Biomedical subjects

Kouichi Nakayama

Publications and source records attributed to Kouichi Nakayama.

3 recordsLinked to original sources

PubMed2004

Denervation and reinnervation of the heart after aortic surgery, estimated by 123I-metaiodobenzylguanidine scintigraphy.

PURPOSE: To investigate whether sympathetic nerve injury occurs during aortic surgery and how reinnervation takes place afterward. METHODS: Imaging with 123I-metaiodobenzylguanidine (MIBG) was performed in 12 patients (aortic group) who underwent aortic surgery (ascending replacement 3, ascending-arch replacement 9) before and 3 weeks after surgery. In 8 of 12 patients, MIBG scintigraphy was performed 1 and 2 years after surgery. Twelve patients (control group) who underwent open-heart surgery (mitral valve repair: 11; tricuspid valve replacement: 1) were studied using MIBG scintigraphy. The heart-to-mediastinum (H/M) activity ratio was obtained from planar images. The myocardial single-photon-emission computed tomography image was divided into five segments and the regional tracer uptake was scored from 0 = absent to 3 = normal uptake. RESULTS: No significant difference in the H/M ratio in either early and delayed planar scans was observed between both groups before surgery. The H/M ratios significantly decreased 3 weeks after surgery in the aortic group, whereas there was no significant change in the control group. The H/M ratio did not recover to the preoperative level within 2 years. In these 8 patients, the regional uptake of MIBG improved in the anterior and septal regions 1 year after surgery. CONCLUSION: During ascending or ascending-arch replacement, the sympathetic nerve was globally denervated and slight reinnervation was observed within 2 years. The anterior and septal regions showed a rapid reinnervation, whereas other regions did not.

3-Iodobenzylguanidine↗

PubMed2003

[Evaluation of hepatic arterial infusion chemotherapy with low-dose leucovorin and 5-FU from reservoir for multiple liver metastases by colorectal cancer].

5 patients with colorectal cancer with multiple liver metastases underwent resection of primary lesions. We then evaluated the effects of hepatic arterial infusion chemotherapy with low-dose leucovorin and 5-FU. Weekly, dl-leucovorin of 30 mg/body or l-leucovorin of 25 mg/body was administered as a bolus, then 5-FU of 500 mg/body was administered for 1 hour through the hepatic artery from the subcutaneous reservoir on an outpatient basis. 2 of 5 patients achieved a CR of liver metastases, but later 1 of these 2 cases had metastases of bone and lung. No adverse effects, such as nausea, vomiting, diarrhea or bone marrow suppression, were seen after this treatment in any of the patients.

Adult↗

PubMed1996

Alkane Oxidation with Molecular Oxygen Using a New Efficient Catalytic System: N-Hydroxyphthalimide (NHPI) Combined with Co(acac)(n)() (n = 2 or 3).

A novel class of catalysts for alkane oxidation with molecular oxygen was examined. N-Hydroxyphthalimide (NHPI) combined with Co(acac)(n)() (n = 2 or 3) was found to be an efficient catalytic system for the aerobic oxidation of cycloalkanes and alkylbenzenes under mild conditions. Cycloalkanes were successfully oxidized with molecular oxygen in the presence of a catalytic amount of NHPI and Co(acac)(2) in acetic acid at 100 degrees C to give the corresponding cycloalkanones and dicarboxylic acids. Alkylbenzenes were also oxidized with dioxygen using this catalytic system. For example, toluene was converted into benzoic acid in excellent yield under these conditions. Ethyl- and butylbenzenes were selectively oxidized at their alpha-positions to form the corresponding ketones, acetophenone, and 1-phenyl-1-butanone, respectively, in good yields. A key intermediate in this oxidation is believed to be the phthalimide N-oxyl radical generated from NHPI and molecular oxygen using a Co(II) species. The isotope effect (k(H)/k(D)) in the oxidation of ethylbenzene and ethylbenzene-d(10) with dioxygen using NHPI/Co(acac)(2) was 3.8.

Journal Article↗