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Y Kashima

Publications and source records attributed to Y Kashima.

51 records · Page 3Linked to original sources
PubMed1989

Application of an ultrahigh-resolution scanning electron microscope (UHS-T1) to biological specimens.

In 1985 we developed an ultrahigh-resolution scanning electron microscope with a resolution of 0.5 nm. It is equipped with a field emission gun and an objective lens with a very short focal length. In this study we report a survey of some different preparation techniques and biological specimens using the new scanning electron microscope. Intracellular structures such as cell organelles were observed surprisingly sharper than those observed by ordinary scanning electron microscopes. However, at magnifications over 250,000 x, platinum particles could be discerned as scattered pebbles on the surface of all structures in coated materials. Using an uncoated but conductively stained specimen, we successfully observed ribosomes on a rough endoplasmic reticulum at a direct magnification of 1 million. In these images some protrusions were recognized on the ribosomes. Ferritin and immunoglobulin G were used as samples of biological macromolecules. These samples were observed without metal coating and conductive staining. The ferritin particles appeared as rounded bodies without any substructure on the surface and immunoglobulin G as complexes of three-unit bodies. In the latter the central body might correspond to the Fc fragment and two side ones to Fab fragments. We assume that ultrahigh-resolution scanning electron microscopy is an effective means for observation of the cell fine structures and biological macromolecules. It will open a new research field in biomedicine.

Animals↗
PubMed1988

Toward understanding women's decisions to continue or stop in vitro fertilization: the role of social, psychological, and background factors.

Two hundred fifty-four infertile women, all of whom had at least one in vitro fertilization-embryo transfer (IVF-ET) cycle, completed a structured questionnaire in which they provided background information and rated their beliefs about the outcomes of continuing on an IVF-ET program. Women not intending to continue IVF had older husbands, a larger proportion was mothers, and more of them had an IVF pregnancy. Those stopping and continuing, however, did not differ in their ages, the length of their infertility, or their number of IVF attempts. Women's intentions about IVF were best predicted by their attitudes toward another attempt and their perceptions of social pressures. While women intending to continue or discontinue IVF had similar beliefs about the value of motherhood, the satisfactions in having children, the importance of happy marriages, and the need to be well adjusted; discontinuers were less optimistic about another attempt making them mothers, making their marriages happier, or improving the quality of their lives. Both groups of women, however, judged another IVF attempt as likely to involve some stress, disappointment, and financial strain. In terms of their perceptions of social pressures, discontinuers also believed that their husbands, family, friends, and doctors did not think that they should have another IVF attempt. Finally, infertile women's attitudes about having another attempt and their perceptions of social pressures to try again or to stop were better predictors of their decisions about IVF than the background characteristics and fertility histories of women and their husbands. At the same time, together these variables explained only half of the variance in women's IVF decisions, and many other factors need to be considered in future research.

Adult↗
PubMed1986

A case of carcinoma arising in the intrapancreatic terminal choledochus 12 years after primary excision of a giant choledochal cyst.

A 27-yr-old woman with carcinoma developing in the intrapancreatic terminal choledochus 12 yr after the initial excision of giant choledochal cyst with Roux-en-Y hepaticojejunostomy is reported. Despite the generally accepted concept that the presence of bile is associated with malignancy in the remnant biliary ducts after excision of a choledochal cyst, this is the first report of a malignant growth developing in the terminal choledochus which had been free from the bile exposure long after the excision of the choledochal cyst. Long-term follow-up of the patient is advisable even after operation for primary resection of the choledochal cyst.

Adult↗
PubMed1986

Three-dimensional architecture of the Golgi complex observed by high resolution scanning electron microscopy.

In spite of many light and transmission electron microscopic studies of the Golgi complex, many important points remain unsettled. Recently, we have devised a method of observing the three-dimensional configurations of intracellular structures by scanning electron microscopy. We have used this method to study the three-dimensional structure of the Golgi complex in several tissues of the rat, paying special attention to three problems: the overall configuration; the spatial construction of each stack, and the relationship to neighbouring organelles. The interconnected stacks which form the Golgi complex are arranged in a manner characteristic of the particular cell type. In rat extraorbital lacrimal gland the stacks form an irregular network spread throughout the cell, while in anterior pituitary cells they form a hollow sphere. Continuities were seen between cisternae within a stack, and in one case a stack actually consisted of one helically wound cisterna. We also observed slender tubules connecting Golgi stacks to neighbouring rough endoplasmic reticulum. Vesicles, presumably transport vesicles, were frequently observed on the surface of the cisternae, most commonly at the cisternal rims. However the continuities among stacks and connections with cisternae and with the rough endoplasmic reticulum demonstrated here offer alternative routes for movement of substances through the cellular endomembrane system.

Animals↗
PubMed1976

Corrosion casts of lymphatics.

After direct injection of Mercox into the thyroid parenchyma we obtained the corrosion casts of lymphatics to be observed by scanning electron microscopy. It seems reasonable to deduce from the following points that these corrosion casts were of the lymphatic system: 1) variable size of columnar vessels, 2) their three-dimensional anastomoses, 3) occurrence of blind endings, 4) V-shaped reliefs on parts of the columns, certainly indicative of valves, 5) bead-like structures formed by closure of valves, 6) depressions and surrounding saw-toothed figures on the surfaces of the casts, probably corresponding to the nuclei and boundaries of endothelial cells. The method described in this study seems useful in the study of the structures and changes of lymphatics in various organs.

Animals↗
PubMedDate not supplied

The Ishikawa classification of cavernous sinus lesions by clinico-anatomical findings.

PURPOSE: The Jefferson classification has been used to localize cavernous sinus lesions. However, this classification occasionally showed dissociation between identified localization and clinical findings. We investigated the clinical applicability of the newly proposed Ishikawa classification based on serial topographic sections of human cavernous sinus and the clinical findings. METHODS: In the Ishikawa classification, the cavernous sinus is divided into three portions, that is, anterior, middle, and posterior, demarcated by the location of the intracranial orifice of the optic canal and the entry of the maxillary nerve into the cavernous sinus. A total of 162 patients with cavernous sinus lesions were classified using both the Jefferson and the Ishikawa classifications and the clinical applicability of these two classifications was studied. Characteristics of the localization of lesions were also examined in each etiological type. RESULTS: By the Jefferson classification, 11% of the 162 patients had the anterior type of lesion, 12% the middle, 8% the posterior type, and 69% the unclassifiable type. However, by the Ishikawa classification, 35% had the anterior type, 10% the middle type, 22% the posterior type, 5% the whole type, and 28% the unclassifiable type of lesion. Furthermore, the Ishikawa classification revealed that the etiology of the anterior type was mainly inflammation, and that the etiology of the posterior and whole types was tumors. CONCLUSION: The Ishikawa classification is clinically useful to identify and classify the localization of cavernous sinus lesions.

Carotid Artery, Internal↗
PubMedDate not supplied

A successful treatment for hepatocellular carcinoma with atrial tumor thrombus.

A 66-year-old man with an advanced hepatocellular carcinoma and tumor thrombus extending into the right atrium was treated by transcatheter arterial infusion of lipiodol and aclarubicin. This brought about a remarkable reduction of the tumor and the disappearance of the right atrial tumor thrombus. The tumor was then radically resected by hepatic posterior segmentectomy with combined resection of the right hepatic vein, where the tumor thrombus remained. He is doing well without any signs of recurrence 22 months after the operation.

Aclarubicin↗