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Biomedical subjects

T Futami

Publications and source records attributed to T Futami.

At least 91 records · Page 5Linked to original sources
PubMed1984

[Actions and mechanisms of counterirritants on the muscular circulation].

Studies were conducted on the direct actions of counterirritants on the peripheral circulation and the reflex actions on muscular circulation that would refer to the skin nerve excitation activated with counterirritants . Blood pressure falling tendencies were observed with menthol, thymol, and methyl salicylate (MS) without any effects on respiration, heart rates, and blood flow in femoral artery and gastrochemius muscle. Vasodilatation was caused by the direct application of menthol, camphor, and MS in the isolated ear vessels of rabbits, but none of the counterirritants had effects when they were externally applied on the skin of the ear in plaster form. An increase (circa 40%) in gastrocnemius muscle blood flow was induced by the external application of plasters which contained menthol, camphor, or nonylic vanilyl amide ( NVA ) on the skin of rabbit's hind limb. A slight augmentation was also observed after the application of plasters with MS and without drugs, but these effects disappeared after the hemisection electrical stimulation on the sural nerve of rabbits disappeared almost completely after the pretreatment with propranolol (40 micrograms/kg, i.v.), but atropine (1 mg/kg, i.v.) had no effect. A rise of blood flow in the deep radial muscle elicited by electrical stimulation on the superficial radial nerve remained after the spinal transection at the C 3 level, and at this time, the A beta and A delta components were involved in the superficial radial nerve. These results suggest that when plasters containing counterirritants were externally applied on the skin, direct actions of percutaneously absorbed drugs on peripheral circulation are not expected, but a rise of muscle blood flow is thought to be induced by the spinal somato sympathetic reflex that will cause a suppression on tonic activity in the sympathetic vasoconstrictor nerve or a stimulation on beta-adrenoceptors referred to adrenaline released from the adrenal gland.

Animals↗
PubMed1984

[Excitable actions of counterirritants on cutaneous sensation].

Studies were conducted on the actions of counterirritants on sensory receptors in the skin and spinal monosynaptic reflex. Nerve discharges in the cat's saphenous nerve were promoted by the external application of menthol and nonylic vanillyl amide ( NVA ) dissolved in ethanol on the receptive field. When plasters containing counterirritants were externally applied on the receptive field, marked activation was recognized in touch-pressure-pin prick fibers immediately after the application as seen with plaster without drugs, but significantly high activity was maintained thereafter, and the increased firing rate in touch-pressure-pin prick-cold fibers lasted for 60 min. The activity of pressure-pin prick fibers was increased with the lapse of time and warm fibers was not influenced. Effects on activities of spinal dorsal horn cells were almost similar to the changes in activities of primary afferent from the skin. Monosynaptic reflex elicited by stimulation on the medial gastrocnemius nerve was weekly inhibited (significantly different from control at P less than 0.05), by the external application of plasters, and motoneuron receiving IPSP from the skin lightly touched on was observed. These findings suggest that the receptors activated with counterirritants were thought to be as follows: A delta and C polymodal nociceptors, A delta and C cold nociceptors, and slow adapting cutaneous mechanoreceptors. The cutaneous mechanoreceptors were also activated by the application of plasters. The volley from sensory nerve excited with counterirritants was thought to cause a suppression on the spinal monosynaptic reflex resulting from an inhibition on the motoneuron.

Administration, Topical↗
PubMed1982

Convergent inputs from the dentate and the interpositus nuclei to pyramidal tract neurons in the motor cortex.

Effects of stimulation of the cerebellar nuclei were investigated by intracellular recordings from fast and slow pyramidal tract neurons and thalamocortical neurons in the cat. The present study demonstrated that: (1) the interpositus and the dentate nuclei excite PTNs in the motor cortex; (2) single pyramidal tract neurons receive convergent inputs from both nuclei, and (3) the convergence of the inputs from both nuclei occurs at the level of the ventrolateral nucleus of the thalamus.

Animals↗
PubMed1981

Divergent projection of individual corticospinal axons to motoneurons of multiple muscles in the monkey.

Intracellular staining with horseradish peroxidase (HRP) of physiologically identified corticospinal (CS) axons originating from the monkey motor cortex revealed the intraspinal morphology of their branching patterns. CS collaterals spread in a delta-like fashion in the intermediate zone and lamina IX. Virtually all CS axons examined terminated in lamina IX, and it was shown by labeling motoneurons with retrograde transport of HRP that individual CS axons made direct contacts with dendrites of motoneurons of different muscle species.

Animals↗
PubMed1980

Glycans and glycoproteins in 0.05M LaCl3-soluble fraction from bovine costal cartilage.

The supernatant fraction (Fr. S) obtained by ten-fold dilution of the 0.5 M LaCl3-extract of bovine costal cartilage was fractionated by DEAE-Sephadex A-25 column chromatography, followed by gel filtration on Sepharose 4B. The resulting five subfractions were characterized by electrophoresis on cellulose acetate membranes before and after digestion with pronase, alpha-amylase, and chondroitinase AC, together with analytical data. The results showed that Fr. S contained a large quantity of glycogen (Fr. 1), three sialoglycoproteins (Frs. 2, 3 and 4-1), hyaluronic acid (Fr. 4-1), a small molecular size proteoglycan consisting of chondroitin sulfates and keratan sulfate (Fr. 4-2), and small quantities of collagen-like protein. The components in the corresponding subfractions of Fr. S from non-calcified (NCC) and calcified (CC) portions of the costal cartilage were similar. It is indicated that consumption of glycogen is remarkable on calcification.

Animals↗
PubMed1979

Comparison of carbohydrate-containing substances from non-calcified and calcified portions of bovine costal cartilage.

Carbohydrate-containing substances were extracted from non-calcified (NCC) and calcified (CC) portions of bovine costal cartilage with 0.5 M LaCl3 by the method of Mason and his co-workers, followed by dilution of the extract with 9 volumes of water. The precipitate formed on dilution yielded Fr. P, while Fr. S was obtained from the supernatant. Fr. P was separated into two subfractions by gel filtration on Sepharose 2B. The experimental results showed that Fr. P contained proteoglycans with different molecular sizes and compositions, while Fr. S contained proteoglycan, hyaluronic acid, glycoproteins, and glycogen. The present data suggest that in the proteoglycan of Fr. P, the relative content of chondroitin sulfate decreases with a concomitant increment in that of keratan sulfate on calcification. In addition, elevation of the ratio of chondroitin 4-sulfate to chondroitin 6-sulfate, together with a small increment of non-sulfated disaccharide units in the chondroitin sulfate chains appear to occur on calcification. The glycogen content in Fr. S diminished on calcification. The present observations suggest therefore that the remodeling of proteoglycan consumption of glycogen in bovine costal cartilage occur on calcification.

Animals↗
PubMed1977

Metabolic changes with inflammation induced by a surfactant.

Studies were carried out to determine the relationship between metabolic histopathological changes in the gastrocnemius muscle of rats in which an acute exudative inflammation had been induced by alkyldimethylbenzylammonium chloride (alkyl-DBAC, a cationic surfactant). Succinate respiration, Na+-K+-Mg2+ ATPase activity and ATP, ADP and AMP levels were determined as the index of metabolic changes. Myofascial edematous swelling with the acceleration of succinate oxidation and Na+-K+-Mg2+ ATPase activity was noted at 30 minutes in the inflamed muscle. The ATP level was also transiently reduced. On the other hand, Na+-K+-Mg2+ ATPase activity and succinate oxidation were inhibited by alkyl-DBAC, at this concentration, in vitro. These results support the possibility that enhancement of energy metabolism is not directly initiated by alkyl-DBAC but may be the result of certain chemical mediators released by alkyl-DBAC. The enhancement of energy metabolism continued after 1 hour and this energy may initiate leukocyte migration as well as increase vascular permeability and edema.

Acute Disease↗
PubMed1977

Possible involvement of cyclic AMP in inflammation induced by a surfactant.

Alkyldimethylbenzylammonium chloride (alkyl-DBAC), a cationic surfactant, produces acute exudative inflammation accompanied by an enhancement of energy metabolism. The mechanism of metabolic changes, consequently the cyclic AMP level and the effects of certain drugs were determined in the gastrocnemius muscles of rats in which acute exudative inflammation had been induced by intramuscular injections of alkyl-DBAC. A transient increase in the cyclic AMP level was noted at 15 to 30 minutes after the injection of alkyl-DBAC, and this elevation was antagonized by chlorpromazine, diphenhydramine, promethazine, aspirin and indomethacin. The time course of increasing tendency in the cyclic AMP level after the injection of histamine closely paralleled that of alkyl-DBAC. These results suggest that cyclic AMP may be involved in the metabolic changes with inflammation induced by alkyl-DBAC.

Animals↗
PubMedDate not supplied

Morphology of single neurones in the cerebello-rubrospinal system.

Axonal branching patterns of physiologically identified cerebellar nucleus neurones and rubrospinal neurones were investigated in the cat with intra-axonal injection of horseradish peroxidase and 3-dimensional reconstruction on serial sections. Axons of dentate and interpositus neurones projected to the VL nucleus of the thalamus and on their way, several axon collaterals were given off from the stem axons to the red nucleus. Axon terminals of interpositus neurones terminated as a sagittal sheet of arborizations in the red nucleus. Their terminal boutons made apparent contact with cell bodies and proximal dendrites of rubrospinal neurones. In rubrospinal axons, multiple axon collaterals were identified at different segments of the cervical spinal cord.

Animals↗
PubMedDate not supplied

Percutaneous reduction of displaced radial neck fractures.

Twenty patients with acute, displaced, radial neck fractures were treated by percutaneous reduction with a periosteal elevator. In all cases acceptable radiographic reduction was achieved, and the reduction position was maintained on serial x-ray examinations with a mean observation period of 3 years. Clinical results were satisfactory in all but one case with slightly limited elbow extension.

Adult↗
PubMedDate not supplied

Thalamocortical organization in the cerebello-thalamo-cortical system.

In the cat, the cerebellum projects via the ventroanterior-ventrolateral (VA-VL) complex of the thalamus to the motor and premotor cortices and also to the parietal association cortex. Cerebellar inputs to each of these regions have been characterized electrophysiologically by depth profiles of cortical potentials following stimulation of the brachium conjunctivum and of the VA-VL complex, and morphologically by the laminar distribution of thalamocortical (TC) terminations, in aggregate and at the single-axon level. One population of TC neurons terminated mainly in layer I and was associated with late surface negative potentials. A second population, with terminations in layers III and IV, was associated with early deep negative potentials. Terminations in layer III of the motor cortex formed multiple patches about 1-1.5 mm wide (mediolateral), which aligned to form 2-5 mm stripes extended rostrocaudally. This pattern correlates with the configuration of individual TC axons, which have two to six separate terminal patches distributed over 6 mm (rostrocaudal). The wide morphological divergence of single TC axons in the cortex may imply functionally multiple innervation of different efferent columns. Alternately, along with other inputs, it may permit a highly dynamic output selection from multiple representations, for example, of a variety of muscle groups in different combinations.

Animals↗
PubMedDate not supplied

Dislocation and subluxation during femoral lengthening.

Femoral lengthening by callus distraction was performed on 26 femurs of 18 patients with various disorders between 1988 and 1992. Age at surgery ranged from 6 to 17 years (13 years on average). The amount of lengthening varied from 2 to 7.5 cm (mean 5 cm). Follow-up evaluation of femoral-head displacement was based on the change of center-edge (CE) angle. The hips were divided into two groups based on the preoperative CE angle; one group consisted of 14 hips with a CE angle > 20 degrees and the other group consisted of 12 hips with an angle of < or = 20 degrees. In the first group, none of the hips deteriorated; however, five of 12 hips in the second group did deteriorate. One hip developed complete dislocation and the other four showed a decrease in the CE angle. Four of five deteriorated hips had a history of congenital dislocation of the hip and the other had multiple epiphyseal dysplasia. In cases in which the CE angle is < or = 20 degrees preoperatively, bony procedures such as innominate osteotomy should precede femoral elongation.

Adolescent↗