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Biomedical subjects

N Kitamura

Publications and source records attributed to N Kitamura.

584 records · Page 33Linked to original sources
PubMedDate not supplied

Is upper mediastinal lymphadenectomy necessary in squamous carcinoma of the lower thoracic oesophagus?

AIM: We examined the indication of upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. METHODS: 49 patients underwent a curative oesophagectomy with upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. Node status and clinicopathological characteristics of these patients were reviewed retrospectively. RESULTS: 16 (94.1%) of 17 patients with superficial tumours had no positive node in the upper mediastinum. Nine (29.0%) of 31 patients with transmural tumours had positive nodes in the upper mediastinum (P = 0.04). Ten (20.4%) of 49 patients had many positive nodes in the upper mediastinum. Of these 10 patients, 6 patients had 5 or more positive nodes in all. The 5-year survival rate for patients with 5 or more positive nodes was 7.7%, which was significantly poorer than patients with 4 or fewer positive nodes. CONCLUSIONS: Upper mediastinal lymphadenectomy is unnecessary in most of the superficial squamous carcinomas of the lower thoracic oesophagus.

Aged↗
PubMedDate not supplied

Surgical treatment of annulo-aortic ectasia.

Replacement of the aortic valve and the entire ascending aorta (modified Bentall's technique) was performed in 11 patients with annulo-aortic ectasia. Nine patients are alive and well postoperatively. In comparison with our previous surgical technique, by which the aortic root was left remaining without removal, the new technique required less bypass time, including less coronary perfusion time and less amount of intraoperative bleeding than the cases handled by the previous technique, whereas amount of postoperative bleeding in both groups was not significantly different. Details of the new technique were described and the advantages of this technique are security of intraoperative hemostasis as well as shortened operation time. The Björk-Shiley tilting disc prosthesis was really convenient for this surgical technique because of its low profil architecture, and also this prosthesis gives excellent postoperative results in combination with the new surgical technique.

Adult↗
PubMedDate not supplied

A comparative study between glutaraldehyde-preserved aortic and pulmonary heterograft valves in the tricuspid position in dogs.

Morphological observations have been presented on 10 metaperiodate-glutaraldehyde-preserved aortic heterograft valves and 5 pulmonary heterograft valves implanted into the tricuspid position for periods ranging from 7 to 183 days. It is recognized that there was a relatively minimal histological change in pulmonary valves. However, calcification of implanted aortic cusps was observed in 20% (2 out of 10) of cases and high incidence of thrombus formation on aortic cusps was recognized, although there were none on pulmonary cusps. It seems reasonable to presume that the high incidence of thrombus formation on the aortic valves is primarily due to the decreased pliability and stiffness of the cusps. It is concluded that the pulmonary valves rather than the aortic valves are recommended for tricuspid valve replacement.

Aldehydes↗
PubMedDate not supplied

Candida prosthetic valve endocarditis. An autopsy review.

Fungal endocarditis after cardiac surgery has been noticed increasingly in the past decade. We report a case of Candida parapsilosis endocarditis after mitral valve replacement in a patient with no predisposing factors. In this report we mainly examined the pathological findings in this patient with post-mortem examination.

Autopsy↗
PubMedDate not supplied

Spontaneous and time-related degeneration of Carpentier-Edwards bioprosthesis in mitral position.

To assess the spontaneous and time-related degeneration of the Carpentier-Edwards (C-E) bioprosthesis at 13 years after implantation, the cases of 48 patients who had undergone mitral valve replacement with C-E bioprosthesis are examined. The time-related clinical findings were started from a new rumbling murmur at an average of 5.9 years. The time-related change of transmitral flow was assessed by pressure half time and peak pressure gradient on pulsed Doppler cardiography, and pressure gradient and effective mitral valve area on cardiac catheterization. These values were expressed as an identical linearized curve: pressure half time Y = 13.3 X +41.9, peak pressure gradient Y = 1.47 X +1.25, pressure gradient Y = 1.90 X -3.79, mitral valve area Y = -0.87 X +1.39. From the combined evidence presented by these results, the initial structural deterioration of C-E bioprosthesis is stenotic change of the cusp, not tear or laceration, and correlates well in length of implantation, as evidenced by a linear curve. We are encouraged that the lack of catastrophic prosthetic valve failure, as has been associated with the pericardial valve, affords the opportunity for an elective safe reoperation.

Adult↗
PubMedDate not supplied

Targeted vinblastine chemotherapy with two preparations of lipiodol contrast medium.

BACKGROUND: Long-term survival and cure can not be achieved in patients with unresectable metastatic liver cancer. In this study, to improve the antitumor activity of oily anticancer agents, which enable targeted cancer chemotherapy, various concentrations of vinblastine dissolved in Lipiodol ultrafluid (vinblastine/Lipiodol U) or Lipiodol F, which has three times the viscosity of Lipiodol ultrafluid, were used. MATERIALS AND METHODS: Rabbits bearing VX2 tumors measuring 1 to 2 cm in diameter in the liver received arterial injections of 0.2 ml of these drugs, and antitumor activity were examined. RESULTS: Complete necrosis of the tumor was observed in three of nine rabbits received vinblastine/Lipiodol U at 2.5 mg/ml. Complete necrosis of the tumor was observed in all eleven rabbits which received vinblastine/Lipiodol U at 5 mg/ml. At concentrations of 7.5 and 10 mg/ml, the necrotic area spread from the tumor to the liver parenchyma surrounding the tumor. The antitumor activity of vinblastine dissolved in Lipiodol F was increased compared with that of vinblastine dissolved in Lipiodol ultrafluid. CONCLUSIONS: The antitumor activity of a kind of the oily anticancer agents, vinblastine/Lipiodol increased with increasing amounts of vinblastine dissolved in Lipiodol ultrafluid and with the increasing viscosity of the carrier, Lipiodol.

Animals↗
PubMedDate not supplied

Change in chemosensitivity of DMBA-induced rat mammary tumor after oophorectomy.

BACKGROUND: A combination of chemotherapy and endocrine therapy is usually employed for the treatment of breast cancer, but the optimal order of this combination has not yet been verified. To determine the appropriate order of this combination, changes in chemosensitivity to anticancer agents after endocrine therapy were examined. MATERIALS AND METHODS: Rat mammary tumors induced by 7,12-dimethylbenz[alpha]-anthracene (DMBA) were used. Chemosensitivity tests were performed before and 3 weeks after bilateral oophorectomy. The MTT assay was used to test eight anticancer agents, and oophorectomy was performed as the endocrine therapy. RESULTS: DMBA-induced rat mammary tumors showed sensitivity to 4'-0-tetrahydropyranyl-doxorubicin, 5-fluorouracil, peplomycin, mitomycin C, and methotrexate. Chemosensitivity to these agents seemed to be somewhat reduced after oophorectomy compared with before the operation, but the difference was not significant. CONCLUSION: The influence of oophorectomy on chemosensitivity of DMBA-induced mammary tumor is thought to be minimal.

9,10-Dimethyl-1,2-benzanthracene↗