Development of KAISTSAT-4 Expanding the Role of Small Satellite for Scientific Research

The fourth Korean small satellite, KAISTSAT-4, is under development by Satellite Technology Research Center (SaTReC) of the Korea Advanced Institute of Science and Technology (KAIST). The KAISTSAT-4 program was commenced on October 1998 with multiple mission objectives, which include exploring space science, deploying satellite-based data collection system and development of precision star sensor. Despite severe constraints on mass and size, these advanced science and engineering payloads are expected to deliver various useful results and exhibit the unique role of small satellite. We present an overview of the KAISTSAT-4 mission and describe its current status. Finally the prospect of future small satellite programs is briefly introduced

Unleashing the full potential of Hsp90 inhibitors as cancer therapeutics through simultaneous inactivation of Hsp90, Grp94, and TRAP1

Cancer therapeutics: Extending a drug's reach A new drug that blocks heat shock proteins (HSPs), helper proteins that are co-opted by cancer cells to promote tumor growth, shows promise for cancer treatment. Several drugs have targeted HSPs, since cancer cells are known to hijack these helper proteins to shield themselves from destruction by the body. However, the drugs have had limited success. Hye-Kyung Park and Byoung Heon Kang at Ulsan National Institutes of Science and Technology in South Korea and coworkers noticed that the drugs were not absorbed into mitochondria, a key cellular compartment, and HSPs in this compartment were therefore not being blocked. They identified a new HSP inhibitor that can reach every cellular compartment and inhibit all HSPs. Testing in mice showed that this inhibitor effectively triggered death of tumor cells, and therefore shows promise for anti-cancer therapy. The Hsp90 family proteins Hsp90, Grp94, and TRAP1 are present in the cell cytoplasm, endoplasmic reticulum, and mitochondria, respectively; all play important roles in tumorigenesis by regulating protein homeostasis in response to stress. Thus, simultaneous inhibition of all Hsp90 paralogs is a reasonable strategy for cancer therapy. However, since the existing pan-Hsp90 inhibitor does not accumulate in mitochondria, the potential anticancer activity of pan-Hsp90 inhibition has not yet been fully examined in vivo. Analysis of The Cancer Genome Atlas database revealed that all Hsp90 paralogs were upregulated in prostate cancer. Inactivation of all Hsp90 paralogs induced mitochondrial dysfunction, increased cytosolic calcium, and activated calcineurin. Active calcineurin blocked prosurvival heat shock responses upon Hsp90 inhibition by preventing nuclear translocation of HSF1. The purine scaffold derivative DN401 inhibited all Hsp90 paralogs simultaneously and showed stronger anticancer activity than other Hsp90 inhibitors. Pan-Hsp90 inhibition increased cytotoxicity and suppressed mechanisms that protect cancer cells, suggesting that it is a feasible strategy for the development of potent anticancer drugs. The mitochondria-permeable drug DN401 is a newly identified in vivo pan-Hsp90 inhibitor with potent anticancer activity

Impact of prior abdominal surgery on postoperative prolonged ileus after ileostomy repair

SummaryBackground and aimsPostoperative ileus (POI) is one of the most common reasons for sustained hospital stays after ileostomy repair. Although many factors have been investigated as POI risk factors, the investigation of the impact of prior abdominal surgery (PAS) before rectal cancer surgery has been limited. This study aimed to identify the impact of PAS as a risk factor for POI after ileostomy repair.Material and methodsA total of 220 consecutive patients with rectal cancer who underwent ileostomy repair were enrolled. The patients were divided into PAS-positive and PAS-negative groups according to the history of PAS before rectal cancer surgery. Univariate and multivariate analyses were performed to identify the clinicopathological factors associated with POI.ResultsThe PAS-positive group had a longer operation time (111 min vs. 93.4 min, p=0.029) and a greater length of hospital stay (10 days vs. 7.8 days, p=0.003) compared with the PAS-negative group. POI was more frequent in the PAS-positive group (23.1% vs. 6.2%, p=0.011). The POI rate in the entire cohort was 8.1%. The repair method (stapled side-to-side vs. hand-sewn end-to-end, odds ratio OR=3.6, 95% confidence interval CI=1.2–11.1, p=0.022) and PAS (odds ratio=4.0, 95% confidence interval=1.2–12.8, p=0.017) were significant predictors of POI in the multivariate analysis.ConclusionsThis study suggests that PAS before rectal cancer surgery is associated with POI after ileostomy repair