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T Komuro

Publications and source records attributed to T Komuro.

At least 109 records · Page 6Linked to original sources
PubMed1986

Three-dimensional visualization of the intraganglionic structures of the rat myenteric plexus: scanning electron microscopy with the connective tissue digestion method.

The rat myenteric plexus was chemically microdissected and the internal structures of the ganglia were demonstrated under a scanning electron microscope. The present preparation offers a view of the three-dimensional features of ganglion cells and permits their surface structures and the size and pattern of varicosities to be observed. Numerous finger-like processes were observed on the cell bodies of the studded neurons in close relationship with the varicose axons. The intramuscular branches of the plexus were also microdissected and their running pattern was observed.

Animals↗
PubMed1986

[Effect of combination immunochemotherapy with an organogermanium compound, Ge-132, and antitumor agents on C57BL/6 mice bearing Lewis lung carcinoma (3LL)].

The antitumor effect of combination immunochemotherapy with Ge-132 and antitumor agent was studied using C57BL/6 mice bearing Lewis lung carcinoma (3LL). Ge-132 was administered orally at a daily dose of 100 mg/kg. Antitumor agents were administered intraperitoneally once a week. Initially, the effect of combination immunochemotherapy with Ge-132 and 5-fluorouracil (5-FU) was studied on 3LL local tumor growth, pulmonary metastases, survival, delayed type hypersensitivity (DTH) and body weight in tumor-bearing mice, and the following results were obtained: Inhibition of tumor growth in the combined group; Enhanced anti-metastatic effect; Prolonged survival time, and; Recovery of loss of both DTH and body weight as a result of combination therapy. These antitumor effects were also obtained by adoptive transfer of Ge-132-stimulated splenocytes in 5-FU-treated mice bearing 3LL. These results therefore suggest that the effects of Ge-132 were expressed through modification of immunocytes. Furthermore, Ge-132 enhanced the antitumor activity of bleomycin as well as that of 5-FU. These facts suggested that Ge-132 is useful for antitumor combination immunochemotherapy.

Animals↗
PubMed1986

Inhibitory effects of Ge-132 (carboxyethyl germanium sesquioxide) derivatives on enkephalin-degrading enzymes.

Twenty-eight species of carboxyethyl germanium sesquioxide (Ge-132) derivatives were examined for their inhibitory effects on enkephalin-degrading enzymes that were purified from monkey brain, the longitudinal muscle layer of bovine small intestine, and human cerebrospinal fluid (CSF). A series of the sulfurized Ge-132 derivatives showed strong inhibition of these purified enzymes. The most effective ones were Ge-014 and Ge-107, which showed IC50 values of 60 and 100 micrograms/ml, respectively, for dipeptidylcarboxypeptidase from the longitudinal muscle layer. They also exhibited inhibitory activity against aminopeptidase from human CSF, the IC50 values being 450 and 440 micrograms/ml, respectively. Furthermore, these compounds showed inhibition of dipeptidylaminopeptidase from monkey brain and the longitudinal muscle layer of bovine small intestine. These compounds are expected to have analgesic effects due to their inhibition of the degradation of endogenous opioid peptides.

Aminopeptidases↗
PubMed1985

Fenestrations of the basal lamina of intestinal villi of the rat. Scanning and transmission electron microscopy.

Fenestrations of the basal lamina of rat intestinal villi were revealed by scanning electron microscopy after removal of the overlying epithelial cells by osmic acid maceration. These fenestrations are circular to oval in shape and are 0.5 micron to 5 microns in diameter. They are richly distributed at a density of 1-2 X 10(4)/mm2 in the upper two thirds of the villi, except at the very tips. Roughly 500 fenestrations are found on each side of an average sized tongue-shaped villus. Transmission electron-microscopic observations showed that these fenestrations were passages for migrating cells of the immune system such as lymphocytes, eosinophils and macrophages. Protrusions from the basal parts of epithelial cells were also observed passing through these fenestrations. These findings are discussed with respect to their immunological implications and to the passage of nutrients.

Animals↗
PubMed1985

Partial purification of two distinct enkephalin-degrading aminopeptidases from human cerebrospinal fluid.

In human cerebrospinal fluid, aminopeptidase, dipeptidyl aminopeptidase, dipeptidyl carboxypeptidase, and carboxypeptidase which were capable of hydrolyzing enkephalins were detected. Among these enzymes, two distinct aminopeptidase, designated C-AP1 and C-AP2, were partially purified. These enzymes were not purified thoroughly, but the characteristics of C-AP2 were similar to those of an aminopeptidase purified from monkey brain. But the inhibitory activity of amastatin on C-AP2 was stronger, and that of substance P was negligible. On the other hand, characteristics of C-Ap1 were extremely differ from those of C-AP2 or an aminopeptidase purified from monkey brain. C-AP1 had an optimum pH more in the acidic range (the highest at pH 6.0) and was not inhibited by any of the protease inhibitor tested including bestatin and amastatin.

Aminopeptidases↗
PubMed1984

A cellular reticulum of fibroblast-like cells in the rat intestine: scanning and transmission electron microscopy.

Fibroblast-like cells of the rat intestinal villi were studied by scanning and transmission electron microscopy. They were observed to be flattened and stellate in shape and had many slender processes. By means of intercellular attachments, the cells formed a network covering the microvascular tree of the villous core. Their cytoplasmic features essentially resembled those of fibroblasts. It is suggested that this three-dimensional network of fibroblast-like cells might act as a skeleton for the villi and also influence the efficiency of absorption and transportation of nutrients by its contraction.

Animals↗
PubMed1984

[Pharmacokinetics of human interferons].

Interferon in the blood was rapidly cleared from the circulation after intravenous injection. Intramuscular injection of alpha-interferon caused low but stable interferon levels in the blood. However, in the case of beta-interferon, interferon was never detected consistently in the blood after intramuscular or subcutaneous administration. Intraarterial administration of beta-interferon also caused low but stable interferon levels in the blood. Our studies suggest that beta-interferon should be given intravenously to see clinical beneficial. No difference in pharmacokinetics was seen between natural interferon and recombinant interferon. No difference was also noted between partially purified interferon and highly purified interferon.

Animals↗
PubMed1982

Three-dimensional organization of smooth muscle cells in blood vessels of laboratory rodents.

Three-dimensional aspects of smooth muscle cells of the microvasculature were studied ultrastructurally in laboratory rodents by means of serial thin sections and reconstruction of muscle cell models. It was demonstrated that a muscle cell of an arteriole (luminal diameter (LD) 17 microns) in hamster striated muscle was spindle-shaped, 70 microns long, and wound twice round the vessel axis. The volume of the cell was calculated as 750 microns3 and its surface area as 1330 microns2. A muscle cell in an arteriole (LD 6 microns) in the rat retina was irregular in shape, about 22 microns long, and had branched processes. The cell volume was calculated as 139 microns3 and its surface area as 298 microns2.

Animals↗
PubMed1982

The interstitial cells in the colon of the rabbit. Scanning and transmission electron microscopy.

The interstitial cells associated with the myenteric plexus of the rabbit colon were studied by scanning and transmission electron microscopy. It was demonstrated that the interstitial cells were stellate or fusiform in shape and located over the ganglia, over nerve bundles and between muscle cells. They were characterized by many slender processes, and resemble fibroblasts. No basal lamina was observed between the interstitial cells and muscle cells. It was concluded that structural features of the interstitial cells are distinctly different from those of neurons, Schwann cells, or of smooth muscle cells, while they show clear similarities to those of fibroblasts. By scanning electron microscopy the shapes and the relations of these cells could be demonstrated in great detail.

Animals↗
PubMed1982

An ultrastructural study of neurons and non-neuronal cells in the myenteric plexus of the rabbit colon.

The myenteric plexus of the rabbit colon showed a degree of structural organization that was unusually high for the peripheral nervous system, providing a basis for the complex integrative activity which is known to occur. It resembled central nervous tissue in several respects: a wide range of neuron types was present; the proportion of glial cells to neurons was about 2:1; and there was a densely packed, avascular neuropil, not penetrated by connective tissue. Most neurons had at least one surface exposed to the extraganglionic space. Clear evidence was obtained for spontaneous neuronal degeneration. Three types of non-neuronal (glial) cells were observed: Type 1, which was most common, contained many 10 nm 'gliofilaments' and resembled enteric glial cells or astrocytes in the central nervous system; Type 2, composing about 5% of the glial cells, had few filaments; Type 3 was seen only rarely, had a small dark nucleus, little cytoplasm, may have been of extraganglionic origin and resembled microglia of the central nervous system. Fibroblast-like cells were also present in extraganglionic sites. Schwann cells could not be identified within the myenteric ganglia.

Animals↗
PubMed1982

An ultrastructural study of nerve profiles in the myenteric plexus of the rabbit colon.

The ultrastructure of the myenteric plexus from the rabbit colon was examined in both conventionally fixed tissue and also material fixed with the chromaffin method. Montages of the ganglia were analysed semi-quantitatively. Six main types of axon profile are described and classified on a morphological consideration of the vesicle population. Most axon types formed synapses with myenteric neurons. Two kinds of chromaffin-positive nerve fibre were seen, one containing a predominance of small granular vesicles, the other containing many flattened vesicles. The difficulties in relating axon profile types to putative transmitters are discussed.

Animals↗
PubMed1981

Fine structural study of the abdominal muscle receptor organs of the crayfish (Procambarus clarkii). Sensory endings and synaptic structures.

The sensory endings, neuromuscular junctions and interneuronal synapses in the crayfish muscle receptor organ have been studied by electron microscopy. The dendrites of the receptor neuron terminate as endings which are either free in the connective tissue matrix of the central region of the receptor strands, or abut on the muscle membrane forming a specialized junction with a narrow cleft of about 18 nm. Efferent nerve endings are classified into three types on the basis of their fine structural features. Type 1 endings contain mainly spherical vesicles with a diameter of about 55 nm and a few large granular vesicles with a diameter of about 100 nm, and synapse exclusively on muscle fibres. Type 2 endings have a high proportion of elongated vesicles measuring about 30 X 80 nm and a few large granular vesicles, and synapse on both sensory neurons and muscle. Type 3 endings are characterized by the high electron density of the axoplasm and numerous large granular vesicles with a diameter of about 100 nm; they synapse only on the sensory neuron of the slow receptor unit. It is suggested that Type 1 endings are excitatory, and Type 2 and 3 endings are inhibitory. Several differences in postsynaptic structure were observed between the putative excitatory and inhibitory neuromuscular junctions. Axo-axonal synapses between endings of Type 1 and Type 2, the latter being presynaptic to the former, are also found. Functional implications and possible roles of these structures are discussed.

Abdomen↗
PubMed1981

Fine structural study of the abdominal muscle receptor organs of the crayfish (Procambarus clarkii). Fast and slow receptor muscles.

Receptor muscles of the abdominal muscle receptor organs of the crayfish, Procambarus clarkii, were examined by electron microscopy. Both the fast and the slow receptor strand comprises a single muscle fibre which is divided by invagination of the cell membrane into numerous cytoplasmic processes in its intermediate region (the so-called intercalated tendon). Most of these myofibrillar processes insert in this region, but some of them pass through the intermediate region without interruption and join the other portion of the fibre. Thus the receptor muscles, whilst maintaining cytoplasmic continuity throughout their whole length, are modified in their intermediate regions, becoming fasciculated and providing spaces which are occupied by the connective tissue and the dendrites of the sensory neurone. Clear-cut differences in fine structure are shown between the muscle of the two types of receptor unit. The fast receptor muscle shows the typical features of arthropod fast muscles, including short sarcomere length (on average 3.3 micron), cylindrical myofibrils, well-developed sarcoplasmic reticulum, and regular hexagonal array of the myofilaments. By contrast, the slow receptor muscle fibre is characterized by long sarcomeres (average 6.5 micron) and unique organization of the myofilaments, with very thick 'thick' filaments having diameters in the range of 25-36 nm surrounded by about 12 thin filaments.

Animals↗