Biofilm formation among methicillin-resistant Staphylococcus aureus isolates from patients with urinary tract infection.

Staphylococci have been confirmed to form biofilms on various biomaterials. The purpose of this study was to investigate biofilm formation among methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with urinary tract infection (UTI) and to assess the relationship between biofilm-forming capacities and virulence determinants/clinical background. Over a 12-year period from 1990 through 2001, a total of 109 MRSA isolates were collected from patients (one isolate per patient) with UTI at the urology ward of Okayama University Hospital. We used the in vitro microtiter plate assay to quantify biofilm formation. We then investigated the presence of several virulence determinants by polymerase chain reaction assay and found eight determinants (tst, sec, hla, hlb, fnbA, clfA, icaA, and agrII) to be predominant among these isolates. Enhanced biofilm formation was confirmed in hla-, hlb-, and fnbA-positive MRSA isolates, both individually and in combination. Upon review of the associated medical records, we concluded that the biofilm-forming capacities of MRSA isolates from catheter-related cases were significantly greater than those from catheter-unrelated cases. The percentage of hla-, hlb-, and fnbA-positive isolates was higher among MRSA isolates from catheter-related cases than those from catheter-unrelated cases. Our studies suggest that MRSA colonization and infection of the urinary tract may be promoted by hla, hlb, and fnbA gene products.</p

Visualization and Measurement of ATP Levels in Living Cells Replicating Hepatitis C Virus Genome RNA

Adenosine 5′-triphosphate (ATP) is the primary energy currency of all living organisms and participates in a variety of cellular processes. Although ATP requirements during viral lifecycles have been examined in a number of studies, a method by which ATP production can be monitored in real-time, and by which ATP can be quantified in individual cells and subcellular compartments, is lacking, thereby hindering studies aimed at elucidating the precise mechanisms by which viral replication energized by ATP is controlled. In this study, we investigated the fluctuation and distribution of ATP in cells during RNA replication of the hepatitis C virus (HCV), a member of the Flaviviridae family. We demonstrated that cells involved in viral RNA replication actively consumed ATP, thereby reducing cytoplasmic ATP levels. Subsequently, a method to measure ATP levels at putative subcellular sites of HCV RNA replication in living cells was developed by introducing a recently-established Förster resonance energy transfer (FRET)-based ATP indicator, called ATeam, into the NS5A coding region of the HCV replicon. Using this method, we were able to observe the formation of ATP-enriched dot-like structures, which co-localize with non-structural viral proteins, within the cytoplasm of HCV-replicating cells but not in non-replicating cells. The obtained FRET signals allowed us to estimate ATP concentrations within HCV replicating cells as ∼5 mM at possible replicating sites and ∼1 mM at peripheral sites that did not appear to be involved in HCV replication. In contrast, cytoplasmic ATP levels in non-replicating Huh-7 cells were estimated as ∼2 mM. To our knowledge, this is the first study to demonstrate changes in ATP concentration within cells during replication of the HCV genome and increased ATP levels at distinct sites within replicating cells. ATeam may be a powerful tool for the study of energy metabolism during replication of the viral genome

A novel intraperitoneal therapy for gastric cancer with DFP‐10825, a unique RNAi therapeutic targeting thymidylate synthase, in a peritoneally disseminated xenograft model

Purpose: In advanced gastric cancer, peritoneal dissemination is a life‐threatening mode of metastasis. Since the treatment options with conventional chemotherapy remain limited, any novel therapeutic strategy that could control such metastasis would improve the outcome of treatment. We recently developed a unique RNA interference therapeutic regimen (DFP‐10825) consisting of short hairpin RNA against thymidylate synthase (TS shRNA) and cationic liposomes. The treatment with DFP‐10825 has shown remarkable antitumor activity in peritoneally disseminated human ovarian cancer–bearing mice via intraperitoneal administration. In this study, we expanded DFP‐10825 to the treatment of peritoneally disseminated gastric cancer. Methods: DFP‐10825 was administered intraperitoneally into mice with intraperitoneally implanted human gastric cancer cells (MKN45 or NCI‐N87). Antitumor activity and host survival benefits were monitored. Intraperitoneal distribution of fluorescence‐labeled DFP‐10825 was monitored in this MKN45 peritoneally disseminated mouse model. Results: Intraperitoneal injection of DFP‐10825 suppressed tumor growth in two peritoneally disseminated cancer models (MKN45 and NCI‐N87) and increased the survival time of the MKN45 model without severe side effects. Throughout the treatment regimen, no significant body weight loss was associated with the administration of DFP‐10825. Interestingly, after intraperitoneal injection, fluorescence‐labeled DFP‐10825 retained for more than 72 hours in the peritoneal cavity and selectively accumulated in disseminated tumors. Conclusions: Intraperitoneal injection of DFP‐10825 demonstrated effective antitumor activity without systemic severe adverse effects via the selective delivery of RNAi molecules into disseminated tumors in the peritoneal cavity. Our current study indicates that DFP‐10825 could become an alternative option to improve the outcomes of patients with peritoneally disseminated gastric cancer

明治数学史の基礎工事

The European mathematics exists as a science and the fundamental tools of thchnology. On the other hand, the Japanese mathematics (Wasan) did not as a science but as an art. However, the Japanese were by no means wanting in scientific spirit. The warriors (Samurai) of the Tokugawa Shogunate were strongly endowed with a zealous yearning for knowledge of the navigation at the Nagasaki Navy College, which was founded in 1855. They were taught and trained by Dutch officers with severity. Some of them were especially diligent, namely Yatabori, Ono, Enomoto, Akamatsu, Nakamuda, Tsukamoto, Sawa, Ban, and Hida. After a few years, they had become the leading members of the Tokugawa Navy. They understood that mathematical thinking was at the foundation of European civilization. Indeed, their mathematical abilities advanced with rapid strides. But, Katsu was a dull student and could not become interested in mathematics. A certain number of Dutch mathematical and astronomical works were in the possession at the Astronomical Board of the Shogunate (Bakufu Tenmonkata). To read these works, the Institute of Occidental Culture (Bansho Chosho) was founded in 1855 by the Shogunate. In this Institute, K. Kanda was the first professor of the department of mathematics. In 1866, Dr. S. Yanagawa was elected to a professorship of this Institute. Kanda wrote "Introduction to Arithmetic" and Yanagawa wrote "How to Use for Arithmetic" in 1857. A friendship between Kanda and Yanagawa continued until Yanagawa\u27s death in 1870. Yamamoto, Sahara, Suzuki, Nagahiro Enomoto, and T. Kikuchi are all graduates of this Institute. Arithmetic was also taught at the Yokohama French College, which was founded in 1864. Zinbo is a graduate of this college. The mathematicians of the old Japanese school (Wasanka) took pains to solve the many difficult problems, but could not discovered the general method of a solution. Ono and Yanagi was the well-known Japanese mathematicians, but they made an effort to learn the European mathematics. In 1868, the political change of the Restoration took place. The leaders of the New Meiji Government were not familiar with Occidental culture. Most of them were terrorists with the exception of Omura. For the most part, the Meiji Government had been conducted by the warriors intelligentsia of the Shogunate. The teaters at the Navy College, Military Academy and University College (Daigaku Nanko) were mostly old warriors of the Shogunate. In 1877, the Tokyo Mathematical Society was founded. The first president was Kanda. One half of the organization\u27s members were mostly old Shogunate warriors and well-known old Japanese mathematicians. The rest were the second-class mathematicians