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Biomedical subjects

Y Sakaguchi

Publications and source records attributed to Y Sakaguchi.

At least 145 records · Page 8Linked to original sources
PubMed1989

Nick translation detection in situ of cellular DNA strand break induced by radiation.

DNA strand break in HeLa cells induced by radiation was detected using the in situ nick translation method. The cells were exposed to radiation of 3, 6, 12, 18, and 24 Gy in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and [3H]-labeled dTTP. Autoradiographic observation was made of the level of break sites in the DNA. The DNA strand break appeared even with a 3 Gy exposure, increased 8.6 times at 24 Gy compared with the control cells, and this level correlated reciprocally to change in cell viability. This nick translation method provides a rapid in situ assay for determining radiation-induced DNA damage of cultured cells, in a semi-quantitative manner.

Animals↗
PubMed1989

[Causes of death after an early gastric cancer operation].

From April, 1972 to December, 1984, 329 early gastric cancer case were operated on by this department. Results of these operations have revealed the following statistics: The 5-year survival rate of those with an m-cancer was 97.6% and for those with an sm-cancer, 92.6% and, the 10-year survival rate of m-cancer was 91.6% and sm-cancer, 89.9%, respectively. Twenty-nine postoperative deaths were recognized in this series, and the causes of death in each case have been analysed. Prophylactic measures to prevent postoperative death also are discussed.

Actuarial Analysis↗
PubMed1989

[The effects of coronary thrombolysis on the short- and long-term mortality in acute myocardial infarction].

Among 263 patients with acute myocardial infarction, 141 were treated with urokinase (UK group) and 122 received no urokinase (conventional group). Urokinase (UK) was administered intracoronarily in 55 cases; intravenously (mainly 1,920,000 units) in 64 cases; and intravenously and intracoronarily in 22 cases. The mortality rates were ascertained three months after admission and during the mean follow-up periods of 17.5 months for the UK group and 24.5 months for the conventional group. The three month mortality was significantly lower in the UK group (10.6%, 15 cases) than in the conventional group (23.8%, 29 cases) (p less than 0.01). The mortality during the entire follow-up period was also lower in the UK group (14.2%, 20 cases) than in the conventional group (26.2%, 32 cases) (p less than 0.05). Fatalities due to cardiac rupture, ventricular fibrillation, cardiac failure, cardiogenic shock and recurrent infarction were uniformly less in the UK group. It was concluded that coronary thrombolysis is an effective means of reducing mortality in acute myocardial infarction.

Aged↗
PubMed1988

Promotive effect of 4,4'-methylenebis(N,N-dimethyl)benzenamine on N-bis(2-hydroxypropyl)nitrosamine-induced thyroid tumors in Wistar rats.

The promotive effect of 4,4'-methylenebis(N,N-dimethyl)benzenamine (MDBA) on 2-stage thyroid tumorigenesis induced by N-bis(2-hydroxypropyl)nitrosamine (DHPN) in Wistar male rats was investigated. Animals were given i.p. injections of DHPN, and then a basal diet containing 0.0375% MDBA for 19 weeks. In addition, localization of the thyroid-stimulating hormone (TSH) in the pituitary gland was investigated. Levels of TSH and T4 in serum were measured by radioimmunoassay (RIA). The addition of MDBA to the diet significantly increased the incidence and numbers of preneoplastic lesion (focal hyperplasia), adenoma and carcinoma of the thyroid. TSH was usually localized in the thyroidectomy-cell in the anterior lobe of the pituitary gland, and the number of TSH-positive cells increased in the group treated with MDBA. Mean circulating levels of TSH were elevated in all MDBA-treated groups, and mean T4 levels in groups treated with MDBA were significantly lower different (P less than 0.05) than those in control groups.

Aniline Compounds↗
PubMed1988

Self-organizing system obtaining communication ability. Primitive model for language generation.

As one of the synthetic approaches to brain functions, the possibility is discussed that two intellectual robots could make "words" for themselves and come to communicate with each other. Associatron, a model for associative memory with a neural network structure, is used as the memory in the brain, and information from the outer world is accumulated in it. Concepts regarding objects and attributes are extracted from the stored information, where the Associatron properties are utilized. The robots give specific names to the concepts and interchange them with each other. When the robots have the same experience at the same time, they modify their own words according to what the other robot says. As they repeat common experiences, the differences between the words become smaller and smaller, and finally the robots agree on a word for each object. At this stage, the robots can exchange information with their words and each can act accordingly on the word from the other. This study shows that the self-organizing system with the above function can be constructed as a neural network model.

Artificial Intelligence↗
PubMed1988

The promoting effects of food dyes, erythrosine (Red 3) and rose bengal B (Red 105), on thyroid tumors in partially thyroidectomized N-bis(2-hydroxypropyl)-nitrosamine-treated rats.

The effects of erythrosine (Red 3), rose bengal B (Red 105) and thyroidectomy on the development of thyroid tumor were examined in male Wistar rats treated with N-bis(2-hydroxypropyl)nitrosamine (DHPN). Red 3 and Red 105 were used at 4% in the basal diet and were administered for 19 weeks from week 2 to 20. Thyroidectomy was performed by resection of the left lobe at week 4. Single injection of DHPN was performed intraperitoneally at 280 mg per 100 g body weight at the beginning of the experiment. Red 3 and Red 105 significantly promoted the development of thyroid tumors in thyroidectomized rats given DHPN, but had no significant effect in non-thyroidectomized rats. The incidence of thyroid tumors was 91% in rats with partial thyroidectomy, Red 3 and DHPN, 100% in rats with partial thyroidectomy, Red 105 and DHPN, and 64% in rats with partial thyroidectomy and DHPN. Serum TSH was 5.5 +/- 3.1 ng/ml in rats with partial thyroidectomy, Red 3 and DHPN, 2.1 +/- 2.2 ng/ml in rats with partial thyroidectomy, Red 105 and DHPN, and 1.5 +/- 0.5 ng/ml in rats with partial thyroidectomy and DHPN.

Animals↗
PubMed1988

A morphological study of the left bundle branch in the normal human heart.

To clarify the distribution pattern of the left bundle branch (LBB) in the human heart, the AV conduction system was studied in 13 autopsied hearts obtained from subjects aged 50 to 80 years. Vertical serial sections (7 micron) of the bundle of His and LBB were prepared and every 20th section was stained alternately with hematoxylin-eosin (HE) or by the elastica van Gieson (EVG) method and examined by light microscopy. Reconstruction was performed using a two-dimensional system in order to histologically differentiate the bundle cells from Purkinje cells. The LBB bifurcated into the anterior and posterior radiations and the cells in the septal portion were almost all Purkinje cells except in two cases showing a septal branch between the two radiations. The LBB usually branched widely from the bundle of His. An extremely anterior fascicle of the LBB was found in all cases. The distribution of the LBB at the top of the ventricular septum was divided into network and continuous types. Purkinje cells were present on both the atrial and apical sides of the two main radiations. It was suggested that these findings resulted from the fact that we morphologically differentiated the bundle cells from Purkinje cells by light microscopy.

Aged↗
PubMed1987

The relationship between natural killer cell activity and delayed-type hypersensitivity reaction to 2,4-dinitrochlorbenzene in the spectrum of chronic, intractable pulmonary tuberculosis.

We examined natural killer (NK) cell activity and delayed-type hypersensitivity reaction to 2,4-dinitrochlorbenzene (DNCB) in the spectrum of chronic, intractable pulmonary tuberculosis. A high reactive group as defined by high NK cell activity and positive reaction to DNCB were characterised by stable clinical courses assessed by radiographical and clinical changes. A low reactive group defined by non-augmented NK cell activity and negative reaction to DNCB were characterised by progressive clinical courses. Although far advanced radiographic lesions were observed more frequently in the low reactive group and moderately advanced lesions more frequently in the high reactive group, there was not a significant statistical trend.

Chronic Disease↗
PubMed1987

Potassium perchlorate, potassium iodide, and propylthiouracil: promoting effect on the development of thyroid tumors in rats treated with N-bis(2-hydroxypropyl)-nitrosamine.

The effect of 1000 ppm potassium perchlorate (KClO4), 1000 ppm potassium iodide (KI) or 1000 ppm propylthiouracil (PTU) in the diet on the development of thyroid tumors was studied histologically and biochemically in Wistar rats given a single ip injection of 280 mg of N-bis(2-hydroxypropyl)nitrosamine (DHPN) per 100 g body weight. Basal diet containing 100 ppm KClO4, 1000 ppm KI or 1000 ppm PTU was given for 19 weeks from week 2 to week 20. The incidence of thyroid adenomas at the end of week 20 of the experiment was 100% (20/20) in rats treated with DHPN followed by KClO4, 85% (17/20) in rats given DHPN followed by KI, 95% (19/20) in rats given DHPN followed by PTU, and 5% (1/20) in rats given DHPN alone. The incidence of thyroid cancers was 100% (20/20) in rats treated with DHPN followed by KClO4, 65% (13/20) in rats treated with DHPN followed by KI and 0% (0/20) in rats treated with DHPN followed by or not followed by PTU. Rats given KClO4, KI or PTU alone and untreated rats had no thyroid tumors. The mean values of TSH in serum were 2.94 +/- 0.79 ng/ml in rats treated with DHPN followed by KClO4, 9.40 +/- 16.0 ng/ml in rats treated with DHPN followed by KI and 60.94 +/- 20.60 ng/ml in rats treated with DHPN followed by PTU. It was confirmed that (1) KClO4, PTU and KI promote the development of thyroid tumor in rats treated with DHPN, (2) the promoting effect of KClO4 or KI is stronger than that of PTU and (3) the value of TSH in serum is not parallel to the promoting effect on the development of thyroid tumor.

Animals↗
PubMed1987

Effects of castration before and after treatment with N-bis (2-hydroxypropyl)-nitrosamine (DHPN) on the development of thyroid tumors in rats treated with DHPN followed by phenobarbital.

The effect of castration on the development of thyroid tumors was studied histologically and biochemically in Wistar rats given a single ip injection of 210 mg of N-bis (2-hydroxypropyl)-nitrosamine (DHPN) followed by phenobarbital (Pb). Castration was performed one week after, or one week before the injection of DHPN. The injection of DHPN was given at the end of the first week, and the rats were fed 500 ppm Pb in the basal diet for 38 weeks from week 3 to week 40. The incidence of thyroid adenomas and cancers was 20% (4/20) and 10% (2/20) in rats treated with DHPN alone. It was 75% (15/20) and 40% (8/20) in rats treated with DHPN and Pb; 30% (6/20) and 15% (3/20) in rats treated with DHPN and Pb, and castrated after DHPN; 20% (4/20) and 0% in rats treated with DHPN and Pb, and castrated before DHPN and Pb; and 0% and 0% in rats castrated either before or after receiving DHPN. Castration thus inhibited the development of thyroid tumor in rats treated with DHPN. The inhibition of tumor development in rats treated with DHPN and Pb, and castrated before receiving DHPN, was greater than in the rats castrated after receiving DHPN. Castration inhibited the secretion of TSH in rats treated with DHPN and Pb.

Animals↗
PubMed1986

Dihydrolipoyl dehydrogenase deficiency: a therapeutic trial with branched-chain amino acid restriction.

A patient with a deficiency of dihydrolipoyl dehydrogenase and neurological disease is described. The patient was placed on a branched-chain amino acid-restricted regimen. After the introduction of the regimen, there were some biochemical improvements and he achieved some developmental milestones, in contrast to previously reported patients whose neurological disease was progressive. Restriction of the branched-chain amino acids is worth trying among therapeutic measures for this disease, although restriction of the amino acids alone may not totally prevent progression of neurological disease.

Amino Acids↗
PubMed1986

Malignant fibrous histiocytoma with widespread metastasis and pulmonary cancer.

An autopsy case of malignant fibrous histiocytoma (MFH) with widespread metastases and lung carcinoma in a 64-year-old Japanese woman is reported. The initial signs were cough and sputum, followed by hemosputum. A chest X-ray photo showed a right pleural tumor, which could not be identified from a biopsy specimen, but was identified as MFH by light and electron microscopic studies on biopsy specimens of tongue tumors. Autopsy examination revealed metastases of the MFH to the brain, lung, liver, kidney, adrenal, pancreas, retroperitoneum, and some bones, and pulmonary adenocarcinoma.

Adenocarcinoma↗
PubMed1986

An in situ experimental model in rabbits for the study of rectal absorption.

An in situ experimental model of rectal absorption was studied in rabbits compared with in vivo determination of drug concentration in the plasma of postcaval vein using indomethacin as drug. Pharmacokinetic parameters were similar between in vivo and in situ. When results from both studies were compared, 60% of the drug administered to the rectum was absorbed from the superior hemorrhoidal vein and the remaining 40% was absorbed from the inferior hemorrhoidal vein. When an aspirin suppository was used in this model, the amount of unaltered aspirin absorbed in the rectal mucosa or space was greater than the absorbed salicylic acid which was metabolized or degradated from aspirin. In the case of insulin, these differences were not seen in the insulin concentration of venous plasma between insulin physiological saline and surfactant suspension. However, using the in situ model, the surfactant effect on rectal absorption of insulin was observed. From the above results, it was concluded that this in situ experimental model of rectal absorption has advantages in that it can be used directly to measure the rectal absorption rate and to determine ratios of easily metabolized and poorly absorbed drugs. Therefore, this model appears to be useful in evaluation of rectal absorption.

Animals↗
PubMed1986

Study of nasal surface basophilic cells in patients with nasal polyp.

Surface basophilic cells in samples obtained from the inferior concha of nasal polyp patients were examined microscopically. Although the cells were believed to be specific to nasal allergy patients, we were also able to observe them in nasal polyp patients without nasal allergy. These cells were found in 5% of normal controls, in 14% of patients with chronic sinusitis without nasal polyp, in 65% with nasal polyp and in 91% with nasal allergy. In patients with unilateral nasal polyp the surface basophilic cells increased on the side with nasal polyp but not on the side without nasal polyp. As the nasal polyp grew in size, so the number of cells grew. After the polyp was removed, the cells decreased appreciably in number. With regard to other nasal diseases, surface basophilic cells were observed in 80% of tracheotomized patients, in 88% of laryngectomized patients due to laryngeal cancer, in 100% of patients with a tumor in nasal cavity, in 100% of patients with irradiation treatment of the nasal cavity and in 90% of patients with atrophic rhinitis. The surface basophilic cells seem to increase in number through some mechanism induced by a blockage of nasal airway by nasal polyp.

Basophils↗
PubMed1986

[Determination of residual lesion in remaining uterus after conization].

For the purpose of predicting the residual lesion in the remaining uterus after conization, the relationship between the residual lesion in the extirpated uterus and the foci in conization specimens was examined. Seventy-seven cases with severe dysplasia, carcinoma in situ and early invasive carcinoma of the uterine cervix diagnosed by punch biopsy were reviewed. The histopathologic diagnosis, the distance from the conization stump to the focus, the length of the focus along the cervical canal, the size of the conization specimens, the number of blocks containing a focus and so on were investigated. It is concluded that there is no residual lesion in the remaining uterus after conization when the following criteria are satisfied. The histopathologic diagnosis is Ia or less. The conization stump is not involved. The distance from the conization stump to the focus is more than 3.1mm and the length of the lesion along the cervical canal is less than 8.5mm. The distance from the conization stump to the focus is no more than 3.1mm, gland involvement is not recognized in this area and the length of the lesion along the cervical canal is less than 8.5mm.

Adult↗