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Biomedical subjects

Y Miyajima

Publications and source records attributed to Y Miyajima.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Analysis of hemostatic abnormality in various disease using molecular-I. Liver disease].

We examined the hemostatic abnormality of liver disease using hemostatic molecular markers, i.e. TAT, FPA and SFMC for coagulation, B beta 15-42, FDP, D dimer and PIC for fibrinolysis, t-PA and TM for vessel wall. The molecular markers for coagulation were generally increased in cases of liver disease, which was most sensitively reflected by FPA. On the other hand, it was postulated that SFMC was a marker reflecting the complication of DIC in these cases. Hyperfibrinolysis of liver disease was sensitively reflected by the increase of B beta 15-42, and an occasional increase of SFMC or FDP was thought to indicate the complication of DIC in these cases. A high correlation was found between t-PA and TM. It was postulated that the increase of the both markers in liver disease was due to deteriorated clearance by liver dysfunction, although TM is regarded as a marker reflecting endothelial injury. It was expected that visualization of hemostatic disorder of liver disease was made practical with the use of radar chart of these molecular markers.

Antifibrinolytic Agents↗
PubMed1991

A method of measuring the peak flow rate and the regurgitant volume of regurgitation based on the characteristics of turbulent free jets.

The issuing flow rate of a jet, Q0, is given by Q0 = U0A, where U0 is the issuing velocity of the jet and A is the cross-sectional area of the orifice. However, measurement of A of a regurgitant jet in the cardiovascular system is difficult. On the assumption that the jet is 'free' and turbulent, the following relations apply between the diameter of the orifice D, the length of the core region of the jet L, the centerline velocity of the jet Uc(chi) at an arbitrary distance chi(greater than L) from the orifice, and U0:L = 6.8D and Uc(chi)/U0 = L/chi. From these equations we obtain Q0 = 0.017 (chi Uc(chi))2/U0. Pulsatile jets issuing into an aqueous glycerol bath through orifices with various diameters were studied. U0, chi and Uc(chi) were measured with a color Doppler system. There was a good linear correlation between the peak flow rates estimated from the above equation and those measured with a flowmeter irrespective of the diameter of orifices (y = 0.93 chi + 3.8, r = 0.95, SEE = 6.6 ml/s). Assuming that the flow rate waveform is similar to the issuing velocity waveform, we estimated the issuing volume per stroke by integrating the issuing velocity. There was a good linear correlation between the estimated issuing volume and the known stroke volume of the pump (y = 1.0 chi + 2.6, r = 0.92, SEE = 2.8 ml).

Blood Flow Velocity↗
PubMed1990

Establishment of enzyme immunoassay of human thrombomodulin in plasma and urine using monoclonal antibodies.

Thrombomodulin, TM, is an endothelial cell membrane protein acting as a cofactor for the activation of plasma protein C. Soluble TM is present in plasma and urine of normal subjects. Enzyme immunoassay, EIA, for human TM was developed using mouse monoclonal antibodies against human placental TM in this paper. We obtained four types of the monoclonal antibodies against human placental TM. EIA sandwich method using three types of the monoclonal antibodies enabled us to measure almost all of 6 and 7 TM subspecies in plasma and urine, respectively, except 1 subspecies, 31 kDa TM. There was no interference from other components of plasma and urine in the assay conditions. Titration curves of purified TM in buffer or in normal plasma were linear within the range from 0.08 to 10 ng/ml. The coefficient of variation at 0.08 ng/ml TM was 4.7%. TM titer with buffer, assayed by this method, was reduced by the addition of thrombin at the final concentration of 20 U/ml, but the titer with plasma was not reduced even at 100 U/ml. These concentrations of thrombin are far larger than those which would be formed in circulation. TM levels in plasma and urine of normal subjects collected in the morning were 35.2 +/- 8.32 ng/ml (n = 346) and 111 +/- 31.6 ng/ml (n = 33), respectively. TM level in plasma did not differ from the level in serum. Circadian fluctuation of plasma TM was not significant in 10 normal adults, although a tendency of increase in TM excretion to urine was found rather in the day time than the other times.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Transient fever with abnormal liver function in patients underwent bone marrow transplantation--clinical symptom of cytomegalovirus infection].

In seventeen (38.6%) out of forty-four children underwent bone marrow transplantation, transient fever with abnormal liver function tests occurred between 30 and 70 days following bone marrow transplantation. More than half of cases suffered from nausea, anorexia and general malaise. C reactive protein was negative in all but one case, and thrombocytopenia occurred in five cases. Transient fever with abnormal liver function tests occurred more frequently in patients with cytomegalovirus (CMV) infection (63.4%) than in patients without CMV infection (16.0%) (P less than 0.01). Therefore, CMV infection was considered to be the cause of transient fever with abnormal liver function tests. The incidence of transient fever with abnormal liver function tests was not significantly different between the patients with pretransplant positive anti-CMV titer and the patients with pretransplant negative anti-CMV titer. Clinical symptoms improved in 16 patients (93.4%), but fatal CMV interstitial pneumonia followed in one case.

Adolescent↗
PubMed1990

[Autologous bone marrow transplantation in children with acute leukemia].

Eight children with acute leukemia were treated with chemoradiotherapy or high-dose chemotherapy followed by infusion of autologous marrow unpurged or purged mainly with monoclonal antibodies. Four were treated in their first remission, three in their second remission, and one in the fourth remission. Patients were isolated in laminar air flow rooms with sterile conditioning. Infused mononuclear cells ranged from 1.0 to 3.8 x 10(7)/kg. Hematologic engraftment was obtained in five patients. The other three patients, who were treated with monoclonal antibody or drug, received unpurged back up marrow because of delayed bone marrow reconstitution. Two recovered, but one died before engraftment. Hematologic recovery was delayed after autologous bone marrow transplantation. The median time to achieve 1,000 leukocytes/microliters, 500 neutrophils/microliters, and last platelet transfusion was 36 days (12-90), 36 days (12-90), and 70 days (39-214), respectively. Moreover, further increases beyond these levels remained unusually slow, especially in platelets. Two of eight patients relapsed at 5 and 15 months and the other patient died of interstitial pneumonitis. Actuarial disease free survival was 62.5%. There was a trend toward improved disease free survival for patients transplanted in the first remission (100%).

Adolescent↗
PubMed1989

[Pharmacokinetic, bacteriological and clinical studies on sulbactam/ampicillin in pediatric field].

Clinical trials were carried out on the use of sulbactam/ampicillin (SBT/ABPC) (combination rate of 1:2) in pediatric infections. Results were as follows: 1. The mean half-lives of SBT and ABPC in the serum following intravenous injection of SBT/ABPC were about 1.05 and 0.90 hours, respectively. 2. The mean urinary excretions of SBT and ABPC in 6 hours after intravenous injection of SBT/ABPC were 71.2% and 62.2%, respectively. 3. SBT/ABPC was administered to 23 pediatric patients with various infections: 17 patients with pneumonia, 3 with tonsillitis, 2 with urinary tract infection and 1 with cervical lymphadenitis. The overall efficacy rate was 95.7%. In particular, 2 urinary tract infections caused by highly beta-lactamase producing Escherichia coli were improved by the treatment with SBT/ABPC. 4. No adverse reactions were observed except 2 cases of mild diarrhea. Abnormal laboratory test values included thrombocytosis in 4 and slight elevation of GOT and GPT in 1, but they were transient.

Age Factors↗
PubMed1987

[Bacteriological and clinical studies of flomoxef in the field of pediatrics].

Bacteriological and clinical studies with flomoxef (FMOX, 6315-S), a new oxacephem antibiotic, were carried out in the field of pediatrics and the results obtained are summarized as follows: 1. The antimicrobial activity of FMOX against clinically isolated organisms was determined. FMOX had a good antimicrobial activity against Streptococcus pneumoniae, Escherichia coli, Haemophilus influenzae and especially against Staphylococcus aureus (including methicillin resistant S. aureus). 2. Mean serum concentrations of FMOX following intravenous bolus injection of 20 and 40 mg/kg (in 7 and 4 cases, respectively) were 35.3 and 77.7 micrograms/ml at 15 minutes after administration with mean serum half-lives (T1/2) of 0.75 and 0.95 hours and mean urinary recovery rates up to 6 hours after administration were 71.9 and 65.1%, respectively. 3. Twenty-five pediatric patients (19 cases of pneumonia, 1 case of pyothorax and 5 cases of urinary tract infection) were treated with FMOX in doses ranging from 50 to 138 mg/kg divided into 3 or 4 times a day. The rate of clinical effectiveness was 100% and the bacterial elimination rate was 90.6%. 4. No adverse reactions were observed. Abnormal laboratory findings were eosinophilia in 1, thrombocytosis in 2 and slight elevations of GOT and GPT in 3 patients. These results indicate the usefulness and the safety of FMOX in the treatment of bacterial infections in the pediatric field.

Age Factors↗
PubMed1987

[Fundamental and clinical studies on cefuzonam in the field of pediatrics].

Fundamental and clinical studies on cefuzonam (L-105, CZON), a newly semisynthesized cephem antibiotic, were carried out in the field of pediatrics and the following results were obtained. Antibacterial activities of CZON against clinically isolated strains of Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae, S. pyogenes, Escherichia coli, Klebsiella pneumoniae, Haemophilus parainfluenzae and H. influenzae were compared with those of cefmenoxime (CMX), latamoxef (LMOX), cefoperazone (CPZ), cefmetazole (CMZ), cefotiam (CTM) and cefazolin (CEZ). CZON was nearly as active as CEZ against S. aureus and S. epidermidis and superior to other antibiotics against other Gram-positive cocci. Against Gram-negative rods, CZON was as active as CMX and superior to other 5 antibiotics compared. Serum concentrations and urinary excretion rates after intravenous bolus injection of CZON at doses of 10 mg/kg, 20 mg/kg and 40 mg/kg for 5 minutes in 1, 5 and 4 cases, respectively, were determined. Mean serum concentrations of CZON at these dose levels were 11.0, 43.8 and 111.5 micrograms/ml at 15 minutes, 2.4, 10.3 and 30.3 micrograms/ml at 1 hour and 0.17, 0.72 and 1.28 micrograms/ml at 4 hours, with serum half-lives of 1.79, 0.88 and 1.19 hours, respectively. Mean cumulative urinary excretion rates within 6 hours after administration were 47.9, 56.3 and 40.3%, respectively. Thirty-four pediatric patients with various bacterial infections (tonsillitis 2, acute bronchitis 1, pneumonia 14, pyothorax 1, sepsis 1, suppurative lymphadenitis 1, UTI 13 and enteritis 1) were treated with CZON at a daily dose of 40-94 mg/kg t.i.d. or q.i.d.. The overall clinical efficacy rate was 94.1%. No adverse reactions were observed except 2 cases with mild diarrhea. Abnormal laboratory findings were also mild; slight elevation of GOT and GPT in 2, eosinophilia in 1 and thrombocytosis in 1. These results clearly indicate the usefulness of CZON in the treatment of bacterial infections in children.

Age Factors↗
PubMed1985

Calcium antagonistic properties of nicardipine, a dihydropyridine derivative assessed in isolated cerebral arteries and cardiac muscle.

Calcium antagonistic properties of nicardipine (YC-93), a 1,4-dihydropyridine derivative, were studied in isolated cerebral artery and cardiac tissues of rabbits and dogs. Calcium antagonism was assessed in electrically stimulated rabbit basilar artery. Nicardipine at 10(-7) mol/l shifted to the right the dose-response curve for Ca of the phasic contraction evoked by electrical stimulation with an alternating current, and at higher concentration it reduced the maximum tension and slope of the dose-response curve. Nicardipine inhibited the augmented contraction produced by high K, k-strophanthin and 5-hydroxytryptamine. It also caused dose-dependent inhibition of 45Ca uptake enhanced by 80 mmol/l K in dog basilar artery, and had a slight effect on the resting 45Ca uptake. In rabbit basilar artery treated with saponin, nicardipine in a dose of 10(-5) mol/l had no apparent effect on the increase in tension induced by excess Ca. Nicardipine had negative inotropic and chronotropic actions. These results suggest that nicardipine, like nifedipine, has a relative high vascular selectivity, and primarily acts by inhibiting Ca influx through the plasma membrane of vascular and cardiac tissues.

Animals↗
PubMed1983

Effects of prolonged administration of indenolol in hypertensive rats.

The effects of 4-week administration and subsequent 2-week withdrawal of indenolol, 50 mg/kg/day p.o., were investigated in spontaneously hypertensive rats (SHR), renal hypertensive rats (RHR) and DOCA-salt hypertensive rats (DHR) at established stage, and compared with those of propranolol, 100 mg/kg/day p.o. Indenolol and propranolol caused a marked decrease in heart rate in SHR, RHR and DHR without showing a pronounced antihypertensive activity. Both drugs did not affect the body weight gain in RHR and DHR. On the other hand, the drugs suppressed the body weight gain in SHR, which recovered during 2-week withdrawal period. Weights of the heart, kidney, liver, spleen and adrenals were not affected by the drugs. Indenolol and propranolol markedly lowered the plasma renin activity (PRA) in SHR, RHR and DHR. PRA in RHR and DHR recovered to the control level during 2-week withdrawal period, while that in SHR did not. The results indicate that indenolol produces essentially the same effect as propranolol in SHR, RHR and DHR. Prolonged administration of indenolol to SHR, RHR and DHR with established hypertension produces a marked suppression of cardiac performance and PRA with showing antihypertensive activity.

Adrenergic beta-Antagonists↗
PubMed1979

[Experimental study on canine gastric motility following selective proximal vagotomy (author's transl)].

Electromyographical studies were made on the gastric motility of dogs following selective vagotomy (SV) and selective proximal vagotomy (SPV) as the subsequent studies on the changes after truncal vagotomy (TV) after which gastric motility is fairly disturbed, and the influence of pyloroplasty additionally performed to SPV. Gastric discharge frequency was suppressed by SV similar to that by TV. Dysrhythmia of motility occurred after gastric vogotomy. Restoration to the normal was the fastest after SPV. Changes in the discharge frequency after SPV did not differ much from those in the normal stomach and other types of vagotomy. With SPV, the decrease in the propagation velocity of basic electrical rhythms (BER) was mild, and a pattern similar to the control was shown compared with TV and SV. The antiperistaltic discharge was observed even with SPV, but the frequency was low compared with TV and SV. The frequency of peristaltic discharge was the highest when pyloroplasty was performed in addition to SPV. The responses to vagostigmine, insulin tetragastrin in SPV were similar to those in the normal stomach. During the gastric emptying time, there was neither difference before and after SPV, nor any significant difference due to the presence or absence of pyloroplasty. The above data show that SPV is advantageous for retaining the function of gastric peristalsis, also for gastric secretion, but the addition of pyloroplasty will not be advantageous for the elimination of gastric content.

Action Potentials↗
PubMed1976

Precipitation hardening in gold-cobalt alloys.

The precipitation hardening in gold-cobalt alloys containing less than 5 wt.%Co was studied by means of resistivity, hardness, X-ray diffraction, and optical microscopic examination. The hardness curves showed two hardness peaks after isothermal ageing below the temperature of 250 or 300 degrees C. It was considered that the first peak was due to the formation of G.P. zone which was confirmed by reversion phenomenon. The second peak was due to the growth of metastable cobalt-rich precipitate, and this stage was found to make a major contribution to the age-hardening in the present alloys. The nodular products at grain boundary do not play an important role in age-hardening. Acitvation energies, order of the reaction involved, and the rate constant for the growth process were established. The difference in growth mechanism of the metastable precipitate was deduced from the kinetics data.

Chemical Precipitation↗
PubMed1975

[Studies on the dental gold-alloys (13). Precipitation hardening in gold-cobalt alloys (author's transl)].

The precipitation of cobalt from gold-rich solid solution was studied about Au-Co binary alloys containing less than 5 wt.% cobalt by correlating the results of metallographic observation and micro-hardness measurement to electrical resistivity measurements. The hardness curves of the alloys showed to hardness peaks after isothermal ageing below a certain temperature. It was considered that the first peak was due to formation of G. P. zone which was confirmed by reversion phenomenon. The second peak was due to growing of metastable cobalt rich precipitate. The maximum hardness obtained by ageing was higher in Au-5 wt.% Co alloy than in Au-1 wt.% Co alloy. Difference in growing mechanism of metastable precipitate was deduced from the kinetics data and the values of time exponent obtained by Johnson-Mehl equation.

Cobalt↗