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Biomedical subjects

C Katoh

Publications and source records attributed to C Katoh.

15 recordsLinked to original sources
PubMed1998

[Incidence of antibodies in raccoon dogs and deer inhabiting suburban areas].

We evaluated the incidence of antibodies against canine distemper (CD) virus, canine parvovirus, Toxoplasma gondii (T. gondii), Aujeszky's disease virus, porcine reproductive and respiratory syndrome virus, Rickettsia tsutsugamushi, Rickettsia japonica, and Coxiella burnetii in 30 raccoon dogs and 5 deer captured in suburban areas in Kanagawa Prefecture. Among the raccoon dogs, anti-T. gondii antibody was detected in 1 animal (3.3%) and anti-CD virus antibody in 9 (30.0%). However, antibodies against the other pathogenic microorganisms were not detected in the raccoon dogs. The deer had none of the examined antibodies.

Animals↗
PubMed1998

Flow cytometric analysis for sperm viability and counts in rats treated with trimethylphosphate or pyridoxine.

Six-week old SD-Slc male rats were treated for 4 weeks with compounds known to induce toxicological changes in male reproductive organs (pyridoxine in saline, 500 mg/kg/day, i.p.) or sperm (trimethylphosphate in distilled water, 100 mg/kg/day, p.o.). Each sperm sample taken from the cauda epididymis was analyzed with flow cytometry for the evaluation of sperm viability and counts. Sperm motility and morphology by microscopical observation, and histopathological examination of reproductive organs were also performed for estimating the adverse effects of each compound on spermatogenesis and sperm. While a decrease in sperm motility was noted for the trimethylphosphate group, the low motile sperm was evaluated as being viable sperm, not moribund, with flow cytometry. In the pyridoxine group, microscopical observation revealed morphological changes of sperm and a decrease of motility. The present sperm analysis with flow cytometry also suggested morphological changes reflected by dot plot as well as decrease of sperm viability and counts. These results indicated that this procedure led to profound findings in the compound-treated animals, with evaluation as viable sperm, not moribund, in a low motile sperm sample, and suggesting morphological changes in the dot plot of flow cytometry.

Animals↗
PubMed1998

Thallium-201 scintigraphy to predict therapeutic outcome of iodine-131 therapy of metastatic thyroid carcinoma.

UNLABELLED: We studied the relationship between 201Tl uptake and the efficacy of radioiodine therapy in thyroid carcinoma. METHODS: Forty-four patients with metastases of well-differentiated thyroid carcinoma received 201Tl scintigraphy within the 2 mo before their initial 131I therapy. Patients were classified into two groups according to the tumor-to-background (T/B) ratio on the late 201Tl scan: high 201Tl uptake (T/B > or = 2.1) and low 201Tl uptake (T/B < 2.1). The therapeutic outcome was judged by the percent reduction in the tumor diameter at 6 mo after the treatment. The treatment was defined as effective when the tumor showed more than 50% reduction in the tumor diameter. The patients in whom radioiodine was ineffective were followed up to determine if the tumor showed further growth. RESULTS: Of the 44 patients, 25 had high 201Tl uptake and 19 had low 201Tl uptake. The therapy was effective in 15 patients and was ineffective in 29. All the patients in whom radioiodine was effective had low 201Tl uptake. On the other hand, 25 of 29 patients in whom radioiodine was ineffective had high 201Tl uptake. Eight patients, in whom radioiodine was ineffective despite good 131I uptake, had high 201Tl uptake. There were no significant differences in the positive predictive value and the negative predictive value for effective treatment between 201Tl scintigraphy and therapeutic dose 131I scintigraphy. Among the 25 patients in whom radioiodine was ineffective and who had high 201Tl uptake, the tumor diameter increased in 7 (28%). However, none of the tumors with low 201Tl uptake increased in size during the follow-up period. CONCLUSION: Thallium-201 scintigraphy has a high predictive value for the efficacy of radioiodine therapy in metastatic thyroid carcinoma. Thus, it is helpful in determining the indication for radioiodine therapy and it seems to be an adjunct to tracer dose 131I scintigraphy.

Adenocarcinoma, Follicular↗
PubMed1998

[Measurement of retinal blood flow velocity by scanning laser ophthalmoscopic fluorescein fundus angiography in experimental retinal vein obstruction].

To study the role of arterial blood dynamics in the thrombogenesis of thrombin-induced experimental retinal vein obstruction, the retinal blood flow velocity was evaluated using scanning laser ophthalmoscopic fluorescein videoangiography in an experimental rabbit retinal vein obstruction model. Retinal vein obstruction was made by transadventitial direct instillation of thrombin to the retinal vessels from the vitreous side. The blood flow velocity in the retinal artery and vein was estimated by measuring the passing velocity of the flow head of the dye bolus and venous filling time, respectively. 23 animals were treated with thrombin and compared with 18 controls not treated. In the control group retinal artery blood flow velocity and retinal venous fluorescein filling time was 5.3 +/- 1.1 mm/sec (mean +/- standard deviation) and 6.2 +/- 1.2 sec, respectively. In the treated group the values were 5.7 +/- 1.3 mm/sec and 5.8 +/- 1.0 sec before the thrombin administration, and 3.0 +/- 0.9 mm/sec at 24 hours after its administration, and 5.7 +/- 2.0 sec and 4.0 +/- 1.5 mm/sec and 4.5 +/- 1.4 sec at 48 hours after the administration. These results indicate that a decrease in retinal artery blood flow velocity is strongly involved in the thrombogenesis in thrombin-induced experimental retinal vein obstruction.

Animals↗
PubMed1998

[Comparison of single sample methods for determination of plasma clearance using 99mTc-MAG3].

We compared relationship among three single blood sampling methods which have been proposed for determination of plasma clearance with 99mTc-MAG3. Russell's and Bubeck's algorithms were employed for 48 adults (average age: 53 years) and Bubeck's and Piepsz's algorithms were used in 9 children (average age: 5.8 years). Three methods showed very high correlation among them. However, Russell's and Piepsz's methods were about 1.4 times higher than Bubeck's method in calculating plasma clearance of 99mTc-MAG3. The present study indicates that three methods discussed here are useful for the determination of plasma clearance with 99mTc-MAG3. In addition, Bubeck's method may be preferable as a reference for single plasma sampling method because of common application to adults and children.

Adolescent↗
PubMed1997

Sequential change of BMIPP uptake with age in spontaneously hypertensive rat model.

UNLABELLED: Changes in myocardial perfusion and metabolism are often associated with myocardial hypertrophy, but there are few reports describing the serial assessment of fatty acid metabolism in hypertrophic myocardium. The aim of this study is to assess fatty acid metabolism serially in hypertrophic myocardium in spontaneously hypertensive rats (SHR) with 125I-BMIPP, a branched fatty acid analog. METHODS: SHR and Wistar-Kyoto rats (WKY) as the control were divided into 4 groups (12, 15, 18 and 51 weeks after birth). The heart was extracted 10 minutes after intravenous injection of 125I-BMIPP and 201Tl at the same time. The accumulation of each radiotracer in the myocardium was counted with a well gamma counter. In addition, 125I-BMIPP uptake was corrected by 201Tl uptake (B/T). RESULTS: The heart weight/body weight ratio was significantly higher in SHR than that in WKY (p < 0.001). In SHR, this ratio increased up to 18 weeks (12 weeks; 0.266 +/- 0.005, 18 weeks; 0.281 +/- 0.006: mean +/- SE, p < 0.05). The 125I-BMIPP uptake tended to be significantly reduced in SHR (12 weeks; 2.373 +/- 0.212, 18 weeks; 1.380 +/- 0.047; mean +/- SE, p < 0.05). Such a difference in BMIPP uptake was more evident when BMIPP uptake was corrected by Tl uptake (B/T), but no regional difference or heterogeneity of BMIPP distribution was observed in the hypertrophic myocardium in SHR. CONCLUSION: A change in fatty acid metabolism with age was observed in association with myocardial hypetrophy in this hypertensive rat model, which was well demonstrated with 125I-BMIPP and 201Tl.

Aging↗
PubMed1997

Incidence and clinical significance of linear defects ascribed to interrenuncular septa on 99Tcm-DMSA SPET.

99Tcm-dimercaptosuccinic acid (99Tcm-DMSA) planar and single photon emission tomographic images from 100 children were reviewed to analyse whether linear defects corresponding to anatomical characteristics of interrenuncular septum (IRS) could be seen. Thirty sites in 30 kidneys (20 right, 10 left) from 27 patients were determined as showing IRS. They were seen less frequently in patients less than 7 years of age. The prevalence of IRS in the patients with vesico-ureteric reflux (VUR) was not significantly different from that in the patients without VUR. The interrenuncular septum was never seen on planar images and was most clearly demonstrated on conventional coronal tomographic images. The linear defects ascribed to IRS on 99Tcm-DMSA scintigrams were of a similar incidence to that reported previously. However, IRS is still an unestablished structure, and there is no evidence that these linear defects actually correspond to the structure described as the interrenuncular septum.

Child↗
PubMed1996

Treatment of radioiodine-negative bone metastasis from papillary thyroid carcinoma with percutaneous ethanol injection therapy.

A 62-year-old woman with metastatic papillary thyroid carcinoma in the sternum was successfully treated with percutaneous ethanol injection therapy (PET) when previous radioiodine therapy and external irradiation were ineffective. The patient tolerated the treatment well and the refractory pain in the anterior chest wall that was alleviated with morphine prior to PEIT completely disappeared. No severe complications were observed. PEIT was performed 4 times (2 times with ultrasound guidance and 2 times with CT guidance). The posttreatment CT scan and 201Tl scintigraphy demonstrated significant decrease in the tumor volume. The serum thyroglobulin level fell to less than one-twentieth of the pretreatment value. It is suggested that PEIT has a value in treating bone metastasis from thyroid carcinoma which do not respond to radioiodine.

Bone Neoplasms↗
PubMed1996

The role of 201Tl scintigraphy in evaluating proliferative activity in thyroid neoplasms.

To identify the relationship between the uptake of 201Tl and the proliferative activity in thyroid neoplasms, 201Tl scintigraphy was performed in 57 patients with thyroid neoplasms. 201Tl uptake ratio was calculated in both the early and the delayed images and then compared with factors representing cellular or practical proliferative activity of the lesions. The labeling index (LI) for proliferating cell nuclear antigen (PCNA) was determined quantitatively by flow cytometry. There was a significant correlation between the uptake ratio and LI for PCNA. The correlation coefficient for the delayed ratio (DR) vs. LI was better than that for the early ratio (ER) vs. LI. As parameters for practical proliferation, the surgical stage in primary thyroid carcinoma or 131I uptake in recurrent thyroid carcinoma was focused on. DR was strongly related to these parameters, regardless of the histopathological features or size of the lesions. Our results suggest that 201Tl uptake in delayed thyroid scan is useful in assessing proliferative activity in thyroid neoplasms.

Adolescent↗
PubMed1996

Percutaneous ethanol injection therapy for autonomously functioning thyroid nodule.

Four patients with solitary autonomously functioning thyroid nodule (AFTN; 2 toxic and 2 subclinically toxic) received ultrasonography (US)-guided percutaneous ethanol injection therapy (PEIT). The pretreatment scintigraphic appearance of the nodule was hot, and radioactivity in the extranodular tissue was completely suppressed throughout. Ninety-nine percent ethanol was slowly injected under US guidance. As a rule, the injection was performed in fractionated sessions and the treatment was repeated until the total amount of ethanol exceeded the baseline nodular volume. The therapy was successful. Complete remission of hyperthyroidism was observed among the patients with toxic nodule. The basal level of TSH and its response to TRH injection was normalized in the patients with subclinically toxic nodule. Posttreatment scintigrams revealed that the extranodular tissue recovered and radioactivity in the hot nodule had noticeably decreased. The rate of reduction in the nodular volume was more than 80% in all. There was no recurrence or development of hypothyroidism during a follow up of 10 to 23 months. The main side effect was mild and transient pain and/or a burning sensation at injection. No severe or permanent complications occurred. Although the number of our cases was small, the results suggest that PEIT is a useful program in treating AFTN.

Adult↗
PubMed1996

[Medical treatment for experimental retinal vein occlusion--thrombolytic effect of nasaruplase].

The anti-thrombolytic effect of urokinase (UK), nasaruplase, and argatroban was studied using an experimental rabbit model of retinal vein occlusion (RVO). Experimental RVO was induced by transadventitial thrombin instillation. Five or fourteen days after thrombin application, the rabbits were injected with gelatin-fluorescein sodium and their eyeballs were enucleated for microscopic observation and flat preparation of the retina. Occlusion of retinal vessels was found to be less in number and distribution in the nasaruplase group than in the control group. On microscopic observation, the retinal arteries and veins of the nasaruplase group showed a vascular subendothelial space formation which suggested a process of thrombogenesis and thrombolysis in the space. The coefficiency of beraprost sodium, aspirin, and ozagrel hydrochloride to UK therapy was studied, but there was no significant difference between these groups and the control group with no after-treatment (the UK group). This result shows the effectiveness of nasaruplase for the thrombolytic therapy of RVO.

Animals↗
PubMed1995

[Quantitative image feature analysis of echographic textures using the normalized first moment of the power spectra: comparison of normal thyroid with chronic thyroiditis].

In order to evaluate the coarseness of echographic textures objectively, ultrasonic B-mode data from the thyroid glands in 10 normal subjects and 10 patients with chronic thyroiditis were digitized. The normalized first moment of the power spectra in the digitized matrix data that were obtained was calculated by computer processing of a Fourier transformation algorithm. On phantom study, when the location of the region to be analyzed or the gray scale level of the images was changed, the normalized first moment of the power spectra in the low frequency region of less than 1.0 cycle/mm varied significantly, and noise components in the high frequency region of more than 2.5 cycles/mm exceeded the signal components. Thus we attempted to calculate the normalized first moment of the power spectra from 1.0 to 2.5 cycles/mm in human thyroid glands. The values of the normalized first moment of the power spectra in the thyroid glands with normal (n = 20) and chronic thyroiditis (n = 20) were 0.989 +/- 0.036 and 1.065 +/- 0.063, respectively. These values were significantly different between the two groups (p < 0.01). It is concluded that the normalized first moment of the power spectra calculated within the limited frequency is useful in characterizing the echographic texture of chronic thyroiditis.

Chronic Disease↗
PubMed1979

Two cases of rubella infection with cardiac involvement.

During the prevalence of rubella infection in Japan in 1975, we experienced 2 cases complicated with cardiac involvement: a 40-year-old housewife and a 52-year-old man. These 2 cases showed enlarged cardiac silhouettes and bilateral pleural effusion on the chest X-ray films. Pericardial effusion was demonstrated by echocardiogram and cardiac RI pool scintigram. A myocardial biopsy specimen showed slight cell infiltration in Case 1. The anti-rubella antibody titer rose from 128x to 4096x in Case 1 and from 265x to 1024x in Case 2. From these findings Case 1 was diagnosed as rubella pancarditis and Case 2 as pleuropericarditis. Only 4 cases with the cardiac involvement of rubella was reported in the past.

Adult↗