Observation of Coulomb-Assisted Nuclear Bound State of Ξ

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21 MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

Search for the Θ+ pentaquark via the π(-)p→K(-)X reaction at 1.92 GeV/c.

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 µb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

[Relationship between pleural indentation on computed tomography scans and pleural invasion in small peripheral lung cancer of 2 cm in size or less].

Eighty-six cases of small peripheral lung cancer without contact with the chest wall on computed tomography (CT) scans were studied on the presence of radiological pleural indentation and pathological pleural invasion. Twenty-three tumors in 44 cases with pleural indentation were found to reach the pleura histologically, but only one in 42 cases without pleural indentation. There is a high possibility of pleural invasion or contact with the pleura in small lung cancers with pleural indentation. There was no relationship between the presence of pleural indentation and the tumor/chest wall distance on CT scans. Pleural indentations were more frequently seen in small adenocarcinomas of low ground-glass opacity (GGO) ratio or Noguchi's type C. Small lung nodules with pleural indentation had better be removed as early as possible because of the possibility of pleural invasion and pleural dissemination.

[Undifferentiated pleomorphic sarcoma in the left atrium; report of a case].

Primary cardiac sarcomas are rare. A 41-year-old woman complaining of dyspnea was admitted to our hospital. Echocardiography and computed tomography (CT) showed a primary cardiac tumor in the left atrium. During surgery, the tumor was noted to be arising from the anterior wall of the left atrium, under the aortic sinuses. Histological and immunohistochemical studies revealed an undifferentiated pleomorphic sarcoma. Eleven months later, echocardiography and CT showed recurrence of the cardiac sarcoma in the left atrium. The patient underwent wide resection of the left atrium and mitral valve replacement because the tumor extended to the mitral valve leaflet. The patient died 3 months after the 2nd surgery because of the 2nd recurrence of the cardiac sarcoma. Although most tumors that develop in the left atrium are benign myxomas, preoperative differential diagnosis is important. It is especially necessary to suspect a sarcoma in the case of a non-septal orgin of the mass.

[Intentional limited resection for lung adenocarcinoma of 2 cm in size or less according to intraoperative frozen section and high-resolution computed tomography].

One hundred twenty-six cases of resected lung adenocarcinoma of 2 cm in size or less were studied about intra and postoperative Noguchi's classification, high-resolution computed tomography (HRCT) findings and lymph node metastases in cases of lobectomy. Intentional limited resection for lung adenocarcinoma of 2 cm in size or less was recommended for selected patients with tumors of type A of Noguchi's classification diagnosed by intraoperative frozen diagnosis or tumors of intraoperative type B of 0.5 in ground-glass opacity (GGO) diameter ratio or more of HRCT. These patients are almost equal to patients of 0.5 in GGO diameter ratio or more with any type of Noguchi's classification. This GGO diameter ratio of 0.5 is easily available as a criteria of intentional limited resection for lung adenocarcinoma of 2 cm in size or less.

[On/off-pump beating coronary artery bypass grafting after thoracoplasty].

Off-pump coronary artery bypass grafting (CABG) [OPCAB] or on-pump beating CABG (conventional CABG) was performed in 3 post-thoracoplasty patients. Considering their poor respiratory function after thoracoplasty, OPCAB is considered more suitable than conventional CABG with cardio-pulmonary bypass in such cases with severe coronary lesions. However, because the sternum inclines or the pleural cavity may be polluted in these patients, special care is necessary for the operation. In such cases, it may be impossible to bypass to the circumflex artery in OPCAB, and is necessary to consider the use of percutaneous cardiopulmonary support (PCPS), cardio-pulmonary bypass or hybrid therapy before the operation.