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Biomedical subjects

K Ishida

Publications and source records attributed to K Ishida.

At least 541 records · Page 30Linked to original sources
PubMed1984

Treatment of staphylococcal pyelonephritis in rats with N-formimidoyl thienamycin.

The therapeutic efficacy of N-formimidoyl thienamycin alone or coadministered with MK0791, an inhibitor of renal dehydropeptidase-I, compared to methicillin in experimental pyelonephritis in rats was investigated. Pyelonephritis was produced with a methicillin-sensitive strain (2776) and a methicillin-resistant strain (Berman) of Staphylococcus aureus. N-formimidoyl thienamycin alone or coadministered with the inhibitor was significantly better than methicillin when treating methicillin-sensitive or methicillin-resistant infection. There was a trend suggesting that N-formimidoyl thienamycin coadministered with MK0791 was overall the best agent. These studies show that N-formimidoyl thienamycin is efficacious in the treatment of S. aureus pyelonephritis in the rat regardless of methicillin sensitivity, and this agent plus the dehydropeptidase inhibitor should be considered in the treatment of such infections.

Animals↗
PubMed1984

Successful surgical ablation of reentrant ventricular tachycardia caused by myocardial fibroma.

We successfully removed a fibroma of the left ventricle in a 13-year-old boy. The tumor had caused recurrent ventricular tachycardia, which was resistant to antiarrhythmic drugs. Preoperative and intraoperative electrophysiological studies led to a diagnosis of reentrant ventricular tachycardia. After surgical excision of the tumor, the ventricular tachycardia stopped completely and until now, 1 year after the operation, no antiarrhythmic drugs have been required.

Adolescent↗
PubMed1984

Recent advances in the prevention, early diagnosis, and treatment of congenital dislocation of the hip in Japan.

Results of animal experiments and then of clinical study of newborn infants suggested that the main mechanical factor causing hip dislocation is prolonged tension on the hamstrings and iliopsoas and that each of these muscles has a synergistic effect in the production of hip dislocation during the perinatal period. It was, therefore, presumed that the high incidence of congenital dislocation of the hip (CDH) in Japan might be due mainly to the Japanese tradition of forcibly maintaining the legs of infants in an extended position with a "swathing diaper." The incidence of CDH in Japanese infants prior to 1965 was as high as 1.1%-3.5%. In an attempt to reduce the incidence of CDH, examination of newborns was performed on a national scale. However, early screening methods for hip abnormalities were not adequately reliable in Japan to allow identification of conditions that would later become CDH. In 1975 a national campaign to avoid prolonged extension of the hips and knees of infants during the early postnatal period was initiated. As a result, there has been a remarkable reduction in the incidence of CDH in infants, to less than 0.2%.

Animals↗
PubMed1983

Changes in cGMP levels on meiosis reinitiation of starfish oocytes.

An intracellular level of cGMP (but not cAMP) transiently decreased the reinitiation of oocyte maturation in the starfish, Asterias amurensis. Exogenously applied cGMP inhibited hormone-induced maturation. Methylxanthines inhibited oocyte maturation by suppressing the decrease in cGMP levels. These results suggest that a decrease in cGMP levels is a prerequisite for meiosis reinitiation of starfish oocytes.

Animals↗
PubMed1983

Antibiotic prophylaxis against streptomycin-resistant and -susceptible Streptococcus faecalis endocarditis in rabbits.

This report describes the capacities of ampicillin, vancomycin, streptomycin, gentamicin, and combinations thereof to prevent endocarditis in rabbits challenged with either streptomycin-resistant (three strains) or streptomycin-susceptible (one strain) Streptococcus faecalis. Vancomycin (15 mg/kg) alone was effective in preventing infection with three of four strains, including two which were streptomycin resistant. Vancomycin (30 mg/kg) alone was effective against the other streptomycin-resistant strain. The vancomycin-gentamicin combination was the only therapeutic regimen to demonstrate complete prophylaxis for all strains regardless of streptomycin susceptibility. The ampicillin-gentamicin combination was variably effective despite in vitro synergism.

Animals↗
PubMed1983

Lack of significance of pili in experimental ascending Escherichia coli pyelonephritis.

The role of pili as a bacterial virulence factor has been studied. The model used was acute ascending Escherichia coli pyelonephritis in the mouse. Three strains of E. coli were injected in lightly or more heavily piliated phases into 15 mice each. At sacrifice of 13-15 animals 2 weeks later, no significant difference in severity of pyelonephritis was found as judged by numbers of bacteria in the kidney, nor intensity or frequency of gross abscesses. 27 strains of E. coli were order ranked for severity of pyelonephritis produced and compared with intensity of piliation in vitro under conditions designed to maximize pilus formation. No significant difference was found. 15 strains derived from patients in whom infections were confined to the bladder were compared for degree of piliation with 12 strains infecting the kidney. No significant difference was found. These studies do not support a significant role for the degree of piliation as a virulence factor in pyelonephritis.

Adhesiveness↗
PubMed1983

Initiation of sperm motility in teleosts.

In salmonid fish (rainbow trout and chum salmon) or freshwater cyprinid fish (goldfish), change of potassium concentration or osmolality of the environment surrounding the spermatozoa at spawning in fresh water directly affect the flagellum and regulate the initiation of sperm motility. A change in these external factors induces intraflagellar cAMP through some changes of plasma membrane in flagellum and cAMP triggers the initiation of axonemal movement through activation of cAMP-phosphorylation system in initiation of sperm motility in teleosts.

Animals↗
PubMed1983

[Left ventricular diastolic performance in patients with myocardial infarction: assessment with backward method of radionuclide angiography].

Radionuclide technique in the evaluation of left ventricular (LV) diastolic performance has been applied in patients with myocardial infarction (MI). But the late diastolic LV volume curve obtained from the radionuclide angiogram is unreliable, whenever we sum up radioactivities by ECG-triggered method (conventional method) because of respiratory arrhythmia. The purpose of the present study was (1) to estimate the reliability of diastolic LV volume curve obtained from the radionuclide angiogram by our new method (backward method: backward ECG-gated radionuclide angiogram to the preceding R wave), and (2) to determine the availability of Phase 1 max and Phase 3 max as the indexes of LV diastolic performance. We analyzed LV volume curve and its dV/dt curve in 29 cases by both conventional and backward methods. The LV diastolic period was equally divided into three time intervals. The early, mid and late trisections of the diastolic period were expressed as phase 1, phase 2 and phase 3, respectively. A Phase max was defined as maximum dV/dt in the phase corrected for end-diastolic counts. At first, ejection fraction (EF), Phase 1 max, Phase 2 max and Phase 3 max were compared between the two different methods to estimate the reliability of diastolic LV volume curve obtained from a backward method. The backward method correlated well with the conventional method regarding EF and Phase 1 max (r = 0.965 and r = 0.940, respectively), but there was no correlation regarding Phase 3 max. This indicated that LV diastolic volume curve obtained from the backward method was reliable. In the second place, we analyzed LV dV/dt curve obtained from the backward method in 8 controls and 28 MI patients to determine the availability of Phase max as the indexes of LV diastolic performance. Phase 1 max was reduced earlier than a decrease of EF, and Phase 3 max was increased prior to a decrease of EF in MI. These data indicated that Phase 1 max and Phase 3 max as the indexes of LV diastolic performance were more sensitive than the indexes of LV systolic performance. Also MI patient had an abnormality in early diastolic filling and an increased atrial contraction in late diastolic filling of the left ventricle. The mechanism of abnormal LV early diastolic filling, even in the absence of abnormal systolic function, might be impaired LV suction because of fibrosis or the relatively ischemic myocardium. In mild to moderate LV failure atrial contraction compensated abnormal early diastolic filling, but there was no such a compensation in severe LV failure. It may suggest the limitation of atrial function as a booster pump.

Aged↗
PubMed1983

[Clinical application of a new right subcostal approach in the evaluation of interatrial septal motion].

We developed a new echocardiographic approach to detect the interatrial septum (IAS) by tilting a transducer leftward, cephalad and backward from the right subcostal area. This technique could allow us to visualize the IAS moving perpendicularly to the ultrasonic beam. In normal subjects the IAS showed a small posterior deflection moving toward the left atrium due to atrial contraction following the P wave of the electrocardiogram. Following the onset of ventricular ejection the IAS rapidly moved anteriorly. During diastole the IAS showed an initial rapid posterior displacement and then a more gradual slope, reflecting rapid and slow filling phases, respectively. The magnitude and configuration of IAS motion showed variations dependent on atrial conditions of cardiac diseases. In atrial fibrillation there were f waves on the IAS echogram and in mitral stenosis a septal notch was recorded at the timing of a mitral opening snap. In mitral valve prolapse there was also a midsystolic notch of the IAS echogram almost coincident in time with the onset of a late systolic murmur. On the other hand, the IAS revealed a systolic increased excursion or paradoxical motion in mitral or tricuspid regurgitation, respectively. In hypertension and myocardial infarction the atrial kick of the IAS echogram showed an exaggerated excursion. In 125 out of the consecutive 150 cases (83.3%) we could record satisfactory IAS echograms by this new approach.

Adolescent↗
PubMed1983

[Evaluation of patients with ischemic heart disease by exercise thallium-201 myocardial imaging: comparison with coronary arteriography and graded treadmill exercise testing].

One hundred and eight patients with suspected ischemic heart disease were evaluated by exercise thallium-201 myocardial imaging (T1-IM), coronary arteriography and graded treadmill exercise test (GTX). They were divided into four groups; Group I consisted of 21 patients without significant coronary artery disease (less than 75% diameter stenosis), Group II of 47 patients with significant coronary artery disease (greater than or equal to 75% diameter stenosis) but without previous myocardial infarction, Group III of 24 patients who had previous myocardial infarction with additional coronary artery disease, and Group IV of 16 patients who had previous myocardial infarction without additional coronary artery disease. In Group I, T1-IM showed positive findings in only two patients (9.5%), whereas GTX showed positive findings in seven (33.3%) and borderline findings in four (19.0%). In Group II, T1-IM showed positive findings in 34 patients (74.5%), while GTX showed positive findings in 31 (66.0%) and borderline findings in 12 (25.5%). In Group II, the sensitivity of T1-IM and GTX for identifying severe stenosis (more than 99%) were 95.0% (19 of 20 patients) and 75.0% (15 of 20), respectively, but only 50.0% (four of eight) and 50.0% (four of eight), respectively, for identifying less severe stenosis (about 75%). In Group III, the sensitivity for detecting infarcted lesion by T1-IM was 95.8% (23 of 24 patients), but the sensitivity for detecting ischemic area in the non-infarcted lesion was 41.7% (10 of 24). In Group IV, a significant defect was detected by TI-IM, corresponding to the infarcted site in 14 of 16 patients (87.5%), and periinfarcted ischemia was shown in seven of the 14 patients (50.0%). In both Group III and IV, GTX was positive in only 50% and 31.3%, respectively. We conclude that T1-IM is a useful technique in the diagnosis of myocardial ischemia, especially severe coronary stenosis, and is more specific than GTX. However, we must be careful for evaluating ischemic, but not infarcted lesion by T1-IM in patients with myocardial infarction.

Adult↗
PubMed1983

[Study on the serum concentrations of gentamicin after intravenous drip infusion].

Serum concentrations of gentamicin (GM) were monitored after intravenous drip infusion of 60 mg over 30 minutes, 1 hour and 2 hours. These concentrations were compared with those after intramuscular injection. The mean peak serum concentration obtained at 30 minutes after intramuscular injection (5.09 micrograms/ml) and those obtained at the end of intravenous drip infusion (5.17--6.66 micrograms/ml) were comparable. Serum concentrations decreased to less than 2.0 micrograms/ml at 6 to 8 hours after injection or infusion in all cases except 1 with less body weight than others. Pharmacokinetic analysis showed that the T1/2 of GM ranged from 2.49 to 4.33 hours and that the AUC ranged from 19.66 to 27.09 hr X micrograms/ml. Results obtained in this study suggested that the usefulness of intravenous drip infusion over the time from 30 minutes to 2 hours is equal to that of intramuscular injection in the GM therapy.

Adult↗