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Biomedical subjects

M Fujino

Publications and source records attributed to M Fujino.

At least 235 records · Page 13Linked to original sources
PubMed1987

Effects of a substance P analogue with antagonist properties ([D-Arg1, D-Trp7,9, Leu11]substance P) on spontaneous activity of the adrenal sympathetic nerve and its evoked reflex discharges in response to somatic afferent stimulation.

The present study was designed to test the effect of a substance P (SP) antagonist, [D-Arg1, D-Trp7,9, Leu11]substance P (Spantide), on spontaneous efferent activity of adrenal sympathetic nerve and the two A- and C-sympathetic reflex components evoked in adrenal sympathetic nerve by stimulation of myelinated A- and unmyelinated C-afferent nerve fibers of a hindlimb nerve, respectively, in anesthetized rats. The spontaneous adrenal nerve activity and both of the A- and C-sympathetic reflex components were proportionally reduced by intrathecal application of the SP antagonist (0.038-0.76 nmol), although the same doses did not affect A- and C-somatic reflex components. These data suggest that the SP antagonist has a greater effect on SP-containing neurons related to the generation of spontaneous activity of sympathetic neurons and somato-sympathetic reflex pathways than on SP-containing primary somatic afferent nerves and somato-somatic reflex pathways.

Action Potentials↗
PubMed1987

Right atrial vegetation in left ventricular-right atrial communication.

We report a case of right-sided endocarditis with left ventricular-right atrial communication in which right atrial vegetation was demonstrated by two-dimensional echocardiography. The present case demonstrates that the right atrial vegetation in ventricular septal defect is suggestive of left ventricular-right atrial communication.

Adult↗
PubMed1987

A monoclonal antibody against a synthetic fragment of bombyxin (4K-prothoracicotropic hormone) from the silkmoth, Bombyx mori: characterization and immunohistochemistry.

Monoclonal antibodies were produced by immunizing mice with a synthetic decapeptide corresponding to the N-terminal portion of the A-chain of bombyxin, a peptide from Bombyx mori which activates the prothoracic glands of the saturniid moth, Samia cynthia ricini, and was previously called 4K-PTTH. We obtained a hybridoma clone secreting an antibody that recognized specifically bombyxin after treatments for disulfide-bond reduction but did not when untreated. Immunoblotting studies demonstrated the presence of highly heterogeneous immunoreactive components in Bombyx brain homogenates. Immunohistochemistry using this antibody indicated that bombyxin was produced by four pairs of mid-dorsal neurosecretory cells of the brain and transferred to and released from the corpora allata of Bombyx.

Animals↗
PubMed1987

Mechanism of luminal enlargement in PTCA and restenosis: a histopathological study of necropsied coronary arteries collected from various centers in Japan.

Necropsy studies of coronary arteries were made in 14 patients who died after percutaneous transluminal coronary angioplasty (PTCA). Eight patients died shortly after PTCA, while the other six patients died some considerable time later. A total of 9,920 serial step sections of necropsied coronary arteries at the site of PTCA were prepared and examined histopathologically by light microscope to determine the mechanism of luminal enlargement in PTCA, as well as the occurrence of restenosis. Of the eight patients who died shortly after PTCA, two had disruption of the intima and the media in the arterial wall located opposite the site that had atheroma, in spite of the fact that the former wall is more normal than the latter. Dissection of the media was camed out in four patients and intimal desquamation performed in six. All the patients revealed fresh thrombus formation. Of the six patients who survived for a long time after PTCA was performed, two had disruption of the intima and the media located opposite the site with atheroma. In one, the media was dissected and in another, intimal desquamation was camed out. In one patient, release of atheroma into the lumen was suspected. Proliferation of intimal cells was revealed in three patients indicating that restenosis had occurred. No compression of the atheroma was observed in any of the 14 patients. The above findings led to the conclusion that the mechanisms of luminal enlargement in PTCA are: 1) intimal and medial disruption in the arterial wall located opposite the atheroma; 2) medial dissection; 3) intimal desquamation; 4) release of atheroma into the lumen; and 5) any combination of 1) -4).

Adult↗
PubMed1987

Prognostic value and limitation of doughnut pattern of technetium-99m pyrophosphate myocardial uptake in acute anterior infarction.

The prognostic significance of the doughnut pattern of technetium-99m pyrophosphate myocardial uptake was evaluated in 140 patients with acute anterior infarction. There were significantly higher early complications, greater mortality and more severe hemodynamic abnormalities in the doughnut pattern group than in the non-doughnut pattern group. The former had a more depressed left ventricular ejection fraction and larger thallium-201 defect size (27.6 +/- 10.4 versus 40.0 +/- 13.5%, p less than 0.001 and 9.9 +/- 3.6 versus 5.6 +/- 3.3, p less than 0.001, respectively). There was, however, considerable overlap of the ranges of these variables for both groups. The patency rate of the infarct vessel during the acute phase of infarct in each group was similar (54.8 versus 45.2%). It is concluded that the prognostic value of the doughnut pattern may be limited to some extent by this overlapping and the presence of this pattern does not appear to correlate with the lack of residual blood flow to the infarcted area.

Cardiac Catheterization↗
PubMed1987

Effect of the substance P antagonist spantide on adrenal sympathetic nerve activity in rats.

In order to elucidate the role of substance P in adrenal nerve activity, the effects of substance P antagonists on tonic activity of the adrenal sympathetic nerve, the response to exogenous substance P and cutaneo-adrenal nerve reflex were investigated in anesthetized rats. Substance P or its antagonist [(Arg1, D-Trp7,9, Leu11)-substance P: spantide] was injected into the subarachnoid space via polyethylene tubing. Intrathecal administration of spantide (0.1-10 micrograms) produced a slight and transient increase in tonic activity of the adrenal nerve. Thereafter, a marked and prolonged decrease in adrenal nerve activity was observed, along with a decrease in arterial blood pressure. Intrathecally administered substance P (0.1-10 micrograms) produced a marked increase in tonic activity of the adrenal nerve in a dose-related manner. This substance P-induced increase in adrenal nerve activity was significantly antagonized by pretreatment with spantide. It was also found that spantide depressed the reflex response in adrenal nerve activity evoked by noxious mechanical pinching of the skin. These findings suggest the possibility that on the spinal level, substance P has an important role in the maintenance of tonic activity of the adrenal nerve and the transmission of nociceptive information to the adrenal nerve in rats.

Adrenal Glands↗
PubMed1987

Effects of percutaneous transluminal coronary angioplasty on segmental left ventricular function in patients with acute myocardial infarction.

In order to investigate the usefulness of percutaneous transluminal coronary angioplasty (PTCA) on subsequent left ventricular (LV) function in patients with acute myocardial infarction (AMI), regional ejection fraction (REF) was calculated from the left ventriculogram and compared in the acute and chronic phases (4 weeks after infarction) in 19 successful cases of PTCA (group A). In addition, 15 successful cases of intracoronary thrombolysis (PTCR) (group R) and 14 unsuccessful cases (group U) were also analyzed in this study. From the results, the following points were elucidated. (1) REF of group A in the chronic phase showed a significant increase compared to that in the acute phase (10 +/- 18% vs 20 +/- 19%, p less than 0.01), and this was similar to that observed in group R (9 +/- 19% vs 21 +/- 16%, p less than 0.01). (2) All cases in group A showed a significant increase in REF (p less than 0.02), if recanalization occurred within 3 hours after the onset of AMI. Some cases in the 3-6 hour recanalization group showed a decrease in REF. (3) In group A, only patients with subtotal occlusion on the initial coronary angiogram showed a significant increase in REF 4 weeks later (p less than 0.01), whereas patients with total occlusion on the initial coronary angiogram showed no significant increase in REF. (4) In group A, only patients recanalized between 3 and 6 hours showed a severe degree of prolonged contrast staining immediately after successful recanalization following PTCA. Thus, chronic phase regional wall motion was markedly improved by PTCA in those cases with residual flow. In contrast, abrupt recanalization after PTCA might causally decrease regional wall motion due to hemorrhagic infarction, if it is performed in cases with total occlusion.

Angioplasty, Balloon↗
PubMed1987

Inhibition of excitation-contraction coupling by a Ca channel blocker nicardipine at low temperature in frog twitch fibers.

Effects of a Ca channel blocker, nicardipine, on excitation-contraction (E-C) coupling were investigated in single twitch fibers dissected from short skeletal muscles of the frog, Rana japonica. The treatment with 20 microM nicardipine at 25 degrees C evoked a reversible twitch potentiation. By contrast, the treatment at the same concentration at 5 degrees C for 30 min evoked an intense twitch inhibition. The inhibition was irreversible. This paralyzed fiber remained at nearly normal resting and propagated action potentials. The treatment with 30 microM nicardipine for 14 min at 6 degrees C completely inhibited a potassium contracture by 190 mEq/l potassium ion for 1.5 h after the removal of nicardipine despite the retention of normal resting potentials. The paralyzed fiber which was previously treated with 20 microM nicardipine for 30 min at 6 degrees C, also remained at normal action potential and at partial potassium contracture, and responded to 3 mM caffeine stimulation with a normal contracture. Dose-dependence curves obtained from the data on the treatments with nicardipine at various concentrations for 30 min at 6 degrees C consisted of an opposite sigmoidal shape with both threshold and half maximum inhibition at 1 and 1.5 microM for twitch and similarly at 5 and 12 microM for potassium contracture. Temperature-dependence curves obtained from the data on the treatments with 20 microM nicardipine for 30 min at various temperatures consisted of a sigmoidal shape with half maximum inhibition at 15 degrees C for twitch and at 12 degrees C for potassium contracture. A working hypothesis "two component-three state model" for E-C coupling was proposed based on the interpreted mechanism of nicardipine action.

Animals↗
PubMed1987

Hypertonicity-induced inhibition of excitation-contraction coupling in Xenopus twitch fibers.

Mechanical responses such as twitch and tetanus were markedly reduced in Xenopus single twitch fibers which were previously treated with either 125 mM NaCl or 250 mM sucrose hypertonic Ringer despite the retention of nearly normal action potential and caffeine contracture. This inhibition of excitation-contraction coupling was accompanied by a large reduction in membrane capacity to approximately 2 microF/cm2 during and after immersion in the hypertonic Ringer and can possible be attributed to the same origin of disruption of the transverse tubular system as "glycerol effect."

Action Potentials↗
PubMed1987

[Myocardial perfusion assessed by dynamic computed tomography before and after percutaneous transluminal coronary angioplasty].

A method for quantitatively and visually assessing myocardial perfusion using a new transmission computed tomography scanner and contrast media injection was devised. Myocardial perfusion was assessed before and after percutaneous transluminal coronary angioplasty (PTCA). Six patients with left anterior descending coronary artery stenosis undergoing PTCA were successfully studied. Dynamic scans, each with a scan time of one sec, were performed at the mid left ventricular level using bolus injections of contrast medium from the inferior vena cava. Regions of interest (ROIs) were located in the left ventricular cavity and in the myocardium perfused by the left anterior descending coronary artery, and gamma-variate fitted time density curves were recorded within the first pass phase, excluding recirculation. Cardiac outputs calculated from the ventricular curves of the ROIs in the left ventricular cavity correlated well with the thermodilution measurements using Swan-Ganz catheters (r = 0.90, p less than 0.01). The ratios of myocardial blood flow (F) to the tissue element volume (V) were calculated (F/V) from the myocardial curves of the ROIs in the myocardium as parameters of myocardial perfusion, according to the Zierler's principle. The F/Vs in the myocardium perfused by the left anterior descending coronary artery before PTCA were significantly less than those of the control subjects (4.4 x 10(-2) +/- 1.2 x 10(-2) vs 8.1 x 10(-2) +/- 2.9 x 10(-2): p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

Echocardiographic and electrocardiographic measures in obese children after an exercise program.

The influence of an exercise training on anthropometric changes and cardiac dimensions was studied in 18 obese children (age 10 to 11 years). Eighteen obese children participated in a jogging program, 5 days/week, for 1 or 2 years and 15 normal weight children (age 10 to 11 years) in the control group participating in their regular physical education class. Anthropometric measurements, echocardiograms and electrocardiograms were obtained before and after the exercise programs. The weight, degree of obesity and resting heart rate had decreased after 1 year of the exercise training. Left ventricular end-diastolic dimension increased after 1 year of the exercise training. Left ventricular wall thickness did not change. The total voltage in SV1 + RV5 decreased after 3 months of the exercise training but returned to pre-training voltage after 1 year of training. There was no change after 2 years of training. In conclusion, 1 year of exercise in obese children decreased resting heart rate and increased left ventricular end-diastolic dimension and left ventricular mass.

Anthropometry↗
PubMed1987

[Regression of mitral valve prolapse to a state masquerading as dilated cardiomyopathy: a case report].

A 40-year-old man was admitted to our hospital in May 1982 for evaluation of a heart murmur. A standard 12-lead electrocardiogram (ECG) showed an abnormal Q wave in lead III. Echocardiography revealed prolapse of the anterior mitral valve leaflet (MVP), but neither dilatation nor wall motion abnormalities of the left ventricle (LV) were observed. Thallium-201 scintigraphy revealed an abnormal thallium uptake at the apex and inferior wall. He had no episode of acute myocardial infarction or myocarditis, but complete right bundle branch block suddenly appeared, and he was hospitalized in October 1984. He had no coronary artery lesions, and only mild mitral regurgitation on left ventriculography. The motion of the interventricular septum and apex was reduced on echocardiography and a persistent perfusion defect was observed at the inferior wall and the interventricular septum on T1-201 scintigraphy. In December 1985, he experienced an Adams-Stokes attack due to complete atrioventricular block. Echocardiographically, the left ventricle became enlarged and the wall motion abnormality and a perfusion defect on T1-201 scintigrams were of relatively severe degree. Thus, left ventricular dilatation and wall motion abnormality may progress in some cases of MVP as it did in this one. We consider this case a very interesting one in speculating on the relationship between MVP and DCM.

Adult↗