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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 1,549 records · Page 86Linked to original sources
PubMed1978

Electron microscopic and cytochemical observations on the membrane systems of the chicken thrombocyte.

A combined electron microscopic and cytochemical study of the thrombocytes of the mature chicken has demonstrated the existence of two membrane systems, the surface connected system (SCS) and the dense tubular system (DTS). The SCS consists of light tubules and vacuoles which are in continuity with the plasmalemma. A ruthenium red-positive reaction product was observed on the inner surface of this membrane system. Ferritin particles were present in the tubules and the vacuoles of the SCS after the thrombocytes had been incubated in vitro with ferritin. The DTS consisted of the nuclear envelope, the rough-surfaced endoplasmic reticulum, dense tubules and concentric double membrane structures, all of which give a peroxidase-positive reaction. Although actual continuity between the DTS and the SCS of thrombocytes was not observed in this study, close approximation between the two systems was observed at many points. These results are discussed in relation to those from comparable studies of human platelets.

Animals↗
PubMed1978

[Intracranial saccular aneurysms in the first three decades of life (author's transl)].

An analysis of surgically-treated 1,000 intracranial saccular aneurysms in our clinic during a period from June, 1961 to September, 1975, revealed 39 cases in patients under the age of 29 years. Some characteristics were emphasized in this studies. The sex incidence was male predominant, which exhibited a ratio of 4 to 1 for the ages below 20 years and 2.1 to 1 for the ages below 30 years. In sites distribution, there were striking incidence of aneurysms of the internal carotid termination, on the contrary, lower incidence of aneurysms of the middle cerebral artery, comparing with the cases in all ages. The common complication of cerebral infarction secondary to the vasopasm associated with rupture of the aneurysm occured less often than in adults cases. The surgical results of 39 cases in the first three decades of life, consisted of 29 excellent cases, 5 good, 4 poor and 1 death, have been as good or better than in the cases of all ages. Furthermore, the results of follow-up studies, which were obtained from 33 cases out of 38 survival cases, revealed 31 cases with full working and no deterioration.

Adolescent↗
PubMed1978

Age-related changes in cholesterol and bile acid metabolism in rats.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipid and bile acids, and fecal excretion of sterols and bile acids were examined in Sprague-Dawley and Wistar strain male rats, 7 to 106 weeks in age. Serum and liver lipid levels increased with age in both strains but the liver phospholipid level remained unchanged. The proportion of serum alpha-lipoprotein increases and that of beta- and prebeta-lipoproteins slightly decreased. Cholesterol and phospholipids in low density lipoprotein and cholesterol in high density lipoprotein fractions also increased with age. Bile flow and biliary secretion of cholesterol and bile acids decreased in aged rats, but when they were expressed in terms of units per rat they were almost constant without regard to age. Pool size, synthesis, secretion, and turnover frequency of bile acids also did not change when they were expressed per rat, though 7-week-old rats showed a low value for turnover frequency. Biliary secretion of phospholipid, however, increased in aged rats. Biliary secretion of chenodeoxycholic and alpha-muricholic acids decreased but that of cholic and hyodeoxycholic acids increased. Daily excretion of feces and fecal neutral sterols decreases in aged rats but the excretion of bile acids remained constant regardless of age. The ratio of coprostanol and cholesterol in the total sterols was not affected. Fecal lithocholic, beta-muricholic and P10 (probably omega-muricholic) acids were decreased with age but the other bile acid components were not changed or were slightly increased.

Aging↗
PubMed1978

Intracranial saccular aneurysms in the first three decades.

To examine the characteristics of cerebral aneurysms in juvenile patients, 39 patients less than 30 years old were chosen from our 1,000 patients with saccular aneurysms who had undergone an intracranial operation on their aneurysm. The frequency, clinical features and surgical results in these young patients are discussed.

Adolescent↗
PubMed1978

Cholesterol from serum and cholesterol-phospholipid dispersions by isolated rat hepatocytes in vitro.

The rate of uptake of cholesterol by isolated rat hepatocytes from incubation medium containing rat serum was low and did not increase by the prolongation of incubation time up to 2 hr at 4 degree. However, the hepatocytes took up cholesterol very actively at 37.5 degree from serum as well as from a cholesterol-phospholipid dispersion. The cholesterol uptake by the cells from liposomes increased linearly with the increase of the cholesterol concentration of liposomes, but that from serum reached the maximum at about 1.5 mu mol/ml cholesterol and remained at a plateau level at higher concentrations. Cholesterol was transfered from every class of serum lipoprotein, although the uptake ratio was the highest from the LDL fraction. As the lipoprotein concentration was increased, the uptake ratio decreased in the same way as that observed in the incubation with whole serum. The concentration of labeled ester cholesterol in the medium decreased more rapidly than free cholesterol during incubation. Cholesterol in the hepatocytes, however, was found mainly as the free form, suggesting that ester cholesterol taken up by the cells was rapidly hydrolyzed. Cholesterol accumulation was not observed in hepatocytes incubated in medium containing serum, but their cholesterol content was increased after the incubation in medium with liposomes of high cholesterol concentration. Therefore the uptake of cholesterol by hepatocytes from serum lipoproteins is probably carried out by a process different from that of uptake from liposomes which is considered to be a physicochemical phenomenon.

Animals↗
PubMed1977

Ultrastructural localization of acid protein polysaccharides and calcium in the vacuoles of the chicken thrombocyte.

The coexistence of acid protein polysaccharides and calcium in the vacuoles of chicken thrombocytes were studied by means of ultrahistochemical methods and electron probe X-ray microanalysis. The thrombocytes possessed large vacuoles of a surface connected membrane system. After both ruthenium red staining and tannic acid fixation the innersurface coat of vacuoles was always strongly and continously visualized. Electron microscopic X-ray microprobe analysis of antimonate precipitates in thrombocytes fixed in K-antimonate-OsO4 revealed calcium localization on the innersurface of vacuoles. From these facts it seems likely that the vacuoles of the surface connected membrane system may take part in the pool or the transport of calcium.

Animals↗
PubMed1977

Congenital cystic dilatation of the common bile duct as a cause of primary bile duct stone.

Of the 101 patients with congenital cystic dilatation of the common bile duct, eighty-eight with adult-type cysts are reported on. The association of primary bile duct stone and adult-type cyst of this anomaly is discussed and found to be higher than previously recognized. In the cases without calculi, abnormal arrangement of the pancreaticobiliary ductal system is indicated to play an important role in the manifestation of the symptom. The anatomic and clinical features and the results of treatment for this type of cyst are reviewed.

Adult↗
PubMed1977

Clinicopathologic classification of congenital cystic dilatation of the common bile duct.

From 1970 to 1975, 103 patients with a localized dilatation of the biliary passages were treated at the First Department of Surgery of Kyoto University Medical Center. Of the 103, 101 had congenital cystic dilatation of the common bile duct (Alonso-Lej type I). These dilatations were classified into two sub-types, "infant type" and "adult type," based on the anatomic location and clinical features. Infant type cyst was typically large cyst of the choledochus and most common in infancy and childhood. Adult type cyst was fusiform dilatation of the biliary tract, and most common in adults. Gallstones were seen in most of the patients with this type cyst.

Adolescent↗
PubMed1977

Surgical treatment of cancer of the pancreas and the periampullary region: cumulative results in 57 institutions in Japan.

In this study the experiences with carcinomas of the pancreas, ampulla of Vater, terminal comma bile duct, and duodenum found in a series of 3,610 patients collected from 57 major Japanese institutions was compiled over a 26 year period. The results were analyzed as to the success of resectional and palliative surgery for the various lesions. The most common lesion was carcinoma of the head of the pancreas. Unifortunately, only 18.3% of these patients were resectable with a 25.3% mortality. Carcinoma of the body and the tail was the second most frequent lesion, and it also exhibited a low resection rate. Carcinomas of the ampulla and the terminal common bile duct and duodenal regions were the most favorable for resection; usually pancreatoduodenectomy with an overall mortality of 20.8%. As a result of the large number of pancreatectomies performed, there was also a large number of postoperative complications, the most frequent being leakage at an anastomotic line. Hemorrhage also occurred frequently. Distal pancreatectomies were reserved for carcinoma of the body and the tail of the pancreas, and the most common postoperative complication of this procedure was hemorrhage. There were only 45 total pancreatectomies among the 973 resections being performed most frequently in patients with carcinoma of the head of the pancreas. Again, the most frequent postoperative complication was hemorrhage, followed by anastomotic leakage. The long term survivals following resection for these lesions were each poor. The best mean survival time was 22.7 months for carcinoma of the ampulla of Vater. Patients having resections for carcinoma of the head of the pancreas had a mean survival time of 12.3 months. At 5 years there were few survivors and most of them were patients who had undergone resections for carcinoma of the ampulla of Vater.

Ampulla of Vater↗
PubMed1977

The passage of thiamine across the rat placenta and its uptake by the fetal organs. I. The transport of thiamine across the placenta.

It is well known that thiamine is highly soluble in water. However, if chloroplatinic acid (H2PtCl6) is used during fixation, an insoluble, electron-dense thiamine-PtCl6 precipitate is formed. Using this method we performed electron microscope autoradiography of the placental labyrinth of rats in their 15th day of pregnancy after injection into the maternal bloodstream of 3H-thiamine, and we also measured the radioactivity of the tissues, in order to study the transport of the thiamine across the placenta. Both developed silver grains and radioactivity were found in the largest amounts 30 min after injection; the amounts of both declined after 2 hrs and declined further after 5 hrs. The majority of the developed silver grains were localized in the smooth-surfaced endoplasmic reticulum, which is generally thought to be the vehicle for the transport of materials in the cell, while in the mitochondria, Golgi apparatus, etc. the grains were few. Considering the substantial depletion of the amounts of both sivler grains and radioactivity after the relatively short time of 5 hrs, we conclude that the greater portion of the thiamine passes quickly across the placenta to the fetus, where it is used in the metabolism of the fetal organs, and that only a small part of the thiamine is retained in the placenta for its own metabolism.

Animals↗
PubMed1977

The passage of thiamine across the rat placenta and its uptake by the fetal organs. II. The uptake of thiamine by fetal organs.

Having injected 3H-thiamine into the maternal bloodstream of rats in their 15th day of pregnancy, the uptake by the fetal organs (liver and cardiac muscle) of the 3H-thiamine which had been transported across the placenta was studied by electron microscope autoradiography and by measuring the radio-activity of the tissues, using the same methods reported in the first paper of this series. In the fetal liver both developed silver grains and radioactivity were found in greates amounts in specimens collected 5 hrs after injection. Developed silver grains were abundant in the mitochrondria, Golgi apparatus, rough-surfaced endoplasmic reticulum, glycogen area, and nucleus, indicating that these cell organelles take up thiamine and utilize it for the cell metabolism. In the fetal cardiac muscle, the developed silver grains and radioactivity were found in greatest amounts 2 hrs after injection. The silver grains were abundant in the glycogen area, Golgi apparatus, and myofibrils, but they were especially abundant in the mitochondria. This indicates that thiamine is taken up by these organelles and employed in the cell metabolism.

Animals↗