Biomedical subjects

T Mimura

Publications and source records attributed to T Mimura.

368 records · Page 21Linked to original sources

PubMedDate not supplied

Papillary microcarcinoma of the thyroid.

Papillary microcarcinoma of the thyroid has been often detected by aspiration biopsy cytology performed with ultrasonographic guidance. Autopsy studies also have often revealed small thyroid carcinomas, and it was concluded that most small thyroid carcinomas should not be regarded as a clinical matter. In this study, 112 patients with papillary microcarcinoma 10 mm or less in size treated between 1992 and 1995 were analyzed. There were 104 females and 8 males, with a mean age of 46.0 years. Diagnosis of papillary carcinoma was made preoperatively in 100 of these patients (89.3%), and 77 patients underwent aspiration biopsy cytology under ultrasound guidance. Seventy of these patients underwent modified neck dissection, and 63.8% of these patients had lymph node metastases. The number of lymph node metastasis increased as primary tumor size increased. There was no clear border or clinical differences between primary tumors 10 mm or less and tumors more than 10 mm. One patient had lymph node recurrence after surgery and another patient had recurrent nerve palsy at the first visit. Based on these findings, papillary microcarcinoma should be treated surgically.

Adult↗

PubMedDate not supplied

Staining for dipeptidyl aminopeptidase IV activity in nodular thyroid diseases.

OBJECTIVE: To determine the effectiveness of staining for dipeptidyl aminopeptidase IV (DAP IV) activity in thyroid nodular diseases. STUDY DESIGN: Imprint smears were made in 76 cases of papillary carcinoma, 10 of follicular carcinoma, 32 of follicular adenoma and 48 of adenomatous goiter after surgery, and staining for DAP IV activity was performed in all cases. RESULTS: All papillary carcinomas stained positively, and most adenomatous goiter cases were negative. Follicular carcinoma and follicular adenoma cases exhibited various degrees of positivity, though the former tended to be stained more than the latter. Of the total 166 cases of thyroid nodules, 53 showed negative staining; of those 53, all except 1 were benign. Follicular carcinoma cases that had vascular invasion tended to show a high DAP IV staining pattern, but no statistically significant difference between it and follicular carcinoma that did not show vascular invasion was found. CONCLUSION: DAP IV activity staining might reveal malignant potential and could have some value in the preoperative diagnosis between thyroid nodular diseases. The DAP IV method is a reliable indicator of benign disease if negative results are obtained.

Adenoma↗

PubMedDate not supplied

Real-time interactive MR imaging system: sequence optimization, and basic and clinical evaluations.

A real-time interactive MR imaging system (real-time MRI) is an MR scanner which has a fast image updating cycle and the ability to freely change slice orientation, just like an ultrasound imaging system. Recently, such a system has been developed and installed on a clinical 1.5-Tesla system. The purpose of this study was to optimize the pulse sequences for clinical use and to evaluate the clinical usefulness and basic functionality of real-time MRI. For T1-weighted imaging, FLASH (fast low angle shot) can be selected, and up to 5 frames per second can be acquired depending on the matrix size. For T2-weighted imaging, true FISP (fast imaging with steady-state precession) can be selected, and up to 4 frames per second can be acquired. Maximum C/N between liver and spleen was obtained at a flip angle of 20 degrees on FLASH. Maximum C/N between cardiac cavity and wall was obtained at a flip angle of 60 degrees on true FISP. Localization of the right and left coronary arteries could be performed within 30 seconds in three volunteers. Although the present real-time MRI system has drawbacks such as low spatial resolution and relatively low contrast resolution, we expect real-time MRI to be one of the most important tools for future clinical MRI.

Adult↗

PubMedDate not supplied

Aortoiliac stenooculusive disease and aneurysms: screening with non-contrast enhanced two-dimensional cardiac gated cine phase contrast MR angiography with multiple velocity encoded values and cardiac gated two-dimensional time-of-flight MR angiography.

PURPOSE: To evaluate the performance of two-dimensional cine phase contrast MRA with multi-velocity encoded values (multi-VENC cine PC) and ECG-gated two-dimensional time-of-flight MRA (ECG-2D-TOF) for the detection of stenoocclusive lesions and aneurysms in the aortoiliac area, when each method was used individually and when the two methods were used together. METHODS: Forty-one patients were included in this study. Multi-VENC cine PC and ECG-2D-TOF were obtained first, then contrast enhanced three-dimensional magnetic resonance angiography (CE-3D-MRA) was performed as the standard of reference. Two observers reviewed the images separately without knowledge of patients' symptoms or histories. Sensitivities and specificities were obtained separately for stenooclusive lesions and aneurysms by two reviewers. RESULTS: When the two methods were applied together, high sensitivities (93.0 by observer 1 and 91.9% by observer 2) and adequate specificities (87.6 and 82.3%) were obtained for stenoocclusive lesions. For aneurysms, moderate to high sensitivities (91.1 and 71.1%) and high specificities (98.8 and 99.4%) were obtained. CONCLUSION: These results suggest that the performance of two non-contrast enhanced MRA techniques may be valuable as a screening tool when the two methods are applied together.

Aged↗

PubMedDate not supplied

Evaluation of hepatic functional reserve in rats with obstructive jaundice by asyaloglycoprotein receptor.

BACKGROUND/AIMS: Until now, there has been no adequate means of evaluating the liver functional reserve in cases with obstructive jaundice. 99mTC-GSA (99mTechnetium-DTPA-Galactosyl-human serum albumin) is a new liver-imaging agent which binds specifically to the asyaloglycoprotein-receptor on the membrane of hepatocytes. So, the liver imaging by GSA excludes the influence of the reticuloendothelial system. Therefore, the uptake of 99mTC-GSA is considered to be a useful method for the estimation of liver functional reserve in cases with obstructive jaundice. METHODOLOGY: In this study, we examined the uptake rate and specific binding capacities of 99mTC-GSA to receptors on the membrane of hepatocytes following 1, and 2 weeks of bile-duct ligation and 1 week after reduction of jaundice using the rat model. RESULTS: The hepatic uptake rate decreased as the period of jaundice was prolonged and returned to nearly normal by the reduction of jaundice. The value of specific binding capacities at 2 weeks after bile-duct ligation decreased significantly compared to the value of the control and the reduced group (P < 0.05). The cause of decrease in specific binding capacities was indicated as the decrease of affinity constant especially in the high affinity part. These results coincide with the change of binding capacities of insulin and glucagon receptors with obstructive jaundice, which accurately reflect the severity of hepatocyte injury. CONCLUSIONS: Taking together these results, 99mTC-GSA liver scintigraphy is thought to be a useful method to evaluate the liver functional reserve in cases with jaundice.

Albumins↗

PubMedDate not supplied

Labeled avidin-biotin enzyme-linked immunosorbent assay for detecting antibody to infectious laryngotracheitis virus in chickens.

A labeled avidin-biotin enzyme-linked immunosorbent assay (LAB-ELISA) for detecting antibody to infectious laryngotracheitis (ILT) virus in chicken sera was developed and compared with ordinary ELISA. Purified ILT virus, biotin-labeled anti-chicken IgG rabbit IgG conjugate, and horseradish-peroxidase-labeled avidin were used in the LAB-ELISA. When sera from farm chickens were tested by serum neutralization (SN) and two kinds of ELISA, the correlation rate between SN and LAB-ELISA was 50/50 (100%), and that between SN and ordinary ELISA was 39/50 (78%). In LAB-ELISA, all of the sera that were antibody-negative by SN had low absorbance (A) values (below 0.05), and the A values were closely correlated with the SN indexes. In ordinary ELISA, however, the sera antibody-negative by SN had various A values ranging from 0.06 to 0.32. LAB-ELISA had much lower nonspecific reactions than ordinary ELISA against sera from ILT-negative chickens, even when chickens were 30 weeks old. ILT antibody production after ILT vaccination could be detected by LAB-ELISA. A values peaked 5 weeks postinoculation and were maintained for 17 weeks.

Animals↗

PubMedDate not supplied

Changes of insulin and glucagon receptors following bile duct ligation and its release.

The specific bindings of insulin and glucagon to 4 x 10(4) g pellets containing hepatic plasma membrane were measured at 1 and 2 weeks after bile-duct ligation and 1 week after reduction of jaundice. At 1 week of jaundice, insulin binding was not decreased compared to control rats, however, glucagon binding 30(6)% was significantly lower than that 43(8)% in control rats (p < 0.01). At 2 weeks of jaundice, insulin binding 35(3)% was significantly lower than that 40(5)% in control rats (p < 0.05), and glucagon binding 26(4)% was also significantly lower compared to control rats 42(4)% (p < 0.01). The decreased insulin and glucagon receptors returned to nearly the levels of controls after 1 week's reduction of jaundice. These results suggested that the measurement of receptor binding may be useful as an indicator of the severity of hepatocyte injury.

Animals↗

PubMedDate not supplied

Selection of acrosome-reacted sperm with MH61-immunobeads.

Separation of acrosome-reacted viable sperm is an important problem in the analysis of sperm function and the micromanipulation of gametes such as the microinjection of sperm into ooplasm and subzonal sperm insertion. In the present study, we collected acrosome-reacted sperm selectively using paramagnetic immunobeads, referred to as MH61-beads, which attach themselves to the head of the acrosome-reacted sperm and are recovered by a magnet. The maximum number of sperm was recovered by the MH61-beads when 3 x 10(5) sperm/100 microliters and 6 x 10(5) MH61-beads were coincubated for 1 hour. The recovery of sperm was significantly correlated with the percentage of the acrosome reaction in the capacitation medium. After incubation for 12 hours, 2.4-9.0 x 10(4) sperm could be collected, and the percentage of viable and acrosome-reacted sperm was 28-60%. To improve the recovery of the acrosome-reacted sperm, we utilized follicular fluid, which induces the acrosome reaction. Addition of follicular fluid to the capacitation medium at a final concentration of 20% induced the acrosome reaction and increased the recovery of acrosome-reacted sperm significantly. In conclusion, separation of acrosome-reacted sperm by the MH61-bead-binding method could become a useful technique in research of sperm function and gamete micromanipulation.

Acrosome↗