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Biomedical subjects

T Yajima

Publications and source records attributed to T Yajima.

At least 163 records · Page 9Linked to original sources
PubMed1990

[A case report of redo A-C bypass for MCLS performed 13 years after initial surgery].

This is the first report of re-aortocoronary bypass for Kawasaki's disease. The patient is a 22-year old female. She was afflicted with Kawasaki's disease at the age of 6 and had the symptom of angina pectoris at the age of 9. She went through the first aortocoronary bypass, to the left anterior descending artery (LAD) and the right coronary artery (RCA) with saphenous vein graft (SVG). After the first operation, the graft to LAD occluded totally, but she remained asymptomatic and well for 11 years. She had a sudden recurrence of anginal attack at the age of 20. The examinations confirmed ischemia of the anterior wall (LAD area) and the lateral wall (LCX area). Coronary angiography revealed patent SVG with a moderate sign of sclerotic change. We decided on re-aortocoronary bypass, left mammary artery to LAD and gastroepiploic artery to LCX, when she was 22-years old. LIMA was anastomosed to LAD, but LCX was not revascularized, because LCX was not identified and exposed in the operation. In spite of incomplete revascularization, postoperative stress ECG test was negative. Tl-myocardial scintigram confirmed no ischemia of the anterior wall and greatly reduced ischemia in the lateral wall. She became asymptomatic and returned to normal life.

Adult↗
PubMed1990

[The effect of chemical ablation with lugol solution for ventricular tachyarrhythmia on cardiac function].

Among various methods to treat ventricular tachyarrhythmia (VT) in the presence of acute myocardial infraction, the surgical approach is a somewhat unsatisfactory method in case of preoperative acute hemodynamic deterioration. The transatrial approach with the "topical" application of Lugol solution on left ventricular (LV) endocardium, without left ventriculotomy, i.e. a transatrial chemical ablation method; has been reported in our department as suggestive to being efficacious. The objective of the present study is to investigate the occurrence of left bundle branch block (LBBB) and the like, as well as to examine the impact on heart function, particularly LV function, by employing the just-above mentioned approach. 15 mongrel dogs were being experimented on. Through a left transatrial approach toward LV endocardium and the application of Lugol solution, with pulmonary artery flow being as constant; we measured pre- and post-operative left atrial (LA) pressure, LV pressure, aortic pressure, LV functional shortening, and stroke volume. In addition, the same protocol was also employed in another group, with the application of physiologic normal saline solution, instead. A comparative study was made between the two groups. In the Lugol solution group, postoperative LA pressure and LVEDP showed a tendency toward exhibiting higher values, when compared to preoperative readings. However, no significant difference was observed in this setting. Furthermore, in comparison with postoperative readings in the saline group, the mean LA pressure in the Lugol solution group exhibited a tendency toward somewhat higher values. Nonetheless, no significant difference was observed in LV functional shortening between the two groups; though it is known a LBB pattern could be noticed on ECG in the Lugol solution group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effects of butyric acid and analogues on amylase release from pancreatic segments of sheep and goats.

The specificity of the structural elements of a short-chain fatty acid for stimulating amylase release was investigated in superfused pancreatic segments of sheep and goats in vitro using butyric acid and analogues. Monocarboxylic (cyclohexanecarboxylic and benzoic) acids were as effective as butyric acid, whilst 4-phenyl-n-butyric and dicarboxylic (succinic and phthalic) acids were weak stimulants. The amylase release evoked by butyric acid was markedly reduced in the presence of these compounds. Replacement of hydrogens by a hydroxyl group or amino group or reduction of the carboxyl group to alcohol diminished, while replacement of hydrogen by chloride at the 3 carbon position did not change, the ability to stimulate amylase release. The dose-response curve for butyric acid was shifted to the right in parallel in the solution containing succinic acid at 8 x 10(-4) mol/l. The maximal increment (but not ED50) of amylase release evoked by ACh was severely reduced in the solution simultaneously containing butyric acid at 10(-3) mol/l. These results suggest that short-chain fatty acids are required to possess both carboxyl (hydrophilic) group and hydrophobic tails in order to have the ability to stimulate amylase release, and that amylase release evoked by butyrate is caused through specific recognizing sites for short-chain fatty acids which might be different from ACh receptors, in the pancreatic segments of sheep and goats.

Acetylcholine↗
PubMed1989

Chemical specificity of short-chain fatty acid-induced electrogenic secretory response in the rat colonic mucosa.

1. Luminal additions of normal short-chain fatty acids (SCFA: 3-6 carbons) increased transmural potential difference (PD: lumen negative) across rat everted colon in a dose-dependent manner. 2. The PD response to SCFA adapted rapidly and was not evoked by further cumulative addition of the same acid (self-adaptation) or different acids (cross-adaptation). 3. A broad range of SCFA derivatives were tested as potential stimulators of the PD response and cross-adaptation with propionate: a single carboxyl group and 3-6 carbon-chain were an absolute requirement for recognition. 4. These results suggest that SCFA-reception mechanism of the rat colonic mucosa has some sort of chemical specificity for stimulating electrogenic secretory response.

Amino Acids↗
PubMed1989

Collagen phagocytosis by cementoblasts at the periodontal ligament-cementum interface.

The periodontal ligament-cementum interface of rat first molars was investigated by electron microscopy. Evidence supporting cementoblast phagocytosis of collagen fibrils of the periodontal ligament was found. In addition, collagen-containing vacuoles were frequently observed within cementoblasts in association with an acid phosphatase activity. The presence of acid phosphatase activity in these vacuoles suggested that intracellular degradation of collagen was occurring. Our results showed that cementoblasts exhibited collagen phagocytic activity and suggest that cementoblasts may play an important role in the physiological remodeling and metabolic breakdown of the collagen at the periodontal ligament-cementum interface.

Animals↗
PubMed1989

[Aging and tongue skill. Ultrasound (motion-mode) evaluation].

In order to investigate tongue skill, upward and downward tongue movements with two constant frequencies were observed by using an ultrasound system in young and elderly adults. Upward and downward movements in accordance with a metronome were recorded by ultrasound recorder from the Motion-mode. Movement rhythm and movement velocity of the tongue were compared in the two age groups. The main findings were: 1. The ultrasound system with 5 MHz ultrasound convex transducer and Motion-mode observation produced clear traces of the tongue surfaces in the sagital plane during upward and downward movements. 2. Upward and downward movement rhythms in the elderly were more irregular than those of young adults. 3. Velocity of tongue upward and downward movements were statistically decreased in the elderly (p less than 0.01). Velocity did not clearly change if the movement speed was different in the elderly. Results of this study revealed that oral motor behaviour in the elderly differed from that of young adults.

Adult↗
PubMed1989

[Connective tissue attachment to root surfaces in periodontal disease. Initial attachment of human gingival fibroblasts].

We studied the effect of periodontal treatment (scaling, SC; root planning, RP; scaling followed by citric acid, SC + CA; and root planing followed by citric acid, RP + CA) of periodontally diseased root surfaces on the initial attachment of human gingival fibroblasts in vitro. Root slices were prepared from surgically extracted human normal and periodontally involved teeth. Each treated root slice was placed in a well of a 24-well plate containing a PBS-antibiotic solution (penicillin, 200 units/ml; streptomycin, 200 micrograms/ml) for 1 hr. at 4 degrees C. Then, to each well was added 1 x 10(4) cells in 1 ml of alpha-MEM, and the plates were incubated for 24 hr. After the root slices were fixed and stained, the morphological changes and the numbers of attached cells were determined under a dissecting microscope. The fibroblasts on the controls (untreated normal roots) and the RP-roots appeared spindle-shaped with a few cell processes. The cells on the SC-roots were rounded or slightly elongated. The cells on the roots treated with citric acid (SC + CA and RP + CA) had were flat and seemed well attached to the surface. The number of cells attached on RP- and RP + CA-roots was increased to the control level, but those on SC- and SC + CA-roots were showed about 60% of the control. No significant differences in the numbers of cells were found between RP and RP + CA treatment or between SC and SC + CA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMed1989

[Effects of hemodialysis on left ventricular performance: a Doppler echocardiographic study].

Left ventricular systolic and diastolic performance was examined using Doppler and M-mode echocardiography in 42 patients with chronic renal failure before and after hemodialysis. Twenty patients with left ventricular hypertrophy, 22 without hypertrophy and 30 normal subjects were studied. Chronic renal failure patients showed significantly larger chamber diameters of the left ventricle, left atrium and right ventricle than did normal subjects. This group also exhibited greater fractional shortening, stroke volume and cardiac output. Before hemodialysis, patients with left ventricular hypertrophy had a significantly higher cardiac output and the greater ratio of late to early diastolic peak flow velocities (A/R) than did patients without hypertrophy. After hemodialysis, there were significant reductions in blood pressure, ventricular and atrial dimensions, stroke volume and cardiac output. The velocities of early and late diastolic left ventricular filling and the deceleration rate were also significantly reduced. The heart rate, A/R, deceleration half time, and the ratio of deceleration half time to acceleration half time (DHT/AHT) were significantly increased. The greater the amount of fluid removed, the greater the changes in the above values. Patients with left ventricular hypertrophy exhibited significant reductions in fractional shortening, ejection fraction, stroke volume and cardiac output, compared to those without hypertrophy. However, patients without hypertrophy showed more significant decrease in the acceleration half time and increase in DHT/AHT than did patients with hypertrophy. These findings demonstrated normal systolic function and impaired diastolic properties in patients with chronic renal failure, who had left ventricular hypertrophy unaccompanied by dilatation.

Adult↗
PubMed1988

Localization of acid phosphatase activity in collagen-secreting and collagen-resorbing fibroblasts.

The ultrastructural localization of acid phosphatase (ACPase) activity was examined in cultured human gingival fibroblasts in the formative and resorptive phases. In the collagen-secreting fibroblasts, weak ACPase activity was demonstrated in the lysosomes, inner Golgi cisternae, and condensing vacuoles, and none was found in the Golgi-associated endoplasmic reticulum-lysosome system (GERL), presecretory granules, or secretory granules. On the contrary, collagen phagocytosis induced strong ACPase activity in the GERL, which was in addition to the weaker activity found in the same sites as those in the collagen-secreting cells. At the same time, collagen secretion was suppressed, and dense elongated secretory bodies associated with ACPase activity accumulated within the cells. When collagen fibrils had been interiorized in whole or in part within the phagosomes, primary lysosomes derived from the Golgi-GERL complex then fused with them to form phagolysosomes. Collagen degradation occurred within these bodies. The observations indicate significant differences in ACPase activity used as a marker for lysosomal enzyme activities in the different functional phases of fibroblasts. These results suggest that fibroblasts work only one way at a given time, viz., collagen synthesis or collagen degradation.

Acid Phosphatase↗
PubMed1988

Luminal propionate-induced secretory response in the rat distal colon in vitro.

1. The stimulatory action of propionate on colonic electrolyte transport and involvement of the enteric reflex in this was studied in vitro using an Ussing chamber in the rat. The short-circuit current (Isc) and bidirectional fluxes of Na+ and Cl- were measured. Mucosa-submucosa preparations, containing the submucosal nerve, from the distal colon were used in most cases. 2. Mucosal application of propionate caused transient increases in the transmural potential difference, with the mucosal side negative, Isc and conductance. Serosal application of the acid had no effect. 3. Adaptation of the Isc response occurred when the acid was applied to the bathing solution cumulatively without washing out the first dose. If tissues were washed and held more than 20 min before the next application, the response was almost completely restored. 4. The increase in Isc in response to propionate was concentration dependent, with a 50% effective concentration of approximately 7 x 10(-5) M. 5. Two other short-chain fatty acids (SCFAs), n-butyrate and n-valerate, but not acetate, increased Isc when added to the mucosal bathing solution. 6. Bumetanide (3 x 10(-5) M) and the serosal chloride-free condition, but not amiloride (10(-4) M), inhibited the responses of Isc to propionate. Propionate-stimulated Cl- secretion resulted mainly from an increase in unidirectional serosal-to-mucosal Cl- movement. Propionate did not affect the Na+ flux. 7. Tetrodotoxin (10(-7) M), somatostatin (10(-7) M) and hexamethonium (10(-4) M) inhibited the propionate-evoked increase in Isc by 40, 70 and 30%, respectively. 8. Atropine (10(-5) M) also inhibited the Isc-increase response to propionate more than 90%. 9. Pre-treatment (2 min) of the mucosal surface with procaine (5 x 10(-4) M) inhibited the propionate-evoked increase in Isc by 90%. 10. The results suggest that luminal propionate transiently stimulated the colonic chloride secretory response that is not due to direct action on colonocytes, but due in large part to release of acetylcholine at neuro-colonocyte junctions, probably via an enteric reflex involving a mucosal sensory mechanism, cholinergic motor nerves and submucosal ganglia.

Action Potentials↗
PubMed1988

Synergism between calcium-mediated and cyclic AMP-mediated activation of chloride secretion in isolated guinea pig distal colon.

Synergistic effects of Ca2+-mediated secretagogues and cyclic AMP-mediated secretagogues on Cl- secretion by guinea pig distal colon were studied in vitro using Ussing chambers. Short-circuit current (Isc) and bidirectional fluxes of 22Na+ and 36Cl- were measured. Bethanechol (10(-4) M, a Ca2+-mediated secretagogue) caused an increase in Isc, which was enhanced 4-20 fold when the tissue was pretreated with prostaglandin E2 (10(-7)-10(-6) M), vasoactive intestinal polypeptide (5 x 10(-9)-10(-8) M) (cyclic AMP-mediated secretagogues), or 8-bromocyclic AMP (5 x 10(-4)-2 x 10(-3) M). Measurement of 36Cl flux showed that the increase in Isc in the presence of both 8-bromocyclic AMP and bethanechol resulted principally from increased Cl- secretion. On the other hand, the net absorptive flux of 22Na was not influenced under these conditions. Potentiation of the increase in Isc was also elicited by the combination of A23187 (5 x 10(-6) M) and 8-bromocyclic AMP (10(-3) M). The results are consistent with the notion that simultaneous activation of the cyclic AMP-mediated and Ca2+-mediated systems produces a synergistic increase in colonic Cl- secretion.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1987

FK-506, a novel immunosuppressant isolated from a Streptomyces. II. Immunosuppressive effect of FK-506 in vitro.

The immuno-pharmacological profile of a novel immunosuppressive agent, FK-506 produced by a streptomycete, is presented here. We proceeded to test the effect of the agent on various in vitro immune systems. It showed that mixed lymphocyte reaction, cytotoxic T cell generation, the production of T cell-derived soluble mediators such as interleukin 2 (IL-2), interleukin 3 and gamma-interferon and the expression of the IL-2 receptor were suppressed by this agent. The IC50 values of FK-506 and ciclosporin (CS) in all tests were approximately 0.1 nM and 10 nM, respectively. Therefore, the novel agent, FK-506 suppressed in vitro immune systems at about hundred times lower concentration than CS.

Animals↗
PubMed1987

Spasmolytic action of the cerebral circulation improver 6,7-dimethoxy-1- (3,4-dimethoxybenzyl)-4-[( 4-(2-methoxyphenyl)-1-piperazinyl]methyl) isoquinoline in isolated canine vessels.

Vasodilating action of a new calmodulin antagonist, 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-4-[( 4-(2- methoxyphenyl)-1-piperazinyl] methyl) isoquinoline (Ro 22-4849) was examined in various isolated canine vessels. Ro 22-4839 was found to dilate basilar and middle cerebral arteries and to non-selectively antagonize submaximal contraction of these arteries under the treatment of various constrictors (K+, Ca2+, PGF2 alpha (dinoprost), serotonin and incubated blood) with IC50 values ranging from 0.043 to 1.69 mumol/l. Vasospasmolytic action of the compound in these cerebral arteries was 9 and 20 times greater than those in coronary and femoral arteries, respectively. The arterial relaxation by Ro 22-4839 was hardly overcome by addition of extra calcium and Ro 22-4839 did not alter calcium channels in the guinea-pig papillary muscle, although the compound inhibited the tension development, confirming its calmodulin antagonistic properties. Ro 22-4839 inhibited norepinephrine (NE)-induced contraction of femoral arterial strips concentration-dependently, and prevented NE-induced lethal extravasation in mice with an ED50 value of 1.96 mg/kg p.o. In in vitro [3H]-dihydroergocryptine binding assay and ex vivo [3H]-WB-4101 (2-[(2',6'-dimethoxy)phenoxyethylamino] methylbenzodioxan) binding assay, the compound showed a potent inhibitory action on alpha 1-adrenoceptor. These findings indicate that Ro 22-4839 exerts the spasmolytic effects on cerebral vessels through calmodulin antagonistic properties combined with alpha 1-adrenoceptor blocking action.

Action Potentials↗
PubMed1987

Cerebral vasodilating and vasospasmolytic action of the cerebral circulation improver 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-4-([4-(2-methoxyphenyl)-1- piperazinyl]methyl)isoquinoline in experimental animals.

Vasodilating action of a new calmodulin antagonist, 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-4-([4-(2-methoxyphenyl)- 1-piperazinyl]methyl) isoquinoline (Ro 22-4839), was examined in anesthetized animals. In anesthetized dogs, Ro 22-4839 when given intra-arterially dilated various vessels in the potency order of vertebral greater than internal carotid greater than femoral = coronary much greater than renal vessels. Ro 22-4839 (0.1-1.0 mg/kg i.v.) produced brief increases in the cerebral parietal cortex, vertebral and coronary arterial blood flows more markedly than in femoral, mesenteric and renal arterial blood flows. The compound given intraduodenally decreased the vertebral vascular resistance more extensively than the femoral one in a dose-dependent (3-30 mg/kg) way. The effect of intraduodenal administration was longer-lasting than brief action after intravenous administration, and tended to decrease heart rate. Ro 22-4839 did not significantly change cerebral oxygen consumption regardless of its increase in cerebral oxygen supply, suggesting that its cerebral vasodilating effect was due to its direct relaxing effect on the vascular smooth muscle. Papaverine and ifenprodil produced a shorter-lasting decrease in vertebral vascular resistance and caused significant tachycardia. In the video camera system monitoring the constrictory response of feline pial small vessels of the parietal cortex to hypocapnia, Ro 22-4839 was found to reverse vasoconstriction of both pial arteries and veins at the dose of 0.3 mg/kg i.v./min, which did not dilate these vessels under normocapnia. The compound uniformly reduced the pressor responses to various stimuli (electrical stimulation, norepinephrine and angiotensin II) in pithed rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Acid phosphatase activity and intracellular collagen degradation by fibroblasts in vitro.

Human gingival fibroblasts were cultured with collagen fibrils. The precise process of collagen phagocytosis and the relationship between acid phosphatase activity and intracellular degradation of collagen were investigated by cytochemical methods at the ultrastructural level. The collagen fibrils were first engulfed at one end by cellular processes, or the cell membrane wrapped itself around the middle of the fibrils. Collagen phagocytosis induced acid phosphatase activity in the fibroblast Golgi-endoplasmic reticulum-lysosome system. By application of the tracer lanthanum, deposits were observed in the intercellular spaces and along the fibrils being phagocytosed. At this stage, primary lysosomes were seen in close proximity to the collagen being engulfed, but no signs of fusion were observed. When the fibrils had been interiorized in whole or in part, they ultimately became enclosed within phagosomes, and no tracer was observed along the interiorized portion of the fibrils. Primary lysosomes then fused with these collagen-containing phagosomes to form phagolysosomes. Collagen degradation occurred within these bodies even though the end of a fibril might have protruded outside of the cell. These results suggest that selective and controlled phagocytosis of collagen and intracellular digestion of it may play a central role in the physiological remodeling and metabolic breakdown of the collagen of connective tissues.

Acid Phosphatase↗
PubMed1986

Opsonic and complement-dependent bactericidal activities of various immunoglobulin preparations for intravenous use.

Some effector functions of various immunoglobulin (IgG) preparations have been compared. Tests for opsonic activity were performed in vitro with human peripheral blood leukocytes and in vivo with mice. The augmentation effects on luminol-dependent chemiluminescence were investigated with human leukocytes. The complement-dependent bactericidal activities were tested with Escherichia coli. Five IgG preparations: pH 4-treated preparation (IG-100), polyethyleneglycol-treated preparation (PEG-G), sulfonated preparation (S-G), pepsin-treated preparation (Pep-G) and a preparation for intramuscular use (GGN) were studied. The results were as follows: (1) IG-100 and PEG-G exhibited strong activities in all test systems; (2) GGN showed a strong opsonic activity; (3) S-G showed relatively weak activities in all test systems, but the revertant S-G preparation exhibited somewhat stronger activities in all systems, and (4) Pep-G showed weak or no activity in all systems. These results suggest that the IgG molecules in IG-100 and PEG-G preparations have satisfactory effector functions. On the other hand, IgG molecules in S-G and Pep-G preparation may have significant deficiencies in their biological functions.

Animals↗