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Biomedical subjects

M Kakishita

Publications and source records attributed to M Kakishita.

17 recordsLinked to original sources
PubMed1989

Twenty-four-hour whole-body retention of 47Ca-chloride: an index of global bone metabolism in rat models.

The 24-h whole-body retention (24-h WBR) of 47Ca-chloride was measured over a 4-week period in three rat models verified by histologic study. In the osteomalacic and osteoporotic groups the 24-h WBR values were significantly lower and higher, respectively, than in the control group from the 2nd week. Quantitative assessment of bone radiographs by microdensitometry revealed significant osteopenia in these groups at the 4th week. The 24-h WBR values of 47Ca were found to differentiate the three rat models from the early stage of disease development.

Animals↗
PubMed1988

Effects of thermal denaturation on the longitudinal relaxation time (T1) of water protons in protein solutions: study of the factors determining the T1 of water protons.

The factors determining the longitudinal relaxation time (T1) of water protons in protein solutions were investigated by analyzing the effects of thermal denaturation on the T1 of the water protons. We treated the water protons and the protein protons "on a protein surface" as a dipole-dipole coupled two-spin system where relative translational diffusion is the dominant mechanism, and measured the change in the time development of the nuclear Overhauser effect (NOE) factors of the water protons. The T1 of the water protons was shortened markedly when the proteins were thermally denatured. Our analysis indicates that this relaxation enhancement is due to an increase in the value of the translational correlation time as well as the fraction of hydration water molecules, though the influence of "proton exchange" between the water protons and the labile protein protons cannot be completely neglected.

Animals↗
PubMed1987

[Whole-body transmission scintigraphy using a line source].

Transmission scanning was proposed to be a useful adjunct to conventional emission scanning for accurately keying radionuclide deposition to radiographic anatomy. After introduction of a scintillation camera, transmission whole-body scintigraphy using a flood source has been performed in a patient with differentiated thyroid carcinoma. Recently immunoscintigraphy with radiolabeled monoclonal anti-tumor antibodies has become popular and transmission whole-body scintigraphy has been re-evaluated to make diagnosis for laterality of metastases. However, there are several problems to handle a flood source for preparation and shielding. We developed a special line source for transmission whole-body scintigraphy. The line source is composed of a plastic tube (inner diameter: 3 mm) with three-way stop in a U-shaped metal. There are several advantages to use this line source as compared to a flood one; (1) a small volume of radioactive solution (less than 5 ml), (2) easy preparation and setting, and (3) less radiation. Moreover good quality of transmission image is obtained using this line source.

Humans↗
PubMed1987

[Attenuation correction of SPECT imaging by dual energy method--quantification of 111In-labeled monoclonal anti-tumor antibody localization].

Application of radiolabeled monoclonal anti-tumor antibodies for diagnosis and therapy has made remarkable progress in the past few years. Quantification of radiopharmaceutical localization is required adequate attenuation correction in SPECT imaging. Attenuation correction by transmission CT (TCT) data is one of the best method at present time. However, if a patient is moved between TCT and SPECT, this method is no more applicable. We developed a new attenuation correction algorithm by dual energy method, using 99mTc and 111In because of similarity of these linear attenuation coefficients. The new algorithm uses data of TCT with an external source of 99mTc, and requires another data from SPECT of 111In labeled monoclonal anti-tumor antibody, which are simultaneously obtained. TCT results in an attenuation map, which then serves as input into the final intrinsic correction algorithm to uncorrected SPECT data. In chest phantom experiment, the attenuation corrected SPECT images revealed nearly same distribution of actual radioactivity of 111In as compared to that of uncorrected one.

Antibodies, Monoclonal↗
PubMed1987

In vivo localization of radiolabeled monoclonal antibody to carcinoembryonic antigen (CEA) in a CEA-producing tumor--comparison with polyclonal antibody.

To compare accumulation of the 125I-labeled antibodies (anti-carcinoembryonic antigen (CEA) monoclonal antibody and polyclonal antibody) to a CEA-producing tumor (SC-2-JCK), an in vivo localization study was performed in nude mice. The tumor-to-blood ratio at 120 hours after injection rose to 4.6 for the monoclonal antibody, but remained at 1.3 for the polyclonal antibody. However, no differences were noted between the antibodies up to 72 hours after injection. In autoradiograms, selective accumulation of the tracer was noted in the tumor for both antibodies. However, no superiority or inferiority of imaging for either of the antibodies could be definitely determined.

Adenocarcinoma, Papillary↗
PubMedDate not supplied

Effect of diets containing different levels of calcium, phosphate, and vitamin D3 on tooth uptake of 47Ca-chloride in rat models: comparison with bone uptake.

The effect of dietary manipulation on global tooth uptake of 47Ca-chloride was evaluated in three rat models of metabolic bone diseases verified by histologic bone study. The 24-hr tooth uptake of 47Ca-chloride was significantly decreased in the osteomalacic group, and was increased in the osteoporotic group at the fourth week. Tooth uptake closely paralleled femoral uptake at a correlation coefficient of 0.73 (p less than 0.01). The uptake of 47Ca-chloride in tooth was found to be more affected by dietary manipulation than that in femur in our rat models.

Animals↗
PubMedDate not supplied

A case of liver echinococcosis mimicing a solid liver tumor.

A case of hepatic echinococcosis mimicing a solid tumor was presented. The echinococcosis appeared as an echogenic mass in US, a low density area in CT, and an area of low (T1-weighted image) and high (T2-weighted image) intensity in MRI. Echo-guided biopsy showed PAS-positive cuticle layer of echinococcus in the necrotic tissue. Anular features around the lesion noted in MRI seemed to imply increased hepatic tissue water (congestion and/or edema). When a solid tumor is noted in the liver, proper history taking and awareness of this disease will decrease the chance of misdiagnosis.

Adenoma, Bile Duct↗
PubMedDate not supplied

Precision of total-body and regional bone mineral measurement by dual-energy X-ray absorptiometry.

The precision of total-body and regional bone mineral measurements from whole body scans obtained by dual-energy X-ray absorptiometry (DEXA) was determined in a phantom and two normal subjects. Whole body scans were performed once a week for three months at the speed of 80 mm/sec. Coefficients of variation for measurements of total-body bone mineral content (BMC) in the phantom and the subjects were 1.7% and 1.5% (average), respectively. Moreover, plots of total-body BMC values with time showed no significant slope, indicating the stability of the instrument. Regional BMC measurement from whole body scans, however, resulted in larger precision errors than total-body BMC measurement. This is attributed to the more rapid scan speed and coarser scan width used in whole body scanning as compared with regional scanning. Good precision of total-body BMC measurement by DEXA is of great clinical value in the assessment of metabolic bone disease.

Absorptiometry, Photon↗
PubMedDate not supplied

Bone mineral density of the lumbar spine by dual photon absorptiometry: age-related regression in normal Japanese subjects and fracture threshold in osteoporotics.

The bone mineral density (BMD) of the lumbar spine was determined by DPA in 280 normal Japanese volunteers and 11 osteoporotic women with compression fractures. In women, bone loss started from the mid thirties and accelerated after the age of 50 years at the rate of 0.75% (0.0074 g/cm2) per year. In men, bone loss started from the mid twenties and occurred linearly at the rate of 0.30% (0.0032 g/cm2). The overall diminutions in vertebral BMD throughout life in men and women were 13.0% and 24.3%, respectively. The mean vertebral BMD of the osteoporotic women with recent compression fractures was 37.5% lower than that of age-matched controls. The 90th percentile for vertebral BMD in this group was 0.584 g/cm2. By the age of 80 years, approximately one-fifth of normal Japanese women have BMD values less than this.

Adult↗
PubMedDate not supplied

Pancrease divisum: CT and ERCP findings.

A case of pancreas divisum diagnosed by CT is reported. ERCP via the major pipilla revealed a very short pancreatic duct, which appeared to be abruptly interrupted by a tumor. CT, however, demonstrated two definite pancreatic moieties separated by a fat cleft, indicating the presence of pancreas divisum.

Aged↗
PubMedDate not supplied

Comparison between air CT and MRI in the detection of small acoustic neurinomas.

Air CT proved useful in yielding images of acoustic tumors as an air filling defect in 11 (24%) of 46 patients. Six of the 11 tumors were small ones of less than 1 cm in diameter. Air CT was also able to exclude an intracanalicular tumor in 29 patients (63%). MRI was performed for comparison in eight patients (nine tumors) already diagnosed by air CT as having an acoustic tumor. MRI detected eight (89%) of nine tumors. A false negative result on MRI was obtained only in one intracanalicular tumor (4.3 mm in size). This was considered to be attributable to limitations of spatial resolution including the wide slice thickness. A protocol for radiological investigation and management of patients whose clinical symptoms and/or audiovestibular examination are highly indicative of acoustic tumor is proposed and discussed.

Adult↗
PubMedDate not supplied

Hemopneumothorax due to pulmonary metastasis with malignant hemangioendothelioma: CT and pathological findings.

Malignant hemangioendothelioma is a rare vascular tumor. The disease frequently recurs and eventually metastasizes to the lung in most cases. Hemopneumothorax developing soon after metastasis to the lung indicates on unfavorable prognosis. We had an opportunity to examine a patient who had malignant hemangioendothelioma in the occipital scalp and developed hemopneumothorax following metastasis to the lung. We report the computed tomographic (CT) and pathological finding in the patient, and review the literature on hemopneumothorax.

Adult↗
PubMedDate not supplied

Evaluation of the degree of severity in liver cirrhosis by computed tomography.

As CT findings useful for the evaluation of the degree of severity in liver cirrhosis, the following items were chosen for statistical analysis: atrophy of the right lobe, enlargement of the left lobe, irregularity of the liver surface, ascites, varices or collaterals, and dilatation of the SMV. According to the frequency with which these six items were found, the CT findings were expressed in the form of a score, and the resulting scores agreed well with ICG values, portal-venous flow (Qp) ratios obtained from radionuclide angiography, and the scores on the Child-Turcotte criteria. A score of 5 or 6 meant severe cirrhosis. A score of 4 meant liver cirrhosis, however, the degree of severity could not be determined, because there was overlap among the cirrhotic groups. A score of 3 meant liver cirrhosis with a probability of about 90%. A score of 1 or 2 was nonspecific for evaluation. When a score of 0 was noted with splenomegaly, there was a probability of more than 90% that it was chronic hepatitis. In conclusion, this approach was considered to be useful for evaluating the degree of severity in liver cirrhosis and differentiating between liver cirrhosis and chronic hepatitis to some degree in Japanese.

Adult↗