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Biomedical subjects

A Kobayashi

Publications and source records attributed to A Kobayashi.

At least 343 records · Page 19Linked to original sources
PubMed1994

Simultaneous dual myocardial imaging with iodine-123-beta-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 in patients with coronary heart disease.

To assess the clinical value of simultaneous dual myocardial imaging with iodine-123-beta-methyl-iodophenyl-pentadecanoic acid (123I-BMIPP) and thallium-201 (201Tl), myocardial imaging was performed at rest and during exercise in seven patients with coronary heart disease. When 123I-BMIPP and 201Tl images were compared, the initial exercise and resting images agreed 87% and 64%, respectively. In the initial resting images, the regional uptake of 123I-BMIPP was frequently less than that of 201Tl. The incidence of exercise-induced reversible defects by 201Tl in the Tl > BMIPP regions was significantly higher than that in the Tl = BMIPP regions (57% vs 4%, p < 0.01) and the incidence of coronary narrowing of more than 90% in the Tl > BMIPP regions was also significantly higher than that in the Tl = BMIPP regions (91% vs 38%, p < 0.01). In addition, this disparity (Tl > BMIPP) was found more frequently in regions with abnormal wall motion than in regions with normal wall motion (hypokinetic regions; 68%, severe hypokinetic or akinetic regions; 50%, vs normokinetic region; 4%, p < 0.01). In contrast, the uptake of 123I-BMIPP correlated closely with that of 201T1 in normal myocardium and the uptake of both 123I-BMIPP and 201Tl was severely reduced in myocardium with severe ischemia during exercise and prior infarction. These results indicate that dual myocardial imaging with 123I-BMIPP and 201Tl may provide a unique means of identifying patients with metabolically disturbed myocardium, such as hibernating and stunned myocardium.

Aged↗
PubMed1994

Clinico-pathological study of the role of infarct expansion in patients with cardiac rupture following acute myocardial infarction.

The purpose of this study was to clarify whether the infarct expansion with cardiac rupture following acute myocardial infarction pathomorphologically differed from expansion without rupture. Eighteen autopsied patients with rupture were classified into acute phase (time between the onset of myocardial infarction and death < or = 36 h) and subacute phase (> 36 h). These patients were compared with 25 patients with no rupture using new parameters of expansion: radius index, cavity index, expansion area index and thinning-dilatation index of the left ventricle. In the acute phase, each parameter was significantly higher in the ruptured group than in the non-ruptured group (radius index: 0.49 +/- 0.28 vs 0.14 +/- 0.16, p < 0.005, cavity index: 0.21 +/- 0.09 vs 0.08 +/- 0.06, p < 0.005, expansion area index: 0.75 +/- 0.25 vs 0.34 +/- 0.23, p < 0.001, thinning-dilatation index: 2.89 +/- 1.31 vs 1.53 +/- 0.52, p < 0.001). However, in the subacute phase there were no differences in these parameters between the two groups. These data suggest that in the acute phase, but not the subacute phase, the degree of expansion and the proportion of expansion to infarcted area are associated with rupture.

Aged↗
PubMed1994

Ca2+ waves and intracellular Ca2+ concentration in guinea pig and rat myocytes.

We measured [Ca2+]i of guinea pig and rat myocytes with Ca2+ waves, using fura-2 fluorescence image processing. In guinea pig myocytes, Ca2+ waves were absent during the control perfusion period, but could be induced by the addition of strophanthidin (100 microM) or sodium cyanide (NaCN: 2 mM) to the perfusate. The [Ca2+]i increased from the control values of 69 +/- 5 nM and 46 +/- 2 nM, to 263 +/- 9 (p < 0.05 vs. control) nM and 225 +/- 20 (p < 0.05) nM, respectively, when cells exhibited Ca2+ waves. Although 13% (16 of 121) of the rat myocytes displayed Ca2+ waves during the control perfusion, the [Ca2+]i with Ca2+ waves (56 +/- 9 nM) did not differ from [Ca2+]i in the absence of Ca2+ waves (54 +/- 3 nM). Ca2+ waves were induced by the perfusion with a high Ca2+ solution (24.5 microM) or NaCN (2 microM), and [Ca2+]i increased from the control values of 67 +/- 11 nM and 74 +/- 5 nM, to 231 +/- 41 (p < 0.05 vs. control) nM and 266 +/- 64 nM, respectively, when cells exhibited Ca2+ waves. The Ca2+ waves were abolished by the removal of extracellular Ca2+, or by the perfusion with ryanodine (10 microM) or caffeine (20 mM). In conclusion, it was shown that Ca2+ waves were due to oscillatory Ca2+ release and that the absolute value of [Ca2+]i is important for the appearance of Ca2+ waves in guinea pig and rat myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Variable activity of protein tyrosine kinase in apparently normal thyroid glands.

We examined protein tyrosine kinase (PTK) activity in apparently normal thyroid tissue (n = 22) obtained from patients undergoing thyroid surgery for papillary thyroid cancer or benign disease. The PTK activity in apparently normal thyroid tissue from patients with papillary thyroid cancer progressively was elevated in the cytosolic fraction compared with that from patients without cancer (p < 0.05). The cytosolic proportion of PTK activity was also significantly increased in the normal thyroid tissue of patients with cancer (62% vs. 51%, p < 0.05). These findings suggest that alterations in PTK activity may indicate apparently normal thyroid tissue at increased risk of developing malignancy.

Adenocarcinoma, Papillary↗
PubMed1994

[A case of simultaneous bilateral spontaneous pneumothorax].

We present a case of simultaneous bilateral pneumothorax. The patient did not have any symptom and the pneumothorax was detected by health care examination. He was introduced to our hospital and two thoracic drains were inserted into both intrathoracic space as soon as possible. Four days after he was performed a bilateral partial resection of the lung through a bilateral axillary incision. Postoperative course was excellent with almost no pain. The thoracic drains were removed on second postoperative day and the patient discharged on ninth postoperative day.

Adolescent↗
PubMed1994

[A case of esophageal cyst resected by thoracoscopic surgery].

A 59-year-old woman was admitted with back pain and an abnormal chest shadow in the left hilar region. Her chest CT scan showed a posterior mediastinal mass surrounding the descending aorta. By transesophageal ultrasonography, a diagnosis of mediastinal cyst was made. She underwent thoracoscopic resection under general anesthesia with new endoscopic devices including endo-scissors, endoscopic hemoclips and electrocautery. Pathologically, the tumor was an esophageal cyst lined by ciliated columnar and squamous epithelium overlying smooth muscle layers. She made an uneventful recovery. Her back pain subsided following the operation. Thoracoscopic resection is a useful technique for patients with mediastinal cystic tumor.

Esophageal Cyst↗
PubMed1994

Fast-type electrophoretic variant of lactate dehydrogenase M(A) and comparison with other missense mutations in lactate dehydrogenase M(A) and H(B) genes.

An electrophoretic variant of lactate dehydrogenase (LD) M(A) subunit was discovered in a female patient with chest pain. Her LD activity in serum was within the normal reference interval, and analysis of her LD isoenzyme pattern showed an abnormal migration indicating a fast-type LD-M(A) subunit variant. DNA analysis of the mutant LD-M gene detected a single base substitution, an A to G transition at codon 220 (AAA-->GAA). This mutation resulted in the replacement of a lysine by a glutamic acid (mutation K220E) and produced a subunit variant (electrophoretic fast type). This missense mutation was also observed in the patient's son, and genotypes of mother and son were consistent with their biochemical phenotypes, as evaluated by LD isoenzyme analysis.

Base Sequence↗
PubMed1994

Pharmacological profile of (R)-1-[2,3-dihydro-1-(2'-methylphenacyl)-2-oxo- 5-phenyl-1H-1,4-benzodiazepin-3-yl]-3-(3-methylphenyl)urea (YM022), a new potent and selective gastrin/cholecystokinin-B receptor antagonist, in vitro and in vivo.

(R)-1-[2,3-dihydro-1-(2'-methylphenacyl)-2-oxo-5-phenyl-1H-1,4- benzodiazepin-3-yl]-3-(3-methylphenyl)urea (YM022) is an extremely potent and highly selective gastrin/cholecystokinin (CCK)-B receptor antagonist. We compared the gastrin/CCK-B receptor-blocking properties of this compound with those of the racemate (mixture of YM022 and its S-form), its enantiomer (S-form), L-365, 260 and Cl-988 in vitro and in vivo. YM022 replaced specific binding of [125I]CCK-8 to rat brain gastrin/CCK-B receptors in a stereoselective and competitive manner. The Ki value of YM022 for gastrin/CCK-B receptors in brain were estimated to be 0.068 nM. The racemate, the S-form of YM022, L-365,260 and Cl-988 also replaced gastrin/CCK-B receptor binding, with Ki values of 0.11, 140, 19 and 6.3 nM, respectively. The affinity of YM022 for gastrin/CCK-B receptor was more than 2 orders of magnitude higher than that for rat pancreatic CCK-A receptor and various other receptors, such as benzodiazepine. In vivo, intravenous (i.v.) administration of YM022 inhibited pentagastrin-induced gastric acid secretion in anesthetized rats, with an ED50 value of 0.0078 mumol/kg. Inhibition by the S-form of YM022 was only 33.8% even at the relatively high dose of 1 mumol/kg i.v. L-365,260 (1-10 mumol/kg i.v.) and Cl-988 (0.3-3 mumol/kg i.v.) also antagonized acid secretion induced by pentagastrin, with ED50 values of 4.23 and 1.01 mumol/kg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

YM022 [(R)-1-[2,3-dihydro-1-(2'-methylphenacyl)-2-oxo-5-phenyl- 1H-1,4-benzodiazepin-3-yl]-3-(3-methylphenyl)urea], a potent and selective gastrin/cholecystokinin-B receptor antagonist, prevents gastric and duodenal lesions in rats.

We evaluated the effect of YM022 [(R)-1-[2,3-dihydro-1-(2'- methylphenacyl)-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl]-3- (3-methylphenyl)urea], a potent and selective gastrin/cholecystokinin-B receptor antagonist, on gastric acid secretion and gastric and duodenal lesions in rats. Oral YM022 (0.1-10 mumol/kg), famotidine (0.3-30 mumol/kg) and omeprazole (3-100 mumol/kg) dose-dependently suppressed acid secretion in pylorusligated rats with ED50 values of 0.83, 1.63 and 10.9 mumol/kg, respectively. YM022 (1-10 mumol/kg p.o.), famotidine (1-10 mumol/kg p.o.) and omeprazole (10-100 mumol/kg p.o.) prevented indomethacin-induced gastric lesions in a dose-related manner. The potency of YM022 was comparable to that of famotidine and was 8 times greater than that of omeprazole. YM022 and famotidine partially inhibited gastric damage induced by water-immersion and restraint stress, whereas omeprazole abolished these lesions. In an acidified ethanol-induced gastric injury model, all three drugs inhibited the formation of erosions. The YM022 dosage required in this model was much greater than that required in the inhibition of gastric acid. The inhibitory effect of YM022 was partially reversed by indomethacin, indicating the involvement of a prostaglandin-mediated pathway. YM022 (3-100 mumol/kg p.o.), famotidine (1-30 mumol/kg p.o.) and omeprazole (3-100 mumol/kg p.o.) inhibited mepirizole-induced duodenal ulcers. On the basis of ED50 values, YM022 was 5 times less potent than famotidine and as potent as omeprazole against mepirizole-induced duodenal ulcers. These results suggest that YM022 possesses antisecretory and antiulcer activities that are as potent as those of famotidine in rats and that YM022 represents a useful therapeutic agent in the treatment of peptic ulcer disease.

Animals↗
PubMed1994

[Multiple cooperative study of UFT-adjuvant chemotherapy for malignant tumor in the jaw and oral cavities. The Oral Surgery Malignant Tumor Research Association in Kanto Kohshinetsu District].

We studied the usefulness and safety of long-term administration of uracil and tegafur (UFT) after primary therapy of the malignant tumor in jaw and oral cavity regions randomized controlled trial. 112 cases were totallized 6 institutes belonging to the Oral Surgery Malignant Tumor Research Association in Kanto Kohshinetsu District during 2 years and 10 months, beginning in September 1986. After completing the primary therapy, treatment was not performed in group A and 400 mg/day of UFT was orally administered in group B for 1 year. A variation was observed in the stages of background factors such as sex and age (more than 30 years old and less than 80 years old), while no such discrepancy was observed in other stages. No significant difference of 1-year-survival ratio and non-recurrence ratio was noted in either group, while the non-recurrence ratio was more favorable in group B than group A, and the usefulness of UFT for adjuvant chemotherapy was suggested. The incidence of side effects in group B was 42.6%, and no serious side effect was observed.

Adenocarcinoma↗
PubMed1994

[Association of antiphospholipid antibodies with valvular heart disease in patients with systemic lupus erythematosus].

The purpose of this study was to evaluate the association of antiphospholipid antibodies with the valvular lesions in patients with systemic lupus erythematosus (SLE). Two-dimensional and color Doppler echocardiographic studies were performed in 65 patients with SLE. Antiphospholipid antibodies were assayed in each patient using two methods: anticardiolipin antibody and lupus anticoagulant. Valvular lesions were observed in 43 patients (66.2%). Mitral or aortic regurgitation (MR or AR) were recognized in 37 patients (56.9%). Moderate or severe MR were significantly associated with antiphospholipid antibodies (20.0%, p < 0.01) compared with patients without antiphospholipid antibodies (2%). Four of nine patients with moderate to severe AR or MR developed cerebral infarctions or digital infarctions. It is suggested that there may be a causal link between antiphospholipid antibodies and moderate to severe valvular lesions in SLE.

Adolescent↗
PubMed1994

Benign stricture of the intrahepatic bile duct with arterial involvement.

The absence of arterial change is one of the definitive findings of benign bile duct stricture. Here we report on a patient with a stricture of the intrahepatic bile duct with arterial involvement. Histological examination of the resected specimen revealed fibrous replacement of arterial media, with no evidence of malignancy.

Bile Duct Diseases↗
PubMed1994

[A case of 15p tetrasomy associated with infantile spasms].

A seven-year-old boy with a 15p tetrasomy: [47, XY, + inv dup (15) (pter-->q13: :q13-->pter)] was reported. The clinical manifestation were as follows; infantile spasms, delayed development and slightly brownish coloured skin. But there were no other abnormal findings in neurological or physical examinations. This was the first case with 15p tetrasomy and infantile spasms.

Child↗
PubMed1994

[A case of left atrial free-floating ball thrombus].

A rare case of left atrial free floating ball thrombus with mitral stenosis is reported. A 66-year-old woman was admitted for epigastralgia and acute heart failure without atrial fibrillation and previous embolization. The patient was treated successfully with removal of ball thrombus and mitral valve replacement. Intraoperative transesophageal echocardiography was effective for monitoring of mobile left atrial thrombus.

Aged↗
PubMed1993

[Development and medical application of Er-YAG laser].

Result of developments of Er-YAG laser and its delivery system were reported. Er-YAG laser's wavelength is 2.94 microns, the beam absorption rate by water is higher than other laser beam. Er-YAG laser has repeated pulse oscillation, pulse width is 400 mu, sec, the repeat frequency is between 5 to 10 pulse per second. The mean power is 4 W maximum, 10 pps. The fibers of laser are made of zirconium-F-glass. We carried out a study on the possible application of the Er-YAG laser on the rabbit arteries and myocardium and human arteries were examined in vitro. Very clear cuts were observed on the histological examination. There were no evidence of thermal damage, no carbonization on the sharp cutting surface. Experimental result showed that Er-YAG lasers had good potential for angioplastic laser.

Angioplasty, Laser↗
PubMed1993

Modification of contractile proteins by oxygen free radicals in rat heart.

This study was undertaken to investigate the effects of oxygen free radicals on myofibrillar creatine kinase activity. Isolated rat heart myofibrils were incubated with xanthine+xanthine oxidase (a superoxide anion radical-generating system) or hydrogen peroxide and assayed for creatine kinase activity. To clarify the involvement of changes in sulfhydryl groups in causing alterations in myofibrillar creatine kinase activity, 1) effects of N-ethylmaleimide (sulfhydryl groups reagent) on myofibrillar creatine kinase activity, 2) effects of oxygen free radicals on myofibrillar sulfhydryl groups content, and 3) protective effects of dithiothreitol (sulfhydryl groups-reducing agent) on the changes in myofibrillar creatine kinase activity due to oxygen free radicals were also studied. Xanthine+xanthine oxidase inhibited creatine kinase activity both in a time- and a concentration-dependent manner. Superoxide dismutase (SOD) showed a protective effect on the depression in creatine kinase activity caused by xanthine+xanthine oxidase. Hydrogen peroxide inhibited creatine kinase activity in a concentration-dependent manner; this inhibition was prevented by the addition of catalase. N-ethylmaleimide reduced creatine kinase activity in a dose-dependent manner. The content of myofibrillar sulfhydryl groups was decreased by xanthine+xanthine oxidase; this reduction was prevented by SOD. Furthermore, the depression in myofibrillar creatine kinase activity by xanthine+xanthine oxidase was protected by the addition of dithiothreitol. Oxygen free radicals may inhibit myofibrillar creatine kinase activity by modifying sulfhydryl groups in the enzyme protein. The reduction of myofibrillar creatine kinase activity may lead to a disturbance of energy utilization in the heart and may contribute to cardiac dysfunction due to oxygen free radicals.

Animals↗