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Biomedical subjects

T Chiba

Publications and source records attributed to T Chiba.

At least 703 records · Page 39Linked to original sources
PubMed1977

Histopathological studies on the prognosis of biliary atresia.

Liver specimens from 68 cases of biliary atresia were histologically studied in reference to postoperative prognosis. The histological findings were classified into 4 to 5 groups by the degree of fibrosis, bile duct proliferation, bile plugs, giant cell transformation, and intralobular cholestasis. Furthermore, morphometrical studies of interstitial area, bile duct (ductules), intrahepatic portal vein, and intrahepatic artery were done and correlated with the age of patients and with operative results. From this study, it was shown that 1) marked fibrosis (cirrhosis) and interstitial areas occupying more than 35% of the sectional area of the liver specimen, 2) severe ductular proliferation, shown by proliferated bile ducts occupying more than 20% of interstitial areas, 3) no or slight intralobular cholestasis and 4) marked interlobular cholestasis are considered to predict poor postoperative bile excretion.

Age Factors↗
PubMed1977

Measurement of digital arterial blood pressure and its recording on usual electrocardiograph paper.

A simple method for measuring digital arterial pressure and its recording on usual EKG heat-writing paper was devised. The method enabled us to measure exactly the digital systolic as well as diastolic blood pressure without providing the calibrating scale of pressure, since the pressure scale is recorded on the paper automatically as pulse signals at the interval of 10mmHg. The pulse waves are also registered on the same paper by means of the finger plethysmograph. By use of a right-angled triangle transparent rule, we could estimate the value of digital systolic pressure at which the pulse wave began to appear when the cuff pressure for compressing the artery was gradually lowered. Estimated values of the digital arterial pressures were compared with those obtained by another method of Mendlowitz and his coworkers.

Adult↗
PubMed1977

Monoamine-containing paraneurons in the sympathetic ganglia of mammals.

1. A combined method for glyoxylic acid induced catecholamine fluorescence and electron microscopy was introduced in this study of the small intensely fluorescent (SIF) or granule-containing (GC) cells of the sympathetic ganglia. 2. Adrenergic interneurons were demonstrated in the sympathetic ganglia of the rat and the rhesus monkey. 3. Existence of adrenergic paraneurons (neuro-endocrine cells) in the sympathetic ganglia of several mammalian species was suggesed by the following observations: a) catecholamines are contained in the granular vesicles of SIF cells; b) SIF cells are innervated by preganglionic cholinergic nerves and are often in close relation with fenestrated capillaries; c) SIF cells develop from the neuroblast which originated from the neural crest, and ; d) substantial surface areas of GC cells are covered by basal lamina alone. Figures indicating exocytosis of granular vesicles were often seen here. 4. There are remarkable species differences in quantity and quality of SIF cells and great discrepancies among the physiological, biochemical and the morphological observations on SIF cells.

Adrenergic Fibers↗
PubMed1976

A method for studying glyoxylic acid induced fluorescence and ultrastructure of monoamine neurons.

Inasmuch as precise correlations of light- and electronmicroscopy are crucial for understanding biostructure, it seemed necessary to bring together the advantages of the glyoxylic acid (GA) method (for inducing monoamine fluorescence) and electron microscopy. A combined fluorescence and electron microscope method using GA is introduced. The brain is perfused by 2% GA in Krebs-Ringer bicarbonate buffer (pH 7.0) and this solution is followed by 4% paraformaldehyde containing 0.5% glutaraldehyde in Sorensen's phosphate buffer (pH 7.4). Sections are cut by cryostat or by vitratome and incubated in 2% GA in phosphate buffer (pH 7.0). Using fluorescence microscopy, features of interest are sketched and/or photographed. Afterwards, the same or subsequent section is processed for electron microscopy. Since axons of catecholamine-containing neurons (as well as their perikarya and terminals) are visualized by GA, the recommended procedure expands the range of studies concerning monoamine neurons that can now be carried out effectively.

Animals↗
PubMed1976

Catecholaminergic axo-axonic synapses in the nucleus of the tractus solitarius (pars commissuralis) of the cat: possible relation to presynaptic regulation of baroreceptor reflexes.

A study was performed on adult cats to investigate synaptic structures of nerve terminals in the commissural portion of the nucleus of the tractus solitarius (NTS); a site where the cardiovascular afferent fibers terminate and where a dense plexus of adrenergic element also resides. Synaptic contacts observed in the commissural portion were predominantly axo-dendritic but a smaller number of axo-somatic synapses were also recognized. A third type of junction, axo-axonic, appears to be unique to the commissural portion of the nucleus, since no axo-axonic contacts were encountered in the medial and ventrolateral portions of the NTS. By labeling with the 'false' neurotransmitter 5-hydroxydopamine (5-OHDA), three types of axo-axonic contacts with different presynaptic components could be identified; namely, axon varicosities with small clear spherical vesicles, axon varicosities containing flat synaptic vesicles and others with small cord vesicles labeled with 5-OHDA. Postsynaptic components were always axon varicosities with clear spherical vesicles. After surgical denervation of the IXth and Xth cranial nerves, no degenerated axon varicosities were observed in the presynaptic side in the axo-axonic contact. The present study clearly demonstrates that the commissural portion of the NTS contains axo-axonic synapses and some of the adrenergic axons in this area provide the presynaptic components for this type of synapse. Possible roles of adrenergic nerves to presynaptic regulation of baroreceptor reflexes are discussed.

Animals↗
PubMed1976

Histopathological studies on intrahepatic bile ducts in the vicinity of porta hepatis in biliary atresia.

Intrahepatic bile ducts in the vicinity of the porta hepatis were histologically investigated in 9 cases of biliary atresia and the pattern of bile duct was divided into two groups. In the first group, there were a few large bile ducts which had continuity to the extrahepatic bile duct. In the second group, many small bile ducts were histologically observed, but there was no large bile duct at the porta hepatis. This type of abnormal bile ducts was seen in the cases of obliteration of bile ducts at porta hepatis.

Bile Ducts↗
PubMed1975

Histofluorescence characteristics and quantification of small intensely fluorescent (SIF) cells in sympathetic ganglia of several species.

Small intensily fluorescent (SIF) cells in the superior cervical ganglion of the cow, cat, rabbit, rat, guinea pig and monkey were studied, using the glyoxylic acid monoamine fluorescence method. SIF cell populations per mg ganglion tissue showed great species variation. The greatest numbers of SIF cells per mg were found in the rat (380+/-30 per mg). Intermediate numbers (76+/-20 per mg) were found in the guinea pig; and SIF cells in other species were much more sparsely distributed (less than 10 per mg). Two types of SIF cell were identified. Type I cells have long (up to 200 mu) processes which ramify among the principal ganglionic neurons, and this type often occurs singly; whereas type II cells tend to occur in clusters near blood vessels in the interstitial or subcapsular regions of the ganglion. As a general hypothesis we propose that type I SIF cells are interneurons whereas type II SIF cells operate through a neurosecretory mechanism.

Animals↗