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Biomedical subjects

T Takishima

Publications and source records attributed to T Takishima.

At least 343 records · Page 19Linked to original sources
PubMed1988

The left ventricular vibration mode in the ventricular transfer function method and at the moment of the first heart sound.

Several investigators have aimed to clarify the patient's left ventricular (LV) physical properties by free vibration analysis of heart sound. Recently we have developed a transfer function (TF) method to calculate the LV viscoelasticity. To clarify whether this TF method and a clinical first heart sound (1 HS) analysis are based on the identical ventricular vibration mode analysis, we examined (1) the visualized LV vibration image in the TF method and (2) the quantitative relationship between the peak frequency of the 1 HS spectrum and that of TF curve in the early and late phase of the 1 HS. Isolated isovolumic potassium arrested canine left ventricles were used to visualize the vibration mode in describing the TF (N = 2). Examination of stroboscopically illuminated, slow-motion images revealed the oscillation of the ventricle to be of mode 2 behavior. To analyze the quantitative relation between the TF method and 1 HS analysis we used ten open-chest dogs. The correlation was good (r = 0.917) when the peak frequency of the TF curve at the early phase of the 1 HS was compared to the peak frequency of the 1 HS. We concluded that both the TF method and 1 HS analysis were based on the common, second-order ventricular vibration mode. Therefore, some information on the ventricular physical properties suggeted by the TF method could also be included in the clinical data obtained by 1 HS analysis.

Animals↗
PubMed1988

[Laboratory and clinical studies on cefotetan in respiratory tract infections].

Seventy five patients with respiratory infections, including 40 cases of acute pneumonia, 33 cases of secondary infection after chronic pulmonary diseases and 2 cases of pulmonary abscess, were treated with cefotetan (CTT, Yamatetan) by drip infusion in order to evaluate its clinical efficacy. The overall rate of effectiveness was 83.8%. CTT was examined comparatively with other beta-lactam antibiotics for antibacterial activity on clinically isolated strains of 3 major respiratory pathogens including Haemophilus influenzae, Branhamella catarrhalis and Streptococcus pneumoniae. Minimum inhibitory concentrations (MIC's) of CTT on H. influenzae were less than 3.13 micrograms/ml regardless of the production of beta-lactamase by these organisms. As to B. catarrhalis, CTT also exerted an antibacterial activity enough to control the proliferation of all the strains at a level of 1.56 micrograms/ml. Against S. pneumoniae, on the other hand, CTT exhibited the lowest activity of all the drugs tested but still showed MIC's of 3.13 micrograms/ml or less. Drip infusion of CTT at a dose of 2 g brought about an average maximum blood concentration of 342 +/- 25.7 micrograms/ml and an average half-life in blood of 2.48 +/- 0.41 hours Maximum sputum concentration of the drug, however, was variable among the cases tested, ranging from 0.40 to 1.80 micrograms/ml. Side effects of the drug were observed in 5 cases or 6.7%. Four of them had some allergic symptoms; i.e., pyrexia and eruption. One patient was especially diagnosed as possible drug-induced interstitial pneumonia during the treatment with the drug. The diagnosis was confirmed by transbronchial lung biopsy and lymphocyte blastogenesis by CTT in vitro. As to abnormal laboratory findings, blood transaminases were elevated during drug administration in 13 cases or 17.3%, but were reduced back to the normal level after the withdrawal of the drug.

Adult↗
PubMed1988

[Clinical trials of flomoxef in patients with chronic respiratory tract infections].

Flomoxef (FMOX, 6315-S), a newly developed oxacephem drug, was administered to 6 patients with chronic respiratory tract infections. Bacteriological examination of these infections using quantitative sputum cultures revealed that 2 patients had Haemophilus influenzae, 2 had Branhamella catarrhalis and 2 had mixed pathogens (one was with H. influenzae + B. catarrhalis and the other with Streptococcus pneumoniae + B. catarrhalis). The administration of the drug was done by drip infusion, twice daily, with a daily dose of 1 to 2 g. As results, all the above mentioned pathogenic organisms were eradicated in 5 to 10 days after the initiation of the drug therapy. No undesirable symptoms were observed in these patients during the course of the chemotherapy. Serum drug concentrations after an intravenous administration of the drug reached their peak values averaging 134.32 +/- 40.32 micrograms/ml immediately after a single dose of 2 g of FMOX in 5 patients with chronic respiratory tract infections. Drug concentration in the sputum was at highest 1.86 micrograms/ml. Susceptibilities to FMOX of clinically isolated 49 strains of H. influenzae and 35 strains of B. catarrhalis from our clinic in the year of 1986 were compared to those to ampicillin and to latamoxef (LMOX). The study revealed that MICs of FMOX against H. influenzae were 0.10 to 1.56 micrograms/ml, hence H. influenzae strains seemed to be sensitive to FMOX regardless of beta-lactamase activities. LMOX had higher activities against H. influenzae than FMOX, however. Activities of FMOX against B. catarrhalis, on the other hand, were distributed from less than 0.05 to 0.39 microgram/ml which were also not as good as LMOX activities.

Aged↗
PubMed1988

[Recent trend of incidence of respiratory pathogenic bacteria and its susceptibility to antimicrobial agents: studies in the year 1984-1986].

Based on a quantitative analysis of sputum cultures, pathogenic bacteria in respiratory ailments isolated in our laboratory during 1984 to 1986 were classified and analyzed. During the study period, the most frequently isolated agent was Haemophilus influenzae followed by Pseudomonas aeruginosa, Branhamella catarrhalis and Streptococcus pneumoniae. They together consisted of 70 approximately 74% of all the respiratory pathogenic bacteria isolated in our study. Susceptibilities of above pathogens to antimicrobial agents were investigated using the agar dilution method. Results are summarized as follows. 1. Ratio of proportion of beta-lactamase producing strains among non beta-lactamase producing strains of H. influenzae markedly decreased in 1986 (6/70, 8.6%) as compared to previous years (11/73, 15.1% in 1984 and 8/49, 16.3% in 1985). In consequence, MIC90 values for penicillins reduced considerably in 1986. Among the antibiotics examined cefmenoxime (CMX) and cefotaxime (CTX) were the most active agents against H. influenzae. A development of resistance to other cephems and new quinolones (norfloxacin, ofloxacin, ciprofloxacin) was not evident during the 3-year survey. 2. Against S. pneumoniae, benzylpenicillin was still the most active agent despite gradual increase of frequency of isolation. Ampicillin (ABPC), piperacillin (PIPC), CMX and CTX were also potent against S. pneumoniae. S. pneumoniae were frequently isolated from patients treated with new quinolones or minocycline (MINO). This phenomenon may be explained by higher MIC values of these agents against S. pneumoniae. 3. Of B. catarrhalis strains isolated, more than 80% were beta-lactamase positive, although MIC90 were not so high (1.56 micrograms/ml for ABPC and 0.20 micrograms/ml for PIPC). Among the antibiotics tested, latamoxef was the most active agent against B. catarrhalis and inhibited all the strains at a concentration of 0.05 micrograms/ml or less. No resistant strains were observed against cephems, new quinolones, erythromycin or MINO. 4. P. aeruginosa appeared to be rapidly developing resistance against new quinolones in patients with chronic P. aeruginosa respiratory infections who had been treated with these agents. In treating chronic respiratory infection due to P. aeruginosa, one must be watchful of rapid development of resistance by the organism or its replacement with S. pneumoniae.

Anti-Bacterial Agents↗
PubMed1987

Bronchodilating effect of intravenous magnesium sulfate in bronchial asthma.

The bronchodilating effect of magnesium sulfate (MgSO4) was studied in ten asthmatic patients with mild attacks. In five patients, 0.5 mmol/min of MgSO4 was administered intravenously for 20 minutes, and the time courses of respiratory resistance, forced vital capacity, and forced expiratory volume at 1 s were studied. In another five patients, MgSO4 dose-response curves were obtained. Soon after administration began, MgSO4 relieved bronchoconstriction in a dose-dependent manner. Maximum responses (mean +/- SE) of respiratory resistance, forced vital capacity, and forced expiratory volume were 71% +/- 3%, 117% +/- 5%, and 118% +/- 1% of initial values, respectively, and were similar to the effects of additional albuterol inhalation. The infusion of MgSO4 also improved dyspnea and piping rales in three other asthmatic patients with a severe attack. We conclude that intravenous infusion of MgSO4 produces a rapid and marked bronchodilation in both mild and severe asthma and may be a unique bronchodilating agent.

Adult↗
PubMed1987

A multicenter study of a new inotropic agent, piperanometozine (OPC-8212) in congestive heart failure: clinical improvement during short-term treatment.

Piperanometozine (OPC-8212) is a new, orally effective inotropic agent. To evaluate the efficacy of this agent on systemic hemodynamics and clinical symptoms in patients with congestive heart failure, a multicenter study was performed. Thirty four patients with New York Heart Association (NYHA) functional classes II to IV and initially treated with digitalis were enrolled from ten centers. After a washout period of one or two weeks (placebo period), digitalis was replaced by piperanometozine (30 or 60 mg/day) for four weeks, while other drugs were continued. Clinical symptoms, routine physical findings, electrocardiogram, chest roentgenogram, echocardiogram, exercise tolerance time, and routine laboratory data were obtained in 34 patients. Four patients were withdrawn from the study before completion. After the withdrawal of digitalis, heart rate was increased and ejection fraction was decreased. Exercise tolerance time was increased while other parameters were unchanged. At the end of the treatment period with piperanometozine, ejection fraction significantly (p less than 0.05) increased with a decrease in LV end-systolic volume (p less than 0.05), whereas heart rate and blood pressure remained unchanged. Systolic blood pressure/LV end-systolic volume (P/V index) tended to decrease after the withdrawal of digitalis and increase during piperanometozine therapy. Exercise tolerance time was further increased (p less than 0.01) and NYHA functional class was improved in 11 patients, whereas it worsened in only one patient. No major adverse effects were observed. These results indicate that a short-term therapy of oral piperanometozine restored the depressed cardiac performance of the heart and improved clinical symptoms in patients with congestive heart failure. Thus, this promising agent deserves further clinical study in long-term trials.

Aged↗
PubMed1987

Iodine-123 IMP SPECT before and after bypass surgery in a patient with occlusion of left anterior and middle cerebral arteries with basal abnormal telangiectasis (unilateral Moyamoya disease).

A case of left anterior and middle cerebral arterial occlusion with angiographic features similar to Moyamoya disease was reported. IMP SPECT of the patient revealed the success of bypass surgery clearly. The patient complained of transient right hemiparesis with aphasia 4 times. The cerebral arteriography disclosed occlusions of left anterior and middle cerebral arteries at their proximal portions. Right internal carotid and its branches were normal. I-123 IMP SPECT study showed hypoperfusion in left temporal lobe, basal ganglia with incomplete reperfusion on the delayed (4 hours after injection) SPECT images. After the superficial temporal-middle cerebral artery anastomosis, I-123 IMP SPECT showed improvement of the brain blood flow. I-123 IMP SPECT was very useful in detecting the ischemic areas and evaluating the revascularizing surgery in this case.

Adult↗
PubMed1987

A new method of inhalation challenge with propranolol: comparison with methacholine-induced bronchoconstriction and role of vagal nerve activity.

To establish a safe procedure for examining propranolol-induced bronchoconstriction, we have developed a new method for performing inhalation challenge with propranolol. Monitoring respiratory resistance during tidal breathing with continuous inhalation of propranolol in 1.5-fold increasing concentrations from 0.78 to 30 mg/ml for 1 minute at each concentration, we tested 43 subjects with stable asthma and 10 normal subjects. We also compared bronchial responsiveness with responsiveness to inhaled methacholine on separate days. In addition, to determine the role of vagal nerve activity in propranolol-induced bronchoconstriction, we studied the effect of atropine. Inhaled propranolol caused dose-related bronchoconstriction in all subjects with asthma but not in normal subjects. None of the subjects suffered severe asthmatic attack during the test, which was performed in 15 minutes or less. The minimum cumulative dose of methacholine and of propranolol, at the point where respiratory conductance began to decrease, was not significantly correlated. Increased respiratory resistance was reversed by atropine in 70% of the subjects with asthma with marked individual differences. These data suggest that, although in most subjects with asthma, vagal nerve activity contributes in varying degree to bronchoconstriction, other constricting factors may contribute in the remaining subjects. It is also suggested that the mechanism of bronchial response to propranolol differs from that of the nonspecific airway reactivity estimated by methacholine challenge.

Adolescent↗
PubMed1987

Myocardial imaging using 11C-CoQ10 with positron emission tomography.

The potential of 11C-labeled coenzyme Q10(CoQ10) as a myocardial imaging tracer was explored with positron emission tomography (PET). Serial myocardial imaging studies were performed using 11C-CoQ10, 45Ti-diethylenetriaminepentaacetic acid (45Ti-DTPA), and 2-deoxy-2-[18F]fluoro-D-mannose (18FDM) in the same dog. Cross sectional images of the heart with 11C-CoQ10 showed relatively high radioactivity in the blood pool, when compared with images taken with 18FDM. However, when the blood spillover of radioactivity is adequately corrected with 45Ti-DTPA data, it was found that 11C-CoQ10 accumulated in the myocardium with time.

Animals↗
PubMed1987

Effect of antibiotics on immediate hypersensitivity reactions in vitro: suppression of IgE-mediated histamine release from peripheral blood basophils by fosfomycin.

The effect of antibiotics on allergic reactions was studied in vitro using the release of histamine from human peripheral blood leukocytes (basophils) after incubation with anti-IgE. For the several antibiotics we tested, including beta-lactams and aminoglycosides, none had the capacity to enhance antigen-induced histamine release, but some of them (minocycline, polymyxin B, and fosfomycin) suppressed the release of histamine in a dose-dependent manner. Since fosfomycin has proved to be capable of suppressing IgE-mediated histamine release non-cytotoxically, the effect of fosfomycin on histamine release induced by other secretagogues was further studied. The suppression of histamine release was also demonstrated when the leukocytes, preincubated with fosfomycin, were challenged with either Ca ionophore A 23187 or a synthetic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP). We concluded that some antibiotics, particularly fosfomycin, have the capacity to suppress histamine release mediated by various secretagogues, suggesting they may possess an anti-allergic property as well as a bactericidal activity.

Anti-Bacterial Agents↗
PubMed1987

Twitch contractions during low Na+-induced [Ca2+]i overload in rat ventricular muscle.

To elucidate the mechanisms of the negative inotropism induced by excessive intracellular Ca2+ ([Ca2+]i), we observed detailed characteristics of twitch contractions during low Na+-induced [Ca2+]i overload. Rat right ventricular trabecular muscles were superfused with a low-Na+ solution ([Na+]o:50, 25, 18, and 14 mM), obtained by substituting choline-Cl for NaCl at 30 degrees C on the stage of an inverted microscope and electrically stimulated at the rate of 12 pulses/min (n = 6). Each low-Na+ perfusion decreased developed tension with the increase in resting tension (Ca2+ overload). As [Na+]o decreased below 50 mM, peak contracture tension increased and developed tension at peak contracture decreased. The decrease in developed tension coincided with the appearance of the marked aftercontractions and with the increase in fluctuating intracellular contractile activities during the resting period, which have been ascribed to [Ca2+]i oscillations. Neither maximum rate of tension development nor minimum rate of relaxation showed significant changes during the phase of Ca2+ overload. These results suggest that the decrease in developed tension during Ca2+ overload is due to [Ca2+]i oscillations, rather than due to depressed contractility and relaxation.

Animals↗
PubMed1987

Neural control of contraction in isolated submucosal gland from feline trachea.

To determine the autonomic innervation to myoepithelial cells of submucosal gland, we applied electrical field stimulation (FS) to the intrinsic nerves in isolated submucosal glands from feline tracheae. FS induced contraction that was voltage or frequency dependent and abolished by pretreatment with tetrodotoxin. DMPP (1,1-dimethyl-4-phenylpiperazinium iodide) did not produce any significant contraction, and pretreatment with hexamethonium did not alter the response to FS. Atropine inhibited the contractile response to FS and neostigmine augmented the response to FS. Serotonin also augmented the response to FS, whereas the response to methacholine remained unchanged in the presence of serotonin. Phentolamine reduced the response to FS by 15% of control, whereas propranolol induced no significant changes in the response to FS. No significant inhibitory responses were observed by FS. Our findings indicate that the contraction of tracheal submucosal glands is mediated mainly by cholinergic nerves via muscarinic receptors and in small part by adrenergic nerves via alpha-receptors, and serotonin potentiates the contractile response to FS at the postganglionic nerve.

Adrenergic Fibers↗
PubMed1987

Ventilatory effectiveness of high-frequency oscillation applied to the body surface.

To determine the ventilatory effectiveness of high-frequency oscillation (HFO) at different sites on the body surface, we applied HFO separately to the abdomen, the rib cage, or the whole body in eight anesthetized and paralyzed dogs. Test frequencies were 5, 7, 9, and 11 Hz with tidal volume kept constant at 2.5 ml/kg. During HFO application to the abdomen, we observed significantly higher arterial O2 partial pressure (P less than 0.05) at 5, 7, and 9 Hz and lower arterial CO2 partial pressure (P less than 0.05) at 7, 9, and 11 Hz than with rib cage or whole-body HFO. There was no significant difference in blood gases between rib cage and whole-body HFO. Thus, using blood gases as an index of ventilatory effectiveness, the present study showed that HFO applied at the abdomen was the most effective of the three kinds of body surface HFO. In comparison to rib cage or whole-body application, abdominal HFO was accompanied by substantial paradoxical movement of the diaphragm and rib cage. The associated lung distortion may result in pendelluft, which in turn may be the mechanism for increased ventilatory effectiveness with abdominal application of HFO.

Abdomen↗
PubMed1987

Effect of digitalis on the diaphragm in anesthetized dogs.

We examined the effect of digitalis on diaphragmatic contractility and fatigability in 19 anesthetized mechanically ventilated dogs. The diaphragmatic force was assessed from transdiaphragmatic pressure (Pdi) developed at functional residual capacity against an occluded airway during cervical phrenic nerve stimulation. In a first group of five dogs, Pdi-stimulus frequency relationships were compared before and after administration of ouabain in doses of 0.01, 0.02, and 0.04 mg/kg. In a second group, diaphragmatic fatigue was produced by bilateral phrenic nerve stimulation at 30 Hz. Ten seconds of stimulation and 15 s of mechanical ventilation were repeated for 30 min. The rates of decrease in Pdi were compared between two groups, one of 0.05 mg/kg deslanoside-treated dogs (n = 7) and one of nontreated dogs (n = 7). After ouabain administration Pdi was significantly greater at each frequency in a dose-dependent manner. On the other hand, the rate of decrease in Pdi in the deslanoside group was significantly smaller than that in the nontreated group, whereas deslanoside did not greatly change the Pdi-frequency curves in fresh diaphragm. We conclude that ouabain improves contractility of the fresh diaphragm and that deslanoside has a protective effect against fatigability.

Animals↗