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Biomedical subjects

N Mizuta

Publications and source records attributed to N Mizuta.

At least 19 recordsLinked to original sources
PubMed2002

Video-assisted total glandectomy and immediate reconstruction for breast cancer.

This paper describes a new surgical technique and our clinical experience with video-assisted endoscopic total glandectomy via a middle axillary incision followed by immediate reconstruction with latissimus dorsi muscle flap (LDMF) performed in 17 patients with bigger, multiple tumors or extensive ductal spread of breast cancer. The novel techniques in this procedure are as follows: (1) By securing patients in a semi-lateral position and suspending the upper extremity, either supine or semi-lateral position can be easily achieved by simply rotating the operating table, resulting in a wider working space from the axillary to hip area. (2) By applying a retractor for skin flap traction, endoscopic glandectomy and reconstruction become safe and reliable. As a result, the mean number and size of tumors were 1.2 and 4.12 cm, respectively. Surgical margins of all the cases were pathologically negative and there were no recurrences observed during 14 months follow-up to date. Esthetic results have been satisfactory and the surgical wounds were not visible from the front in any case. Compared to mastectomy, this procedure shows the same therapeutic results, but offers a greater esthetic and psychological advantage to all the patients.

Breast Neoplasms↗
PubMed2001

Fas/FasL-dependent apoptosis of alveolar cells after lipopolysaccharide-induced lung injury in mice.

To determine the possible contribution of apoptosis in the pathogenesis of acute lung injury (ALI), we investigated Fas antigen (Fas), Fas ligand (FasL), perforin, granzyme A, and granzyme B expressions in a murine model of ALI after intratracheal instillation of Escherichia coli lipopolysaccharide (LPS: 0.3-30 microg) into the left lung. Lung injury, examined by water-to-dry weight ratio and albumin leakage, demonstrated maximal epithelial injury 1 d after 30 microg LPS instillation. Expressions of the proapoptosis molecules' mRNA were dose-dependently up-regulated, with maximal expression in the early phase in the instilled lung and most apparent 1 d after LPS instillation. Negligible mRNA expression of proapoptosis molecules was observed in noninstilled lungs. The terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) demonstrated positive signals in neutrophils and macrophages as well as in alveolar wall cells of the instilled lung 1 d after LPS instillation. Immunohistochemistry demonstrated that Fas was up-regulated in alveolar and inflammatory cells and FasL-positive inflammatory cells migrated into the air spaces in the LPS-instilled lung. Intratracheal administration of P2 antibody, which is an anti-Fas blocking antibody, attenuated the lung injury after 30 microg LPS instillation without attenuating mRNA expressions of proapoptosis molecules and neutrophil accumulation in the lung. In contrast, concanamycin A, which inhibits the function of perforin, did not alter the outcome after LPS instillation. These results indicate that the Fas/FasL system could be important in the pathogenesis of LPS-induced ALI, and proper regulation of the FasL/Fas system might be important for potential treatment of ARDS.

Animals↗
PubMed2001

[Minimally invasive surgery for breast cancer].

Breast conservation surgery has become a standard operation as a minimally invasive surgery for breast cancer in Japan. Now sentinel lymph node biopsy (SLNB), day surgery, and endoscopy assisted surgery are being introduced as more minimally invasive surgeries for breast cancer. When blue dye and/or isotope are injected into the peri-tumoral breast gland, the sentinel lymph nodes (SLN) can be detected easily, and node negative patients can be selected with certainty. When no metastasis is found in SLN by frozen section, T1N0 breast cancer patients can be treated without lymph node dissection. Using this technique, day surgery for patients who have clinically node-negative small breast cancer (less than 1.5 cm in diameter) is performed under local anesthesia. We have developed an endoscopy assisted conservation surgery for breast cancer. Using endoscopy, partial or total glandectomy with radical axillary lymph node dissection is performed via a 5 cm skin incision on the middle axillary line. When the amount of glandectomy is over one third, we perform immediate reconstruction using the latissimus dorsi. These minimally invasive surgeries for breast cancer will result in a better quality of life for breast cancer patients.

Adult↗
PubMed2000

Caspase-dependent apoptosis by ectopic expression of E2F-4.

E2F is a family of transcription factors which regulates cell cycle and apoptosis of mammalian cells. E2F-1-3 localize in the nucleus, and preferentially bind pRb, while E2F-4 and 5 have no nuclear localization signal and preferentially bind p107/p130. E2F-6 suppresses the transcriptional activity of other E2F proteins. DP-1 and 2 are heterodimeric partners of each E2F protein. Using tetracycline-responsive promoters, here we compared the effects of ectopic expression of E2F-1, DP-1 and E2F-4 on cell cycle progression and apoptosis in Chinese hamster cell lines. We found that E2F-4, as well as DP-1 and E2F-1, induced growth arrest and caspase-dependent apoptosis. E2F-4 did not have a marked effect on cell cycle progression, while E2F-1 induced DNA synthesis of resting cells and DP-1 arrested cells in G1. Ectopic expression of E2F-4 did not activate E2F-dependent transcription. Our results suggest that expression of E2F-4 at elevated levels induces growth arrest and apoptosis of mammalian cells through a mechanism distinct from E2F-1 and DP-1.

Animals↗
PubMed2000

Novel diketopiperazine metabolism in a microorganism: two-step hydrolysis of cyclo(Gly-Leu) to amino acids and preliminary characterization of cyclo(Gly-Leu) hydrolase and dipeptidase.

A bacterium, strain NM 5-3, isolated from soil exhibited the highest cyclo(Gly-Leu) (CGL)-hydrolyzing activity and was identified as Agrobacterium radiobacter. The reaction products from CGL were dipeptides (Leu-Gly and Gly-Leu) and amino acids (Leu and Gly). Inhibitors for the dipeptidase of this strain did not inhibit the hydrolysis of CGL to dipeptides, indicating that two distinct enzymes, CGLase and a dipeptidase, were involved in its hydrolysis. The activities of these two enzymes were separated by anion-exchange column chromatography. The results indicated that strain NM5-3 hydrolyzed CGL via the dipeptides to the corresponding amino acids. The CGLase fraction was found to catalyze the hydrolysis of cyclo(Gly-D-Leu), cyclo(Gly-Gly), cyclo(L-Ala-Gly), and cyclo(D-Ala-Gly). On the other hand, the dipeptidase fraction exhibited L-specific substrate specificity.

Journal Article↗