Search PubMed⌕ Search

Biomedical subjects

T Toyama

Publications and source records attributed to T Toyama.

189 records · Page 11Linked to original sources

Subtracted synthetic images in Gd-DTPA enhanced MR.

The evaluation of Gd-DTPA contrast enhancement (CE) in high intensity tissues on T1-weighted magnetic resonance images, such as fat and bone marrow, is quite difficult. In this study, we used subtraction and subtracted color images in an attempt to show more clearly the Gd-DTPA CE. In addition, we also carried out sequential post-Gd-DTPA imaging to assess the changes in enhancement of lesions with time. Twenty patients were studied with these methods and our results are illustrated.

Adult↗

Painless myocardial infarction in identical diabetic twins.

A pair of 37-year-old identical twins with diabetes mellitus are described. One of the brothers was admitted for heart failure without pain, and autonomic neuropathy was found. The clinical diagnosis was inferior myocardial infarction with anteroseptal healed myocardial infarction. Cardiac catheterization revealed triple coronary vessel involvement. The diagnosis was confirmed at autopsy after sudden death. The other brother was also examined by cardiac catheterization, which revealed total right coronary occlusion and hypokinesis of the wall. There had been no previous pain nor upper body discomfort until that time in either twin. Thus, genetic factors should possibly be considered in the genesis of asymptomatic or silent myocardial infarction.

Adult↗

Sensitive measurement of serum abnormal prothrombin (PIVKA-II) as a marker of hepatocellular carcinoma.

BACKGROUND/AIMS: The usefulness of abnormal prothrombin (PIVKA-II) for diagnosis of small HCC has been limited by its low sensitivity, despite a high specificity. METHODOLOGY: The serum concentration of PIVKA-II was determined by using a new sensitive enzyme immunoassay (EIA) kit in patients with hepatocellular carcinoma (HCC), liver cirrhosis (LC), or chronic hepatitis (CH) and normal controls (NC). alpha-Fetoprotein (AFP) was simultaneously determined in same patients. RESULTS: This kit has made it possible to detect low concentrations of PIVKA-II in the NC. The serum PIVKA-II concentration (mean +/- SE) was 15.7 +/- 1.1 mAu/ml, 16.1 +/- 2.0 mAu/ml, 26.3 +/- 7.2 mAu/ml and 5420.3 +/- 3960.0 mAu/ml in NC, CH, LC and HCC, respectively. Among 106 patients with HCC, 74 patients (69.8%) were positive for PIVKA-II (> or = 40 mAu/ml), while only 9 patients out of 68 patients with LC were positive (13.2%) and only 2 out of 90 patients with CH were positive (2.2%). No significant correlation was observed between AFP and PIVKA-II levels. With combined assay of AFP and PIVKA-II, the positive rate for HCC was increased to 78.3%. Among 14 patients with HCC < 20 mm in diameter. 7 were positive for PIVKA-II, and 6 out of 10 patients with HCC between 20 and 30 mm in diameter were positive for PIVKA-II. There was a correlation between tumor size and the PIVKA-II level. CONCLUSIONS: Determination of PIVKA-II by this new EIA kit could be useful for the diagnosis of HCC, especially combined with determination of AFP.

Biomarkers↗

Effect of sealant viscosity on the penetration of resin into etched human enamel.

This study was designed to investigate the relationship between the etched depth, penetration of sealants and marginal seal. Sixty unerupted lower first premolars extracted from patients for orthodontic reasons were thoroughly cleaned and stored in an antiseptic Ringer's solution at 4 degrees C. A "window" on the occlusal of 15 of the premolars, including both mesial and distal pits, was developed by painting nail varnish around the border of the occlusal surfaces. Etching was then done with 35% phosphoric acid for 60 seconds to all 60 premolars. Five of the "window" teeth were evaluated by microradiography to determine the etched depth of the superficial and subsurface enamel. Five were prepared for SEM analysis to observe the change of the superficial etched enamel surface. Another five "window" teeth were embedded in epoxy resin and sectioned parallel to the long axis of the tooth through the fissures in order to observe the subsurface depth of the etch by SEM analysis. The other 45 teeth were divided into three groups of 15 teeth each. Fissures of each group of teeth were sealed using Prisma-Shield (LD Caulk), Concise White Sealant (3M Dental Products) or Teethmate A (Kuraray) sealants and stored in water (37 degrees C) for 24 hours. They were then sectioned and demineralized before being examined by a scanning electron microscope. Photographs of secondary electron image (SEI) were done to gradate the resin-infiltrated enamel and resin tags for these sealants. After SEM observation, the 15 samples of each applied sealant were polished to a high gloss again and placed in a silver nitrate solution for 24 hours before being examined under the SEM equipped with a back-scatter electron detector. Data were then analyzed using the Welch and Student t-tests. Results showed that fissured enamel of unerupted human lower first premolars became porous after etching with 35% phosphoric acid. The low viscosity sealant Teethmate A (approximately 260 mPa.s), penetrated fully and formed a resin-infiltrated layer in enamel beyond the etched depth. However, the high viscosity sealants (Prisma-Shield and Concise White Sealant) did not penetrate enough to ensure that the acid-etched enamel was infiltrated sufficiently by the sealant to insure good marginal seals.

Acid Etching, Dental↗