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Biomedical subjects

T Fujimoto

Publications and source records attributed to T Fujimoto.

At least 685 records · Page 38Linked to original sources
PubMed1984

[Cell kinetics and nuclear ploidy pattern in relation to the growth of gastric cancers as analyzed by DNA-RNA cytofluorometry].

We investigated the cell kinetics and nuclear ploidy pattern of human gastric cancers (12 early and 30 advanced cancers) using DNA-RNA cytofluorometry (NIKON SPM-RF1-D) with AO stain. The results showed that the gastric cancers studied could be divided into two main groups on the basis of ploidy pattern determined both by DNA and RNA contents: group I without, and group II with polyploidization. Cells having nuclear DNA contents between 2 n and 4 n were regarded as representing those in the S phase, and it was found that both groups had similar proliferative activity. In group I, cell proliferation without polyploidization seemed to be maintained during tumor growth regardless of the extent of invasion, and the fraction of 2 n cells was 72-94%, compared to 93-99% in control cells from the non-neoplastic gastric epithelium. In group II, however, the extent of polyploidization appeared to be increased in association with both the tumor growth and its invasion into deeper tissues; thus the fraction of 2 n cells was low, ranging from 12 to 79%. Especially, the fraction of 2 n cells in cancers with aneuploid-polyploidization was further decreased to 6-25%. Based on these results, it is hypothesized that, in the early stages of gastric cancers, the cell population may be composed mostly of diploid cells, but with both further tumor development and its invasion, the neoplastic cells may gradually differentiate into two distinct cell populations.

Adult↗
PubMed1984

[Cytofluorometric analysis of cell kinetics in relation to tumor growth of advanced gastric cancers].

Correlated studies on both cell kinetics in association with nuclear ploidy pattern and pathological morphology of advanced gastric cancers were carried out using DNA-RNA cytofluorometry (NIKON SPM-RF1-D) with AO stain. The results showed that advanced gastric cancers could be divided into two main groups. Group 1 (12 cases) was the diploid cell population, commonly found in Borrmann type 4 showing diffuse infiltration of cancer cells, and group II (14 cases) was characterized by polyploidization, usually found in Borrmann type 2 or 3 showing adenocarcinomas composed of markedly pleomorphic cells. In addition, we further differentiated from group II four cases of cancers which included aneuploid cells with more pronounced pleomorphism than group II, and classified them as group II'. These results suggest that cell kinetics and nuclear ploidy pattern of the advanced gastric cancers are closely related to pathological characteristics, i.e., groups I and II to undifferentiated (gastric type) and differentiated (intestinal type) carcinomas, respectively.

Adenocarcinoma↗
PubMed1984

[Clinical trials of cefmetazole for pneumonia and pyothorax caused by Staphylococcus aureus resistant to cefazolin].

Cefmetazole (CMZ), an antibiotic agent of the cephamycin group, is resistant to beta-lactamase and has a broad antibacterial spectrum covering Gram-positive cocci and Gram-negative bacilli. However, it has not been indicated for Gram-positive cocci. We examined its clinical, bacteriological and side effects in 2 infants with pneumonia and 2 with pyothorax, which had been suggested to be caused by CEZ-resistant and CMZ-sensitive Staphylococcus aureus or other inflammatory organisms by a disc sensitivity test, for 2 years and 3 months from January, 1981 to March, 1983. The patients aged 1 to 22 months, and a mean daily dose of 108 to 115 mg/kg was divided into 2 to 4 equal doses and injected into the vein at one shot for a mean fo 19 days. The following results were obtained: The clinical effect of CMZ was evaluated to be good in 1 and fair in 1 of 2 infants with pneumonia, and excellent in 1 and good in 1 of 2 with pyothorax. Bacteriologically, S. aureus was removed in an infant with pneumonia and in 2 with pyothorax. Bacteriological test was not conducted in the remaining 1 with pneumonia. No side effects were found in any cases. Eosinophilia appeared as an abnormal clinical test value in a case, but the number of eosinophils became normal after termination of the medication. As mentioned above, CMZ manifested an excellent clinical effect in infants with pneumonia or pyothorax caused by S. aureus although the number of the patients was small. From the results the antibiotic agent can be expected to be effective in these disease.

Age Factors↗
PubMed1984

[A phase I study of 4'-epi-adriamycin, a new anthracycline anticancer agent].

A phase I study of 4'-Epi-Adriamycin, a new derivative of Adriamycin, was carried out in 36 cases with various malignant tumors, among which 30 cases were evaluable. Starting dose was 10 mg/m2 and this was increased up to 80 mg/m2. The dose limiting factor was leukopenia. Leukocyte nadir was reached about two weeks after administration and about nine days (mean) were needed for recovery. Other main side effects were anorexia, nausea vomiting, and alopecia. These side effects were mainly observed in cases given doses of over of 60 mg/m2. However, there were only a few serious cases suggesting that the clinical toxicities of 4'-Epi-Adriamycin were milder than those of Adriamycin. From the result of this study, it appeared that maximum tolerated dose of the drug is 80 mg/m2, and the dose recommended for the phase II study is 60 mg/m2 every three weeks.

Anorexia↗
PubMed1983

Variant strain of Propionibacterium acnes: a clue to the aetiology of Kawasaki disease.

By means of anaerobic culture for 3-4 weeks a variant strain of Propionibacterium acnes was isolated from one lymph-node biopsy specimen, and from blood samples of five of twenty-three patients with early Kawasaki disease, but from only one of fifteen blood samples from patients after 8 days' illness. No anaerobe was isolated from sixty age-matched controls with various disorders, but the same bacillus with the same serotype was isolated from house-dust mites from six patients' homes. Patients had significantly higher serum agglutination titres to these strains than controls. The antigen moiety of P acnes was found in the patients' circulating immune complexes. Inoculation of animals caused various inflammatory lesions, particularly in the reticuloendothelial system, and coronary arteritis, myocarditis, and endocarditis in one of them, suggesting that the bacillus is pathogenic. The culture filtrate of this strain showed toxicity in tissue culture. This variant strain of P acnes may have a causative role in Kawasaki disease and house-dust mites a role as vectors.

Acute Disease↗
PubMed1983

Active locomotion of human primordial germ cells in vitro.

The locomotion of human primordial germ cells (PGCs) in vitro was observed using 16-mm time-lapse microcinematography. PCGs dissociated from 5- to 6-week human embryos were cultured in vitro using L-15 medium and human cord serum, and their movement on three artificial and two natural substrates was compared. Three-dimensional collagenous fiber nets reconstructed in the culture dish were found to be appropriate for PGC movement, although the cells did not migrate actively on any of the other substrates. The PGCs moved actively in an amoeboid fashion, extending pseudopodlike cytoplasmic processes toward the direction of movement. The direction of PGC locomotion was random. One PGC showed the most active motility; the velocity of the cell locomotion averaged 25 microns/h and it became extremely elongated, measuring 92 microns in its longer axis, whereas in the stationary state the PGC was rounded and measured 20 microns in diameter. Thus, the present study offers evidence that human PGCs can migrate actively.

Cell Movement↗
PubMed1983

Relationship between initial hepatic uptake of indocyanine green and hepatic energy status in hepatectomized rabbits.

The relationship between initial hepatic uptake of indocyanine green (ICG) and hepatic energy status was studied in about 70% hepatectomized rabbits. At 24 h after hepatectomy, the initial plasma disappearance rate (K) and the maximal removal rate (Rmax) of ICG fell to 27 and 26%, respectively, and the mitochondrial phosphorylative activity was enhanced maximally with a concomitant decrease in the energy charge ( (ATP+1/2ADP)/(ATP+ADP+AMP) ) level. Afterward, the initial reduction of ICG removal rate was followed by a rapid increase in week 1 and more gradual return to preoperative values by week 6 after hepatectomy. In the early period after hepatectomy (1-7 days), the mitochondrial phosphorylative activity was the higher the smaller the %K value was, while in the late period after hepatectomy (1-6 weeks), the mitochondrial phosphorylative activity remained unchanged irrespective of increasing %K. It is suggested that the mitochondrial phosphorylative activity may be a better guide to evaluate the functional status of the remnant liver than the initial hepatic uptake of ICG, especially in the early period after hepatoctomy.

Adenosine Triphosphate↗
PubMed1983

Electrophysiologic effects of bretylium on canine ventricular muscle during acute ischemia and reperfusion.

Electrophysiologic effects of bretylium were assessed on a recently developed animal model for analysis of conduction of premature impulses and excitation threshold. Bretylium was administered intravenously 10 mg/kg over 10 minutes followed by 2 mg/min of infusion immediately after coronary ligation. Conduction of the premature impulse was recorded in the epicardial and endocardial sites both in the base-to-apex and apex-to-base directions, in the normal, in the center, and across the border of ischemic myocardium. Compared to the control group of animals, bretylium did not cause any significant change in the conduction characteristics in the ischemic myocardium; however, it delayed the conduction of premature impulses in the normal myocardium. Thus the disparity in conduction times between the normal and the ischemic myocardium was lessened by bretylium. Further, conduction of impulses from normal tissue across the border of ischemia was also delayed. Bretylium also decreased the excitability threshold in the ischemic myocardium, although the normal myocardial excitation threshold was unaffected. These unique effects of bretylium on conduction and excitability in the normal, in the center, and across the border of ischemic myocardium, when a therapeutic dosage of the drug is used, further validate its antiarrhythmic potential and offer an insight into its mechanism of action in the setting of acute myocardial ischemia.

Animals↗
PubMed1983

Electrophysiologic observations during the spontaneous initiation of ischemia-induced ventricular fibrillation.

Electrophysiologic features of spontaneous, ischemia-induced ventricular fibrillation were studied in 17 dogs using multiple endocardial bipoles positioned in normal and ischemic zones and at the border of ischemic myocardium. All dogs showed ventricular tachyarrhythmias prior to the initiation of ventricular fibrillation. The heart rate prior to the fatal arrhythmia in the ventricular fibrillation dogs was significantly faster than that of nonventricular fibrillation dogs. There was no difference in the coupling intervals of the initial premature complex between episodic and sustained ventricular arrhythmia in most dogs. However, shorter coupling intervals initiated sustained arrhythmia in some dogs. Sites of initiation of arrhythmia were mostly in the ischemic zone. Furthermore, diastolic electrical activity was consistently observed in the ischemic zone during fatal arrhythmia in dogs showing diastolic activity. Cycle length during the fatal arrhythmia prior to ventricular fibrillation gradually shortened, whereas cycle length of episodic ventricular tachycardia remained approximately 200 msec followed by lengthening prior to restoration of sinus rhythm. The disparity of local activation (time differences between the earliest and latest onset of the activation in the five recording sites) increased during the fatal arrhythmia. Examples of progressive intraventricular block (Wenckebach-like) between the border and the center of ischemic myocardium leading to ventricular fibrillation are resynchronization of this disparity leading to the termination of ventricular tachycardia are shown. The recording of continuous electrical activity using bipolar electrodes with an interelectrode distance of 1 mm suggests a smaller reentrant pathway during fatal arrhythmia. Our observations confirm the importance of endocardial recordings within ischemic myocardium, and adds new insight into the events leading to both episodic and sustained ventricular tachycardia.

Animals↗
PubMed1983

Electrophysiologic observations on ventricular tachyarrhythmias following reperfusion.

The threat of reperfusion fibrillation could potentially deter attempts of reperfusion in patients with acute myocardial infarction. Delineation of the mechanisms of this arrhythmia could pave the way to newer interventions designed as prevention or definitive treatment. Therefore the purpose of the present study was to investigate the features of initiation of reperfusion-induced ventricular fibrillation, and further to distinguish between episodic and sustained ventricular arrhythmias following reperfusion. Nine instances of reperfusion ventricular fibrillation and five instances of episodic tachyarrhythmia were analyzed in the study utilizing endocardial bipolar electrograms from normal, ischemic, reperfused, and border of these myocardial segments. In 11 of 14 instances, the site of initiation of the tachyarrhythmias was in the reperfused myocardium; however, maintenance of the arrhythmia defined as diastolic and or continuous electrical activity suggestive of reentry was not seen in the reperfused myocardium in any of these instances. Diastolic electrical activity was observed in 8 of 14 instances, and was seen either in the center or border of ischemic myocardium. Neither heart rate or mean aortic pressure was different between episodic and sustained arrhythmia groups; however, the initial beat of the fatal arrhythmia was significantly more premature than that of episodic arrhythmia. In addition, shorter cycle length, greater variations in the cycle length, and greater disparity in local activation during the tachyarrhythmia were seen in the sustained arrhythmia group compared to the episodic group; cycle length increased and the disparity in local activation improved gradually prior to the termination of the arrhythmia. There was no particular difference in conduction delay immediately prior to reperfusion between control and reperfusion ventricular fibrillation groups. We conclude that different mechanisms exist for the initiation and maintenance of reperfusion-induced arrhythmias. Further, several features seem to distinguish episodic from fatal arrhythmias following reperfusion.

Animals↗
PubMed1983

Comparative study of the effect of slow channel inhibiting agents on ischemia-induced conduction delay as relevant to the genesis of ventricular fibrillation.

Conduction delay has been shown to be an important factor in the genesis of ventricular fibrillation (VF). We evaluated the relationship between conduction delay and (1) initiation of VF and (2) the effects of Ca++ blockers on conduction delay in 41 dogs: eight control (nontreated, non-VF); nine ischemic VF; eight verapamil-treated (0.15 mg/kg bolus followed by 7.5 micrograms/kg/min); eight diltiazem-treated (20 micrograms/kg/min); and eight nifedipine-treated (0.1 mg/kg bolus). Propagation of electrically-induced premature impulses from the midmyocardial bipole of one transmural electrode was recorded at epicardial and endocardial bipoles of other electrodes before and 5, 15, and 30 minutes after coronary ligation. Conduction delay (i.e., conduction times compared to preligation levels) of VF, verapamil, diltiazem, and nifedipine groups were compared to control group in normal and in the center and border of ischemic zones in both base to apex (anterograde) and apex to base (retrograde) directions. Results showed that there was no change in conduction delay in the normal zone between control and VF groups or the treated groups, but both in the center and border of ischemic zone VF was quantitatively related to conduction delay and Ca++ blockers, except that nifedipine significantly reduced conduction delay. We conclude that our model provides a new approach to the assessment of anti-VF intervention. Further, verapamil and diltiazem appear to be useful agents in reducing the risk of ischemia-induced reentrant ventricular tachyarrhythmias.

Animals↗