Yasuyuki Watanabe

Publications (2)12.22 Total impact

• Article: Embolic attack in patients with atrial fibrillation and atrial thrombus depends on the character of the thrombus.

  Yukihiko Abe, Tukasa Asakura, Nobuo Sakamoto, Shunichi Ishikawa, Syuichi Muroi, Fujiko Saitoh, Masahiko Satoh, Shigebumi Suzuki, Masahiro Ono, Atsushi Sakabe, Masumi Iwai, Masahito Sando, Jun Gotou, Yasuyuki Watanabe, Kenji Nagata, Kazuhira Maehara, Yukio Maruyama
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  ABSTRACT: It is very important to prevent embolisms from left atrial thrombi (LAT). The present study was a trial for the management of patients with AT using 122 patients with atrial fibrillation and LAT who were followed for 1 year after transesophageal echocardiography. LAT were classified by their shape and mobility into the mobile ball type (MB, n=28), fixed ball type (FB, n=32) and mountain type (MO, n=42). The patients were given warfarin (INR: 1.5-2.0, n=43), aspirin 81 mg (n=74) and/or ticlopidine 200 mg/day (n=31). The embolic rate (ER) in the MB group was significantly higher than in the other groups [ie, MB 39.3% vs FB 15.6% (p<0.05), vs MO 2.4% (p<0.05)]. The ER in the FB group was significantly higher than in the MO group (p<0.05). Therapy with a combination of ticlopidine and aspirin reduced the ER in the patients with ball thrombi. The ER of the ball thrombus type group, especially the MB group, was very high in spite of therapy with anti-coagulants and/or anti-platelet agents, and such patients should be treated by early surgical intervention. However, the combination of ticlopidine and aspirin may be useful for preventing embolism.
  Circulation Journal 03/2003; 67(3):203-8. · 3.77 Impact Factor
• Article: Heme oxygenase-1 reduces murine monocrotaline-induced pulmonary inflammatory responses and resultant right ventricular overload.

  Jun Goto, Kazunobu Ishikawa, Keiichi Kawamura, Yasuyuki Watanabe, Hayato Matumoto, Daisuke Sugawara, Yukio Maruyama
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  ABSTRACT: Monocrotaline (MT), a pyrrolizidine alkaloid, causes pulmonary hypertension (PH) in rats and is widely utilized to analyze the pathophysiology of PH. However, a murine PH model with which transgenic animals may be used has not been established. To establish a murine MT-induced PH model, we administered different amounts of MT and determined the extent of right ventricular (RV) overload and PH. We also examined the expression of heme oxygenase-1 (HO-1), a potential antistress protein in MT-treated animals, and evaluated the functional role of HO-1 by administering an HO-1 inhibitor. Significant pulmonary inflammation and RV hypertrophy were observed when mice were given 600 mg/kg weight of MT weekly for 8 weeks. In addition, elevated RV pressure and induction of HO-1 in lung and RV were observed with this dose of MT. Interestingly, inhibition of HO activity promoted inflammatory changes in the lung and the resultant RV hypertrophy. HO-1 may play defensive roles against murine MT-induced pulmonary inflammation and the resultant RV overload.
  Antioxidants and Redox Signaling 09/2002; 4(4):563-8. · 8.46 Impact Factor