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Biomedical subjects

S Katsuda

Publications and source records attributed to S Katsuda.

At least 91 records · Page 5Linked to original sources
PubMed1987

Hepatocellular carcinoma with chondrosarcomatous variation. A case report and review of the literature.

An autopsy case of hepatocellular carcinoma with a sarcomatous component in a 63-year-old woman was described. A massive tumor measuring 15 X 15 X 10 cm almost replaced the left lobe of the liver and extended to the right atrium of the heart. Histologically the tumor was a typical hepatocellular carcinoma of adult type, except in the central portion where there was gradual replacement of the carcinoma by spindle-shaped atypical cells with areas of chondrosarcomatous tissue. Some of the spindle cells were immunohistochemically positive for keratin, and the sarcomatous component was not found in the metastatic foci of liver and lungs. Reported cases of mixed hepatic tumor of adults in the literature were reviewed, and discussion was made concerning the nosology of the present tumor.

Carcinoma, Hepatocellular↗
PubMed1986

Effect of atherosclerosis on the responsiveness of the rapidly acting arterial pressure control system in WHHL rabbits.

The open loop gain of the rapidly acting arterial pressure control system was estimated in 15 Watanabe heritable hyperlipidaemic (WHHL) rabbits aged 3-31 months. Twenty five normal Japanese white rabbits, aged 6-30 months, were used as controls. After being anaesthetised by an intravenous injection of pentobarbital sodium, the rabbits were bled by 2 ml X kg-1 body weight within 1-2 s through a catheter inserted into the aortic arch. The arterial pressure change after this rapid haemorrhage was recorded for more than 2 min by a catheter placed in the aortic arch. The open loop gain was calculated as (delta API/delta APS)-1, where delta API was the immediate fall and delta APS the steady state fall. The pulse pressure, delta API, and delta APS increased and the open loop gain decreased with age in the WHHL rabbits, but the mean arterial pressure did not change significantly with age. After aortic denervation the open loop gain also decreased with age in the WHHL rabbits. These results indicate that the progress of atherosclerosis with aging in the Watanabe heritable hyperlipidaemic rabbit decreases the vascular compliance and impairs the arterial pressure restoring function of the rapidly acting arterial pressure control system.

Animals↗
PubMed1986

The presence of intracytoplasmic confronting cisternae of the endoplasmic reticulum in osteosarcoma cells in interphase.

Confronting cisternae of the endoplasmic reticulum recognized in tumor cells of 7 cases of osteosarcoma were presented. They were found in the mitotic cells as well as in the cytoplasms of interphase cells. The more the mitotic cells were observed in 1 micron-thick sections, the more frequently those membranous structures were encountered in the corresponding ultrathin sections. In the interphase cells, such structures were located around Golgi apparatus or close to the nucleus. Occasionally, they were composed of a pair of closely apposed cisternae of the nuclear membrane and the rough endoplasmic reticulum. These results seem to indicate that the nuclear envelope which is disrupted and reformed during mitosis in rapidly proliferating cells takes part in the formation of the confronting cisternae of the endoplasmic reticulum.

Adolescent↗
PubMed1986

Papillary carcinoma of the thyroid gland with anaplastic transformation in the metastatic foci. An immunohistochemical study.

An immunohistochemical study was made on an autopsy case of papillary carcinoma of the thyroid with anaplastic transformation in the metastatic foci occurring in a 72-year-old woman. The anaplastic carcinoma cells were sarcomatous in appearance, and they were vimentin-positive and cytokeratin-negative. Whereas, papillary tumor cells which were intermingled in the anaplastic carcinoma contained both cytokeratin and vimentin. The close correlation between tumor cell anaplasia and the expression of the different intermediate filament proteins in thyroid carcinoma was briefly discussed.

Aged↗
PubMed1986

Interactions among reflex compensatory systems for posthemorrhage hypotension.

The open-loop gains of the carotid sinus, aortic, and cardiopulmonary baroreflex systems defined as the ratio of posthemorrhage hypotension without a reflex to that with the reflex were estimated from experiments with a mild and quick hemorrhage (2 ml/kg body wt in 1-2 s) in 81 pentobarbital-anesthetized rabbits. The overall gain when all the nerves were intact was 7.4. After the carotid sinus nerves were sectioned the gain decreased to 3.0. After aortic nerve sectioning, the gain was 2.8, whereas vagotomy decreased it to 3.8. When both the carotid sinus and aortic nerves were cut, the gain was 0.9. When the aortic and vagus nerves were severed, it was 1.8. When the vagus and carotid sinus nerves were cut, it was 1.6. From these gain values the gain of the interacting component between the carotid sinus and aortic reflexes was calculated as 0.4; that between the aortic and cardiopulmonary reflexes was 0.5; and that between the cardiopulmonary and carotid sinus reflexes as 0.1. The gain of the interaction among all of these baroreflex systems was estimated to be 2.1. The results suggest that all these facilitatory interacting components play an important role in restoration of arterial pressure decrease caused by mild hemorrhage.

Animals↗
PubMed1985

Comparative responsiveness of the rapidly acting arterial pressure control system to quick mild hemorrhage and infusion in conscious rabbits.

The responsiveness of the rapidly acting arterial pressure control system to hemorrhage and infusion was investigated. Two catheters, one for pressure measurement and the other for inducing hemorrhage and infusion, were chronically implanted in 19 rabbits. A few days after the operation, each animal was quickly bled and transfused (2 ml/kg body weight) at intervals of 5 min while it was conscious. The hemorrhage-infusion experiment was repeated 16 times in each animal. The 16 strings of data were pooled for each animal. The overall open-loop gains (G) of the rapidly acting arterial pressure control system were estimated from the individually pooled responses to hemorrhage and infusion. There was no significant difference between the G-values, i.e., 7.2 +/- 1.2 by hemorrhage and 7.1 +/- 1.2 by infusion (mean +/- SD), as evaluated by the paired t-test (p greater than 0.5). Thus, the responsiveness of the rapidly acting arterial pressure control system to quick mild hemorrhage and to infusion appears to be similar.

Animals↗
PubMed1984

Studies on the off-response of the rod photoreceptors in the isolated frog retina.

Transretinal potential changes induced by a 30 sec exposure to 503 nm light were studied in the dark-adapted frog isolated retina. The retina was treated with aspartate and 0.5 mM Ba2+ to suppress the PII and slow PIII components of the electroretinogram, and therefore the response to the light stimulus consisted of the on-response (fast PIII response) and the off-response. The amplitude of the off-response was proportional to that of the on-response when the stimulus intensity was weak. The amplitude ratio of the off-response to the on-response was unaffected by partial bleachings of rhodopsin. In the presence of 700 nm background illumination, the amplitude of the on-response was decreased, whereas that of the off-response was increased. The amplitude of the off-response increased to about four-fold that of the original response at 3 hr after turning on the background illumination, but the effects of 480 nm background light were less remarkable. Both the on- and off-response, however, had a peak spectral sensitivity at about 500 nm, regardless of the presence of background light. From these findings, it was suggested that the red rods contribute to the development of the off-response, but the cones would also contribute through small focal gap junctions between the cones and the red rods.

Action Potentials↗
PubMed1984

Studies on the enteropathogenic mechanism of non-O 1 Vibrio cholerae isolated from the environment and fish in Toyama Prefecture.

Enteropathogenic mechanisms of non-O 1 Vibrio cholerae were investigated using strains from the environment and those from fish in Toyama Prefecture. None of the 93 non-O 1 V. cholerae strains produced a detectable level of choleratoxin-like-enterotoxin (CT-like-enterotoxin) in Syncase medium, while 23 strains showed a distinct fluid accumulation in the rabbit ileal loop test (RIL). These RIL-positive strains neither produced CT-like-enterotoxin in vitro in the other four kinds of media which are considered suitable for CT production, nor in vivo in the ligated ileal loop. Approximately one-third of RIL-positive strains produced a fluid accumulating factor (FAF) which was not neutralized with anti-CT serum. FAF of a representative strain (Strain 79-9-2) was inactivated by heating at 100 C for 10 min, and has a molecular weight within the range of 50,000 to 100,000 daltons. Most accumulated fluids in RIL after inoculation with whole cultures of RIL-positive strains contained both hemolytic and cytotoxic principles. Desquamation of epithelial cells, inflammatory edema, neutrophile infiltration, loss of goblet cells and frequent hemorrhages were observed in sections of ligated ileal loop inoculated with whole cultures or concentrated culture filtrates of CT-like-enterotoxin-negative but RIL-positive strains. In contrast, neither desquamation of epithelial cells nor hemorrhage was observed in sections after inoculation with those of a CT-like-enterotoxin positive strain (Strain E 8498). These results indicated that most RIL-positive non-O 1 V. cholerae strains from the environment and fish isolated in Toyama Prefecture produce little CT-like-enterotoxin, but some of them produce FAF with cytotoxic activities.

Animals↗
PubMed1984

Secretory granules in benign and malignant glucagonomas of the pancreas.

Two cases of glucagonoma, one benign and the other malignant, was presented. Benign glucagonoma in a 29-year-old man with multiple endocrine neoplasia type 1 was composed largely of tumor cells with secretory granules ranging from 139 to 417 nm in diameter identical to A cell granules. There were a few tumor cells which contained no A cell granules but smaller granules of approximately 166 nm diameter similar to those of pancreatic polypeptide containing cells. Radioimmunoassay of the tumor extract showed 319 micrograms/g wet weight of glucagon and 0.72 microgram/g wet weight of pancreatic polypeptide. Malignant glucagonoma in a 34-year-old man was a massive tumor of 7 X 6 X 5 cm replacing the tail and body of the pancreas with multiple metastases. The tumor contained 0.2 microgram/g wet weight of glucagon and 0.065 microgram/g wet weight of vasoactive intestinal peptide. The electron microscopic examination revealed that the tumor cells had variable numbers of atypical secretory granules measuring 110 to 200 nm in diameter different from A cell granules. An analysis of plasma glucagon by the gel filtration technique showed the heterogeneity of glucagon molecules indicating the presence of large glucagon. Atypical secretory granules in malignant glucagonoma were considered to represent immature granules containing the precursor or intermediate of glucagon.

Adenoma, Islet Cell↗
PubMed1984

Mucoepidermoid carcinoma of the liver.

An autopsy case of mucoepidermoid carcinoma of the liver associated with congenital cysts in a 78-year-old man was reported. The liver weighed 1,900 g, and there was a massive tumor of 11 X 10 X 6.5 cm in the left lobe with multiple sero-mucinous cysts. Histologically, the tumor cells consisted of four types of cells: mucus-secreting cells, squamous cells, intermediate cells, and oxyphilic cells. The variety of tumor cells quite resembled that of mucoepidermoid carcinoma of the salivary gland. The sero-mucinous cysts were lined with a single layer of cuboidal or columnar cells and were not communicated with the biliary ducts. Part of the cysts with benign lining cells was in continuity with tumor cells of the intermediate type. Discussion was made on the histogenesis of hepatic mucoepidermoid carcinoma in particular emphasis on the association of the congenital cysts.

Aged↗
PubMed1984

Sensitivity of rapidly acting arterial pressure control system in conscious adult rabbits at different ages.

Changes in sensitivity of the rapidly acting arterial pressure control (AP) system with aging were investigated. Two catheters, one for pressure measurement and the other for inducing hemorrhage from the aorta, were chronically implanted in 25 rabbits from the same colony (aged 6 to 30 months). A few days after the operations, each animal was quickly bled (2 ml/kg body weight) while it was conscious. The hemorrhage experiment was repeated 16 times and the mean arterial pressure responses were sampled with an A/D-converter and stored in a digital computer, the 16 strings of data being pooled for each animal. The overall open-loop gain (G) of the AP-system was estimated from the individually pooled responses. In the present study, aging exerted no significant effect on the value of G (7.1) as evaluated by Kruskal-Wallis' non-parametric one criterion variance analysis (p greater than 0.05). The reflex sensitivity of the AP-system over the pressure ranges used in this experiment thus appears to be unaffected by aging over the range from 6 to 30 months.

Aging↗
PubMed1984

A case of malignant mesothelioma containing fibrous long-spacing fibers in the sarcomatous stroma.

Fibrous long-spacing fibers (FLS) of a 90- to 120-nm period found in malignant mesothelioma of a 73-year-old woman were described. The FLS were observed in the reticular stroma with a fibroblastic variety of tumor cells, and they appeared to blend with bundles of thin collagen fibers and a moderate amount of ruthenium red (RR)-positive materials. No FLS were recognizable in the myxomatous stroma with abundant RR-positive materials or in the collagenous stroma packed with thick collagen fibers. Therefore, the presence of both thin collagen fibers and tumor cells of fibroblastic differentiation is presumed to be responsible for the formation of the FLS in the particular tumor.

Aged↗