Biomedical subjects

M Yasuda

Publications and source records attributed to M Yasuda.

At least 397 records · Page 22Linked to original sources

PubMed1990

Circulating immunoreactive endothelin in ischemic heart disease.

Circulating immunoreactive endothelin (ir-ET) was measured in nine patients with acute myocardial infarction (AMI), 10 patients with stable angina pectoris (SAP), and 25 normal control subjects. In patients with AMI, the plasma ir-ET level was elevated in the acute phase and was highest on the day of onset (AMI: 3.8 +/- 1.7 pg/ml, normal control value: 0.5 +/- 0.2 pg/ml). The plasma ir-ET level showed a positive correlation with the wall motion abnormality index (rs = 0.56, p less than 0.01), thrombin-antithrombin III complex (rs = 0.55, p less than 0.01), and beta thromboglobulin (rs = 0.39, p less than 0.05). An especially high plasma ir-ET level was detected in patients in whom the Killip subset was IV. The plasma ir-ET level was not increased in patients with SAP (0.8 +/- 0.3 pg/ml). The plasma ir-ET level is increased in the acute phase of AMI. A pathophysiologic state characterized by cardiac dysfunction, an activated coagulation system, and platelet hyperactivity may be associated with this increase in plasma ir-ET.

Angina Pectoris↗

PubMed1990

A new apparatus for hair regrowth in male-pattern baldness.

A newly devised apparatus (Scalp-Tension-Relaxer, STR) can efficiently promote hair regrowth in patients with male-pattern baldness. When this apparatus is applied, the scalp is pushed up to relieve tension on the vertex. The efficacy rate of hair regrowth in alopecia patients was 40%. An investigation into the basis for the hair regrowth caused by this apparatus was directed toward the changes in hemodynamics and skin temperature of the scalp. During and after use of this apparatus, subjects exhibited an increase both in the cutaneous blood flow rate (as determined by laser Doppler flowmetry) and in the cutaneous temperature (as determined by thermography).

Adult↗

PubMed1990

The complement system in ischemic heart disease.

The mechanisms by which tissue injury after acute myocardial infarction (AMI) occurs has not been fully elucidated. Recent evidence in experimental models has suggested involvement of the complement system in microvascular and macrovascular injury subsequent to AMI. With respect to angina pectoris, whether or not the complement system is activated is not clear. The present study assessed the role of complement as a mediator of myocardial inflammation by quantifying products of complement activation, including C3d, C4d, Bb, and SC5b-9 complexes, in 31 patients with AMI, 17 patients with unstable angina pectoris, 19 patients with stable angina pectoris, and 20 normal volunteers. The plasma C3d levels increased in patients with AMI and in those with unstable angina pectoris (p less than 0.01). The plasma levels of C4d, Bb, and SC5b-9 increased only in patients with AMI (p less than 0.01). The plasma SC5b-9 level was related to peak creatine phosphokinase (r = 0.71) and inversely related to the ejection fraction (r = -0.71). The plasma SC5b-9 level of patients with congestive heart failure was higher than that of patients without congestive heart failure in AMI. These results show that activation of complement system occurs after AMI and show an association of myocardial damage with complement activation. With respect to angina pectoris, the complement system is mildly activated in patients with unstable angina pectoris; however, the cardiac function of patients with unstable angina pectoris is not damaged. The complement system of patients with stable angina pectoris is not activated.

Angina Pectoris↗

PubMed1990

Significance of Q wave disappearance in the chronic phase following transmural acute myocardial infarction.

The mechanism and prognostic implications of Q wave regression following transmural acute myocardial infarction (AMI) were assessed in 54 patients. Of these subjects, 14 lost their Q waves. Exercise myocardial thallium-201 (201Tl) scintigraphy and two-dimensional echocardiography were performed before the patients were discharged from hospital. Two-dimensional echocardiography and electrocardiography were simultaneously repeated about 18 months after AMI. Both the relative 201Tl activity in the infarcted area and the improvement of echocardiographic wall motion index were higher in patients who had lost their Q waves than in those with retained Q waves (70 +/- 14% vs 58 +/- 13%, p less than 0.01; 5.2 +/- 3.0 vs 2.0 +/- 3.4, p less than 0.01, respectively). The prevalence of post-infarction angina pectoris was significantly higher in the former (29% vs 0%, p less than 0.01). We concluded that remnants of viable myocardial muscle might be responsible for Q wave regression following transmural acute myocardial infarction, and the prevalence of post-infarction angina pectoris was high among these patients.

Adult↗

PubMed1990

Developmental toxicity potential of grayanotoxin I in mice and chicks.

Developmental toxicity potential of grayanotoxin I (GTX I), a toxic diterpenoid contained in plants of the family Ericaceae, with sodium ionophore activity, was studied in mice and chicks. In mice, intraperitoneal injections of 1.5 mg GTX I/kg body weight of mouse for three consecutive days during the organogenetic period caused some dams to die, but neither embryotoxicity nor teratogenicity was detected. In chicks, a single injection of 0.1-1.0 microgram GTX I per egg into the extraembryonic coelom on day 1.5 or 2 of incubation, or into the amnionic cavity on day 3 or 4 of incubation induced neither embryotoxic nor teratogenic signs, but 10 micrograms GTX I per egg showed lethal effects when applied on each of those days.

Animals↗

PubMed1990

Surgical approaches to foramen magnum meningioma--report of three cases.

Although foramen magnum meningiomas are usually removable, their location poses considerable surgical risk. The authors present three cases of foramen magnum meningioma. The first involved a ventral type tumor extending to the second cervical body. Following bilateral mandibulotomy, surgery was performed via the anterior transoral approach and the tumor was totally removed. Nine days postoperatively, she developed meningitis, which was successfully treated with antibiotics. The second patient's tumor was dorsal type and was deeply embedded in the lateral part of the vermis. The tumor was totally removed via the midline suboccipital approach and she recovered uneventfully, with only slight upper-extremity paresthesia. In the third case, the tumor was ventral type and situated mainly in the clivus. Craniotomy was performed by the bilateral suboccipital approach and extended nearly to the jugular tubercle. The tumor, which severely displaced the lower cranial and upper cervical nerves, was totally removed. The postoperative course was lengthy and complicated. Artificial ventilation was required for 2 months, and difficulty in swallowing persisted during long-term follow-up. As illustrated by the second case, dorsal and lateral type foramen magnum meningiomas can usually be removed via the lateral suboccipital approach. In the case of ventral type tumors, the anterior transoral approach entails the risk of infection, as occurred in the first case. The authors conclude that the lateral suboccipital approach is preferable; craniotomy extending to the jugular tubercle lowers the risk of brainstem damage.

Adult↗

PubMed1990

Antibodies to cytoskeletal systems in normal human serum.

Serum antibodies to cytoskeletal systems were measured by indirect immunofluorescence using human skin fibroblasts as the substrate for actin and vimentin, and HEp2 cells for cytokeratin. IgM concentration in 12 umbilical cord blood was less than 20 mg/dl, but antibody to cytokeratin was detected in samples that contained more than 10 mg/dl of IgM. Sera from 8-year-old pupils had elevated antibody titer to vimentin of IgG, IgM and IgA class and to cytokeratin of IgG and IgM class. Healthy adults had IgM anti-vimentin and anti-cytokeratin antibody at 60 times serum dilution, but other antibodies were lower than 10 times serum dilution. IgG and IgA concentration did not have any correlation with anti-cytoskeletal system antibodies. IgM concentration tended to correlate with IgM antibody titer to vimentin and cytokeratin. With increasing age in adults, antibody to actin of IgG class appeared.

Actins↗

PubMed1990

Hyperinsulinemia in Macaca nigra: precession to obesity and/or diabetes?

A subset of Macaca nigra have been identified with elevated levels of fasting and secretory insulin. The insulin increment between 0 and 15 min in an intravenous glucose tolerance test (IV-GTT) was 511 +/- 42 microU/ml in hyperinsulinemic (HYPER) monkeys compared to 191 +/- 16 microU/ml in nondiabetic (ND) controls (p less than 0.01). Fasting insulin increased from 37 +/- 4 in ND to 57 +/- 7 microU/ml in HYPER monkeys (p = 0.02). Glucose clearance also increased from 3.87 +/- 0.18 in ND to 5.78 +/- 0.52%/min in HYPER monkeys (p less than 0.01). The acute (239 +/- 31 versus 137 +/- 19 microU/ml/min) and secondary insulin responses (542 +/- 75 versus 207 +/- 32 microU/ml/min) were significantly greater in the HYPER monkeys than in the ND controls, respectively (p less than 0.05). The rate of glucose clearance per amount of insulin secreted was diminished about 40% in both the acute and the secondary phases of HYPER monkeys (p less than 0.02). Total C-peptide secretion was two times greater in HYPER than in ND monkeys (p = 0.05). The HYPER monkeys averaged 12-20% greater weight and 41-44% greater body mass than the ND monkeys (p less than 0.05), although both groups were fed the same amount of diet and were well within nonobese limits. These Macaca nigra appear to have a functional lesion with excess insulin secretion, relatively impaired clearance of glucose, and possible insulin resistance, but no islet pathological lesion. Development toward overt diabetes might be exacerbated if obesity became a more dominant factor.

Animals↗

PubMed1990

Diabetes mellitus in nonhuman primates: recent research advances and current husbandry practices.

Primates can be utilized for a variety of studies to give insight into the mechanisms of the onset and progression of diabetes mellitus and obesity, and into the development of secondary manifestations. Results can be used to understand the etiologies and effects of diabetes in human beings. Investigators and animal care personnel should be continually aware of the potential for development of diabetes among primates and should seek to identify the earlier stages before the appearance of overt diabetes. In addition to updating recent research in which nonhuman primates have been used in studies on the different forms of diabetes, this review also furnishes some information about therapeutic management and husbandry of monkeys with predispositions toward diabetes or with overt diabetes.

Amyloidosis↗

PubMed1990

Effects of L-2-oxothiazolidine-4-carboxylate, a cysteine pro-drug, on teratogenicity of 5-fluorouracil in mice.

Embryotoxicity and teratogenicity of 5-fluorouracil (5-FU) and modulation of its effect by L-2-oxothiazolidine-4-carboxylate (OTC), a cysteine pro-drug, were evaluated in mice. Pregnant ICR mice were intraperitoneally (i.p.) injected with 25 mg/kg of 5-FU on day 11 of gestation (vaginal plug = day 0). Mice were pretreated i.p. with 950 mg/kg of OTC 4 hours before dosing with 5-FU. Dams were killed on day 17 of gestation. Fetuses were examined for external malformations, especially limb malformations. Pretreatment with OTC decreased the frequency and severity of oligodactyly induced by 5-FU, although the differences were not significant statistically. There was little difference in either liver glutathione levels, or body weight gain during gestation of dams between the 5-FU group and the 5-FU plus OTC group. Fetal mortality and fetal weight of the group treated with 5-FU alone were comparable with those of the group pretreated with OTC. In the present study, teratogenicity of 5-FU seemed to be slightly mitigated with OTC pretreatment.

Animals↗

PubMed1990

[Role of oxygen-derived free radicals for antitumor effects of intra-arterial injection with adriamycin].

This study examined the role of oxygen-derived free radicals for antitumor effects of intra-arterial injection with adriamycin (ADR). The effect of chemoembolization using ADR and degradable starch microspheres (DSM) was studied in rabbits with VX2 carcinoma of the hind leg. The tumor growth in rabbit treated with chemoembolization (ADR: 3.0 mg/kg + DSM 20mg/kg) was completely suppressed, but the therapeutic effect of chemoembolization combined with dimethylsulfoxide (DMSO) was reduced. On the other hand, the therapeutic effect of chemoembolization combined with superoxide dismutase and catalase was not reduced. These results indicate that the production of oxygen-derived free radicals, especially hydroxyl radical in the cancer cell, plays an important role in the antitumor effect of adriamycin.

Animals↗

PubMed1989

[Pharmacokinetic evidence for the renal reabsorption of CDDP].

CDDP has had a wide use and a remarkable progress in cancer chemotherapy. Among others nephrotoxicity is the principal dose-limiting factor in this drug. So that the pharmacokinetics of CDDP mainly for the kidney was investigated in 4 patients with gynecological malignancies. CDDP was administered by short-term (about 45 minutes) intra-arterial infusion at a dose of 100 mg/body. Total CDDP (T) and non-protein-bound CDDP (NPB) concentrations in plasma declined in a biphasic manner, with a half life values of 0.506, 0.551 hr in alpha phase and 102, 96 hr in beta phase respectively. Protein-bound plasma CDDP (PB) in the time concentration curve showed two peaks, at the end of infusion and at about 3-5 hours after infusion to be followed by biphasic declining, which showed similarity to the simulation curve supposing the delayed influx. Total urinary excretion rate (up to 48 hours after infusion) was 15% on the average. It was shown that there was a close relation between urinary volume of less than 3 ml/min and NPB clearance (R = 0.877). And then there was a significant difference of NPB clearances by the kidney between cases of less than 200 ng/ml of NPB plasma concentration and those over 200 ng/ml. Binding proteins at the first and the second peak were analyzed by gel filtration method. At the second peak PB was mostly detected on the albumin fraction, which was different from the first peak. The mean estimated renal reabsorption of CDDP after 3 hours following injection was about 2 mg. (ABSTRACT TRUNCATED AT 250 WORDS)

Cisplatin↗

PubMed1989

[Prognostic study of ovarian clear cell carcinoma].

Prognostic studies were performed on 17 cases with clear cell carcinoma of the ovary. The results are follows: 1) The average age was 45.9 years and ranging from 35 to 57 years. 2) Regarding the FIGO clinical stage, all of 5 patients with stage I and 3 of 5 with stage II survived over 2 years, while all of patients with stage III and 2 with stage IV were dead within 2 years. 3) Of 9 patients who had complete resection for primary operation, 8 (89%) survived over 2 years. All of 8 patients who had incomplete resection were dead within 2 years. 4) All cases had been received various chemotherapy; CQ + 5-FU (n = 5), CPM + ADM + CDDP + 5-FU (n = 7), 5-FU + CPM + MMC (n = 2), CDDP (n = 1), CDDP + MMC + 5-FU (n = 1), MCNU + VCR + 5-FU (n = 1), but none of them improved the prognosis of this histological type. 5) With or without administration of CDDP, there was no significant difference in the prognosis. These results suggest that early diagnosis of disease, curative surgical resection and selection of effective chemotherapeutic agents are important things to improve prognosis of clear cell carcinoma of the ovary.

Adenocarcinoma↗

PubMed1989

Directionally selective response of cells in the middle temporal area (MT) of the macaque monkey to the movement of equiluminous opponent color stimuli.

Based on the fact that a great majority of cells in the middle temporal (MT) area of the macaque respond to movement of luminance contours with directional selectivity, this area has been thought to be concerned with the analysis of visual motion. However, objects can be discriminated from the background not only by differences in luminance but also by differences in color. It is possible that color signals are also used for motion analysis in MT. In the present study, we examined whether MT cells respond to movement of a pattern composed of pure color-contours. Using a color TV system, a moving color bar was displayed on a uniform background whose color was opponent with that of the bar. The main bar/background color combination we examined was magenta/cyan. Yellow/blue and cyan/magenta combinations were also examined for some cells. The response of MT cells to movements of opponent-color stimuli was recorded while the bar/background luminance ratio was changed from 1/10 to 10/1. In half of 89 cells tested in 3 monkeys, the response decreased considerably (disappeared completely in some cells) at a luminance ratio close to the human equiluminous condition. In the other half, a directional response persisted at any bar/background luminance ratio, though the response decreased to a varied extent (30-90% of the maximum response) near the ratio 1 (human equiluminous condition). The average magnitude of the equiluminous response to the magenta/cyan stimulus for the overall population was about 35% of the maximal response when the length of the bar (0.5 degrees in width) and the movement amplitude were set to be optimal for individual cells, i.e. smaller than 15 degrees and 10 degrees of visual angle, respectively. This fall to 23% when the bar length and movement amplitude were limited to 2 degrees. The same cell responded to pure color-contours of yellow/blue as well as of cyan/magenta combinations. Thus, MT can detect the direction of movement of pure color-contours, although the sensitivity is less than for luminance contours.

Animals↗

PubMed1989

Changes in the arrangement of actin bundles during heart looping in the chick embryo.

We assessed the arrangement of actin bundles in the looping chick heart. Actin filaments were stained with rhodamine-labeled phalloidin, and their total arrangement was observed in whole mount specimens. Before the straight heart tube was formed, actin bundles were in a net-like arrangement as if to indicate the cell borders. With progress of the heart tube formation, actin bundles were gradually arranged in a circumferential direction. In the looped heart, regional differences in actin arrangements were observed. In the truncus arteriosus, actin bundles ran in a net-like arrangement. In the bulbus cordis, actin bundles ran in random directions. In the ventricle, actin bundles were roughly arranged in a circumferential direction. Between these three regions, actin bundles ran in a circumferential direction especially on the concave side. Near the right contour on the ventral face, some actin bundles ran in a longitudinal direction along the axis of the tubular heart. In the bulbus cordis and the ventricle at the looped stage, there was another group of actin bundles in the inner layer of the myocardium which ran in a circumferential direction. We presume that the arrangement of actin bundles is related to heart looping.

Actin Cytoskeleton↗

PubMed1989

The complement system in the acute phase of myocardial infarction.

Although some studies suggest that complement activation is involved in the development of acute myocardial infarction, there has been little convincing evidence of a change in the complement system in patients suffering from myocardial infarction. In this study circulating levels of C3a, C3, C4 and the total hemolytic complement titer (CH50) were serially measured in 12 patients with acute myocardial infarction up to 10 days after an attack. The plasma C3a level was greatly elevated throughout the post-attack observation period. The C3, C4 and CH50 levels were significantly increased above those controls on days 8, 9 and 10 after infarction. These findings indicate that there is complement activation in patients with acute myocardial infarction, and suggest a pathogenetic role for complement activation in the development of myocardial damage after infarction.

Acute-Phase Reaction↗

PubMed1989

Role of free radicals and lipid peroxidation in gastric mucosal injury induced by ischemia-reperfusion in rats.

Ischemia and reperfusion are of the greatest importance in the pathology of many diseases. We investigated the roles of oxygen-derived free radicals and lipid peroxidation in gastric mucosal injury, such as spotty and linear hemorrhagic erosions, induced in rats by ischemia-reperfusion. The gastric mucosal injury and the increase in thiobarbituric acid (TBA) reactants in the gastric mucosa induced by ischemia-reperfusion were significantly inhibited by treatment with SOD and catalase. These results suggest that oxygen-derived free radicals and lipid peroxidation play important roles in the pathogenesis of acute gastric mucosal lesions induced by ischemia-reperfusion.

Animals↗

PubMed1989

[Diagnosis and treatment of endometrial hyperplasia].

Endometrial hyperplasia (EH) was found to coexist in 13 of 21 patients (cystic glandular hyperplasia, 13; adenomatous hyperplasia, 9) with endometrial adenocarcinoma (EC), but in only 44 of 940 patients with other than EC. In this study, blood type (A, B, H), c-myc translation products, estrogen receptor and DNA polymerase alpha were examined on endometrium of proliferative phase (EPP), EH and EC. Patient blood type products were shown in EH surrounding EC, and yet they were detected in only small portion or none of EC itself. H products were detected in EC of other than O type. c-myc translation products were shown in only a small portion of cancer cells. EPP had many ER positive cells and a few proliferating cells as they were shown by staining with anti-DNA polymerase alpha monoclonal antibody. EC can be divided into two types, one has few ER positive cells and many proliferating cells, other many ER positive cells and a few proliferating cells. In EH, the numbers of ER positive cells and DNA polymerase alpha positive cells were between those of EPP and EC. In a patient with atypical hyperplasia, high dose Medroxyprogesterone acetate (MPA) therapy induced that stratification and papillary growth of gland lining epithelia disappeared, and that cytoplasmic enlargement and vacuolation appeared. These findings were important histopathological changes in high dose MPA administration to EH and EC.

ABO Blood-Group System↗