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Biomedical subjects

K Hamamoto

Publications and source records attributed to K Hamamoto.

At least 127 records · Page 7Linked to original sources
PubMed1989

[Evaluation of serum pepsinogen I and II of patients with gastric cancer].

Serum pepsinogen levels were examined by immunoradiometric assay method for evaluating its clinical usefulness in gastric cancer. In patients with gastric cancer, serum PG-I tended to decrease but PG-II stayed normal level, resulting in low PG-I/PG-II ratio. Combination of PG-I and PG-I/PG-II discriminated 53.7% of gastric cancer, 70.6% of scirrhous type gastric cancer, and 66.7-100% of those arisen in the upper portion of the stomach, but 13.7% of normal subjects. As the aged normal subjects tended to show decreased PG-I/PG-II ratio (about 30% of the normal subjects aged over 40 years were discriminated as abnormal), the usefulness for detection of gastric cancer seems to be limited, but some types of gastric cancer such as scirrhous type or one arisen in the upper portion may be discriminated by this method. It is also suggested that this method may detect the recurrence of the cancer in some patients.

Adult↗
PubMed1988

Availability of tumor-antigen 4 as a marker of squamous cell carcinoma of the lung and other organs.

The serum level of tumor-antigen 4 (TA-4) was measured in 401 patients with squamous cell carcinoma (SCC) of various organs (76 lung, 82 esophagus, and 234 head and neck). The mean serum level of TA-4 in patients with lung SCC was 3.6 times higher than that in healthy controls and even higher in the advanced stages of disease (III, IV). In patients with benign diseases or other types of lung cancer, however, the TA-4 serum level was not different from the controls regardless of the clinical stage. During radiation therapy, the TA-4 levels in patients with lung SCC decreased with reduction in tumor size. It increased again markedly during recurrence. Similarly, patients with SCC of the esophagus and head and neck also showed elevated TA-4 levels but only at advanced stages and in recurrence. It was concluded that TA-4 is highly related to SCC not only of the uterine cervix but also of other organs and that serum level determinations are useful for monitoring therapeutic effects and recurrence of these diseases, despite some limitations.

Antigens, Neoplasm↗
PubMed1988

The Perrault syndrome: clinical report and review.

We report on two Japanese sisters with Perrault syndrome, i.e., autosomal recessive ovarian dysgenesis associated with sensorineural deafness. They also had ataxic gait, pes equinovarus, nystagmus, limited extraocular movements, and short stature. One older affected sister had partial growth hormone deficiency. Our review included 21 patients from 8 families, including our patients; 16 are women with ovarian dysgenesis and deafness, 3 deaf males without gonadal defect, one a woman with ovarian dysgenesis without deafness, and one a girl with deafness in whom ovarian function was not evaluated. Perrault syndrome may not be uncommon; some cases may have gone unrecognized, especially when a single child in a family is affected.

Adolescent↗
PubMed1988

Quantitative aspect of two-factor analysis applied to radionuclide gated cardiac studies.

The quantitative aspect of two factor analysis (TFA) applied to radionuclide gated cardiac studies was investigated using clinical data and a computer based simulation method. In the clinical investigation, the ejection fraction (EF) calculated from the extracted ventricular pattern (EVP) significantly correlated with the left ventricular EF(LVEF) determined from multiple gated cardiac blood pool scans (MUGA), while the regression line deviated considerably from the line of identity. The contribution of the EVP(CEVP) to the total information inversely correlated significantly with the LVEF. In the computer simulation, a model simulating the atrial, ventricular, and background regions was studied. In the case with no statistical noise and constant background, the EF calculated from the EVP was nearly equal to the true EF, and the CEVP decreased as the EF increased. The statistical noise increased the EF and decreased the CEVP, this tendency was most marked when the true EF was less than about 50%. When background varied largely with time, the quantitative aspect deteriorated considerably. In conclusion, the clinical investigation results suggest that TFA has some possible use in quantitative analysis, however, the stimulation results suggest that it should be used carefully because its quantitative aspect is affected by various factors.

Algorithms↗
PubMed1988

Evaluation of common bile duct stenosis in chronic pancreatitis using cholescintigraphy.

To evaluate a stenotic change of the common bile duct (CBD) in chronic pancreatitis (CP), cholescintigraphy with 99mTc-N-pyridoxyl-5-methyltryptophan (PMT) was performed in 28 patients with CP and 15 normal subjects. The patients were divided into 3 groups on the basis of their endoscopic retrograde cholangiopancreatography (ERCP) findings: minimal CP (MIP; n = 14), moderate CP (MOP; n = 10), and advanced CP (ADP; n = 4). After intravenous injection of 5 mCi 99mTc-PMT, digital images were obtained and time activity curves of the ROIs (liver, hepatic duct, gallbladder, and duodenum) were generated. No radioactivity was seen in the duodenum within 1 hour in 12 of 28 (43%) with CP and 2 of 15 (13%) normals. Reflux to the hepatic duct after cerulein injection was found in 6 of 20 (30%) examined patients with CP and more frequently in ADP, whereas there was no reflux in MIP and normals. When the finding of reflux in cholescintigraphy was interpreted as positive for CBD stenosis, the sensitivity, specificity, and accuracy were 100%, 88%, and 90%, respectively. We conclude that reflux is a reliable scintigraphic finding in detecting CBD stenosis.

Adult↗
PubMed1988

[Left ventricular volume curve analysis using gated blood pool emission computed tomography].

Analysis of the left ventricular volume curve was performed using gated blood pool emission computed tomography (SPECT) in six patients with old myocardial infarction (MI), five with hypertrophic cardiomyopathy (HCM), three with dilated cardiomyopathy (DCM), and five normal controls (N). Image collection was synchronized with the QRS complex, and each cardiac cycle was divided into nine to 10 frames. In each frame, left ventricular volume was determined based on the number of voxels above the threshold level (50% cut-off level), and the volume curve was fitted to the third harmonics of Fourier analysis. From the fitted curve, the peak ejection rate (PER), the peak filling rate (PFR), end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated. 1. There were good correlations between SPECT and the conventional gated blood pool (MUGA) for PER (r = 0.694, p less than 0.005), PFR (r = 0.527, p less than 0.025) and EF (r = 0.682, p less than 0.005). 2. PER in MI (2.21 +/- 0.55, mean +/- SD) was lower than in N (3.68 +/- 0.80, p less than 0.05) and HCM (4.85 +/- 2.39, p less than 0.05), and EF in MI (36.6 +/- 6.4) was lower than in HCM (68.7 +/- 23.7, p less than 0.05). 3. There were good correlations between EDVs (y = 1.11x + 5.71, r = 0.877, p less than 0.01), and ESVs (y = 1.05x - 3.88, r = 0.876, p less than 0.01) estimated by MUGA and SPECT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[An immunoradiometric assay of serum SCC antigen using a monoclonal antibody--a comparison with the conventional double antibody method].

The serum level of the squamous cell carcinoma-related antigen (SCC-Ag) has been measured by a new immunoradiometric assay (IRMA) method that has been recently developed by using a monoclonal antibody, and compared with the results obtained by the conventional double-antibody method using a polyclonal antibody. Both methods gave essentially the same results, that the serum SCC-Ag level was high in patients with squamous cell carcinoma of various organs when compared with other types of lung cancer or benign diseases. However, the percentages of the serum SCC-Ag level over the normal range were found to be higher by the new IRMA method than by the conventional method. This may be due to the improvement in sensitivity and accuracy of this newer method of assay, which also results in a considerable decrease in the normal range estimated in healthy subjects. Therefore, it has been concluded that this new method is more suitable than the conventional method for an early diagnosis of squamous cell carcinoma in all organs.

Antigens, Neoplasm↗
PubMed1987

Simulation and experimental study of respiratory motion effect on image quality of single photon emission computed tomography (SPECT).

The effect of respiratory motion on the image quality of single photon emission computed tomography (SPECT) was investigated by computer simulation and experimentation. In the computer simulation, the phantom was assumed to be cylindrical with a uniform background and a spherical cold or hot spot. To simulate respiratory motion, a cyclic linear motion parallel to the axis of rotation of a gamma camera was assumed. The contrast in the transaxial images was calculated for various respiratory amplitudes and its dependence on lesion size and object contrast was investigated. In the experiments, a moving phantom was used to simulate respiratory motion. The simulation and the experimental results were in good agreement within the range of statistical error. The effect on the lesion detectability was investigated using receiver operating characteristics (ROC) analysis, and a method for correcting respiratory motion was devised.

Computer Simulation↗