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Biomedical subjects

K Takaya

Publications and source records attributed to K Takaya.

At least 91 records · Page 5Linked to original sources
PubMed1981

Elastic fibers associated with collagenous fibrils surrounded by reticular cells in lymph nodes of the rat as revealed by electron microscopy after orcein staining.

Electron microscopy of the rat lymph node disclosed reticular cells in close association with bundles of collagenous fibrils 30-45 nm in diameter, and electron lucent "amorphous" substances surrounded by microfibrils 11 nm in diameter, with junctional complexes. The amorphous substances, distinctly revealed by orcein staining, and the microfibrils showed morphological characteristics of elastic fibers. Since elastase digestion of 2% glutaraldehyde fixed specimens induced the selective disappearance of the orcein-stainable substances, it was concluded that they are elastin. Elastin often had a close contact with the plasma membrane of reticular cells. It is suggested that reticular cells synthesize elastic fibers.

Animals↗
PubMed1980

Effects of strong electrolytes on the iron alum--Alcian Blue--Safranin staining of mast cell granules of the rat.

Rat mast cells fixed in Carnoy's fluid were stained with iron alum-Alcian Blue--Safranin solution after pre-treatment with strong electrolyte solutions including acids, neutral salts and alkalis. Although both red and blue mast cells were observed without pre-treatment, most mast cells were stained blue and a few red when they were stained after the pre-treatment. Mast cell granules contain salt complexes formed between basic proteins and acidic polysaccharides through ionic linkages between protein basic groups and polysaccharide sulphate and carboxylic acid groups. It is suggested that when sections are treated with strong electrolyte solutions, complexes are broken by disruption of ionic linkages and sulphate and carboxylic acid groups of polysaccharides masked by basic proteins become available for binding Alcian Blue. This was confirmed by model experiments performed with smears of a heparin-lysozyme complex. When mast cells were fixed in aldehyde-containing fixatives, no effects of strong electrolyte solutions on the staining properties of mast cell granules were revealed.

Alcian Blue↗
PubMed1979

Ultrastructure of basophilic leukocytes and mast cells in normal and cutaneous basophil hypersensitivity-reacted guinea pig dermis.

Basophilic leukocytes and mast cells in guinea pig dermis in normal and cutaneous basophil hypersensitivity (CBH) reaction were examined by light and electron microscopy. Basophils were rare in the normal dermis and predominantly revealed in the CBH-reacted skin. Some infiltrating basophils of the reacted displayed an immediate attachment to mast cells. Cytoplasmic continuities were partially seen between them. They were most plentiful at 48 h after phytohemagglutinin injection and decreased in number thereafter. The basophils contained three types of granule. The vast majority of granules were Type I granules, basophil-specific granules. Type II granules were less frequently encountered and resembled a mast cell granule in the fine structure. Type III granules were scant and small-cored vesicles.

Animals↗
PubMed1979

Electron microscopy of unstained, fresh air-dried spreads of the mouse brain and application to energy dispersive X-ray microanalysis.

Electron microscopy of unstained, fresh air-dried spreads of the mouse brain revealed well-preserved ultrastructures of neurons and synaptic boutons filled with synaptic vesicles. Energy dispersive X-ray microanalysis of the neuron nucleus disclosed peaks for phosphorus, sulfur, chlorine and potassium. Analysis of large regions (spots of ca. 1 micron in diameter) on the neuron nucleus revealed peaks for magnesium, whereas that of regions on the cytoplasm rarely disclosed the element, which was confirmed by removal of the background noise using a micro-Edit computer system. Analysis of regions on synaptic boutons except mitochondria also indicated peaks for magnesium.

Animals↗
PubMed1977

Electron microscopy of human melanosomes in unstained, fresh air-dried hair bulbs and their examination by electron probe microanalysis.

Electron microscopy of unstained, fresh air-dried spreads of plucked human hair bulbs revealed relatively well preserved melanocytes and dense storage granules of melanin. Energy dispersive X-ray microanalysis of melanosomes and premelanosomes from black facial hair bulbs disclosed high peaks for potassium and sulfur, intermediate peaks for magnesium and calcium, and low but distinct ones for phosphorus and chlorine. No peaks for magnesium were found in the central portion of mature melanosomes, but at their edges and in premelanosomes conspicuous peaks for this element were obtained.

Electron Probe Microanalysis↗
PubMed1976

Dense particles in subcutaneous collagen fibrils.

Electron microscopy of unstained, fresh air-dried spreads of the subcutaneous connective tissue disclosed dense particles (6-20 nm in diameter) at the dark bands of collagen fibrils with 67 nm periodicity. The particles appear to consist of chlorides from the X-ray microanalysis of collagen fibres.

Animals↗
PubMed1976

Eelctron microscopy of unstained fresh air-dried spreads of mouse pancreas acinar cells and energy dispersive x-ray microanalysis of zymogen granules.

Electron microscopy of unstained, fresh air-dried spreads of the mouse pancreas has disclosed various substructures of acinar cells. The nucleus with a nucleolus, rough endoplasmic reticulum with ribosomes, mitochondria with dense granules, lysosomes, intracisternal granules, and zymogen granules with a core surrounded by a halo, and a boundary membrane were observable under a conventional electron microscope. Five zymogen granules of an acinar cell were examined by energy dispersive X-ray microanalysis. Peaks for phosphorus, sulfur, chlorine and potassium were detected in all of the zymogen granules examined, which confirmed a previous report (Takaya, 1975b). By increasing the integrated pulse counting time up to 300 seconds, calcium and magnesium were detected in two of the granules in addition to the elements mentioned above. No peaks for either copper or zinc were observed when nylon grids were used. The electrolyte content of zymogen granules and of acinar initial fluid is discussed in relation to the secretory mechanism of the exocrine pancreas.

Calcium↗
PubMed1976

The variable refractivity of the protein or polypeptide hormone-producing cells showing a unique luminescence in the dark-field microscope.

When cryostat sections of endocrine tissue were examined in a dark-field microscope, a brillant granular luminescence was revealed in the endocrine cells thought to be concerned with protein or polypeptide horome production. The sections were prepared from fresh materials either frozen in a cryostat chamber at --25 degrees C, in dry ice-acetone, or fixed in formalin-calcium for 24 hr. The neurosecretory substance in the hypothalamus and the posterior lobe of the pituitary showed a blue luminescence; the acidophil cells of the anterior lobe of the pituitary, orange; basophile cell, green or blue; intermediate lobe cells, no luminescence; thyroid C cells, white-blue; pancreatic A cells, blue; B cells, orange; adrenomedullary cells, greenish blue; enterochromatin cells, green; and other endocrine cells in the gastrointestinal tract, blue or orange. After tearing and spreading the pituitary and hypothalamus with a pair of needles on a glass slide, and examining the teased specimen by dark-field microscopy, various cells of different lumunescent colours became apparent in the anterior lobe of the pituitary, a blue fluorescent substance in the posterior lobe, and neurosecretory cells bodies in the hypothalamus. The different colours appear to be inherent in the granules of living tissues.

Adrenal Medulla↗
PubMed1976

Preparation of fresh-frozen dried ultrathin sections by drying without vacuum.

Fresh-frozen dried ultrathin sections were prepared without fixation, embedding or staining. Small blocks of tissues were chilled by making contact with copper blocks precooled with liquid nitrogen according to a procedure modified from that of Christensen. Sections were cut at -95 degrees C with a Reichert Um 2 ultramicrotome fitted with cryoaccessories, using dry glass knives. The sections were dried for 15 min or more on formvar-coated grids by a flow of dry nitrogen gas at -95 degrees C in a newly devised glass chamber placed in the cryokit compartment. The sections showed only a few holes attributable to ice crystal formation. Holes were found in the intercellular spaces as well as within cells. The sections were observed without staining and gave enough contrast to permit recognition of organelles such as nucleus, perinuclear cisternae, nucleolus, interchromatin granules, perichromatinic granules and secretory granules in the pancreatic exocrine cells. In the basal part of the proximal convoluted tubules of mouse kidney, abundant mitochondria were seen. Mitochondrial cristae and lines corresponding to the basal infoldings of the renal convoluted tubules were less dense than their surroundings. This method can yield ultrathin sections lending themselves to investigations of the distribution of elements with electron-probe X-ray microanalyzer and of diffusible substances by dry-mount autoradiography at the electron-microscopic level.

Animals↗
PubMed1975

Energy dispersive x-ray microanalysis of neurosecretory granules of mouse pituitary on fresh air-dried tissue spreads.

Electron microscopy of fresh air dried spreads of unstained posterior lobe tissue from mouse pituitary disclosed neurosecretory granules. Each granule showed a seemingly homogeneous dense core surrounded by a halo and a bounding membrane. The area between granules in the cytoplasm was relatively well preserved. The energy dispersive X-ray microanalysis revealed peaks for sulfur, chlorine and potassium in two granules. The third granule displayed peaks for phosphorus and chlorine. These elements probably contribute to the high electron density of the granules. There was no peak for calcium, in contrast to the dense bodies of human blood platelets.

Animals↗
PubMed1975

Intranuclear silicon detection in a subcutaneous connective tissue cell by energy-dispersive x-ray miscroanalysis using fresh air-dried spread.

Silicon was detected by energy-dispersive x-ray microanalysis in the nucleus of a subcutaneous connective tissue cell of mice fed normally. To eliminate contamination, pieces of connective tissue were spread on copper grids and examined without any treatment by an energy-dispersive spectrometer with a scanning transmission apparatus attached to an electron microscope. Scanning transmission electron microscopy of the spread has demonstrated a well-preserved ultrastructure. Fibrous structures, nuclei and nucleoli of cells and mitochondrial granules were recognized. Electron probe analysis showed peaks for silicon at three spots on the nucleus of a cell in addition to those for phosphorus, sulfur, chlorine, potassium and calcium, whereas no peak of silicon could be detected at the spots on nuclei of other cells, mitochondrial granules and electron-lucent area on the same grid as the above. Silicon appears to play a significant role in the nucleus. Applicability of the technique to know the distribution of easily contaminating elements and diffusible substances is shown.

Air↗
PubMed1975

Energy dispersive X-ray microanalysis of zymogen granules of mouse pancreas using fresh air dried tissue spread.

Electron microscopy of fresh air dried pancreas spreads revealed a well preserved ultrastructure of pancreatic exocrine cells. The zymogen granules were identified as homogenously electron dense round bodies of approximately 300 nm in diameter, the same as were seen in fresh frozen dried sections. Energy dispersive X-ray microanalysis of zymogen granules and spots 200 nm distant from the granules used as controls disclosed peaks for chlorine, potassium and sulfur in all of five granules examined and in three of them, phosphorus was found in addition to the above elements. The results seem to suggest that pancreatic juice may be contributed from the electrolyte content of secretory granules in contrast to the general assumption that enzymes and electrolytes are separately excreted in pancreatic juice.

Animals↗