Biomedical subjects

Rieko Yamada

Publications and source records attributed to Rieko Yamada.

3 recordsLinked to original sources

PubMed2002

Apoptotic lymphocytes induced by surgical trauma in dogs.

PURPOSE: An investigation was made of the population and function of lymphocytes in canine peripheral blood, in animals with or without laparotomy under inhalation anesthesia. METHODS: Fourteen healthy beagles were allocated to two experimental groups: laparotomy (group A) and without laparotomy (group B). Induction of anesthesia in both groups was carried out with an intravenous injection of thiopentone, and was maintained by isoflurane inhalation. Ten blood samples, consisting of 10 ml of venous blood withdrawn by venipuncture into syringes containing 200 units of preservative-free heparin, were taken, from before anesthesia to the 28th postoperative day. The blood samples were collected, and the number of lymphocytes, the lymphocyte subpopulations, the proportion of apoptotic lymphocytes, and plasma cortisol level were measured, and the blastoid transformation of lymphocytes was observed. RESULTS: Lymphopenia was observed in both groups after anesthesia. Flow cytometry indicated a greater reduction in the proportion of T lymphocytes than of B lymphocytes. Blast transformation was also depressed in both groups. Progression of apoptosis after anesthesia was demonstrated in both groups, with a higher percentage of apoptotic cells being observed in group A at 12 h after anesthesia (28.5 +/- 3.2% by TUNEL assay). Plasma levels of cortisol were elevated to a greater extent in group A at the end of anesthesia (10.3 +/- 0.8 microg/dl) than in group B (7.8 +/- 1.9 microg/dl). CONCLUSIONS: These results indicate that surgical trauma concomitant with anesthesia could impair immunocompetence by reducing the number and function of lymphocytes.

Journal Article↗

PubMed2002

Effect of using self-etching primer for bonding orthodontic brackets.

Questions over the use of self-etching primers with composite resin adhesives in the bonding of orthodontic brackets remain unsolved. In addition, there are no previous reports on the efficacy of self-etching primers with resin-modified glass ionomer cements for bonding orthodontic brackets in orthodontic dentistry. The purpose of this study was to determine the shear bond strengths of orthodontic brackets bonded with one of four protocols: (1) a composite resin adhesive used with 40% phosphoric acid, (2) the same composite resin used with Megabond self-etching primer, (3) a resin-modified glass ionomer cement adhesive used with 10% polyacrylic acid enamel conditioner, and (4) the same resin-modified glass ionomer cement used with Megabond self-etching primer. The appearance of the tooth surfaces after acid etching or priming was observed with a field-emission scanning electron microscope (FE-SEM). When used with resin-modified glass ionomer cement, Megabond self-etching primer gave no significantly different shear bond strength compared with polyacrylic acid etching. But when used with composite resin adhesive, Megabond self-etching primer gave significantly lower shear bond strength than phosphoric acid etching. However, the shear bond strength of orthodontic brackets bonded with composite resin adhesive after Megabond priming was almost the same as that of brackets bonded with resin-modified glass ionomer cement after polyacrylic acid etching. FE-SEM observation revealed that Megabond self-etching primer produced less dissolution of enamel surface than did phosphoric acid and polyacrylic acid etching. Megabond self-etching primer may be a candidate for bonding orthodontic brackets using the resin-modified glass ionomer cement for minimizing the amount of enamel loss.

Acid Etching, Dental↗

PubMedDate not supplied

A new staging system for colorectal carcinoma with liver metastasis.

PURPOSE: The prognosis of colorectal carcinoma (CRC) with liver metastasis varies from case to case. A standardized classification system for evaluation of the prognosis and the treatment is needed. Therefore, we developed a new staging system for CRC with liver metastasis (HM-stage) based on the survival data. PATIENTS AND METHODS: We evaluated 148 CRC patients with liver metastasis treated between 1985 and 1999. Prognostic factors were identified based on a multivariate analysis. According to the final prognostic factors and hazard ratios, we defined the HM- stage. RESULTS: Three factors, including extent of liver metastasis, depth of tumor invasion and peritoneal metastasis, were identified to be the final prognostic factors. These factors were then assigned points. The patients were classified as being HM-stage I to IV by the sum total. The median survival time for each HM-stage were 37 months for HM-stage I, 23 months for II, 10 months for III and 7 months for IV respectively. A significant difference among each stage was recognized (p<0.0001). CONCLUSION: This new staging system for CRC with liver metastasis is simple and should be clinically useful for both estimation of the prognosis and evaluation of the therapy in patients.

Colorectal Neoplasms↗