Biomedical subjects

S Yamamoto

Publications and source records attributed to S Yamamoto.

At least 109 records · Page 6Linked to original sources

PubMed2004

[Posterior mediastinal paraganglioma with a 60-year history; report of a case].

We report a case of a 68-year-old man with a posterior mediastinal tumor. He remembered having difficulty in food passage through his esophagus in childhood. The preoperative thoracic computed tomography (CT) revealed a 5 x 3 cm mass with strong enhancement in the posterior mediastinum. A right thoracotomy was performed to resect this indeterminate mass. Complete resection was achieved. The pathologic diagnosis was paraganglioma. Postoperatively, he experienced more comfortable food passage through his esophagus than ever before. There has been no sign of recurrence 3 years after the operation. The tumor was clinically diagnosed as benign paraganglioma because of its long silent course.

Aged↗

PubMed2004

[A large nontuberculous mycobacterial granuloma mimicking lung cancer; report of a case].

A 45-year-old woman with no immunodeficiency or clinical symptoms presented to our hospital for treatment of an enlarging spherical lung tumor in 4.0-cm-diameter. Chest radiography 8 years ago had shown a 1.5-cm-diameter tumor. Chest computed tomography (CT) showed the solitary tumor, located in the right apical segment, to have an irregular margin without satellite lesions or cavitations. Mycobacterium avium complex (MAC) was cultured in tumor specimens incised during transbronchial biopsy. Right upper lobectomy was performed because of resistance to 6-month antituberculosis treatment. Pathological findings showed a MAC-infected granuloma with caseous necrosis. Postoperative course was uneventful and she had no recurrence 3 years after surgery. These findings suggest that nontuberculous mycobacterial granuloma can enlarge without clinical manifestations or any satellite lesions and cavitations, leading to a misdiagnosis of lung cancer.

Diagnosis, Differential↗

PubMed2003

Observation of helicity-induced Alfvén eigenmodes in large-helical-device plasmas heated by neutral-beam injection.

The helicity-induced Alfvén eigenmodes (HAEs) with the toroidal mode number n=2 and 3 are observed for the first time in the Large Helical Device plasmas heated by neutral beam injection. The observed mode frequency is about 8 times higher than that of the observed toroidicity-induced Alfvén eigenmodes, and is proportional to the Alfvén velocity. The modes are excited when the ratio of the beam velocity to the Alfvén velocity exceeds about unity. The frequency lies just above the lower bound of the HAE gap in the plasma edge region of rho>0.7 (rho: normalized minor radius).

Journal Article↗

PubMed2003

Laparoscopic surgery for stage I colorectal cancer.

BACKGROUND: This study analyzed the short- and long-term outcomes of laparoscopic surgery (LS) in patients with stage I colorectal cancer. METHODS: A total of 130 patients with stage I colorectal cancer underwent LS between 1992 and 1999. Median follow-up was 61 months (range, 30-114). RESULTS: Oral intake was started on median postoperative day 1, and the median postoperative hospital stay was 8 days. Postoperative complications included wound sepsis in eight patients (6.2%), anastomotic leakage in four patients (3.1%), and bowel obstruction in three patients (2.3%). Five patients developed recurrences. No port site recurrences were observed. The calculated 5-year survival rate was 97.9%. CONCLUSION: LS was shown to be technically feasible and oncologically sound for the treatment of patients with stage I colorectal cancer, and favorable short- and long-term outcomes were obtained.

Adult↗

PubMed2003

Randomized controlled trial of laparoscopic versus open colectomy for advanced colorectal cancer.

BACKGROUND: After confirming a favorable outcome of laparoscopic surgery for early colorectal cancer, we conducted a randomized controlled trial to compare short-term outcomes of laparoscopic and open colectomy for advanced colorectal cancer. METHODS: Fifty-nine patients with T2 or T3 colorectal cancer were randomized to undergo laparoscopic (n = 29) or open (n = 30) colectomy. Median follow-up was 20 months (range, 6-34 months). RESULTS: Operative time was longer (p <0.0001) and blood loss (p = 0.0034) and postoperative analgesic requirement were less in the laparoscopic group than in the open group. An earlier return of bowel motility and earlier discharge from the hospital (p = 0.0164) were observed after laparoscopic surgery. Serum C-reactive protein levels on postoperative days 1 (p <0.0001) and 4 (p = 0.0039) were lower in the laparoscopic group than in the open group. Postoperative complications did not differ between the two groups. CONCLUSION: Laparoscopic surgery for advanced colorectal cancer is feasible, with favorable short-term outcome.

Adult↗

PubMed2003

Indications of neutrino oscillation in a 250 km long-baseline experiment.

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Journal Article↗

PubMed2003

Lateral pelvic lymph node dissection for advanced lower rectal cancer.

BACKGROUND: The oncological outcome of patients who underwent curative surgery for lower rectal cancer was investigated to clarify whether lateral pelvic lymph node dissection (LPLD) conferred any benefit. METHODS: A total of 246 patients who underwent curative surgery for stage II and III lower rectal cancer (below the peritoneal reflection) between 1985 and 1998 was reviewed. Forty-two of these patients did not undergo LPLD. RESULTS: Patients who did not undergo LPLD were older, more likely to have anterior resection and pelvic nerve preservation, and had smaller tumours and lymph node metastasis at an earlier stage than those who underwent LPLD. There was no difference in survival among patients with stage II and III disease between the two groups. However, in patients with pathological N1 lymph node metastasis, the 5-year disease-free survival rate was 73.3 per cent in patients who had LPLD compared with 35.3 per cent among those who did not (P = 0.013). Multivariate analysis showed that LPLD was a significant prognostic factor. CONCLUSION: LPLD improved the prognosis of patients with stage III disease and a small number of lymph node metastases. A randomized clinical trial is needed to verify the benefit of LPLD.

Blood Loss, Surgical↗

PubMed2003

An Na+/H+ exchanger inhibitor suppresses cellular swelling and neuronal death induced by glutamate in cultured cortical neurons.

We examined the effects of a selective Na+/H+ exchanger inhibitor, SM-20220 (N-(aminoiminomethyl)-1-methyl-1H-indole-2-carboxamide methanesulfonate), on neuronal death induced by glutamate in rat cortical neurons. Morphological changes in neurons were observed with a differential interference contrast microscope, and cellular swelling was analysed. Neuronal death was assessed by staining the cell with propidium iodide. The intracellular calcium concentration ([Ca2+]i) and the intracellular pH were measured by fluorescence imaging with fluo-3/AM as an indicator for [Ca2+]i and BCECF/AM for pH, respectively. SM-20220 (0.3 to 30 nM) dose-dependently attenuated glutamate (300 microM)-induced neuronal death in a dose-dependent fashion over 6 hours, and inhibited acute cellular swelling following glutamate (100 microM) exposure. SM-20220 suppressed the persistent [Ca2+]i increase following glutamate (500 microM) exposure, and inhibited intracellular acidification induced by glutamate (1 mM). The activation of the Na+/H+ exchanger system may enhance the progress of cerebral damage and oedema following glutamate exposure. SM-20220, a Na+/H+ exchanger inhibitor, suppressed neuronal death and cellular swelling induced by glutamate through inhibition of both Ca2+ influx and acidification in neurons.

Amides↗

PubMed2003