167 research outputs found
The probability of double-strand breaks in giant DNA decreases markedly as the DNA concentration increases
DNA double-strand breaks (DSBs) represent a serious source of damage for all
living things and thus there have been many quantitative studies of DSBs both
in vivo and in vitro. Despite this fact, the processes that lead to their
production have not yet been clearly understood, and there is no established
theory that can account for the statistics of their production, in particular,
the number of DSBs per base pair per unit Gy, here denoted by P1, which is the
most important parameter for evaluating the degree of risk posed by DSBs. Here,
using the single-molecule observation method with giant DNA molecules (166
kbp), we evaluate the number of DSBs caused by gamma-ray irradiation. We find
that P1 is nearly inversely proportional to the DNA concentration above a
certain threshold DNA concentration. A simple model that accounts for the
marked decrease of P1 shows that it is necessary to consider the
characteristics of giant DNA molecules as semiflexible polymers to interpret
the intrinsic mechanism of DSBs
How are small ions involved in the compaction of DNA molecules?
DNA is a genetic material found in all life on Earth. DNA is composed of four types of nucleotide subunits, and forms a double-helical one-dimensional polyelectrolyte chain. If we focus on the microscopic molecular structure, DNA is a rigid rod-like molecule. On the other hand, with coarse graining, a long-chain DNA exhibits fluctuating behavior over the whole molecule due to thermal fluctuation. Owe to its semiflexible nature, individual giant DNA molecule undergoes a large discrete transition in the higher-order structure. In this folding transition into a compact state, small ions in the solution have a critical effect, since DNA is highly charged. In the present article, we interpret the characteristic features of DNA compaction while paying special attention to the role of small ions, in relation to a variety of single-chain morphologies generated as a result of compaction
VALIDITY OF REAL-TIME SINGLE-BEAT VERSUS MULTI-BEAT FULL-VOLUME CAPTURE THREE-DIMENSIONAL ECHOCARDIOGRAPHY FOR QUANTIFICATION OF RIGHT VENTRICULAR VOLUME: VALIDATED BY CARDIAC MRI
Surgical Treatment for Skeletal Metastases From Soft Tissue Sarcomas: Experience With 23 Lesions in 20 Patients
Purpose. This paper reports the procedures and the clinical results of a series of surgical treatments for skeletal metastases from soft tissue sarcomas
<Abstract of Published Report>Seasonal Variation of Glycyrrhizin and Isoliquiritigenin Glycosides in the Root of Glycyrrhiza glabra L..
シュヨウナイ シュッケツ ニヨリ ゾウダイ シタ イ GIST ノ 1レイ
Although there are a lot of case-reports of GIST (Gastrointestinal stromal tumor) with bleeding into the alimentary tract, cases of bleeding inside of the GIST are rare. We report a case in which a GIST increased its size associated with bleeding inside and was resected successfully. An 82-year-old man was diagnosed as GIST (1.0×2.0 cm in size) and followed for 3 years. Its size increased to 11×8 cm in size, therefore, we performed an operation. During laparotomy, the tumor was elastic hard and located on the upper body and posterior wall of the stomach. The tumor size was approximately the head of child. A total gastrectomy with splenectomy was done. A case of sudden increasing of the tumor was histologically thought to bleed inside of it. The increased size of tumors revealed a malignant potential and/or hemorrage, the tumor should be resected as soon as possible
Expression of Smooth Muscle Calponin in Synovial Sarcoma
Purpose. Histogenesis of synovial sarcoma remains controversial
and reliable molecular markers for diagnosis are necessary. Expression of basic calponin,
a smooth muscle differentiation-specific actin-binding protein, was studied in
synovial sarcoma
Astrodynamics Science About Itokawa, Gravity and Ephemeris
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76347/1/AIAA-2006-6658-569.pd
Validation of radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas: Japanese Orthopaedic Association Committee on Musculoskeletal Tumors Cooperative Study
AbstractBackgroundThe radiographic evaluation of the response to preoperative chemotherapy for bone and soft tissue sarcomas is based mostly on the change in primary tumor size before and after chemotherapy, as is done for many solid cancers. Its prognostic correlation, however, has hardly been validated.MethodsWe conducted a retrospective validation study of the Japanese Orthopaedic Association (JOA) radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas as a JOA Committee on Musculoskeletal Tumors cooperative study. A total of 125 consecutive patients with high-grade bone (n = 77) and soft tissue (n = 48) sarcomas treated with neoadjuvant chemotherapy and definitive surgery in 25 tertiary referral hospitals were selected for the study. We investigated the correlation between the tumor size-based radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas provided by the JOA Committee on Musculoskeletal Tumors (hereafter called the JOA criteria) and the patients’ overall survival using the Kaplan-Meier method and the log-rank test.ResultsThe JOA criteria correlated relatively well with survival for malignant bone tumors (mostly comprising osteosarcoma and Ewing’s sarcoma) but not for soft tissue sarcomas, suggesting that the tumor size-based radiographic evaluation criteria for the response to preoperative chemotherapy in patients with soft tissue sarcomas is invalid.ConclusionsThe JOA criteria, based on the change in primary tumor size, is valid for malignant bone tumors but invalid for soft tissue sarcomas. Other new evaluation modalities of the response to preoperative chemotherapy using innovative functional imaging techniques are needed for soft tissue sarcomas
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