNS also improved quality of life in this group of patients, including improved memory in 9 (32.1%), improved mood in 12 (42.9%), improved behavior in 11 (39.3%), improved altertness in 12 (42.9%), improved achievement in 6 (21.4%), and improved verbal skills in 8 (28.6%). Adverse events included hoarseness in 7 patients, dyspnea at sleep in 2 patients, and wound infection in 1 patient, but all were transient and successfully managed by careful follow-up and adjustment of parameters. These results indicate that VNS is a safe and effective alternative therapy for pediatric refractory epilepsy, without significant adverse events

Colorectal cancer cell-derived microvesicles are enriched in cell cycle-related mRNAs that promote proliferation of endothelial cells

<p>Abstract</p> <p>Background</p> <p>Various cancer cells, including those of colorectal cancer (CRC), release microvesicles (exosomes) into surrounding tissues and peripheral circulation. These microvesicles can mediate communication between cells and affect various tumor-related processes in their target cells.</p> <p>Results</p> <p>We present potential roles of CRC cell-derived microvesicles in tumor progression via a global comparative microvesicular and cellular transcriptomic analysis of human SW480 CRC cells. We first identified 11,327 microvesicular mRNAs involved in tumorigenesis-related processes that reflect the physiology of donor CRC cells. We then found 241 mRNAs enriched in the microvesicles above donor cell levels, of which 27 were involved in cell cycle-related processes. Network analysis revealed that most of the cell cycle-related microvesicle-enriched mRNAs were associated with M-phase activities. The integration of two mRNA datasets showed that these M-phase-related mRNAs were differentially regulated across CRC patients, suggesting their potential roles in tumor progression. Finally, we experimentally verified the network-driven hypothesis by showing a significant increase in proliferation of endothelial cells treated with the microvesicles.</p> <p>Conclusion</p> <p>Our study demonstrates that CRC cell-derived microvesicles are enriched in cell cycle-related mRNAs that promote proliferation of endothelial cells, suggesting that microvesicles of cancer cells can be involved in tumor growth and metastasis by facilitating angiogenesis-related processes. This information will help elucidate the pathophysiological functions of tumor-derived microvesicles, and aid in the development of cancer diagnostics, including colorectal cancer.</p

The Role of TURP in the Detection of Prostate Cancer in BPH Patients with Previously Negative Prostate Biopsy

Purpose: We aimed to investigate the significance of early detection of transition zone prostate cancer by transurethral resection of prostate (TURP) in benign prostatic hyperplasia (BPH) patients with lower urinary tract symptoms (LUTS) in whom prostate cancer was suspected despite a negative transrectal ultrasonography (TRUS) biopsy result. Materials and Methods: From January 2006 to January 2009, a total of 165 patients who underwent TURP were evaluated. The prostate cancer detection rate was compared between patients who underwent TRUS biopsy before TURP (group A) and those who did not (group B). All charts were evaluated retrospectively, including prostate-specific antigen (PSA), digital rectal examination (DRE), TURP results (including resection volume and pathology report), TRUS, and TRUS biopsy results. Group A was subdivided into group A1, who were diagnosed with prostate cancer after TURP, and group A2, who were diagnosed with BPH after TURP. Results: The cancer detection rate showed no significant difference between groups A and B (8.9% vs. 7.5%, p > 0.05). The mean PSA levels in groups A1 and A2 were 15.5??14.0 ng/ml and 9.1??5.1 ng/ml, respectively (p > 0.05). In group A1, 40% had an abnormal DRE, compared with 6.7% in group A2 (p < 0.05). After TURP, the mean percentage of resected prostatic chips of the prostate cancer group and BPH group were 33.9% and 18.6%, respectively (p=0.001). A positive correlation was found between the detection rate of prostate cancer and PSA (p=0.01). Conclusions: BPH patients in whom prostate cancer is suspected and who have lower urinary tract symptoms (LUTS) with a previously negative TRUS biopsy result can undergo TURP, which results in immediate improvement in bladder outlet obstruction and early diagnosis of clinically significant transition zone prostate cancer. ?? The Korean Urological Association, 2010

Sicyos angulatus ameliorates atherosclerosis through downregulation of aortic inflammatory responses in apolipoprotein E-deficient mice

Sicyos angulatus (SA), a summer annual vine originating from Northeastern USA, is a widely distributed noxious invasive plant. However, the clinical application of SA has not been investigated previously. The purpose of present study was to determine the effects of SA on atherosclerosis and its underlying mechanism. Atherosclerosis was induced by feeding apolipoprotein E-deficient (apoE(-/-)) mice with an atherogenic diet for 8 weeks. SA was administered daily by oral gavage during induction of atherosclerosis. ApoE(-/-) mice treated with SA demonstrated a significant reduction in atherosclerotic plaque area in the whole aorta and aortic sinus compared with vehicle-treated mice. The plasma lipid profiles, including triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein, were not affected by SA administration. Of note, gene expression levels of proatherogenic cytokines including tumor necrosis factor alpha (Tnf alpha) and interleukin-6 (Il-6) were significantly decreased in the aorta of SA administered apoE(-/-) mice. In lipopolysaccharide-stimulated RAW 264.7 macrophage cells, SA also inhibited the induction Tnfa, Il-6 and Il-1 beta in a dose-dependent manner. Furthermore, gene expression levels of endothelial cell adhesion molecules, including vascular cell adhesion protein 1 and intercellular adhesion molecule 1 were reduced in the aorta of apoE(-/-) mice treated with SA, which was followed by diminished aortic infiltration of monocytes/macrophages. In conclusion, to the best of our knowledge, this is the first study to demonstrate that SA is able to suppress the development of atherosclerosis by inhibiting the aortic expression of proinflammatory factors in atherogenic diet-fed apoE(-/-) mice. The present study may provide novel insights into the application of the environmentally problematic weed SA as a therapeutically effective natural product for preventing atherosclerosis.N

Immunomodulatory effects of human amniotic membrane-derived mesenchymal stem cells

Human amniotic membrane-derived mesenchymal stem cells (hAM-MSCs) are capable of differentiating into several lineages and possess immunomodulatory properties. In this study, we investigated the soluble factor-mediated immunomodulatory effects of hAM-MSCs. Mitogen-induced peripheral blood mononuclear cell (PBMC) proliferation was suppressed by hAM-MSCs in a dose-dependent manner as well as hAM-MSC culture supernatant. Moreover, interferon-gamma and interleukin (IL)-17 production significantly decreased from PBMC, whereas IL-10 from PBMCs and transforming growth factor beta (TGF-β) production from hAM-MSCs significantly increased in co-cultures of hAM-MSCs and PBMCs. Production of several MSC factors, including hepatocyte growth factor (HGF), TGF-β, prostaglandin E2 (PGE2), and indoleamine 2, 3 dioxygenase (IDO), increased significantly in hAM-MSCs co-cultured with PBMCs. These results indicate that the immunomodulatory effects of hAM-MSCs may be associated with soluble factors (TGF-β, HGF, PGE2, and IDO), suggesting that hAM-MSCs may have potential clinical use in regenerative medicine