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Biomedical subjects

I Kajiwara

Publications and source records attributed to I Kajiwara.

17 recordsLinked to original sources
PubMed2001

Enhanced platelet aggregation in the coronary circulation after coronary spasm.

A recently developed platelet aggregometer using a laser light scattering method is capable of monitoring the increase in size of small-sized platelet aggregates (diameter 9-25 microm), which cannot be detected with the conventional methods. Whether coronary spasm can cause platelet aggregation in the coronary circulation is unknown. We investigated platelet aggregation, especially small-sized platelet aggregates, simultaneously in the coronary sinus and the aortic root in 18 patients with coronary spastic angina before and after a left coronary artery spasm induced by intracoronary injection of acetylcholine, and in 15 patients with stable exertional angina before and after acute myocardial ischemia induced by rapid right atrial pacing. Platelet aggregation in 12 patients with chest pain syndrome was also examined before and after coronary spasms provoked by acetylcholine. The number of small-sized platelet aggregates increased significantly in the coronary sinus [2.0+/-0.6 x 104 to 4.1+/-1.0 x 104 (V), P<.01] and in the aortic root [1.7+/-0.6 x 104 to 3.2+/-0.6 x 104 (V), P<.05], and the coronary sinus-arterial difference in the number of small-sized platelet aggregates [2.3+/-1.9 x 103 to 1.1+/-0.4 x 104 (V), P<.01] increased significantly after attacks in the coronary spastic angina group, but remained the same in the stable exertional angina group after attacks and in the chest pain syndrome group after the administration of acetylcholine. Therefore, we can conclude that acute myocardial ischemia induced by coronary spasm causes platelet aggregation in the coronary circulation.

Acetylcholine↗
PubMed2001

The prognostic value of small-sized platelet aggregates in unstable angina: detection by a novel laser-light scattering method.

Platelet activation plays a pivotal role in the pathogenesis of acute coronary syndromes. This study was designed to evaluate the platelet aggregability in patients with unstable angina using a new aggregometer with laser-light scattering. We also examined whether there was a relationship between these platelet aggregabilities and unfavorable outcome during in-hospital stay. We measured platelet aggregability, in particular small-sized platelet aggregates in 31 patients with unstable angina, 31 patients with stable exertional angina, and 30 patients with chest pain syndrome. The patients with unstable angina were divided into two groups by their cardiac events during in-hospital stay, cardiac events (+)(n=11) group and cardiac events (-)(n=20) group. On admission, the number of small-sized platelet aggregates (V) was higher in patients with unstable angina (3.0+/-0.5x10(4)) than in those with stable exertional angina (1.4+/-0.3x10(4), P=.017) and chest pain syndrome (0.7+/-0.2x10(4), P=.0003). The number of small-sized platelet aggregates was higher in the cardiac events (+) group than in the cardiac events (-) group (5.5+/-0.9x10(4) vs. 1.6+/-0.4x10(4), P=.0001). A previous study elucidated that small-sized platelet aggregates ultimately developed into medium-sized and large-sized aggregates as platelet aggregation proceeds. Therefore, the production of small-sized platelet aggregates is more sensitive for hyperaggregability. Furthermore, the production of small-sized platelet aggregates increased significantly in patients with unstable angina than in those with stable exertional angina and chest pain syndrome. These findings suggest that a tendency toward thrombus formation increases markedly in patients with unstable angina and increased number of small-sized platelet aggregates on admission predicts poor prognosis during in-hospital stay in patients with unstable angina.

Adult↗
PubMed2001

Increased autoantibodies against oxidized low-density lipoprotein in coronary circulation in patients with coronary spastic angina.

Oxidized low-density lipoproteins are important in the progression of atherosclerosis. Autoantibodies against malondialdehyde-modified low-density lipoproteins have been reported to be predictive of the progression of atherosclerosis. This study sought to examine whether plasma levels of autoantibodies against oxidized low-density lipoprotein increase in the coronary circulation in patients with coronary spastic angina. The authors examined plasma antioxidized low-density lipoprotein antibody levels (activity unit values (AcU)/mL) simultaneously in the coronary sinus and the aortic root in 20 patients with coronary spastic angina, 23 patients with stable exertional angina, and 15 control subjects by measuring plasma levels of immunoglobulin G (IgG) autoantibodies against malondialdehyde-modified low-density lipoproteins by enzyme-linked immunosorbent assay. The plasma antioxidized low-density lipoprotein antibody levels (AcU/mL) in the coronary sinus increased in coronary spastic angina (38 +/- 16) compared with stable exertional angina (23 +/- 7) and control subjects (20 +/- 6) (p < or = 0.0001). The levels (AcU/mL) in the aortic root also increased in coronary spastic angina (33 +/- 12) compared with stable exertional angina (23 +/- 7) and control subjects (20 +/- 6) (p < 0.005). Furthermore, the coronary sinus-arterial differences of the levels (AcU/mL) were also higher in coronary spastic angina (5 +/- 9) than in stable exertional angina (0 +/- 6) and healthy subjects (-1 +/- 5) (p < 0.05). The generation of malondialdehyde-modified low-density lipoproteins is reported to be associated with atherothrombosis. These findings suggest that elevated levels of autoantibodies against malondialdehyde-modified oxidized low-density lipoproteins in coronary circulation are associated with the development of atherothrombosis from the progression of atherosclerosis rather than with the extent of coronary atherosclerosis in patients with coronary spastic angina.

Acetylcholine↗
PubMed2000

[Clinical study of an outbreak of aseptic meningitis due to echovirus type 30 in Munakata City in 1997-1998].

From October, 1997 through July, 1998, an outbreak of aseptic meningitis due to echovirus type 30 occurred in the northern part of Kyushu area in Japan. In this outbreak, clinical and virologic observations were carried out on 157 in-patients with aseptic meningitis at our hospital. The age of the patients ranged from 1 year and 9 months to 57-year old. One hundred and twenty out of 157 cases were the children under 15 years of age, and in this age group, male/female ratio was 2:1. The largest proportion of cases occurred in the 5- to 9-year age group. The number of cases reached a peak in December, 1997, but the epidemic extended to the next summer. In 12 families, more than one person became ill (total 22 cases). Virus isolation from cerebrospinal fluid (CSF) was tried on 130 out of 157 cases. Echovirus 30 was isolated in 74 cases (58 children, 16 adults), and echovirus 18 in 9 cases from June, 1998 until the end of the study. Paired acute and convalescent sera were available from the 25 patients with negative virus isolation, and 7 out of 25 patients had a fourfold or greater rise in neutralizing antibodies. Headache, fever, vomiting, nuchal rigidity were detectable in most cases, but in this outbreak, continued severe headache was characteristic. Eye pain was experienced by 2% of the total cases. In children, gastrointestinal symptoms were noted in 12% of the cases, but were not in adult patients. The CSF cell counts ranged from 2 to 3,478 cells per cubic millimeter. Fifty-eight percent were predominantly lymphocytic, while 42% were polymorphonuclear predominant. Virus was highly isolated from the CSF when the specimens were obtained within three days after the onset of the acute illness, but in one case, virus was isolated on day 7. In a few cases, virus was isolated without pleocytosis in CSF.

Adolescent↗
PubMed2000

Increased blood vascular endothelial growth factor levels in patients with acute myocardial infarction.

Vascular endothelial growth factor (VEGF) is a growth factor for vascular endothelial cells in vitro. The present study was designed to determine whether serum VEGF levels increase in patients with acute myocardial infarction (AMI) compared with patients with stable exertional angina and control subjects, and to examine the serial changes of serum VEGF levels in patients with AMI. We examined serum VEGF levels by using antibody prepared from serum immunized with human VEGF(121). The serum VEGF level (pg/ml) was higher (p < 0. 0001) on admission in the patients with AMI (177 +/- 19) than in those with stable exertional angina (61 +/- 7) and control subjects (62 +/- 6). The serum VEGF level (pg/ml) of the patients with AMI was 177 +/- 19 on admission, 125 +/- 9 on day 3, 137 +/- 11 on day 5, 242 +/- 18 at 1 week, and 258 +/- 22 at 2 weeks after admission. The value was higher on admission than on day 3 after admission (p = 0.014), the values were higher at 1 week and 2 weeks than on admission, on day 3, and 5 (p < 0.01). Furthermore, there were correlations between peak VEGF levels at 1 week or 2 weeks after admission and peak creatine kinase levels. The increase of VEGF on admission in the patients with AMI may be due to the hypoxia of acute myocardial ischemia. The elevation at 1 week and 2 weeks from the onset may cause the development of collateral circulation in relation to the healing of the infarction site.

Aged↗
PubMed2000

Increased rate of formation of small-sized platelet aggregates in patients with acute coronary syndromes.

Coronary thrombosis has been implicated in the pathogenesis of acute coronary syndromes, and platelet activation plays a pivotal role in the pathogenesis of coronary thrombus. A new platelet aggregometer using a laserlight scattering beam was trialled for assessment of platelet aggregation. Platelet aggregability, especially small-sized platelet aggregates, was investigated on admission using the laser-light scattering method and again after treatment in 23 patients with acute coronary syndromes. The platelet aggregability in 14 patients with stable exertional angina and in 14 control subjects was also examined. On admission, the number of small- and medium-sized platelet aggregates in the acute coronary syndromes group was significantly greater than in the stable exertional angina group or control group. However, the number of large-sized platelet aggregates on admission was not increased in the acute coronary syndromes group. Furthermore, the number of small- and medium-sized platelet aggregates decreased significantly after treatment in the acute coronary syndromes group. The increased number of small-sized platelet aggregates may sensitively reflect attacks of thrombosis in patients suffering acute coronary syndromes.

Acute Disease↗
PubMed1997

Renal angiosarcoma: a case report.

We report the first case of angiosarcoma in the kidney occurring in a woman; the tumor was initially believed to be renal cell carcinoma. This malignant tumor was discovered in a patient with macrohematuria. The final diagnosis was confirmed by histologic and immunohistochemical findings. A review of the literature on this tumor is also included in the discussion.

Angiography↗
PubMed1996

The influence of oxygen free radical scavengers on the reduction of membrane-bound Na(+)-K(+)-ATPase activity induced by ischemia/reperfusion injury in the canine kidney.

The present study was designed to determine whether the administration of free radical scavengers, superoxide dismutase (SOD), catalase or dimethylsulfoxide (DMSO) is able to ameliorate ischemia/reperfusion injury in the canine kidney and also ascertain whether or not a relationship exists between oxygen free radicals and membrane-bound Na(+)-K(+)-ATPase activity. In 23 dogs, the vascular pedicle of the left kidney was clamped for 75 min at room temperature. The experimental animals received free radical scavengers for 30 min starting at 2 min prior to reperfusion. Renal tissue specimens were enzyme-histochemically examined regarding the activity of membrane-bound Na(+)-K(+)-ATPase, and a marked reduction just before reperfusion was revealed. The SOD- and the DMSO-treated groups showed a marked recovery of the membrane-bound Na(+)-K(+)-ATPase activity; however, the untreated and the catalase-treated groups still demonstrated a marked reduction 1 day after reperfusion. At the same time, widespread acute tubular necrosis in the cortex was observed in the untreated and catalase groups in comparison with the SOD and the DMSO groups. In addition, the SOD and the DMSO groups significantly preserved better renal function. Based on these findings, it was thus concluded that free radical scavengers ameliorate the recovery of depressed membrane-bound Na(+)-K(+)-ATPase activity and ischemia/reperfusion injury in the canine kidney.

Animals↗
PubMed1996

An analysis of monocyte/macrophage subsets and granulocyte-macrophage colony-stimulating factor expression in renal allograft biopsies.

The role of infiltrating macrophages in the pathogenesis of acute rejection was investigated in biopsy specimens obtained from human transplanted kidneys using immunohistochemical methods. Thirty-one allograft tissue specimens obtained from 26 patients were histologically classified into 18 with acute rejection, 7 with borderline change and 6 with chronic rejection according to the Banff working classification (1993). These specimens were analyzed by avidin-biotin peroxidase complex method on frozen sections in order to examine the utility of some antimonocyte/macrophage monoclonal antibodies in differentiating acute rejection from other conditions. The ratio of CD68, CD11b, LeuM3, OKM5 and HAM56-positive infiltrating monocytes/macrophages to leukocyte common antigen (LCA)-positive cells in the renal cortex were calculated. As a result, the ratio of the positive cells for CD68, which stains mature macrophages, significantly increased in the cases of acute rejection compared with those of other groups. In addition, a strong expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was observed in the acute rejection group. In our study, the expression of class II major histocompatibility antigens (HLA-DR) in the proximal epithelial tubules was also strongly observed in the cases of acute rejection. It was thus concluded that the increase of CD68-positive infiltrating cells and the expression of GM-CSF may play a possible role as a reaction effector in the process of acute renal allograft rejection.

Adolescent↗
PubMed1994

[Phimosis as a pathogenetic factor in urinary tract infection and vesicoureteral reflux].

The present study has been carried out to clarify relationship between phimosis and urinary tract infection or vesicoureteral reflux. The subjects consisted of 654 boys up to 15 years old with phimosis who had been treated at the outpatient division, Fukuoka University Hospital during 13 years from 1974; 393 boys (60%) with false phimosis, 261 boys (40%) with true phimosis. Thirty three cases (5%) had abnormal voiding (weak stream, preputial ballooning, dribbling etc.) Boys with true phimosis without abnormal voiding showed high incidence of urinary tract infection compared with normal subject, and if these boys had abnormal voiding symptoms as well, the incidence of urinary tract infection, particularly in the form of pyelonephritis, was noted to be high. Therefore, we suggest that boys with phimosis should be treated surgically. The incidence of urinary tract infection in boys with false phimosis were similar to normal group. All cases except one of vesicoureteral reflux accompanied by true phimosis was diagnosed as primary reflux cystoscopically. Therefore in most cases of phimosis associated with reflux, phimosis is determined to be only an accessory factor of vesicoureteral reflux. And refluxing patients should be worked up for urinary tract infection after they have had circumcision. Only in one boy with phimosis and reflux, was the reflux thought to be secondary reflux caused by phimotic obstruction.

Adolescent↗
PubMed1992

[Antiandrogen therapy of benign prostatic hypertrophy: clinical effects of allylestrenol evaluated by transrectal ultrasonographic measurement].

A multicenter trial was carried out on 100 patients with benign prostatic hypertrophy to elucidate the efficacy of anti-androgen therapy with allylestrenol (AE). AE was administered at a daily dose of 50 mg for 16 weeks to the patients and its efficacy was evaluated with subjective symptom scores, residual urine volume and uroflow rates. The effects of AE on prostatic volume and morphology were evaluated using transrectal ultrasound. Of these patients 65 completed the protocol, and only three patients withdrew from the study owing to side effects. Very modest adverse effects on sexual performance were seen in one patient. In this study, significant beneficial effects of AE on symptom scores, residual urine, maximum flow rate, and prostate size were demonstrated. However, volumetric reduction was not associated with urodynamic improvement. Prostatic shape was not changed throughout the study. These findings suggest that allylestrenol can be used as an alternative to prostatectomy in patients who are at high risk for surgery.

Aged↗
PubMed1981

Highly selective inhibitors of thromboxane synthetase. 1. Imidazole derivatives.

The structure--activity relationships of imidazole derivatives as inhibitors of thromboxane (TX) synthetase were investigated. Introduction of various substituents (e.g., one or two methyl groups, a halogen atom, a methylidene group, unsaturated bonds, or a phenylene group) into the alpha position or other positions in the carboxy-bearing side chain of 1-(7-carboxyheptyl)imidazole (15) was found to increase the inhibitory potency. The length of the side chains with the phenylene group was optimum for the inhibitory potency on TX synthetase in the region of 8.5-9.0 A. Among the tested imidazole derivatives, 1-(7-carboxy-7-methyl-2-octynyl)imidazole (47), 4-[3-(1-imidazolyl)-propyl]benzoic acid (50), and (E)-4-(1-imidazolylmethyl)cinnamic acid (54) and its alpha-methyl analogue (57) showed the highest potency with an IC50 in the range of 10(-8) to 10(-9) M. Inhibition by these derivatives was highly selective for the TX synthetase, since other enzymes such as fatty acid cyclo-oxygenase and prostacyclin synthetase were not affected.

Animals↗
PubMed1981

Highly selective inhibitors of thromboxane synthetase. 2. Pyridine derivatives.

The enzyme thromboxane (TX) synthetase is inhibited by pyridine. The beta-substituted pyridine derivatives showed higher inhibitory potency than the gamma-substituted ones having the same side chain. Among the beta-substituted derivatives containing the omega-carboxyalkyl group, the compounds with 6-8 carbon atoms in the side chain were especially effective. The derivatives holding the phenylene group in the side chain exhibited much higher inhibitory activity than those of the alkylene type. Among them, (E)-3-[4-(3-pyridylmethyl)phenyl]-2-methylacrylic acid hydrochloride (5a) had the highest potency (IC50 = 3 x 10(-9) M). The beta-substituted pyridine derivatives and 1-substituted imidazole derivatives which had the same side chain showed almost the same potency. The beta-substituted pyridine derivatives do not inhibit arachidonic acid cyclooxygenase or prostaglandin I2 synthetase, two other enzymes of the arachidonic cascade.

Animals↗
PubMed1980

Prostaglandin analogues possessing antinidatory effects. 1. Modification of the omega chain.

Novel prostaglandin analogues modified in the omega chain were prepared by the reaction of the vinyl aldehydes 1a--e with a variety of organometallic reagents as a key step of the syntheses. Compared with the natural prostaglandin F2 alpha in antinidatory effect, the analogues 4, 7, and 10 were 40 times more potent and the analogue 11 was 50--100 times more potent in the rat.

Abortifacient Agents, Nonsteroidal↗
PubMedDate not supplied

Platelet hyperaggregability persists even after the improvement of increased blood coagulation and impaired fibrinolysis with the stabilization of symptoms in patients with unstable angina.

BACKGROUND: Platelet aggregation, blood coagulation, and fibrinolysis play a pivotal role in the pathogenesis of unstable angina. METHODS: Platelet aggregability was examined on admission and after 2 weeks of treatment in 22 patients with unstable angina, in particular with regard to small-sized platelet aggregates, plasma tissue factor (TF) antigen levels as a marker of blood coagulation, and plasma plasminogen activator inhibitor (PAI) activity levels as an indicator of fibrinolysis. We also examined the same parameters in 19 patients with stable exertional angina and 17 patients with chest pain syndrome. RESULTS: The number of small-sized platelet aggregates increased more significantly in the unstable angina group than in the stable exertional angina and chest pain syndrome groups. In the unstable angina group, the number of small-sized platelet aggregates decreased significantly after 2 weeks of treatment, but was still higher than that in the stable exertional angina and chest pain syndrome groups. Plasma TF antigen and PAI activity were higher in the unstable angina group than in the stable exertional angina and chest pain syndrome groups. TF and PAI activity decreased to normal ranges after 2 weeks of treatment in the unstable angina group. There were significant positive correlations among the three parameters on admission. CONCLUSIONS: It was demonstrated that small-sized platelet aggregates, plasma TF antigen and PAI activity levels increased concomitantly in the unstable angina group. While the blood coagulation and fibrinolytic parameters decreased after stabilization of the clinical symptoms, platelet hyperaggregability still persisted. These results suggest that continuous antiplatelet therapy is essential for the treatment of unstable angina.

Adult↗